TWI751315B - Method and equipment for manufacturing brush and injection molding half mold part - Google Patents

Abstract

With regard to a method or a device for anchoring bristles in a bristle carrier (10) without anchoring, the present invention proposes: after pushing the bristles into the anchoring openings (12) in the bristle carrier (10), The anchor openings (12) are closed by applying pressure and heat. A chamfer (322) is provided around the transition edge (320) of the anchor opening (12).

Description

Method, apparatus and injection molding half-mold part for making brushes

The present invention relates to a method, an apparatus and an injection moulding half part for the manufacture of a brush having a bristle carrier made of thermoplastic and comprising anchoring openings into which at least one bristle is inserted and anchored hole.

Two methods are commonly used in practice for the manufacture of brushes, especially toothbrushes and household brushes, namely: fixing the bristle tufts with anchors (sheet metal or rope loops) or without anchors. Unlike anchors, the anchorless method does not bend the bristle tuft and fix the bristle tuft on the bristle carrier at the bend of the bristle tuft, but locks one end of the bristle tuft to the bristle carrier by adhesive or thermal means. superior. One method commonly used in practice is for the bristle carrier to have openings through which tufts of bristles pass. In this case, the tufts of bristles protrude from the openings with the rear ends of the tufts and are heated on the rear of the bristle carrier. The thermoplastic material of the bristles is then melted, so that the bristle materials join each other and form a thickening, by means of which the individual bristles are prevented from being pulled forward. The numerous tufts of bristles are liquefied from the back, usually by hot air or a hot punch (Stempel), so that the material of the individual tufts join each other and form some sort of layer-like structure on the back of the liquefied bristle ends. Next, the back surface is specifically covered by spraying.

The drawback of the above solutions is that, due to the need to cover the back side, considerable additional costs must be incurred in terms of methods and equipment. Here it is to be noted that it is precisely in toothbrushes that the joint surfaces between adjacent layers are implemented as gapless as possible in order to avoid hygienic problems.

The term "bristle carrier" refers to the part of the finished brush that carries the bristles or tufts of bristles. Wherein, the bristle carrier can be the entire brush body, in the case of a toothbrush, it is an integral injection-molded part consisting of the handle, neck and head, or it can also be only a prefabricated part of the brush body in the future. In the latter case, the bristle carrier is usually a sheet of thermoplastic, which sheet is provided with one or more openings for filling one or more bristles or bristle bundles. After packing and fixing the bristles, the lamellar bristle carrier is inserted into the prefabricated brush body, which for example has corresponding recesses for accommodating the lamellar bristle carrier. An alternative, which is the usual case, is to extrude the bristle carrier in sheet form to form a brush body consisting of a prefabricated bristle carrier and the remainder injection-molded onto the prefabricated bristle carrier.

CH 672 579 A5 proposes a method for fixing tufts of bristles to a bristle carrier by means of anchor sheets. That is, the tufts of bristles are folded, the anchor tabs are located in the folded area and are pressed into the walls of the anchoring openings, whereby the tufts of bristles are finally fixed on the bristle carrier. However, in order to optimally close the openings on the end or front face of the bristle carrier so that bacteria and spores do not grow there, the projections on the bristle carrier extending around the anchoring openings and protruding from the end face should be pressed inward. However, the bristle tufts themselves are secured by the anchors and not by this shaping of the protrusions. The individual bristle tufts are sequentially inserted into the bristle carrier by a plugging tool which pushes the bent bristle tufts through the tube. The tube itself has a heater on the end face of the tube, the heater only abuts the protrusion and melts or plasticizes the protrusion, and then presses the protrusion radially inward.

In addition to the above-mentioned method of fixing the bristles or tufts of bristles to the bristle carrier in an anchor-free manner, other methods exist in theory, but have never been realized in practice, namely: pushing the tufts of bristles into the bristle carrier, which Has open pores and is preheated. After the tufts are pushed into the soft bristle carrier, pressure is applied by the press to the face of the bristle carrier on which the tufts protrude, thereby compressing the soft material around the edge of the aperture and reducing the aperture cross-section. Several related options are described below.

DE 198 53 030 A1 proposes that the tufts of bristles have bristles on the rear side of the tufts that are fused to one another to form a thickening. The bristle carrier has openings into which the cylindrical extension of the heater is inserted, but does not touch the edge of the opening, before the tuft of bristles is pushed in. The inner edge of the opening is locally heated by this radiant heat. In the edge region, the bristle carrier reaches a temperature which can change the structure, eg the softening temperature. The purpose of increasing the temperature is to reduce the cross-section of the hole so that the tufts of bristles must burrow into the wall when they are pushed in. After removing the heater, the tufts of bristles with thickened ends are pushed into the opening, wherein the cross-section of the thickening is larger than the cross-section of the opening, so that the thickening drills into the soft zone that defines and surrounds the edge of the opening, That is, drilling into the corresponding wall. Next, it is necessary to deform the front side of the bristle carrier by means of a punch, so that the material of the bristle carrier presses against the bristle tufts and anchors the bristle tufts.

A similar method is known from US Pat. No. 5,224,763, in which the bristle carrier has a convexly protruding perforated edge. The edges of the openings are also heated here, either by protruding pin-shaped heating elements into the openings or by machining with hot air. The aperture cross section is smaller than the thickened end of the tuft of bristles, so that this end is pushed into the wall of the soft aperture and secured therein. The retainer for the bristle tuft then compresses the heated wraparound protrusions to provide additional material to close the openings where the bristle carrier end faces meet.

A method is known from EP 0 355 412 A1 for heating the thickened ends and/or the perforated edges of tufts of bristles in a bristle carrier, wherein the dimensions and the temperature are selected in such a way that after the thickened ends are pushed in, , the edge of the aperture is pressed inward and surrounds the thickened end like a snap connection and accommodates the thickened end in a form-fitting manner.

EP 0 472 857 B1 proposes to drill into a plate-shaped bristle carrier made of plastic by means of a heated punch having pins so that the pins form openings for accommodating bristle bundles. The tufts of bristles are then pressed into the hot punched holes, and the melt rises around the thickening of the tufts of bristles. In addition, the template can be pressed against the top surface of the bristle carrier in order to further deform the melt. Among them, extensions or protrusions that protrude from the top surface of the undeformed bristle carrier are particularly preferred, and these extensions or protrusions form a material that can be pressed against the opening.

The method proposed in DE 34 22 623 A1 involves welding a plate-shaped bristle carrier without perforations to bristle bundles, which bristle bundles and the bristle carrier consist of the same plastic. Move the heating tool between the bristle carrier and the sides where the tufts of bristles have not been welded together to melt both sides. The tufts of bristles are then pressed into the melted material of the bristle carrier.

However, the present invention relates to another method described in DE 10 2015 111 312 A1. Here, the bristles or tufts of bristles with usually thickened fixed ends are pushed into the anchoring openings beforehand. Subsequently, under the application of pressure and heat, the bristle carrier deforms and narrows at the edges of the anchoring apertures. Here, the bristle carrier is heated to a relatively low temperature only in the frontal region without reaching the melting temperature. The material displaced by temperature and pressure only closes the anchoring openings on the front side, so that the bristles or tufts of bristles can no longer be pulled out. The material moves to the outside of the single bristles or the outside bristles of the tufts of bristles. Therefore, in order to produce bristles with high pull-out force, sufficient material must be provided to largely close off the anchoring openings to the front face. For this purpose, there are bristle carriers in which one or more projections or projections, which are formed when the bristle carrier is injection-molded, protrude in the front edge region of the anchoring openings. These protrusions form additional material that is first contacted by the tool and then moved inward to close the anchor opening. Another advantage of these protrusions is that the pressure applied for molding can be relatively low and the actual thickness of the bristle carrier (not counting the protrusions) decreases with little or no reduction during molding. So the settings need not be too precise when the tool is moved in and depressed.

For high-quality brushes, especially toothbrushes, it is important that there is not much material available during the pressing process, which is then pressed into the housing openings in the tool for the bristles or tufts of bristles. This additional material would then be like thin, non-specifically shaped ridges (Kragen) abutting the outside of a single bristle or tuft and protruding from the front.

The object of the present invention is to improve the known method and to accordingly provide a device for carrying out the method, by means of which such a ridge is avoided.

This object is solved by a method for producing a brush comprising: a bristle carrier made of thermoplastic, the bristle carrier having a front side and a back side and at least one anchor opening, the brush made of thermoplastic is thickened At least one bristle of the fixed end is inserted and anchored in the anchoring opening, so that the bristle protrudes from the front surface of the bristle carrier, wherein the at least one anchoring opening is defined by the inner side, and is in the The front face has an end edge surrounding the anchor opening, characterized by the following steps: a) Providing the bristle carrier, which has a transition edge to the inner side in the region of the end edge, the transition edge at least partially chamfered on the periphery of the transition edge, wherein the anchor opening and the transition edge are created during injection molding of the bristle carrier, b) receiving the at least one bristle in the receiving opening of the tool part In the hole, c) the at least one bristle is pushed into the bristle carrier by the thickened fixed end of the at least one bristle while the at least one bristle is still in the accommodating opening formed during the manufacture of the bristle carrier the anchoring aperture, d) reducing the distance of the tool piece to the bristle carrier so that the tool piece contacts the bristle carrier, e) bringing the front face of the bristle carrier to a temperature that is lower than the bristle material and (or) the melting temperature of the bristle carrier material, in particular up to 85% of the corresponding melting temperature in °C of the bristle material and/or the bristle carrier material, f) the tool applies pressure to the heated The bristle carrier, and at least in the region of the end side edge surrounding the anchoring opening, with the cross-section of the anchoring opening reduced, the bristle carrier is deformed in such a way that the at least one The bristles are embedded and anchored in the anchoring opening, wherein in the region of the edge and the inner side the material of the bristle carrier is pressed laterally into the anchoring opening and into the region of the transition edge , and pressing against the at least one bristle, and g) increasing the distance from the tool piece to the bristle carrier to pull out the at least one bristle from the accommodating opening.

Heating of the bristle carrier can be done before or during reducing the distance of the tool piece to the bristle carrier, or after the tool is first in contact with the bristle carrier. Therefore, the sequence of steps d) and e) is not necessarily consecutive.

The invention is based on the idea that the material that will close the anchoring openings at the front and ensure that the bristles or tufts of bristles are not pulled out is only provided by the bristle carrier between the front and the back, so that no extensions are formed, wherein the bristle on the transition edge The chamfer provides a buffer space into which material can enter without protruding as a ridge over the end face formed by the front face. Thus, in the chamfered area, less material is available to be pushed inward, so that material can be pushed axially outward from the deeper areas in the anchoring aperture. In contrast to the prior art which provides additional material, the present invention deliberately reduces material at the transition edges. Although the bristle carriers must be pressed together precisely for this, by reducing the material and by thus obtaining space at the exit of the anchoring aperture, there is more room for moving the tool than without such chamfers large tolerance.

The chamfer can extend along the entire circumference of the transition edge, and here optionally has the same cross-section along the entire circumference of the transition edge, i.e. of the same shape and of the same size, which is optimal for the production of injection moulding tools of.

Alternatively, the chamfer can also have a different cross-section along the circumference of the transition edge, which can be optimized such that the material in the different sections is squeezed inward to different degrees, and therefore more or less is required buffer space.

The chamfers may, for example, have different cross-sections along the circumference of the transition edge, starting from the same axial depth of the anchoring aperture. The axial depth is measured from the front face of the bristle carrier adjacent the chamfer. Typically (and this is not limited to this embodiment) the front face has a flat, convex or concave shape. In convex or concave shapes, the depth is measured from the envelope (Umhüllenden) of the front.

As practice has shown, the following chamfers are sufficient: in the anchoring openings starting at a depth of at least 0.1 mm and at most 0.5 mm, in particular at most 0.35 mm, from the front face of the bristle carrier adjacent to the chamfer of depth.

The chamfer only requires a radial width of at least 0.1 mm and at most 0.5 mm, especially at most 0.35 mm.

The chamfer can be formed in part by a chamfer and/or an arc, in particular a radius, in cross section. These simple geometries facilitate the production of injection moulding tools and, on the other hand, as experiments have shown, are absolutely sufficient to prevent extrusion of material from the anchoring apertures.

As previously mentioned, the front side of the carrier can be flat, convex or concave curved.

In particular, a plurality of anchor openings are provided, wherein at least some of the anchor openings each have a chamfer, and the chamfers of the anchor openings are each different. By this method, it is also ensured that the anchoring openings are individually considered and customized, which on the one hand achieves a high pull-out force and on the other hand an optimal appearance of the brush.

In the method according to the invention, the at least one anchoring opening of the bristle carrier is not completely compressed, but only in the region of the outlet, ie in the region surrounding the end edge of the anchoring opening. In this case, the at least one anchoring opening of the bristle carrier is reduced in cross section only up to the beginning of the thickened fixed end of the bristles or tufts, in particular down to a depth of up to 1 mm. The rest of the anchor opening remains in its original shape.

The bristle carrier is compressed in such a way that the material of the bristle carrier is pressed laterally into the anchoring opening and into the region of the transition edge in the area of the edge and inside of the anchoring opening, without protruding outward beyond The envelope formed by this front face of the bristle carrier.

The chamfer also does not form a lead-in bevel, since no lead-in is required here at all. This is especially the case when the thickened fixing end has a rounded or chamfered bottom surface, by means of which the bristles or bristle bundles were previously introduced into the anchoring openings. This rounded or beveled underside is usually created when the bristles of the tufts are fused.

The tufts of bristles are previously pushed into the anchoring openings by the thickened fixed ends of the bristle tufts in such a way that the thickened fixed ends do not touch the chamfers of the anchoring openings.

In particular, the lateral dimension of the thickened fixing end is smaller than the lateral dimension of the respective associated anchoring aperture in the region of the bottom of the anchoring aperture. Thus, there is a lateral gap that allows the bristles or tufts of bristles to be pushed quickly into the anchoring apertures. Furthermore, if the bristles or tufts are squeezed together and compressed at the "root" (ie, at the thickened fixed end), the shape of the bristles or tufts is not affected. With the above features, the alignment of the bristles or the parallel alignment of the bristles of the bristle bundle is more ensured.

Contrary to the prior art, the bristle carrier is injection-molded together with at least one anchoring opening, ie the anchoring opening is not produced by pressing with a hot stamping die. The inner side of the anchoring opening is provided with a so-called draft angle, which can for example be up to 2°. Due to this release angle, the bristle carrier is easily and sometimes only possible to release from the injection mold. However, this draft bevel is not part of, and does not belong to, the chamfer.

Individual tufts of bristles or all tufts of bristles can be inserted perpendicular to the adjacent front face and inserted into the anchoring openings of that face.

Alternatively, there are also bristles or tufts of bristles that are inserted into the anchoring openings obliquely to the front face. In this case, the present invention provides that the chamfer is formed larger on the transition edge on the side close to the bristles or bristle bundles than on the remaining circumference of the transition edge. Alternatively, there is no chamfer at all on the side remote from the bristles or tufts and there is a chamfer on the remainder of the periphery of the transition edge. Material is removed from the anchoring apertures since less material has to be shaped in the area of the front edge of the anchoring aperture (this is because the bristles or tufts are angled on the side the bristles tend to) increased risk. Therefore, in this area, additional or larger buffer space needs to be provided by chamfering.

When pressure is applied to the bristle carrier, the backside of the bristle carrier should be actively cooled to keep the backside stable and not deform the backside area when compressing the bristle carrier.

The bristle carrier typically has a plurality of anchor openings. One embodiment of the invention provides that none of the edges of the anchoring apertures are provided with protrusions protruding from the front face of the bristle carrier.

Of course, such protrusions may optionally be provided partially, especially where the anchoring openings are particularly close to each other and only thin webs are present.

Preferably, in the method according to the invention, the front side of the bristle carrier is heated. For this purpose, the front side is brought to a temperature which is lower than the melting temperature of the bristle material and/or the bristle carrier material, in particular up to 85% of the respective melting temperatures of the bristle material and/or the bristle carrier material in °C. According to feature e), the tool piece exerts pressure on the heated bristle carrier and deforms the corresponding heated bristle carrier.

The front side of the bristle carrier is preferably heated by means of a heated tool. If the end face of the tool piece is in contact with the front face for a few seconds (as is the case in the preferred variant), the temperature of the end face of the tool piece is also equal to the temperature of the front face of the bristle carrier, so that these temperatures coincide. This means bringing the end face of the tool to a temperature which is lower than the melting temperature of the bristle material and/or the bristle carrier material, in particular up to the corresponding melting temperature of the bristle material and/or the bristle carrier material in °C 85%.

Although the above-mentioned processing steps are preferably carried out in the above-mentioned order, this is not required. For example, it is also possible to heat the front side of the bristle carrier and then reduce the distance from the tool piece to the bristle carrier, or both steps can be performed simultaneously or partially simultaneously.

The distance change is achieved by relative movement of the tool and holder, ie the tool moves while the holder is stationary, or vice versa, or both the tool and holder move.

The "at least one bristle" mentioned below refers to both the only bristle located in an accommodation opening and an anchoring opening, and the plural number of the only bristle bundle located in an accommodation opening and an anchoring opening. A bristle also refers to a plurality of bristle bundles located in a plurality of accommodation openings and anchoring openings, therefore, the present invention is not limited to the anchoring of a single bristle or a plurality of separate single bristles. Additional reference to tufts of bristles is added in several places below to increase readability, but the invention generally applies to both bristle carriers with one or several individual bristles and bristle carriers with one or several tufts of bristles or a combination of the two. In addition, this point is related to both the method request item and the device request item.

Several improvements will be described below, which are inventions in their own right, but can be combined to form an optimized solution. It should be emphasized that the apparatus, which will also be described below, may also have the features described herein in connection with the method, wherein only the controller is programmed accordingly.

Due to the aforementioned heating, it is possible for the holder for accommodating the bristle carrier to be heated during operation, eg radiatively. In addition, extensive testing has shown that it is possible to apply pressure to the bristle carrier for so long that the deeper areas of the bristle carrier away from the front face are overheated so that the bristle carrier is also shaped in these deeper areas. To prevent this, according to a variant of the invention, the backside of the bristle carrier is actively cooled during the application of the pressure to the bristle carrier. That is to say, there is a separate cooling device that works, for example, in a liquid-cooled manner. This makes it possible to set, within narrow limits, the volume region of the bristle carrier in which, during the application of pressure, a sufficiently high temperature exists for shaping. In addition, the cooling device forms a deformation-free safety zone inside the bristle carrier.

Active cooling of the backside of the bristle carrier during application of pressure. Of these, it is preferable to ensure that the bristle carrier becomes warm during this process, up to 25°C.

Specifically, the aforementioned holder is actively cooled in a liquid-cooled manner, and the holder is used to exert a reaction force on the bristle carrier from the back side and for the bristle carrier to abut against.

This cooling can take place not only on the rear side of the bristle carrier, but also optionally at least on the so-called lateral sections of the bristle carrier. The side refers to the side connecting the front and back of the bristle carrier. This cooling prevents the side surfaces from being plastically deformed laterally outwards when the bristle carrier is pressed between the front and the back. For this purpose, for example, the holder can have a receiving recess for the bristle carrier, which is constructed so as to be complementary to the bristle carrier and ensure that the back and sides rest against the holder.

The bristle carrier is preferably heated by the heatable tool only after the at least one bristle has been inserted.

The tool can be heated by an integrated resistive heater or by a heated adjacent part that temporarily contacts the tool outside the contact surface that contacts the bristle carrier and conducts heat to the tool while in contact superior. The tool parts are heated to a predetermined temperature in a controlled manner, not by "accidentally" heating more or less adjacent hot parts, but by heaters assigned only to the tool parts. The pressure is applied in a device, wherein during the application of the pressure to the bristle carrier, the bristle carrier contacts the tool on the front side and the holder on the back side. In particular, the device overtravels to a hard stop (auf Block gefahren) to apply the pressure. That is, there is no distance between the holder and the tool piece, since the two are in contact with each other on the end faces. This contact is preferably full contact and takes place around the enclosed bristle carrier in the separation plane between the holder and the tool part. In this way, the cavity formed between the holder and the tool piece to accommodate the bristle carrier is sealed within this separation surface. Here, the material of the bristle carrier does not enter a gap and form burrs on the finished bristle carrier.

The test results have surprisingly shown that the stability of the bristle carrier can be improved if the device is not separated and the bristle carrier is removed immediately after the so-called action time (i.e. the time during which pressure is applied to the bristle carrier between the front and the back) and accuracy, as well as improving the orientation stability and orientation accuracy of the at least one bristle, especially the bristles in the bristle bundle. Although this is extremely disadvantageous for the cycle time, after the action time a ventilation gap is formed between the front face and the tool part. That is, the tool piece and the holder are slightly separated from each other. There is no complete separation of the device, nor is the device brought into a state in which the bristle carrier is removed or can be removed. The bristle carrier, together with the at least one bristle, preferably together with one or several bristle tufts, is temporarily brought into a resting phase in which a ventilation gap is used in the apparatus to cool the front face. In this resting stage, the back surface continues to contact the holder depending on the situation, and the side surface also continues to contact the holder depending on the shape of the holder, which can play a role in stabilizing the shape.

The duration of the predetermined rest period should be at least 1 second, in particular at least 1.5 seconds. During this time, preferably no further movement between the holder and the tool piece occurs. As an alternative, a slow opening movement can occur.

It is particularly advantageous that the at least one bristle, in particular the tuft or tufts of bristles, stays in the corresponding accommodation opening during this entire resting phase. The accommodating apertures keep the bristles or the bristles of the tuft or tufts in shape during the resting phase. The area around the opening is thereby stabilized and anchored. Obviously, the internal stress is eliminated.

The ventilation gap shall have a height of at least 1 mm measured in the direction of travel of the device (the direction of movement between the holder and the tool when the device is separated and closed).

As previously mentioned, the ventilation gap can preferably be kept constant during the rest phase.

Optionally, cooling air can be blown to the front side of the bristle carrier through the ventilation gap. Thereby, the duration of the rest phase can be shortened.

Another feature of the invention is that the pressure is applied to the closed position for a predetermined holding time after the feed movement of the tool piece relative to the bristle carrier, terminating in the closed position of the device. The bristle carrier. Despite the desire to keep cycle times as short as possible, according to this feature of the invention, the device is not closed and reopened immediately, as is often the case when pressing, shaping or stamping objects. The pressure does not have to be constant during the holding time, since it is related to the resistance of the bristle carrier. Therefore, this pressure decreases with increasing degree of deformation of the bristle carrier.

The hold time should be at least 1 second, preferably at least 1.5 seconds.

The results show that hold times of up to 3 seconds, specifically up to 2.5 seconds, are optimal. Longer hold times are not required.

The bristle carrier can be heated on the front face during the holding time, in particular during the entire holding time, but optionally also already on the front face during the feeding movement. Cycle time can be saved if heating is already performed during the feed movement. Because even during the feed movement, the front surface is heated, for example by radiation. In this case, as soon as the front side contacts the heated tool piece, during the subsequent closing of the device, the front side and the bristle carrier are heated and reach a certain temperature.

The action time of the pressure on the bristle carrier is the sum of the holding time and the period during the feed movement during which the tool part first contacts the front side and at the same time the holder contacts the back side, and is compressed to a fully closed position. This action time should be at least 4 seconds, in particular at least 5 seconds.

The results show that the action time of up to 15 seconds, specifically up to 10 seconds, is the limit.

Therein, the holding time is preferably shorter than the above-mentioned period of time during which the bristle carrier is compressed when closed. This closing and compression takes place at an extremely slow feed rate of the holder relative to the tool. In particular, this period of time is at least 3 seconds, in particular at least 4 seconds.

Test results have shown that the holding time is up to 50% of the above-mentioned period of time during which the bristle carrier is compressed when closed, and in particular up to 40% of the above-mentioned period of time when the bristle carrier is compressed when closed.

In order to shorten the cycle time, it may make sense that the front side of the bristle carrier has been heated by other measures than just by contacting the tool part. The bristle carrier can be preheated. For example, hot air can be blown to the front of the bristle carrier while it is already in the holder, or the bristle carrier can be briefly exposed to a heat source (eg radiant heat) which does not form the tool. This point can occur during the feed movement of the tool piece relative to the holder, or it can also occur temporally prior to this feed movement. For example, the bristle carrier can be heated during the adjustment movement of the holder or the tool piece or before the tool piece is moved laterally towards the holder. As a result, the time required for subsequent heating by contact with the tool can be shortened.

Another feature of the invention is that the free end of the at least one bristle is end-supported in the device. This support should determine the axial position of the bristles or the axial position of the bristles of one or several tufts inside the same tuft or the relative axial position of the tufts. Where there are several tufts of bristles, the ends of the tufts should be serrated if the brush is viewed from the side, for example. Other options are: the tufts are serrated, tapered at one end or tapered at one end.

Desirably, the above-mentioned support as a stop or forming means should also function during the application of pressure to the bristle carrier to prevent movement of the bristles, bristles or tufts of bristles during this time. It turns out, however, that it is beneficial that this support has been removed at least during the application of pressure to the bristle carrier, preferably before pressure is applied or during the feeding movement of the device before the tool or holder contacts the front face of the bristle carrier with the bristle carrier. This support has been removed after the back. That is, at least in the final stage of application of the pressure, and optionally also during the entire application of the pressure, the above-mentioned supports used are removed. The minimum pressure introduced by the support into the bristles, at least in the final stage or also during the entire deformation process stage, can cause the bristles to deform, or to skew or to be non-parallel to each other, even within a tuft of bristles.

In this case, it may make sense that the cross-section of the at least one bristle is adapted to the cross-section of the corresponding receiving opening in the tool part, so that the at least one bristle or the at least one bristle bundle is clamped Axial positioning can be obtained in the accommodating opening and through the clamping. That is, if the bristles of the bristles or of a tuft of bristles are oriented axially, the bristles are clamped in the receiving openings and are thereby positioned axially. Of course, this clamping is only minimal clamping, generally allowing movement during the pre-prepared shaft orientation process. However, the own weight of the bristles or tufts of bristles or the inertia of the device during movement can prevent undesired self-movement of the bristles or tufts of bristles in the receiving apertures.

The following is similar to anchorless fixing as used in practice: the at least one bristle or the entire bristle bundle can obtain a thickened fixing end by thermoforming the bristle material by heating the bristle material to above the melting temperature . Where a tuft of bristles is used, the bristles of the tuft are combined by thermoforming. However, instead of also merging adjacent tufts of bristles, each tuft of bristles itself has a thickened fixed end into which the tuft of bristles is inserted into the anchoring opening with the thickened fixed end facing forward.

The shaping is performed outside the anchoring station in which at least the steps c) to f) are performed.

Thus, the material of the thickened fixed end is preferably cured when the corresponding fixed end is inserted into the anchoring aperture.

The present invention can not only fix the bristle tufts to the anchoring openings by shaping the edges of the openings, but also fix prefabricated so-called elastic cleaning elements (for example, made of thermoplastic) to the anchoring openings. The thickness of these cleaning elements Ordinary filaments several times larger than a tuft of bristles. These cleaning elements are used to improve cleaning and, in the case of toothbrushes, to massage the gums. Furthermore, these cleaning elements do not have to be pin-shaped, but can have any cross-section, in particular elongated, arcuate, cross-shaped or circular (round or oval) and corresponding annular shapes including a central opening .

The at least one anchor opening can be filled with a single prefabricated bristles composed of an elastomeric material, in particular a thermoplastic elastomer (thermoplastischem Elastomer; TPE). The bristle carrier is deformed to anchor the single bristle to the anchoring aperture.

The individual prefabricated bristles preferably have a maximum wall thickness greater than 0.6 mm, in particular greater than 0.9 mm, measured in cross-section. Taking a rectangular cross-section as an example, this maximum wall thickness is measured longitudinally.

The single prefabricated bristle has a thickened fixed end by which the bristle is pushed into the anchoring aperture and which is surrounded by the shaped edge of the anchoring aperture of the bristle carrier . The thickened fixed end is produced when the individual bristles are produced, rather than, for example, by pressing and elastic deformation of the bristles and shaping of the edges of the anchoring apertures. Alternatively, if the bristles are thick enough and the edges are pressed into the elastic bristles, this can be done without thickening the fixed end, so that the fixed end is thickened by the extruded material.

The thickened fixed end has, for example, the shape of a flat cylinder, and/or the single prefabricated bristles are multi-component injection moulded parts. In this case, the thickened fixed end may be constructed of a material that is at least different from the outer surface of the single preformed bristles outside the anchoring aperture, preferably at least harder than the outer surface, eg polypropylene. The fixed end is preferably even stiffer than the entire rest of the single prefabricated bristles. The stiffer fixing end results in better retention of the bristles in the anchoring apertures.

The bristle carrier is usually provided with several anchor openings, of which at least one anchor opening, preferably several anchor openings are only provided with the single prefabricated bristles or bristles. At least one other anchor opening, preferably the remaining anchor openings, are provided with prefabricated bristle tufts, such that the brush includes a hybrid of conventional bristle tufts and thicker elastic cleaning elements.

Viewed in side view, the free ends of the individual bristles extend, for example, at least as far as the free ends of the tufts of bristles, ie the individual bristles are not shorter than the tufts of bristles. It may be beneficial that the elastic cleaning elements (ie the individual bristles) are even longer than the tufts and protrude frontally from the ends of the tufts. Of course, the elastic cleaning elements can also be shorter than the tufts of bristles.

Another feature of the present invention is that the wall portion defining the anchoring aperture in the bristle carrier is deformed only from the front face over the thickened tip after the deformation. Wherein, the fixed end can also be, for example, a thickened end or a thickened fixed end of a bristle bundle, and the bristles are integrally connected in the thickened fixed end. Desirably, the entire anchoring aperture rests against the fixed end as tightly and without play as possible to prevent movement of the bristles or tufts in either direction. But the present invention is different from this. The fixed end is not fully compressed, but has some clearance inside the anchor opening. Thereby, the position of the at least one bristle, in particular the position of the bristles inside a tuft of bristles, can be set more precisely. For example, when the thickened ends of a tuft of bristles are fully compressed, the bristles will try to diverge and no longer be oriented parallel to each other.

For example, the deformation should only take place in the edge region of the anchoring opening, that is, in the region of the wall segment located at the exit region of the anchoring opening.

Viewed from the finished brush, the wall of the anchoring opening does not hold the fixed end and/or the bristles or the at least one entire tuft for a depth of at least 1 mm, especially at least 0.8 mm. Deform the fixed end. This area, in which the fixed end is not clamped and/or deformed, starts from the bottom of the anchoring opening and extends beyond the at least 0.8 mm further towards the front of the bristle carrier.

There may even be an air gap between the wall and the at least one bristle or the tuft of bristles, especially in the area of the bottom or the area of the bottom adjacent to the anchoring aperture.

As previously mentioned, the at least one bristle or the at least one entire tuft of bristles may have a thickened fixed end. The edge of the anchoring opening is deformed, ie the area of the wall which is located in the exit area to the front face. The edge is narrowed in this region in such a way that the anchoring opening expands in the direction of the bottom and the thickened fixing end is caught from behind by the deforming edge in the pull-out direction, so that by means of a stopper The edge prevents the bristles or the tufts of bristles from being pulled out.

The narrowing "neck" of the anchoring opening adjacent to the outlet formed by deformation, ie the deformed edge of the anchoring opening that catches the thickened fixed end from behind, may for example have 0.5 to 1.3 mm, in particular An axial extension of 0.6 to 0.9 mm (in the context of the present invention, axial always refers to the direction from the front to the back or from the back to the front). This is a fairly small height.

Brushes, in particular toothbrushes, produced by the invention can have a very small thickness in the region of the bristle carrier based on the invention. Whereas conventional toothbrushes have a thickness of more than 4 mm in the head area, with the present invention a thickness of less than 4 mm can be achieved, while holding the bristles or tufts of bristles better than the prior art. In addition, the present invention also enables tufts of bristles (including larger tufts) to be positioned very close to the edge of the front face, which has not been possible in the past.

By deforming the edges of the anchoring apertures, the cross-section of the tufts of bristles can also be narrowed. That is, a tuft of bristles is secured to the anchoring aperture and the edge of the anchoring aperture is deformed such that the edge compresses the tuft of bristles in the area where the bristles are juxtaposed. The area where the bristles are juxtaposed preferably directly adjoins the fixed end formed by the melted bristles. Thereby, the tuft of bristles obtained after the deformation and narrowing of the anchoring aperture has a smaller cross-section than it had before after being inserted into the anchoring aperture.

Preferably, the tufts of bristles are compressed by at least 3%, in particular by at least 5%. This compression is the result of the cross-section of the receiving opening in the tool piece (to be precise, the cross-sectional area) and the deformation of the edge region (ie the outlet of the anchoring opening to the front face) of the cross-section of the anchoring opening. difference is defined.

In toothbrushes, however, this cross-section is reduced by at most only 0.4 mm, for example.

Preferably, the anchoring opening has an interference of less than 0.2 mm in the lateral direction relative to the enlarged cross-section of the bristle bundle or the fixed end of the bristles only before the anchoring opening is deformed, so that the fixed end can be easily removed. Push in the anchor opening. After deformation, the form fit is formed by the narrowed edge of the anchoring opening, wherein the cross-section of this edge can only be narrower than the maximum cross-section of the fixed end by 0.1 to 0.3 mm. This minimum excess is sufficient to achieve a prominent pull-out value (Auszugswerte).

The present invention can also process bristle carriers whose backsides have been injection-molded into elastomers. That is, when the bristles or the tufts of bristles are inserted into the anchoring apertures on the front side, the elastomer has been injection-molded on the back side of the bristle carrier. The holder for receiving the bristle carrier when pressure is applied has a groove. This groove is constructed to accommodate the bristle carrier from the back together with the elastomer. In particular, the groove can be constructed to complement the shape of the encapsulated bristle carrier. Since the elastomer is mostly implemented in toothbrushes as tongue cleaners with protruding bumps, the holder accordingly has recesses complementary to these bumps.

However, the depth of the groove is preferably implemented such that the volume of the groove for accommodating the elastomer is less than the uncompressed volume of the elastomer. This allows the volume in the groove to match the actual volume of the compressed elastomer when pressure is applied to deform the edge of the anchoring aperture. Since the elastomer is softer than the bristle carrier, it is necessary to prevent the interposed elastomer from making the pressure too low.

The reaction force exerted by the holder when deformed can be directed entirely by the elastomer into the front of the bristle carrier. That is, the backside of the bristle carrier does not necessarily have to be in direct contact with the holder in order to introduce the reaction force into the bristle carrier without interposing the elastomer.

The aforementioned various options of the method of the present invention may have the following optimization steps:

heating the tool so that the end face of the tool opposite the bristle carrier reaches a temperature that is lower than the melting temperature of the bristle material and/or the bristle carrier material, in particular lower than the bristle material and/or the bristle carrier material ) 85% of the corresponding melting temperature of the bristle carrier material in °C. The tool piece is moved relative to the bristle carrier so that the tool piece contacts and heats the bristle carrier.

According to another aspect, the method of the present invention for the manufacture of a brush is further developed by the following steps, the brush comprising a bristle carrier having at least one anchor opening and inserted without anchor anchored to the anchor At least one bristle in the fixed opening, wherein the bristle carrier and the at least one bristle are composed of thermoplastics, which may be the same or different:

bringing the end face of the tool piece opposite the bristle carrier to a predetermined temperature, the predetermined temperature being in the range between ambient temperature and 210°C, in particular between ambient temperature and 150°C;

The tool is moved relative to the bristle carrier so that the tool contacts the bristle carrier and brings the bristle carrier to the predetermined temperature without melting the bristle carrier and the at least one bristle.

In all embodiments, the thermoplastic is preferably selected from polyesters, especially polyethylene terephthalate (Polyethylenterephthalat; PET), preferably BR003, and polybutylene terephthalate (Polybutylenterephthalat; PBT) ), polypropylene (Polypropylen; PP), polycarbonate (Polycarbonat; PC), polyamide (Polyamid; PA), polyvinyl acetate (Polyvinylacetat; PVA), polyethylene (Polyethylen; PE), acrylonitrile-butyl Diene-styrene copolymer (Acrylnitril-Butadien-Styrol-Copolymer; ABS) and styrene-acrylonitrile copolymer (Styrol-Acrylnitril-Copolymer; SAN) composed of groups. Homopolymers and copolymers comprising the above thermoplastics can be used.

According to the invention, the bristle carrier and the at least one bristle inserted into the tool should not melt when the tool contacts the bristle carrier. For this reason, the predetermined temperature is preferably at most 85% of the melting temperature of the thermoplastic. This will certainly prevent damage to the bristles and/or the bristle carrier.

The predetermined temperature is preferably in the range between 30°C and 150°C, more preferably between 60°C and 140°C, in particular between 90°C and 130°C or between 100°C and 115°C.

Further preferably, the predetermined temperature is higher than the glass transition temperature of the thermoplastic. Thereby, the thermoplastic plastic has sufficient deformability.

The method of the present invention is fundamentally different from the prior art because, on the one hand, the method only proposes anchor-free fixation of the bristles, the tufts of bristles or the tufts of bristles. The anchoring apertures themselves are prefabricated, meaning that instead of pressing a heated punch into the bristle carrier to form the apertures, the present invention creates the receiving apertures already when the bristle carrier is formed by injection molding. Furthermore, the receiving opening is not first heated from the inside to soften the inside edge of the opening so that the bristles or bristle bundles are pressed into the soft wall of the receiving opening. Specifically, the bristles or the tufts of bristles are preferably pushed into the receiving openings before heating but not melting the front side of the bristle carrier opposite the tool piece. Operation is performed below the melting temperature of the bristle material and/or the bristle carrier material, wherein the heating is effected by means of a tool part containing the bristles or bristle tufts, rather than, for example, by means of dedicated pure heating means, when the bristles or bristle tufts are provided. , the heating tool must be removed again. The reason why such heating by means of a tool part containing bristles or tufts is neither conceivable nor obvious in the prior art is that in the prior art the tufts of bristles should penetrate into the heated soft walls of the bristle carrier and therefore must have a high inherent stability in order to be able to transmit the pressing force exerted on the tufts of bristles. The anchoring end can be pressed into the softened wall of the bristle carrier only by the pressing force applied to the back of the tuft and the inherent rigidity of the cold tuft. In addition, the heating is achieved by contacting the bristle carrier with a heating tool, rather than the non-contact heating commonly used in the prior art. As a result, on the one hand, the energy transfer rate can be increased, and on the other hand, the number of parts of the device can be reduced.

During the entire shaping process, the bristle carrier is heated to a temperature below the melting temperature, preferably to a temperature well below the melting temperature, if the bristle carrier material has a glass transition of 300°K or greater temperature, the temperature is, for example, at least 15% lower than the relevant melting temperature in °C, and preferably up to 15% higher than the glass transition temperature in °K. If the bristle material has a glass transition temperature of less than 300°K, the bristle carrier is heated to a temperature up to 50% higher than the glass transition temperature in °K during the entire shaping process. Preferably the bristle carrier is heated to a temperature above the glass transition temperature.

The present invention, as well as the preceding and following advantageous variants of the present invention, specifically propose the use of polypropylene as bristle carrier material, some groups of polypropylene having a glass transition temperature of less than 300°K and other groups having a glass transition temperature of more than 300°K . Other preferred bristle carrier materials are PET, PBT, PA, ABS, SAN and PC. These bristle carrier materials all have glass transition temperatures in excess of 300°K.

The glass transition temperature can be determined, for example, by dynamic mechanical thermal analysis (Dynamisch-Mechanische Thermoanalyse; DMTA). For partially crystalline thermoplastics, the melting temperature refers to the upper end of the melting point range. The melting temperature can be determined, for example, by dynamic differential calorimetry (Dynamische Differenzkalorimetrie; DSC). For amorphous thermoplastics, the transition to the flow or process range is the melting temperature.

In order to make the cycle time for the production of the bristle carrier relatively short, one embodiment of the invention proposes that the tool part is heated before the tool part contacts the bristle carrier. Of course, this has the disadvantage that the bristles or tufts of bristles are heated together, which is undesirable in the prior art since the tufts of bristles should be pressed into the soft wall. According to the invention, the tool can be heated to a predetermined maximum operating temperature of the tool before the tool contacts the bristle carrier.

The present invention also proposes in a technical solution of the present invention that the melting temperature of the plastic of the bristle carrier is lower than the melting temperature of the bristles or the bristles. However, there are also brushes in which the bristle carrier material is the same as the bristle material, such as polypropylene and PA.

As previously mentioned, the bristle carrier should not be heated by the tool until after insertion of the at least one bristle, and preferably only by contact. Of course, if the bristle carrier is close to a warm or hot tool, minimal warming may occur, but this warming is absolutely negligible and occurs only on the immediate surface.

However, if the feeding movement takes an extremely long time, as an alternative, the tool part can bring the bristle carrier to a temperature in the region of the contact surface with the tool during the feeding movement of the tool part, the temperature being low At the melting temperature of the bristle carrier material and preferably greater than or equal to the glass transition temperature of the bristle carrier material. Alternatively or additionally, the bristle carrier can also be brought to the above-mentioned temperature when the tool part contacts the bristle carrier.

According to an embodiment of the present invention, the heating operation of heating the bristle carrier to the above-mentioned predetermined temperature or temperature range should reach 0.25 mm to 0.5 mm below the surface (front side) of the bristle carrier facing the tool until the deformation process ends. The thermal energy also penetrates deeper into the interior of the bristle carrier because the tool piece is pressed against the bristle carrier for a longer period of time and heats the bristle carrier therebetween. In this way, when the tool part contacts the bristle carrier for the first time, the tool part does not have to be heated deeply, it is sufficient to effect this heating during the feed movement and the action time (contact time).

The tool may, in the first phase of the feeding movement relative to the bristle carrier, heat the bristle carrier to a temperature at least in the edge region surrounding the anchoring opening, but preferably in the entire contact region A temperature, which is higher than a limit temperature, if operating with a bristle carrier material with a glass transition temperature of 300°K or more, the limit temperature is equivalent to 60% of the glass transition temperature of the bristle carrier material in °C, specified In other words 80%. This is especially true for bristle carrier materials such as polypropylene variants with glass transition temperatures ≥ 300°K, PET, PBT, PA, ABS, SAN and PC. As an alternative, if operating with a bristle carrier material with a glass transition temperature of less than 300°K, the extreme temperature is ambient temperature, especially when using polypropylene variants with such a low glass transition temperature. The heating occurs before the tool piece deforms the edge and presses the edge against the at least one bristle during the second phase of the feed movement.

In particular, the bristle carrier material can be heated to a temperature in the range between the glass transition temperature and about 85% or less of the thermoplastic's melting temperature in °C. Depending on the thermoplastic material used, this temperature is preferably in the range between 30°C and 210°C, preferably between 60°C and 140°C, preferably between 90°C and 130°C or between 100°C and 115°C Inside.

Test results show that the tool should be heated to a temperature before the tool comes into contact with the bristle carrier, especially before the bristle carrier is heated to a temperature at least in the edge region (preferably over the entire contact area) surrounding the anchor opening. The bristle or the bristle bundle is pushed into the accommodating opening, and the temperature is higher than a limit temperature. If the operation is performed with a bristle carrier material whose glass transition temperature is greater than or equal to 300°K, the limit temperature is higher than the bristle carrier material. Calculated in °C 40% lower glass transition temperature, specifically 20% lower (this is especially true for bristle carrier materials such as polypropylene variants with glass transition temperatures ≥ 300°K, PET, PBT, PA, ABS, SAN and PC) , or if operating with bristle carrier materials with a glass transition temperature of less than 300°K, ie especially polypropylene variants with such a low glass transition temperature, the limit temperature corresponds to the ambient temperature. The edge of the anchoring aperture is at least the outer edge on the front face of the bristle carrier.

Another variant of the invention proposes that before the edge of the anchoring opening is heated to a temperature at least 30° C. higher than the ambient temperature, especially before the edge of the anchoring opening located inside the anchoring opening is heated by the The at least one bristle or the bristle bundle is pushed into the accommodating opening before the tool is heated to a temperature exceeding the ambient temperature. That is, in the latter variant, the edge inside the opening is not appreciably heated, whereas in the prior art, a pin that could be heated should be drilled into the opening to place the inside edge of the opening (i.e., the edge that defines the opening). wall) to the bottom of the hole.

The deformation should take place in such a way that the edge of the bristle carrier is pressed against the outer bristles of the fixed bristle tuft over a full turn at the junction with the front or end face of the bristle carrier, thereby compressing the bristle tuft. Of course, the manner of compression and the extent of compression depend on the cross-section of the tufts of bristles. Taking a toothbrush as an example, the cross-section of the anchoring opening is reduced by at most 0.3 mm, preferably by at most 0.15 mm.

Not heating the walls of the openings is preferably also applicable to the other embodiments. This means that the edge is brought to a specified limit temperature or temperature generally only in the frontal area, i.e. at the junction of the frontal face to the anchoring opening, as the case may be, while the environment is generally maintained in the opening as long as the tool part does not contact the bristle carrier. temperature.

A preferred embodiment of the present invention proposes that the tool is also heated in the entire contact area for the tool to contact the bristle carrier, and not only in dotted or linear areas around the edge of the anchoring opening . This has the advantage that the tool part can utilize the entire contact area and thus the entire adjoining material area of the tool part in order to move and shape this material area by the higher pressure applied. In addition, it is beneficial that the tool piece even contacts the entire end face of the bristle carrier facing the tool piece, ie the front face of the bristle carrier, at least contacting and applying pressure to at least 70% of the area of the face face. In the prior art, the protrusions on the bristle carrier were made to form some sort of flange-like structure that formed the only heated and shaped material. The present invention, however, differs significantly from this, as it is the sections of the bristle carrier remote from the end edge of the anchoring aperture that are heated and shaped.

The back side of the bristle carrier should not be heated by the tool piece during the anchoring, so only the front side facing the tool piece is actually heated and shaped, while the back side forms a stable plate-like structure that can A substrate called a bristle carrier. Consequently, this part of the bristle carrier is also not shaped or changed during pressure application.

The tool can also heat the bristle carrier from the end face at least for the entire time that the tool exerts pressure on the bristle carrier. That is, the present invention does not preheat the bristle carrier for a short period of time and then rapidly move the bristle tufts into the heated material section of the bristle carrier, whereas the prior art preheats the bristle carrier and pushes the bristle tufts into the bristle carrier.

The plastics used in the present invention are, for example: copolyesters, especially Eastar ^TM BR003 (having a melting temperature range of 230°C to 280°C), polypropylene, especially homopolymers with a melting temperature of 165°C, such as PPH5042, Carbonate, polyamide, polyvinyl acetate or polyethylene. If these materials have a glass transition temperature above the ambient temperature (here 300°K), the energy should be transferred to the bristle carrier through the tool element. This is also beneficial for materials whose glass transition temperature is lower than ambient temperature. According to a variant of the invention, however, in the case of a bristle carrier of this type, it is also not necessary to use a tool to heat the bristle carrier. The shaping is achieved only by the pressure exerted by the tool on the bristle carrier at ambient temperature.

Advantageously, in the method of the present invention, the bristle carrier material is heated to the following temperature by means of the apparatus of the present invention, which will be described below:

In particular, the present invention proposes heating the front side of the bristle carrier in the range of 75°C to 95°C, in particular 80°C to 90°C for PET, 115°C to 125°C, in particular 110°C to 120°C for PP The range heats the front of the bristle carrier.

In particular, PP having a melt flow index (Melt-Flow-Index; MFI) of 6 to 35, preferably 10 to 15 is used.

In a preferred embodiment, the method of the invention does not provide only one bristle which is generally inserted into the receiving opening, but provides several anchoring openings in the bristle carrier and several receiving openings in the tool part hole. The accommodating openings are respectively aligned with the corresponding anchoring openings. The tufts of bristles are inserted into the receiving apertures, and the bundles of bristles are then pushed into the anchor apertures, preferably simultaneously. The tool element simultaneously heats at least the edges of the anchoring openings, preferably the entire contact surface, thereby heating the entire area between the anchoring openings. By applying pressure to the front face of the bristle carrier, the anchoring apertures are closed at the same time and thereby the bristle tufts are simultaneously anchored.

The contact area between the tool part and the bristle carrier is preferably flat on the tool part, and the front side of the bristle carrier facing the tool part is also flat. However, there are also bristle carriers that have convexly or concavely curved front surfaces. The tool piece has complementary end faces.

The feed movement of the tool piece relative to the bristle carrier can be carried out in a pressure and time controlled and/or pressure and stroke controlled manner.

As an alternative, the device is overtraveled to a hard stop, for example by setting up an electric motor (eg through a spindle drive), wherein the current consumption or power consumption of the electric motor is detected and the device is considered to be the device since reaching a specified limit In the closed position, in which the holder and the tool part preferably contact each other. This point in time serves as the starting point for the so-called hold time.

The term "movement or feed movement of the tool element relative to the bristle carrier" refers to the relative movement of one or both of the two parts.

Another variant of the invention proposes that the tool element exerts a preferably constant pressure on the bristle carrier for a defined time from the point of contact with the bristle carrier. This alternative method is particularly easy to implement, since it is simply a matter of applying pressure to the bristle carrier for a period of time, the so-called action time, before separating the tool piece from the bristle carrier. As with the remaining variants of the invention, no further processing steps have to be carried out here to anchor the bristles or the tuft(s) of bristles in the bristle carrier.

The feed movement of the tool relative to the bristle carrier and/or the pressure exerted by the tool on the bristle carrier may be in time from the tool contacting the bristle carrier until the maximum feed stroke is reached is nonlinear. Thereby, for example, a longer or shorter initial exposure time of the temperature can be achieved, followed by application of a further pressure to further permanently deform the bristle carrier material.

Unlike the aforementioned prior art, the fixed end of the at least one bristle or the or the entire tuft of bristles can be smaller than the cross-section of the corresponding anchoring opening when pushed into the corresponding anchoring opening, of course when the bristle carrier is deformed. and before being heated. That is, the tufts of bristles are not pressed into the lateral walls of the anchoring apertures as suggested in the prior art. Nor is the fixed end pressed into the bottom of the anchor opening because the bottom is not heated or heated enough to soften. Furthermore, no axial force is applied to the bristles in excess of the force required to push the bristles out of the receiving aperture.

An important point of the method and a major difference from the prior art is that the tool piece acts on the bristle carrier for a relatively long period of time, during which time pressure is applied to the bristle carrier and the bristle carrier is additionally heated. The action time is at least 4 seconds, specifically at least 5 seconds and at most 15 seconds, specifically at most 10 seconds. This pressure can remain constant and/or continuously heat the bristle carrier during such a long duration of action. The anchoring opening may be a blind hole, in particular having a depth of up to 4 mm, in particular up to 2.7 mm.

The method of the present invention reduces the thickness of the bristle carrier by deforming the bristle carrier in the frontal area.

The shaped and narrowed depth of the anchoring opening only accounts for at most 85% of the total depth of the anchoring opening, specifically at most 70%, preferably even at most only 60%, that is, in the blind The bottom area of the hole does not narrow the anchor opening.

Another major difference between the present invention and the prior art is also the pressure applied, which is much higher than in the previously proposed methods. In particular, the tool applies a pressure of at least 200 bar, in particular at least 400 bar, to the bristle carrier.

The invention also enables the manufacture of brushes with tufts of bristles extending obliquely to the front face. This is surprising because, due to the oblique orientation of the tufts of bristles, the outlet edge of the anchoring apertures can be said to be partly located below the obliquely extending bundles, and therefore on the one hand more difficult to reach for tools used for shaping, And on the other hand shaping the material in this area should actually result in the erection of the obliquely extending bundle. However, as found in experiments, this is not the case. With the method and the device according to the invention, the tufts of bristles can thus also be installed in the bristle carrier at an angle.

In particular, a magazine is used as the tool piece to which the at least one bristle or the at least one bristle bundle is assembled. If several bristles or tufts of bristles are to be fastened on the bristle carrier, all bristles or tufts of bristles are placed in the same magazine and pushed in simultaneously after assembly.

The fixed end(s) of the bristles or tufts of bristles project out of the pocket with the fixed end after assembly and are heated on the fixed end without having to leave the pocket in between. In this case, the thickening is formed on the fixed end projecting freely from the cassette. That is, the cassette is not a pure punch tool, but is also a transport tool which is moved laterally towards the bristle carrier from the assembly station and then pressed against the bristle carrier.

The thickening (ie, the thickened fixed end) can then be actively cooled (ie, immediately after the thickening is formed) before it is pushed into the anchoring apertures in the bristle carrier. This increases cycle time. In addition, it is avoided that the thickening is subsequently deformed when the pressure is applied in such a way that the bristles are no longer optimally aligned with respect to each other. Active cooling does not refer to using the ambient temperature present in the device to cool the thickened fixed end. Instead, there is a cooling device, such as an active airflow generated by a fan. This air flow can convey ambient air away from the heated part, for example, or it can also convey cooled air from an air conditioning system. Another possibility is to provide a cold chamber through which the fixed end is transported with the bristles or bristles.

As already mentioned, the tool has, for example, a flat end face facing the bristle carrier (at least in the area of contact with the bristle carrier) and/or a geometry that does not extend into the anchoring opening, i.e. does not With pin-like projections or the like as proposed in the prior art.

The results show that the position of the so-called separation surface between the holder and the tool part, on which the two rest against each other, relative to the bristle carrier is important. It is therefore advantageous that the cavity formed for accommodating the bristle carrier is not only formed in the holder but also partly in the tool part. However, in view of the thickness of the bristle carrier, the majority of the cavity is formed by a depression in the holder. The separating surface should preferably adjoin or directly adjoin a rounded junction between the side surface and the front face of the bristle carrier, ie be located outside the rounded junction. In this way, there will be no bumps or burrs on this rounded interface formed by the extruded material of the bristle carrier.

By applying pressure and heat, or just pressure, the total thickness of the bristle carrier is permanently reduced, that is, not only partially, but overall. In particular, the end face of the tool piece facing the bristle carrier is brought to a temperature of at most 140°C, in particular at most 130°C. By way of example, polypropylene, PET, ABS or SAN are used here as materials for the bristle carrier.

The results show that in the case of using PET as the bristle carrier material, the front side of the bristle carrier should be shaped so that it reaches 75°C to 95°C, in particular 80°C to 90°C, and when using PP (eg with 6°C) In the case of a Melt-Flow-Index (MFI) to 35, preferably 10 to 15, the front side of the bristle carrier should be brought to 105°C to 125°C, specifically 110°C to 120°C .

As already mentioned, before or after fixing the at least one bristle, at least one elastic cleaning element protruding from the front can be formed and fixed on the bristle carrier by injection moulding, the cleaning element being composed of an elastomer, in particular TPE , wherein the cleaning element is arranged on the edge of the bristle carrier and/or into the edge between the bristles or bristle bundles. Thus, a mixture of cleaning elements can be employed in the same brush. Cleaning elements formed by injection moulding, bristle bundles fixed to the bristle carrier by edge shaping of the anchoring apertures and elastic prefabricated cleaning elements also fixed to the bristle carrier by edge shaping of the anchoring apertures The individual bristles can be mounted on the bristle carrier in any combination. Furthermore, the bristle carrier can be constructed as a multi-component injection-molded part.

The bristles can also be chemically or mechanically pre-sharpened bristles or can be pre-rounded.

Several bristle tufts can be anchored in the same bristle carrier, wherein at least one bristle tuft consists of bristles whose material and melting temperature are different from those of at least one other bristle tuft. Bristle tufts of different bristle materials are heated at different intensities to fuse the bristles of a tuft to each other to form thickened fixed ends, respectively. This can be achieved in different ways: depending on the bristle material, setting different distances between the ends of the tufts close to the heating device and the heating device, and/or heating the heating device to different temperatures depending on the bristle material, and (or), use different heating devices heated to different temperatures for corresponding bristle materials.

For example, the tufts of bristles are pushed out of the pocket to varying degrees. The tufts of more fusible material, for example, are located closer to the cassette than other tufts, so that the tufts of bristles protruding more are closer to the heating device than the other tufts, and are thus heated with greater intensity. As an alternative, the bristle tufts can also be processed sequentially, in that the fixed ends of the bristle tufts with different bristle materials are pushed out of the cassette in sequence so as to be closer to the heating device. Then, the heating device is heated to two suitable different temperatures, or different temperature heating devices are used for the corresponding bristle tufts.

When the brush has nylon bristles and PBT bristles, for example, the nylon bristles are heated first, and then the PBT bristles are heated.

The aforementioned advantageous variants can also be explicitly combined with one another arbitrarily.

The invention also relates to a device for carrying out the method as claimed in any one of the preceding claims to manufacture a brush comprising at least one bristles or at least one bristle bundle, the brush having a bristle carrier having at least one bristle carrier Anchoring aperture for the at least one bristle or the at least one bristle bundle, characterized in that the apparatus comprises a plurality of stations, including an injection moulding station for producing the bristle carrier and for fixing the at least one bristle in the The latter anchoring station in the bristle carrier, where on the injection molding station there is an injection molding half-mould part having at least one pin extending into the injection molding cavity, the pin forming the injection molding A portion of the injection molding half-mould portion is formed, and the pin creates the anchoring opening constructed as a blind hole, wherein the pin protrudes from the bottom surface of the injection molding half-mould portion, and wherein at the transition from the bottom surface to the pin Constructed with a chamfer for forming the complementary chamfer on the bristle carrier in the region of the transition edge, and wherein the apparatus comprises a tool with a tool for the at least one bristle or the at least one at least one receiving opening of the bristle bundle, wherein the outlet of the receiving opening is located on the end face of the tool piece facing the bristle carrier, and wherein the tool piece has a heater that heats at least a section of the end face, the The heater is constructed and controlled such that the end face is heated to a temperature of up to 140°C, in particular up to 130°C.

The term "injection moulding halves" is hereinafter understood to mean a one-piece component that completely forms the inside of a cavity in an injection moulding half, or an assembly formed by one or more parts of a multi-part injection moulding half, The multiple parts together form the inside of the cavity in the injection moulding half. In the latter case in particular the bottom of the cavity in the injection moulding half is a separate part which is slidingly inserted into the opening of the second part which in turn defines the edge of the cavity.

The plant according to the invention does not necessarily have stations housed in the same production plant or at the same production site. Conversely, the individual stations can of course also be spatially separated from each other at different locations. By forming a chamfer on the bottom surface of the pin, a desired chamfer is created on the transition edge during injection molding, which chamfer is then beneficial for compressing the bristle carrier and anchoring the bristle tuft.

The tool applies a pressure of at least 200 bar, preferably at least 400 bar, to the bristle carrier.

In order to produce the above-mentioned advantageous dimensions of the chamfer on the transition edge, the complementary chamfer on the injection moulding half-mould part has an axial length and a radial width at the transition between the pin and the bottom surface, the axial The length is from at least 0.1 mm to at most 0.5 mm, in particular at most 0.35 mm, the radial width is from at least 0.1 mm to at most 0.35 mm.

Finally, the invention also relates to an injection moulding half-mould part for the above-mentioned injection moulding station. The injection moulding half has at least one pin protruding into the injection moulding cavity, the pin forming part of the injection moulding half and the pin creating the anchoring aperture constructed as a blind hole, wherein the pin extends from the The bottom face of the injection moulding half-mould part protrudes and wherein a chamfer is formed at the transition from the bottom face to the pin for forming the complementary chamfer on the bristle carrier in the region of the transition edge . The chamfer on the injection moulding half part has an axial length and a radial width at the transition between the pin and the bottom surface, the axial length being from at least 0.1 mm to at most 0.5 mm, especially at most 0.35 mm mm, the radial width is from at least 0.1 mm to at most 0.35 mm.

The injection moulding half-mould part can have an insert made as a separate part which protrudes into the bore of the remaining injection moulding half-mould part and protrudes with a free end from the front face and thus forms the pin. This greatly simplifies the production of the entire injection moulding half, since the grooves do not have to be milled or eroded from the underside. The hole is made instead, and the insert with the pin is inserted into the hole.

The insert itself may also be constructed with a base located in the hole and the free end forming the pin having a reduced width relative to the base. In this case, the chamfer is formed entirely on the insert, since the base forms the transition between the pin and the remaining bottom surface. The base itself may also define a portion of the bottom surface.

In particular, polypropylene, PET, ABS or SAN is used here as material for the bristle carrier.

In the apparatus of the present invention, the tool piece serving as a temporary carrier for the bristles or the bundle or bundles of bristles serves both as a punch and as a transport means. The heater on the end face of the tool is constructed and controlled by the controller such that when the end face is pressed against the bristle carrier, the end face is heated to a temperature of up to 140°C, in particular up to 130°C. Equipment that can theoretically achieve higher temperatures, but the controller or regulator correspondingly limits the temperature in a predetermined manner, of course, also belongs to the defined equipment.

As described above in connection with the method, the feed movement of the tool piece relative to the holder of the bristle carrier can be achieved by a movement of the holder and/or the tool piece, wherein the feed movement can be pressure and time Control and/or pressure and stroke control are either time-only or stroke-only.

The device of the invention can apply a pressure of at least 200 bar, preferably at least 400 bar, to the bristle carrier, that is, in the direction of the holder.

The tool should be heatable over the entire area of contact with the bristle carrier, or even over the entire region of the end face of the tool facing the holder and thus the bristles inserted in the holder end face of the carrier.

Furthermore, as described above in connection with the method of the invention, the tool is, for example, a magazine to which the at least one bristle or the at least one bristle bundle is assembled on the assembly station of the device. The at least one bristles or the at least one tuft of bristles (for the entire specification and the scope of the patent application, "at least one bristles" generally also includes one or more tufts of bristles) are assembled with the fixed end of the bristles or the tuft of bristles. The fixed end extends out of the box. On a melting station located after the assembly station, the fixed end(s) are heated to form thickenings, respectively. Where one or several tufts are used, the bristles of the respective tufts are combined by thermoforming. In particular, a mushroom-shaped, hemispherical or spherical thickening is formed.

In general, in the apparatus of the present invention, the cassette can be moved and the stations stationary, or the cassette can remain stationary and the plugging tool or heating device or holder is moved relative to the cassette. Such tools or holders can be provided, for example, on a rotating turntable, which in turn transports the stationary cassettes away. The device of the invention has a controller which controls the feed movement of the tool piece relative to the bristle carrier and the heating process of the tool piece so that the tool piece is heated before the tool piece contacts the bristle carrier . That is, the tool piece is already warm before the feed movement in the direction of the holder. A maximum operating temperature may but need not exist at this stage. The bristle carrier is heated by the tool after insertion of the at least one bristle by increasing the distance of the end protruding from the pocket and through the end face of the pocket to the corresponding contact surface on the bristle carrier.

The apparatus of the present invention is specifically constructed such that the tool is continuously heated to the desired temperature required to heat the front face of the bristle carrier to effect the deformation process. That is, when the at least one bristle or the bristle bundle(s) is inserted into the receiving opening or the receiving openings, the tool is also already warm and at this desired temperature. If the tool element also accommodates the at least one bristle or a tuft of bristles when the bristle ends are melted to form the thickened fixed end, care must be taken that the temperature of the tool element and/or the at least one bristle or tuft of bristles are The dwell time in the hole does not result in deformation of the bristles or the bristles of a tuft of bristles.

The controller may heat the tool to a temperature and control the feeding of the tool relative to the bristle carrier such that the tool is during the feeding movement of the tool relative to the bristle carrier and/or ) upon contacting the bristle carrier, bringing the bristle carrier to a temperature in the area of the contact surface with the tool that is lower than the melting temperature of the material of the bristle carrier and preferably greater than or equal to the glass transition temperature of the material of the bristle carrier , in particular, wherein the controller is programmed such that the controller sets the temperature of the tool to be at most higher than the glass transition temperature in °K when the glass transition temperature of the bristle carrier material is greater than or equal to 300°K 15% higher, and when the glass transition temperature of the bristle material is less than 300°K, the temperature of the tool is set up to 50% higher than the glass transition temperature in °K.

Of course, the method of the present invention or the apparatus of the present invention can provide brush bodies or bristle carriers made by standard one-component or multi-component injection molding methods. It is thus possible to use a handle, (more generally) a brush body or a bristle carrier used by toothbrushes that would otherwise be plugged with conventional (metal) anchor techniques. However, such handles or brush bodies or bristle carriers typically have anchoring openings that are deeper than those required by the method of the present invention.

In anchor technology, multi-component handles or brush bodies or bristle carriers have also existed for many years, in which, in the head region of these brush bodies, between the anchor openings and/or the brush head edges are injection-molded form an elastic structure. It can also be installed on the back of the brush head and formed by injection molding, for example, an elastic tongue cleaner. All these possibilities also apply to the method of the invention and the device of the invention.

Anchor technology attaches these elastic structures to the front or back prior to bristles. The only exception is to install the elastic structure after the bristles, but this is not common. These elastic structures are typically injection-molded onto a relatively rigid carrier structure in a multi-component injection-molding tool. Such multi-component tools for toothbrush bodies are extremely common.

The handle, brush body or bristle carrier provided by the method of the invention and/or the device of the invention can be formed without any problems by means of all brush body injection moulding techniques and brush body injection moulding tools known to date. Wherein, the anchoring openings are pre-formed by injection molding by forming pins, which can have a circular shape or any cross-sectional shape and protrude out of the molding cavity. After the injection plastic has sufficiently cooled and/or hardened, the pins can be pulled out from the cavity, for example, by means of a slider, and then the injection molded part can be completely demolded. Therein, the so-called forming pins can be mounted parallel to each other and/or at an angle, so as to correspondingly produce parallel and/or angled anchor openings in the injection-molded part. In the method of the present invention and the apparatus of the present invention, when such parts are formed by injection molding, the depth of the pins extending into the injection molding cavity can generally be slightly less than the injection molding method to form the brush body that needs to be plugged by the anchor technique or the penetration depth of the bristle carrier. Accordingly, the depth of the anchor opening in the injection molding length (Spritzlänge) is somewhat smaller. Due to the smaller depths of these openings, the overall thickness of the heads of the brushes made by the method of the invention and the apparatus of the invention can be implemented to be significantly smaller than brush heads plugged with anchor techniques. Thereby a clinical benefit is achieved in the manufacture of toothbrushes.

The method of the invention and the apparatus of the invention have particular advantages when using clear (ie transparent) materials for the bristle carrier or the brush body. Such materials are usually PET, copolyester, SAN, ABS, etc. These materials can also have anchoring openings pre-formed by injection moulding and/or can be provided with an elastomer (eg TPE) by a multi-component process, like a bristle carrier or a brush body or a handle made of polypropylene. , TPU). After the bristle carrier or the brush body or the handle has been formed by injection moulding by a multi-component method, the bristle carrier or the brush body or the handle can be further processed as proposed in the present invention in the manner described above and below in connection with the apparatus Department.

In the process of making the brush, an injection moulding station for producing the bristle carrier can be provided (in time and/or in space) before the station with the holder and the tool piece, for example acting as a punch , wherein on the injection molding station there is an injection molding half-mould part with at least one pin extending into the injection molding cavity, the pin being immovably fixed to the injection molding half-mould part or for the injection molding half-mould part Part of the injection moulded half-mould section (may be a one-piece component). As a result, the active slider part used in the past for injection molding halves may even be completely redundant. Specifically, each pin creates an anchoring opening constructed as a blind hole. The slider is not only difficult to manufacture, it is also troublesome in terms of maintenance and repair. The apparatus of the present invention does not require anchor openings with a minimum depth of anchors to secure bristles or tufts to the bristle carrier, therefore, anchor openings with a smaller depth are fully sufficient for securing bristles or tufts. It should be emphasized that, of course, the injection molding station does not necessarily have to be spatially located next to the station with the holder. Rather, the injection molding station can be located locally at another manufacturing station or at a remote manufacturing location, eg, in another city, so that, for example, the bristle carriers can be manufactured in stock and then shipped to another station or another manufacturing location. place to set tufts of bristles.

In an embodiment, the injection moulding half-mold part may be formed by the first part and/or an insert housed in the first part. The insert contains pins that protrude from the insert from the front. The insert is slidable relative to the first part, ie in a corresponding opening in the first part closed by the insert.

The device according to the invention has at least one electric motor, preferably a servomotor, for applying the pressure to the bristle carrier. Electric motors have the advantage of being able to easily set the pressure and readjust the pressure reliably and easily.

Several electric motors can be provided for applying this pressure. In addition, one electric motor can simultaneously apply pressure to several bristle carriers by defining several cavities between a tool piece and a holder. In order to increase the output of the device, in particular several electric motors are provided, which respectively apply pressure to several bristle carriers.

In addition, the use of a turntable or the like also contributes to an increase in yield. For example, several units can be set according to which stations require longer cycle times.

The apparatus of the present invention should have a controller programmed so that, during operation, the tool is continuously heated to the temperature desired when the pressure is applied to the bristle carrier. In this way, there is no desired temperature fluctuation during operation, so that there is no heating time for the tool piece that would adversely affect the cycle rate.

Furthermore, it should be clearly pointed out that the advantages and features mentioned above in connection with the method of the present invention are also applicable to a plurality of devices of the present invention individually or in combination corresponding to the method of the present invention.

It should also be emphasized that the method of the present invention and the apparatus of the present invention are applicable to any brush, not limited to toothbrushes. For example, the method and the apparatus are also applicable to household brushes, floor brushes, household brooms or brooms of any kind, dish brushes, toilet brushes, hair brushes, vacuum cleaner brushes, hand washing brushes and any type of bristle brush (for example with brushes or nail polish brushes for painting or painting), grooming brushes (and manual or electric toothbrushes). Accordingly, the details and variations illustrated in the following figures also apply to all such brushes.

Figure 1 illustrates an apparatus for making brushes such as toothbrushes. As is known, such toothbrushes have a head, a neck and a handle that include tufts of bristles protruding from the front. These three sections can be joined together to form a so-called brush body. The brush head can be perforated directly, or it can be implemented in two parts, comprising a sheet-like bristle carrier, which already has prefabricated blind hole-like anchoring openings after injection moulding, which is then welded, glued or extruded. The encapsulation technique joins the laminar bristle carrier to the rest of the head. The alternative is: the brush head adopts an integrated design, so the brush head itself forms the bristle carrier.

Such an embodiment is illustrated in Figure 1 with the brush head also forming a bristle carrier 10 . In this view, the bristle carrier 10 is at the same time the brush body because it includes the handle, neck and head of the brush. The bristle carrier 10 is a prefabricated injection-molded part. As illustrated in Figure 2, the bristle carrier 10 has a large number of prefabricated openings 12 on the bottom surface of the bristle carrier 10, created during injection molding, into which the bristle bundles are inserted and anchored . The following description applies equally to the bristle carrier 10 in sheet form.

The plant shown in Figure 1 comprises several stations, namely: the assembly station 14 shown in Figures 1a and 1b, the melting station 16 shown in Figure 1c, and the Figures 1e and 1f An anchoring station 18 for tufts of bristles is shown in the figures.

All stations are passed through a cassette 20 (also called a tool piece), which transports the bristle tufts through each station.

Although the pocket 20 illustrated in Figure 1 includes a receiving opening for one brush (see below for details), in practice the pocket 20 is preferably so large that pockets for several brushes are formed on the pocket 20. Several juxtaposed accommodation opening groups. There may also be rows of sets of housing apertures for several brushes.

The cassette 20 is, for example, a plate-shaped member having a uniform thickness, and this member has a straight upper end surface 22 shown in FIG. 1 . As an alternative, the generally plate-shaped cassette has a depression 200 on the flat end face 22 of the cassette containing a bottom 202, which, as illustrated in Figure 14, may also be flat, so as to form a A portion of the cavity that houses the bristle carrier 10 .

Since the cassette passes through several stations and is then used to make other brushes, there is a cassette circulation mode in the apparatus, where a large number of identical cassettes 20 are cycled through each station in turn. Thus, the cassette 20 is the transport means for transporting the bristle tufts 24 through the apparatus. As an alternative, the cassette may be stationary, around which the stations circulate, for example on a carousel. Here, several stationary pockets can be processed simultaneously, to be precise the bristle tufts arranged in these pockets.

The cassette 20 has a large number of accommodating openings 26 , and the accommodating openings 26 have a hole pattern corresponding to the hole pattern of the bristle carrier 10 .

Each tuft of bristles 24 is composed of several bristles, which are separated from a bristle reservoir and pushed into the pocket 20, eg by pins, as illustrated in Figure 1a, as described in detail below. The individual bristle tufts 24 can be transported into place by means of tubing, compressed air or vacuum.

The bristles consist of thermoplastic materials, in particular PA, PBT, polyester, copolyester or polypropylene, these bristles can also consist of elastomers. In addition, coextruded bristles can also be used, eg comprising a PA core with an elastic coating. As will also be explained below in connection with Figures 11 and 12, it is not necessary to use only tufts 24 of bristles and insert them into the anchoring openings, but can also follow the methods explained above and below , only a single prefabricated bristle, eg in the form of an elastomeric cleaning element, is inserted and secured into the anchor opening of the elastomeric cleaning element. Such cleaning elements are individually made by injection molding or foaming techniques and are softer than the bristle carrier 10 .

The tufts 24 of bristles have opposite ends and project slightly beyond the pocket 20 with the rear ends 28 (referred to as fixed ends) of the tufts of bristles 24 , ie, the tufts of bristles 24 protrude slightly beyond the end face 22 . This point is illustrated by Figure 1b.

The cassettes 20 filled with bristle tufts 24 are transported laterally to the melting station 16 illustrated in Figure 1c. On the station there is a heating device 30, which can be, for example, a plate heater or a hot air heater. The rear end 28 of the tufts 24 of bristles is heated in a non-contact manner so that each bristle exceeds the melting temperature of the bristle and the bristles in one tuft are fused to each other to form a thickened fixed end. As a result, the bristles of one bristle bundle 24 are integrally connected. The thickenings 32 of the bristle tufts 24 do not engage with adjacent thickenings of the adjoining bristle tufts 24, but remain spherical or lenticular thickenings. It is also preferred not to press the punch against the thickened portion or the still liquid material that has melted the ends of the bristles.

Several bristle tufts 24 can be anchored in the same bristle carrier 10, wherein at least one bristle tuft 24 consists of bristles that meet the following conditions: the material of the bristles and the melting temperature of the material are different from at least one other bristle tuft 24 bristles. Bristle tufts 24 composed of different bristle materials are heated at different intensities to fuse the bristles of the tufts to each other to form thickened fixed ends, respectively. This can be achieved in different ways: depending on the bristle material, setting different distances between the end of the bristle bundle 24 near the heating device 30 and the heating device 30, and/or heating the heating device 30 to Different temperatures, and/or different heating devices 30 that will be heated to different temperatures are matched to corresponding bristle materials.

For example, the tufts of bristles are pushed out of the cassette 20 to varying degrees depending on the bristle material. The bristle tufts 24 made of a more fusible material, for example, are closer to the cassette 20 than other bristle tufts, so that the more protruding bristle tufts 24 are closer to the heating device 30 than the other bristle tufts, and thus are heated with greater intensity.

As an alternative, the bristle tufts 24 can also be processed in sequence, in that the fixed ends of the bristle tufts 24 with different bristle materials are sequentially ejected from the cassette so as to be closer to the heating device 30 . Then, the heating devices 30 are heated to two suitable different temperatures, or the heating devices 30 with different temperatures are used for the corresponding bristle bundles of the heating devices 30 .

The individual bristle tufts or groups of bristle tufts are ejected, for example, by means of a geteilt base plate 44 (see FIG. 5 ), the parts of which can travel in the longitudinal direction of the bristles independently of each other.

While still on the melting station 16, or on the way to the next anchoring station 18, or on the anchoring station 18, the thickening 32 is optionally actively cooled. This is achieved, for example, by means of a cold air flow 214 provided by a fan (see FIG. 1 d ) or by means of the fact that the station 1 d is constructed as a cold room through which the cassette 20 passes with the still soft rear thickening 32 . Cooling the thickened portion 32 may increase cycle time.

The cassette 20 further transports the bristle tufts 24 to the next anchoring station 18 . The purpose of this anchoring station is to permanently lock the bristle bundles 24 in the anchoring openings 12 of the bristle carrier 10 only in an anchor-free manner.

The anchoring station 18 includes at least one retainer 34 (preferably a plurality of retainers 34 ) having a groove 38 (if there are several) on the end face 36 (see FIG. 2 ) of the retainer 34 facing the end face 22 . bristle carriers 10 to be accommodated, then recesses), the recesses 38 being constructed to complement the corresponding shape of the bristle carrier 10 so that the bristle carrier 10 rests with the rear surface of the bristle carrier 10 on the holder 34 above (see also Figure 14).

The holder 34 itself has a flat end face 36, but as shown in Figure 2, the bristle carrier 10 protrudes slightly beyond this end face 36 in order to extend into a recess 200 in the pocket 20 that is complementary to the frontal area of the bristle carrier 10. This is illustrated, for example, by FIG. 14 .

The cassette 20 can be heated, for example by means of a plate heater provided from the outside, which is moved laterally towards the cassette 20 on the anchoring station 18 and can be heated rapidly since the cassette 20 consists of metal.

As an alternative, heaters, in particular resistive heaters 39 as illustrated in Figures 2 and 14, are provided in the cassette 20 . The heating coils are shown symbolically, the heating coils being arranged adjacent to the end face 22 or, if a recess 200 is involved, adjacent to the bottom 202 of the recess 200 which forms part of the end face 22 .

Electrical connection contacts 41 , such as sliding contacts on the sides of the cassette 20 , can be electrically coupled to the cassette 20 to activate the heater 39 when the cassette 20 is moved into the anchoring station 18 . Of course, the end surface 22 including the bottom 202 of the recess 200 can also form a resistance heating layer by itself, so that the end surface is directly heated here.

If the cassette 20 is fixed, electrical connections for the heater can be easily implemented, which can be of permanent design.

The function of the heater 39 is to preferably heat the entire end face 22 in contact with the bristle carrier 10 , that is to say also the section between the thickenings 32 .

The temperature reached by the end face 22 (in the area contacting the bristle carrier 10 ) is lower than the melting temperature of the bristle material and/or the bristle carrier material, preferably lower than the melting temperature of the two materials. In particular, the temperature is at most 85% of the melting temperature in °C of the materials. For example, if the melting temperature of the two materials is 100°C, the temperature of the finally heated cassette 20 on the end face 22 is at most 85°C.

Figure 3 shows a sectional view of the anchoring station 18 shown in Figure 1e before the cassette 20 and the bristle carrier 10 are moved towards each other.

Viewed in the longitudinal direction A (also referred to as the axial or feed direction), the thickened portion 32 has dimensions such that the thickened portion 32 is smaller than the corresponding cross-section of the anchoring opening 12, so that the thickened portion 32 can be The inside edge of the anchoring opening 12 (also referred to as the inside 40 limiting the wall of the anchoring opening) or is pushed into the anchoring opening 12 without touching the inside 40 .

In particular, the cylindrical anchoring opening 12 has at this point in time an excess size of only a maximum of 0.2 mm, in particular a maximum of 0.15 mm, relative to the maximum cross-section of the thickening 32 (fixed end). In other words, even in the region of the bottom 208 of the anchoring aperture, the lateral dimension of the thickened fixed end is smaller than the lateral dimension of the anchoring aperture 12 .

The underside of the thickened fixing end 32 is rounded or chamfered, by means of which the bristle bundles 24 are guided into the anchoring openings 11 .

As described later, at least one anchor opening is injection molded. The anchor opening has an inner side 40 with a draft angle, ie, the inner side still extends slightly inward toward the bottom 208 .

The cassette 20 and/or the holder 34, which are heated to the desired temperature continuously (ie during the entire operation), move towards each other, in this example only the holder 34 carrying the bristle carrier 10 moves so that first the thickening 32 The anchoring aperture 12 is entered, and then the end face 22 comes into contact with the flat end face 42 of the bristle carrier 10 that the end face 22 faces. During the feed movement, as long as the bristle carrier 10 is not in contact with the magazine 20, the bristle carrier 10 is not actually heated because the feed movement is extremely fast and in the open position of the anchoring station 18 as illustrated in Figure 3 , there is no dwell time.

A base plate 44 (see FIG. 3 ), which supports and against which the free ends of the positive end faces of all bristle tufts 24 abut, can be used to align the front ends of the bristle tufts 24 with each other and at the same time create a distance between the thickened portion 32 and the end face 22 as desired. Bottom plate 44 is used to support individual bristles and tufts 24 of bristles.

As illustrated in Figure 4, the end face 22 contacts the front face 42 of the bristle carrier 10 and thereby heats the bristle carrier 10 over the entire contact surface between the two parts.

The bristle carrier 10 consists of a thermoplastic material, in particular of the aforementioned plastics such as polypropylene, ABS, PA, PBT, PET or PC.

However, the movement of the holder 34 is not maintained at the first contact position shown in FIG. 4 because extremely high pressure is applied to the bristle carrier 10 by the holder 34 and the pocket 20 .

For example, a pressure of at least 200 bar, preferably at least 400 bar, is applied to the bristle carrier 10 by means of this opposite movement. This pressure is already applied from the first contact of the bristle carrier 10 with the pocket 20 and remains constant during the action time (contact time).

While heating the bristle carrier 10, this pressure is maintained for an action time of at least 4 seconds, in particular at least 5 seconds and at most 15 seconds, in particular at most 10 seconds.

The action time consists of the holding time and a period during the feeding movement, called the compression time, which begins when the cassette 20 contacts the front face 42 and at the same time the holder 34 contacts the back face of the bristle carrier 10 . The compression time ends when the maximum closed position is reached and the distance between the holder and the tool piece remains constant for the holding time. The holding time refers to the time at which the feeding movement ends (ie the device is fully closed) and the bristle carrier 10 is accommodated in the closed cavity. This holding time is preferably at least 1 second, preferably at least 1.5 seconds and/or at most 3 seconds, specifically at most 2.5 seconds.

During the compression time, the distance from the holder to the tool piece decreases very slowly at a constant rate. For example, a total compression distance of 0.3 mm can be accomplished in as little as 3 seconds.

During the active time, the heating of the cassette 20 is preferably continued, wherein the greater mass of the cassette 20 also allows the heating to be stopped after the first heating to the working temperature. Nevertheless, the bristle carrier 10 continues to be heated during the action time.

The device is specifically overtraveled to a hard stop, that is, the retainer 34 contacts the area of the end face 22 outside the cavity 200 with the end face 36 (see FIG. 14 ) outside the cavity formed by the groove 38 and the depression 200 part. In this contact zone there is no gap through which material from the cavity can enter, rather the cavity is sealed by the annularly surrounding contact zone.

Furthermore, preferably generally (and not limited to the illustrated embodiment), there is no heater in the area of contact between the holder 34 and the cassette 20 , so that the heater is only present in the area of contact between the front face 42 and the cassette 20 and function.

The separation plane between the holder 34 and the tool piece (in this case the pocket 20 ) defined by the end face 36 is preferably closer to the front face 42 of the bristle carrier 10 than to the rear face of the bristle carrier 10 . Specifically, the separation surface is close to or next to a rounded joint connecting the side surfaces 212 of the front side 42 and the back side.

It is beneficial that the support in the form of the base plate 44 is removed at least during the final stage of application of the pressure (ie at the end of the action time) and no longer contacts the bristles. This improves the alignment accuracy of the bristles with each other and with respect to the bristle carrier 10 . However, as symbolically represented by arrow Y in Figures 3-5, it is preferred that the base plate 44 is removed before the start of the hold time or even before the action time. For example, the backplane 44 is only used on the stations c) and optionally d) illustrated in Figure 1 .

However, in order to also be able to fix the axial position of the tufts of bristles and of the individual bristles during the entire action time, the cross-section of the receiving opening 26 is adapted to the cross-section of the bristle tuft 24 inserted into the receiving opening 26, so that The bristle bundles 24 are clamped in the receiving openings 26 and are thus securely positioned axially. The own weight or inertia ensures that the tufts of bristles do not move during movement within and between stations.

In the above example, the entire flat end face is heated, at least where the front face 42 of the bristle carrier 10 contacts the pocket 20 . If the cassette 20 has a recess 200, it is only necessary to install the heater in the area of the bottom 202 of the recess 200, and this is beneficial. And since the cassette 20 is typically constructed of steel, the entire cassette 20 is heated. Setting the temperature means bringing the front side 42 of the bristle carrier 10 to the desired temperature.

The front surface 42 area of the bristle carrier is heated to a temperature during the action time below the melting temperature of the bristle material and/or the bristle carrier material, in particular 85% of the relevant melting temperature in °C or below the melting temperature in °C 85% of the calculated relative melting temperature. Therefore, this temperature corresponds to the aforementioned maximum operating temperature of the cassette 20 in the region of the end face 22 or bottom 202 .

As an alternative, at least the edge 50 of the anchoring aperture 12 in the area of the front face 42 , which edge 50 forms the wall area of the anchoring aperture 12 , can be heated, which edge 50 adjoins the outlet to the front face 42 .

The temperature reached by the bristle carrier 10 at least in the region of the edge 50 and preferably over the entire contact area with the cartridge should be not only below or well below the melting temperature of the materials, but also within the glass transition temperature range of the bristle carrier material . The bristle carrier 10 can be heated in the region of the front side 42, at least in the region of the edge 50, by means of a super-high pressure of, for example, more than 600 bar, only to a temperature which is higher than a limit temperature if the bristle carrier material has a temperature of ≥ 300°K. Glass transition temperature, the limit temperature is 60% of the glass transition temperature of the bristle carrier material calculated in °C, specifically 80% of the glass transition temperature of the bristle carrier material calculated in °C. However, the limiting temperature is preferably the glass transition temperature or at least exceeding the glass transition temperature. When the glass transition temperature of the bristle carrier material is below 300°K, the heating temperature is at most 50% of the glass transition temperature in °K.

Another variant is to heat at least the edge 50 of the front face 42 , in particular the bristle carrier 10 on the front face 42 , in particular before the inner side 40 in the interior of the anchoring aperture 12 is heated by the cassette 20 above the ambient temperature The heaters of the entire contact surface of the zone are heated to a temperature which is at least 30°C above the ambient temperature.

As illustrated in the figures, the cassette 20 does not have any extensions or similar structures that would assist the cassette 20 in extending into the anchoring aperture 12 because the cassette 20 has a flat end face 22 or a flat bottom in the area of the front face 42 202.

Since the front face 42 is also straight and there is no flange or similar structure in the exit area of the anchoring aperture 12, ie in the area of the edge 50 (as was the case with the prior art), during application of pressure and temperature, the front face The bristle carrier material in area 42 is optionally even fully deformed. The material wants to transfer and thereby enter the anchoring openings 12 in the exit area and shrink the anchoring openings 12 .

By applying heat and pressure, the overall thickness D and the maximum thickness of the bristle carrier 10 in the region of the exit of the anchoring apertures 12 to the front face 42 are permanently reduced. A projection or constriction is formed which catches the thickened fixing end from behind in the pull-out direction and thereby locks the bristle bundle 24 .

No adhesion is created between the thickened fixed end and the wall of the anchor opening 12 .

Edge shaping doesn't have to be extreme. The results show that, taking the toothbrush as an example, the cross-section of the anchoring aperture 12 having the original width or diameter D3 is reduced to only a width or diameter D1 in the region of the edge 218 (see FIG. 5A ), so that the thickened portion 32 The difference between the width or diameter D2 of the thickest part (relative to the relevant cross-sectional plane) and the width or diameter D1 of the edge 218 region is only about 0.1 to 0.5 mm, which is sufficient.

It is beneficial that the thickened portion 32 is undersized relative to the anchor opening 12 which has not yet been deformed (ie, D2 is smaller than D3) when pushed in.

Through the concept of pushing the thickening into the anchor opening 12 when the thickening 32 is not yet fully solidified, it is also possible to use the thickening 32 in general, which is constructed relative to the anchoring The cross-sectional dimension of the opening 12 is too large, that is, D2 is greater than or equal to D3.

FIG. 5A shows an exaggerated illustration of the space formed by the anchor opening 12 and bounded outwardly by the narrowed edge 218 for accommodating the thickened portion 32 , as is the ratio of the thickened portion 32 to the diameter D1 .

The fact is, however, that not the entire wall forming the anchoring opening 12 rests on the thickening 32 or on the outer bristles starting from the thickening 32 . Rather, the wall is shaped only in the region of the edge 218 and in the section 220 which directly adjoins the edge 218 and expands outwards in the direction of the base 208 , and only in these regions abuts the bristles or the thickening 32 and apply pressure to the bristles or the thickened portion 32 .

However, the thickening should contact the bottom 208 to precisely fix the axial position of the bristle tufts.

In the remaining areas, for example between the bottom 208 and the thickening 32, or in the peripheral area where the wall adjoins the bottom 208, there are one or more air gaps 222 between the wall and the outside of the thickening 32, so that the The thickened portion 32 is not compressed, clamped and/or deformed in this area.

In the region of the edge 218 , the bristle tufts 24 are compressed relative to the state of the bristle tufts 24 in the cassette 20 by narrowing and shrinking the edge 218 by at least 3%, in particular by at least 5%. Here, the cross-sectional area of the receiving opening in the cassette is compared with the cross-sectional area of the edge 218 at the narrowest part of the edge 218 .

All anchoring openings 12 are closed at the same time by means of the apparatus shown and the corresponding method, whereby all tufts 24 of bristles are anchored in the bristle carrier 10 at the same time.

As further illustrated in Figures 5 and 5A, not the entire anchoring aperture is shaped, but only to a depth t corresponding to at most 85% of the total depth T of the anchoring aperture 12 , in particular 70%, and/or, the depth t has an axial extension of 0.5 to 1.3 mm, in particular 0.6 to 1.0 mm. The depth t is measured from the front face 42 . If the front face 42 is flat, the plane against the front face 42 is taken as the reference surface. If the front face 42 is concavely or convexly curved, an envelope of the front face 42 is formed, from which the depth t is measured.

The thickening 32 itself is preferably only retained in the anchoring opening in the axial direction for at most 50% of the total axial length of the thickening 32 . The rest of the clamping takes place in the area of the bristles starting from the thickening 32 .

The wall of the anchoring aperture 12 does not deform and/or clamp the thickening 32 and the bristles in this area over a depth Z (see Figure 5A) of at least 0.8 mm from the bottom 208.

The depth T of the anchoring openings after the brush has been made is a maximum of 4 mm, in particular a maximum of 2.7 mm.

All anchoring apertures 12 are blind holes and thus do not have to cover the backside of the bristle carrier 10 as no tufts of bristles are visible or protruding from this face.

The anchoring thus achieved is the only anchoring for the bristle carrier without the use of metal anchors or metal ropes.

It is generally emphasized (and not limited to the illustrated embodiment) that the bristle carrier 10 should not be brought close to the melting temperature of the bristle carrier 10, but rather close to the glass transition temperature and away from this melting temperature. Specifically, the heating temperature and the temperature of the end face 22 region of the pocket 20 and the end face of the bristle carrier 10 should be no more than 15% higher than the glass transition temperature of the bristle carrier material and/or the bristle material.

According to a preferred variant of the invention, when PET is used, the front face 42 is heated to a temperature of 75°C to 95°C, in particular 80°C to 90°C, during shaping, and to 105°C to 125°C when PP is used, Specifically, a temperature of 110°C to 120°C. In particular, the PP is selected such that it has a melt flow index (Melt-Flow-Index; MFI) of 6 to 35, preferably 10 to 15, in the initial state.

One embodiment of the invention proposes to heat the end face 22 and the bristle carrier 10 to a temperature of up to 140°C, in particular up to 130°C, preferably to a temperature in the range of 100°C to 115°C. In particular, the material of the bristle carrier is here polypropylene, PET, ABS, copolyester and SAN.

The rear side 206 of the bristle carrier 10 and the area starting from the rear side 206 and extending at least to the bottom 208 of the anchoring opening 12 (preferably even further in the direction of the front side 42 ) should not be deformed. In order to bring the temperature limit that can cause deformation due to the applied pressure as close as possible to the front face 42 of the bristle carrier 10 , the holder 34 can be provided with an active cooler.

Figure 3 symbolically illustrates this cooler with cooling passages 210 through which the cooling liquid flows. The cooling channel 210 is connected to a cooling water circuit which pumps cold water preferably below 20°C, in particular even below 10°C, through the holder 34 . Thus, the backside 206 becomes warm during application of pressure, up to 25°C. The side of the bristle carrier 10 connecting the front face 42 and the back face 206 may also be cooled to a sufficient degree in the holder 34 to prevent deformation and to remain below the corresponding temperature that would cause deformation and deformation.

After a defined action time, the holder 34 is separated from the magazine 20 again to pull the bristle bundles 24 out of the receiving openings 26 . No post-processing is required, that is to say no further shaping processes have to be carried out on the bristle carrier 10 .

However, the above-mentioned separation is preferably not accomplished in one step, but is provided with a resting stage during the separation. For this purpose, the tool piece (ie pocket 20 ) and the holder 34 are minimally separated from each other so that a small ventilation gap 228 ( See Figure 5A). When this prescribed ventilation gap 228 is reached in height, the distance is preferably kept constant during the rest period of at least 1 second, in particular at least 1.5 seconds.

During this resting phase, cooling air can optionally also be blown through the ventilation gap 228 to the front side of the bristle carrier 10 to cool the front side.

During this resting phase, as illustrated in Figure 5A, the bristles rest in the receiving apertures 26. The shaped areas of the anchoring openings are stabilized during the resting phase so that the bristles of the tufts are parallel and aligned neatly with each other.

The device is separated after the resting phase so that the finished bristle carrier can be removed.

In order to precisely control the corresponding movement and temperature, the device has a controller 51, which is used to control not only the heating temperature, but also the applied pressure and the movement process. The heater 30 can also be controlled by the same controller 51 .

If the bristle carrier material is a material whose glass transition temperature does not exceed ambient temperature, such as certain types of polypropylene, heating of the bristle carrier can be eliminated, but this is not required. Minimal heating to barely above the glass transition temperature, but still well below the melting temperature, may also be beneficial here. If such a bristle carrier material does not have to be heated or not heated, the anchoring openings 12 are closed only by applying the aforementioned pressure during the aforementioned action time. In this case, the cassette 20 can be used without heaters, or with heaters, but without the heaters activated.

The following is irrelevant to the bristle carrier material: In the feed movement of the magazine 20 relative to the holder 34 and thus relative to the bristle carrier 10 (relative movement of components means that one or both of these components may be oriented towards the other component traverse), pressure and time controlled feed movements and/or pressure and stroke controlled feed movements may be beneficial.

It is particularly beneficial that, in the first phase of the feed movement, the edge 50 or the entire front face 42 is heated to a temperature which is above a limit temperature. If the bristle carrier material has a glass transition temperature in excess of 300°K, this limit temperature is 60% lower, in particular 80% lower, than the glass transition temperature in °C of the bristle carrier material. However, the limiting temperature is preferably the glass transition temperature, which is at most 20% higher than the glass transition temperature in °C. In the next second phase of the feed movement, the edge 50 is deformed and pressed against the bristles.

As an alternative, if the front and back sides of the bristle carrier are contacted and thus compressed axially, the feed movement is done at a constant lower speed and the cassette 20 and holder 34 are overtraveled to a hard stop.

In the embodiment illustrated in FIG. 5 , the material is also pressed against the bristles in the region of the edge 50 in the closed state, so that there is no gap between the bristles and the edge 50 .

The assembly of the cassette 20 can be achieved directly by means of a bristle separator, as shown in FIG. 1 a , or by another variant shown in FIG. 6 . In this case, the box 60 with a large number of accommodating openings is first filled with tufts of bristles. This box can then also be used to store the separated tufts of bristles until they are finally pressed directly into the box 20 , for example by the movable pins 62 .

As an alternative, there may also be a deflector plate 64 between the cassette 60 and the cassette 20, the deflector plate having inclined transport openings 66 for the bristle tufts 24 passing through the deflector plate. For example, when the brush is required to contain bristle tufts of different thicknesses, several bristle tufts 24 can also be combined into a larger bristle tuft through the meeting and conveying opening 66 shown in the left part of FIG. 6 . Of course, the box can further have the accommodating openings 26 extending obliquely, because the bristle bundles of some brushes are not perpendicular to the front surface 42 and extend cylindrically, but are arranged obliquely to the front surface 42 . The anchoring at this time is also illustrated in the figure. As an alternative, the anchoring apertures 12 can of course also be slightly inclined or tapered for such obliquely oriented tufts 24, or, as illustrated in Figure 7, only if the tufts 24 are inclined towards the anchoring apertures 12 The area on one side is tapered. This means that the accommodating openings 26 may have differently inclined edge portions.

In the embodiment according to FIG. 7 , an edge segment 80 of the anchoring opening 12 is provided which extends obliquely, in particular parallel to the oblique receiving opening 26 , and an edge segment 81 opposite this edge segment 80 is provided. In the embodiment shown, the edge section 81 extends perpendicular to the front face of the bristle carrier 10 . Alternatively, however, as indicated by the dashed lines, the edge segment 81 can also extend likewise obliquely, possibly with a different inclination than the edge segment 80 .

The bristle carrier 10 is manufactured on an injection moulding station belonging to the apparatus of the invention in an injection moulding mould comprising injection moulding halves 100 and 102 (two variants of moulding moulds as illustrated in figures 8 and 10) . As previously mentioned, this injection moulding station is temporally and/or spatially located in front of the aforementioned station for perforating the bristle carrier 10 . The injection molding station forms the bristle carrier injection molding device. A cavity 104 is formed between the injection moulding halves 100 and 102 into which liquid plastic is injected to manufacture the bristle carrier 10 . In the injection molding stations used in the past, the injection molding half 100 is equipped with pin-shaped active slides, which pass through the injection molding half 100 into the cavity 104 and are pulled out before the injection molding mold is opened. , this variant offers a much simpler solution by comparison. Specifically, this variant immovably mounts on the injection moulding half 100 one or several integrally formed pins 106 of arbitrary cross-section, which pins 106 freely protrude into the cavity 104 . The pins 106 then create the anchoring apertures 12 . The depth of the anchoring openings 12 is much smaller than in previous bristle carriers made by plugging holes using anchor technology. As an alternative, the bottom of the injection moulding half 100 may have a movable insert 107 (see dashed line in Figure 10) on which the extension 106 is located. After injection molding, the insert 107 is pulled down into the depression in the molding half to facilitate demolding, so that the extension is also pulled out of the anchor opening 12 formed by injection molding, thereby simplifying subsequent removal Operation of the bristle carrier 10.

In Figure 10, it can be seen on the right side pin 106 that can be used to make the obliquely extending aperture 12 as illustrated in Figures 7 and 8.

In the case of integrally formed injection moulding halves (see Figure 10), one of which defines the entire inside of the cavity, the injection moulding half is called the injection moulding half part.

. The insert 107 (FIG. 8) preferably contains all of the pins 106 required to make the anchoring apertures 12. After injection molding, the insert 107 is pulled down into the depression in the molding half to facilitate demolding, so that the pin 106 is pulled out of the injection-molded anchor opening 12, thereby simplifying subsequent removal or The operation of removing the bristle carrier 10 .

In this case, the injection moulding half 100 comprises a first injection moulding half part 101 which defines the entire lower mould half 100 excluding the area of the insert. Furthermore, the injection moulding half 100 comprises an insert 107 received in a complementary opening in the first part 101 to the insert 107, the insert 107 forming a second injection moulding half part. The insert 107 is movably mounted relative to the first part 101 of the injection moulding half-mold 100 towards and away from the tuft carrier. exist Preferably, no gap is provided between the first portion 101 and the insert 107 into which the liquid plastic can be injected.

In Fig. 10, it can be seen on the right side pin 106 that can be used to make the obliquely extending aperture 12 as illustrated in Fig. 7 . The pin 106 may have at least one edge segment extending obliquely to the adjustment direction of the insert 107 (see double arrow in Figure 10)

The insert 107 preferably defines the entire area of the front face of the brush head. By means of the insert 107, brushes can be easily manufactured which comprise the same bristle carrier 10, but with different aperture patterns and different bristle tuft patterns.

In the variant according to Fig. 8a, all the pins 106 are integrally formed on an insert 107 which defines the injection moulding half. In the variant according to Fig. 8b, the injection moulding half-mould part is implemented in multiple parts, since the injection moulding half-mould part comprises a base 300 with a plurality of holes 302 and inserts 304 inserted in the holes 302. The inserts 304 have bases 306 by which the inserts 304 close corresponding holes in the base 300 . Corresponding pins 106 protrude from base 306 . This variant is easier to manufacture.

When producing the bristle carrier 10 it is important that the so-called transition edge 320 (see FIG. 14 ) between the front face 42 and the inner side 40 of the anchoring opening 12 is chamfered if necessary.

As can be seen in Figure 14, not all transition edges 320 need to contain such a chamfer 322.

In the cross-sectional view of FIG. 15, the chamfer 322 is shown partially enlarged. In the enlarged view, the shaded face K symbolically illustrates the material that the transition edge 320 no longer has due to the chamfer 322 . As lines of comparison, a continuation of the front face 42 (also called envelope 323 ) and a line 324 are provided here, which illustrate the linear continuation of the inner side 40 up to the envelope.

The chamfer 322 may have a different cross-section from the anchor aperture 12 to the anchor aperture 12 , such as illustrated in the enlarged view of FIG. 15 . Alternatively, as illustrated in FIG. 18 , the chamfer 322 may have a different cross-section along the perimeter of the transition edge 320 . Here, for example in FIG. 18 , the portion 330 of the same chamfer 322 is chamfered more steeply than the portion 332 .

The chamfer 322 may extend along the entire circumference of the transition edge or only over a partial area. For example, as can be seen from anchor opening 12' in Figure 15, transition edge 320 includes a chamfer 322 on the left side and no chamfer on the right side, so that in this area, inner side 40 extends at right angles to front side 42 and is The front faces 42 meet to form a sharp transition edge.

When there are different cross-sections in the chamfer 322 along the circumference of the transition edge 320 , the cross-sections may start from the same axial depth of the anchoring aperture 12 from the front face 42 adjacent the chamfer 322 Either measure the depth of the adjacent portion of the front face 42 .

As illustrated in the two middle enlarged views in Figure 15, the chamfers 322 can be formed by rounding, in particular radii or chamfers.

The chamfer 322 is present only at the entrance of the anchoring opening 12 , ie in the region of the transition edge 320 and hardly extends into the anchoring opening 12 . Measured from the front face 42 adjoining the chamfer 322, the chamfer 322 extends in the anchoring opening 12 at most 0.5 mm, in particular at most 0.35 mm and at least 0.1 mm.

The radial width of the chamfer 322 is in particular at least 0.1 mm, at most 0.5 mm, in particular at most 0.35 mm.

As with reference to Fig. 15 (but also to Fig. 14), even in the case of very thin webs 340 between adjacent anchoring openings, the webs 340 protrude to the front face 42 of the bristle carrier 10 and form part of this front. That is, the tabs protrude to the envelope of the front face 42 (if the front face is formed convex or concave), or if the front face 42 is flat, to the plane of the front face 42 without protruding beyond it.

Since the anchor opening 12 and the front face 42 and the chamfer 322 are all formed by injection molding, the associated injection molding half-mould portion is at the transition between the pin 106 and the bottom surface (end surface) of the injection molding half-mould portion There is a chamfer 342 complementary to the associated chamfer 322 . The above-described preferred dimensions of chamfer 322 also correspond to the corresponding dimensions of chamfer 342 .

In the embodiment according to Fig. 8b, the bottom (end face) is also partly formed by an insert, more precisely in the base 306 . Thus, the chamfer 342 is completely formed in the insert 304 .

The thickened fixed end does not contact the chamfer 322 when the bristle tufts 24, 24' are pushed into the associated anchoring apertures because the receiving apertures in the pocket 20 are well aligned for this purpose Anchor opening 12 .

When deformed, the chamfer 322 forms an additional buffer space or containment space for the material that is compressed and narrows the anchoring aperture 12 at the exit of the anchoring aperture 12 .

It can be seen in FIG. 16 that the bristle tufts 24 are inserted at right angles or, like the bristle tufts 24 ′, are inserted obliquely to the front face 42 . In the inclined tufts 24', the chamfers 322 are formed larger on the side of the transition edge proximate the tufts 24' than around the remainder of the transition edge. In the situation shown, there is not even a chamfer on the (right) side away from the tufts 24 of bristles, and in the remainder of the circumference there is a chamfer 322 on the transition edge 320 .

In Figure 17, the tufts 24 of bristles that have been anchored can be seen in detail.

In FIG. 17 , the corresponding pocket 20 has deformed the material of the bristle carrier 10 in the region of the front face 42 , so that the overall thickness of the bristle carrier 10 is reduced.

The material partially closes the anchoring aperture 12 (eg, the neck of the neck), and as such may be pressed against the outer tufts 24 (see left half of Figure 17) or may be slightly away from the outer tufts 24 (see right half of Figure 17). However, the inwardly displaced material does not enter the gap 350 between the receiving openings in the cassette 20 and the outside of the bristle tufts 24 . Thus, no material moves out of the anchoring apertures 12 to protrude beyond the front face 42 .

Preferably, as shown in Figure 14, prior to deformation, none of the anchoring apertures 12 have protrusions protruding from the front. That is, the entire material used to close the anchoring apertures 12 must be provided by reducing the thickness between the back side 206 and the front side 42 of the bristle carrier 10 .

Figure 9 illustrates various variations on how the bristle carrier 10 may be implemented. Not only perfectly circular or oval anchor openings 12 can be provided, but any shape can be designed. For example, elongated, X-shaped, C-shaped anchoring openings or anchoring openings in any other design can be implemented. The larger anchor openings are fitted with tufts of separated tufts, and the ends of the tufts are melted to join the tufts into one larger tuft. These larger tufts of bristles form corresponding wall-like bristle structures.

It should be emphasized that the device according to the invention and the method according to the invention can be applied not only to several bristle tufts, but also to only one bristle tuft, for example to manufacture bristle pens, and to fix a bristle or a single bristle to the bristle vector.

That is, in general, the anchoring openings 12 do not necessarily have to be used only to accommodate and fix the bristle tufts, rather, a single prefabricated bristles made of any elastic plastic and of any shape can be described above in connection with the bristle tufts. way to be accurately accommodated and fixed. The bristles can be plate-shaped and can eg be fed into the elongated anchoring opening 12 and embedded in the anchoring opening 12 by shaping the edges of the anchoring opening 12 . The C-shaped anchor openings 12 may, for example, allow for the insertion of cleaning elements having a C-shaped cross-section, preformed by injection moulding, as individual bristles. Furthermore, bristle bundles 24 consisting of a large number of bristles 24' can of course also be inserted into the bristle carrier 10. A single bristle 24' can for example also be located in the middle of several bristle tufts 24, or conversely surround a single or several bristle tufts 24.

It is emphasized that the aforementioned features described in connection with tufts of bristles can also be applied to larger individual bristles. The following is just an example: the plate-shaped bristles extending obliquely to the bristle carrier 10 are inserted and anchored in the oblique anchoring openings 12 shown in FIG. 7 . A single bristle may also have an anchoring end 32 from which the remainder of the elongated shape is curved and protrudes so that the single bristle can be pushed into the cylindrical anchoring aperture 12 shown in Figure 4, However, the bristles outside the anchoring openings 12 extend obliquely.

A single, separately made bristle 24' or bristles 24' are preferably secured to the bristle carrier 10 simultaneously with the bristle tufts 24 by shaping the corresponding edges of the anchoring apertures 12. As an alternative, several separate, sequential shaping operations can be carried out for different bristles or tufts of bristles. Wherein, since the bristles or bristle bundles are composed of different materials, different pressures and/or temperatures can also be applied by the heated tool piece(s) as appropriate.

In addition to or as an alternative to the aforementioned variants, the elastic cleaning elements 108 can be formed, for example, by injection moulding at the edges of the bristle carrier 10 . The cleaning elements 108 are not prefabricated, but they also protrude from the bristle carrier 10 on the front side and serve to massage the gums.

For this purpose, the bristle carrier 10 can, for example, have holes or edge slots on the edge through which the cleaning elements 108 can be injection-molded. In addition, the back side of the bristle carrier 10 can also be encapsulated with a softer plastic, which is more and more common in brushes.

In the latter case, the cleaning element 108 is adapted to integrally engage the back layer composed of a softer plastic. As shown in the upper half of FIG. 9 (which shows a variation on the lower half), the back layer of softer plastic can also form a harder plastic surrounding the bristle carrier 10 frame, to act as a shock absorber, for example.

Another variant is that the bristle carrier 10 (here, the toothbrush head) is coupled to the neck of the brush body through a hinge 110 made of softer plastic.

The following applies in general to all variants: The bristle carrier may be a sheet as part of a future brush body or the entire brush body. For example, the bristle carrier can also be a multi-component injection-molded part, and when the bristles are embedded, the multi-component injection-molded part has already formed a finished brush body. However, it is also possible, conversely, to embed bristles in a portion of the brush body which will subsequently form the bristle carrier, and then to carry out the subsequent extrusion encapsulation of the bristled carrier.

Accordingly, the injection molding station can also be implemented as a multi-component injection molding station, or several injection molding stations can be provided, in which case the station for anchoring the bristles is located between the injection molding stations.

The cleaning elements 108 and/or individual prefabricated bristles of any cross-sectional shape comprised of an elastic material preferably extend forward at least to the same extent as the tufts, however, the cleaning elements 108 and/or are comprised of an elastic material and have a cross-sectional shape. The single prefabricated bristles of any shape can also protrude beyond the tuft of bristles or be shorter in length than the tuft of bristles.

As illustrated in FIG. 11, not only are the bristle bundles 24 inserted into the anchoring opening 12 through the thickened portion 32 on the fixed end and anchored in the anchoring opening 12 through edge shaping, as previously described, Individual prefabricated bristles 24' (of any shape in both side and cross-sectional views) can also be embedded in the bristle carrier without anchors by the aforementioned methods and apparatuses. The bristles 24' are formed by injection molding from an elastic material, particularly TPE.

In the section in which the bristles 24' protrude from the bristle carrier 10, the bristles 24' have a maximum wall thickness d (measured in cross section) which is greater than 0.6 mm, in particular greater than 0.9 mm.

In addition, the bristles 24' may or should have thickened fixed ends 32' that have a height that is less than the depth of the corresponding anchor apertures 12, such that the inwardly shaped edge surrounds the fixed ends 32' for a form-fit retention effect . The fixed end 32' is, for example, a flat cylinder whose shape matches the shape of the anchoring opening 12. The dimensions of the fixed end 32' are adapted to the cross-section of the anchoring aperture 12 so that upon insertion, there is a lateral gap between the fixed end 32' and the wall of the anchoring aperture 12 before shaping takes place.

The fixed end 32' may be constructed of a different material than the remainder of the bristles 24', such as a harder material than the remainder of the bristles 24'. For example, the fixed end 32' is constructed of polypropylene. It is also possible to construct only the core of the bristles 24' from a harder material, in which case the core is then encapsulated with a softer material. It is therefore possible to use a disk of relatively hard material which forms the entire or core of the fixed end 32'.

As shown in the left part of FIG. 12 , the disc 112 forming the core may likewise have an extension 114 integrally formed on the disc 112 , which extends into the area where the bristles 24 ′ will be located outside the bristle carrier 10 . section.

The right part of FIG. 12 shows a variant of bristles 24' having a fixed end 32' of hard plastic and a region of softer plastic that is injection-molded on the fixed end 32' Paragraph 118.

The individual bristles 24' illustrated in Figure 12 are tapered at one end and should not be construed as limiting.

Figure 13 illustrates a complete plant including various stations. It is emphasized that the device of the present invention does not necessarily have all the stations described below.

In particular, all variants and details explained with reference to the preceding figures, especially in connection with Figure 1, whether for example cooling, ventilation, etc., as well as the aforementioned temperatures, temperature ranges, times and materials used, are also possible. This is implemented individually or in combination in this embodiment.

At station A the bristles or tufts of bristles are separated and transported further. The figure on the left illustrates a so-called fiber box 120 from which a tuft separator 122 removes finished bristles, which can be mechanically or chemically sharpened, in bundles.

The tufts 24 of bristles are transported by the transport device to station B, where the tufts of bristles 24 have optionally been transformed into the final tuft geometry and the hole pattern of future brushes.

For example, the bristle tufts 24 are pushed into a first intermediate magazine 124, which is in particular in the form of a plate. The tufts 24 of bristles are then pushed through the intermediate box 124 by the tappets 126 into another plate body 128, in which there are shaped or deflected openings 130 as appropriate or for merging several tufts of bristles 24 One and the same larger tuft of bristles or openings 132 for the oblique orientation of the tufts of bristles 24 .

The bristle bundles 24 are then pushed further into the cassette 20 . The hole geometry of the future brush is then preferably implemented in the cassette 20, but this is not required, as will be explained below.

However, the plate body 128 and/or the intermediate box 124 can also be omitted as appropriate, so that the bristle bundles 24 are directly fed into the box 20 . All of this depends on the desired final tuft distribution or tuft geometry and the hole pattern of the finished brush.

After the separation is completed, the bristle bundles 24 can be mechanically sent into the first intermediate box 124 and/or the box 20 on the station B by means of the slider or the tappet 126 shown in FIG. 2 . On station A, the second picture from the left illustrates another alternative: the separated tufts of bristles are fed into the intermediate magazine 124 or the magazine 20 by means of a pipe or hose 134 which is internally over- or under-pressured. .

Regardless of the transport means used for the bristle tufts, the bristle tufts can be provided and/or pushed into the cassette 20 individually, sequentially, in groups, or all at the same time.

The third alternative at station A illustrates a coiled strand 136 of parallel filaments. The strands 136 are wound on and continuously unwound from the spool 138 . The ends of the strands 136 are inserted into openings in the intermediate cassette 124 or cassette 20 and then severed. After severing the ends of the strands, cut-to-length tufts 24 of bristles are formed. Then, for example by means of a movable XY stage, on the one hand the reel or the end of the strand housed in the movable guide is moved relative to the magazine 20 or the intermediate magazine 124 or on the other hand the magazine 20 or the intermediate magazine 124 Move at the end of the strand to fill all of the openings in cassette 20 or intermediate cassette 124 in sequence. In addition, several reels or strands may also be moved relative to the cassette 20 or the intermediate cassette 124 . Next, the fully loaded cassettes 20 or intermediate cassettes 124 are transported away from this station and sent to station B or directly to station C. At station B, the tappet 126 presses the tufts 24 of bristles into the pocket 20 .

To eliminate the X-Y stage, strands from several spools 138 at the same time can also be fed into openings in cassette 20 or intermediate cassette 124, and the strands then cut.

Station C is a so-called modeling station. The tufts 24 of bristles are moved axially here so that the ends of the tufts that will be used to form the brush in the future lie in a plane, or more generally, terminate in an arbitrary predetermined plane.

A wavy shape is specified in the illustrated embodiment, thus separating the baffle 140 from the cassette 20 with a complementary wavy shape. Then, the bristle tufts 24 are pressed down by a pressing plate 142 preferably having a shape complementary to the surface of the baffle 140 until all the ends of the tufts abut against the baffle 140 .

However, if the desired shape can already be achieved at station B by means of tappets 126 of suitable different or equal lengths, then station C may also be omitted as appropriate. The two variants can also be mixed with each other, by means of so-called pre-styling at station B by means of tappets 126 of different lengths, followed by fine moulding at station C by means of baffles 140 .

Station D is a cutting station at which the rear ends of the tufts of bristles are cut off in order to melt the ends of the tufts with optimum effect on the following station. The bristle tufts 24 , which may protrude from the back of the pocket 20 to varying degrees, are severed relatively close to the pocket 20 , either mechanically by the blade 144 or thermally by the hot wire 146 . If a mechanical blade 144 is used, the cassette 20 may also function as a mating blade depending on the situation. In this case, the tufts of bristles 24 are slightly pushed out of the back of the box 20 after cutting, so that the tufts of bristles slightly protrude from the box 20 .

If the ends of the tufts already protrude neatly from the back of the cassette 20 after station B or station C, station D may be omitted as appropriate. This is especially true when the front tuft ends should end in a plane.

The protruding sections of the tufts of bristles 24 are then melted at station E so that all the filaments in one tuft are interconnected through the ends of the mushroom-shaped thickened tufts thus formed. The thickness of the tuft ends is controlled by the amount of material of the filaments protruding from the back of the box 20 . In this way, the geometry of the ends of the tufts can also be set.

The melting operation may be accomplished by a heated punch 148, which may be in contact with or at a distance from the tuft ends, to melt the filaments using radiant heat, particularly infrared light. As an alternative, melting can also be accomplished by hot air. It is important that only one corresponding thickening is always produced for the formed bristle tuft, since only those filaments that should also be fixed in the same anchoring opening in the future should be connected to each other by melting. As previously mentioned, the thickened portion 32 may optionally be cooled here.

At the next station F, the tufts of bristles are pushed into the anchoring openings 12 of the bristle carrier 10 with the thickened fixed end facing forward and the tufts of bristles are pressed against the anchoring openings 12 in the manner previously described middle. This push can be done simultaneously, sequentially, or grouped sequentially.

Another variant is to provide a deflecting plate with corresponding channels, push the bristle tufts 24 into the deflecting plate with the thickened fixed end facing forward, and then push the bristle tufts further into the anchoring openings of the bristle carrier. hole. This variant is suitable for situations in which the future hole pattern of the brush or the orientation of the bristle tufts 24 has not yet been fully realized in the cassette.

The aforementioned individually fabricated individual bristles 24' may optionally be provided at each station, either to the cassette 20, or to the bristle carrier 10 first.

Pressure is preferably applied to the holder 34, for example by at least one drive, such as an electric motor 240 (see Fig. 1f), optionally with a transmission element such as a spindle nut 242 interposed therebetween. Of course, this applies to all implementations.

The electric motor is in particular a servo motor.

In general, several bristle carriers 10 can also be deformed simultaneously by one drive in order to hold the at least one bristle or the at least one bristle bundle 24 in the anchoring opening. For this purpose, the holder 34 has several grooves 38 of complementary shape to the bristle carrier.

In order to increase the yield of finished brushes, there are in particular juxtaposed drives which in turn drive several holders 34 which in turn house several bristle carriers 10 .

The controller 51 is accordingly programmed to implement the aforementioned method in the apparatus.

By means of the apparatus of the present invention and the method of the present invention, ultra-long and ultra-thin tufts of bristles can be anchored in a bristle carrier. The present invention provides a bristle carrier containing tufts of bristles, wherein the tufts of bristles have a length of more than 8 mm and a width of less than 2 mm, in particular less than 1 mm.

At such large edge lengths as described above, the corresponding edges of the anchoring apertures do not necessarily have to be deformed inwardly to the same extent. The results show that it is sufficient to provide a number of overhanging edge segments that deform inwardly to the anchoring opening to a greater extent, and that these edge segments are alternately distributed with edge segments that deform inwardly to a lesser degree.

10‧‧‧Bristle carrier 12‧‧‧Anchor opening 14‧‧‧Assembly station 16‧‧‧Fusing station 18‧‧‧Anchoring station 20‧‧‧Cassette 22‧‧‧End face 24‧‧‧Bristle bundle 24 '‧‧‧Bristle 26‧‧‧Accommodating opening 28‧‧‧Rear end 30‧‧‧Heating device 32‧‧‧Thickening, anchoring end 32'‧‧‧Fixing end 34‧‧‧Retainer 36 ‧‧‧End face 38‧‧‧Groove 39‧‧‧Resistance heater 40‧‧‧Inner edge 41‧‧‧Electrical connection contact 42‧‧‧Front 44‧‧‧Bottom plate 50‧‧‧Edge 51‧‧‧ Controller 60‧‧‧Box 62‧‧‧Pin 64‧‧‧Deflector 66‧‧‧Transportation opening 80‧‧‧Edge section 81‧‧‧Edge section 100‧‧‧Injection molding half 101‧‧ ‧First injection molding half-mould 102‧‧‧Injection molding half-mould 104‧‧‧cavity 106‧‧‧pin 107‧‧‧insert 108‧‧‧cleaning element 110‧‧‧hinge 112‧‧‧disk 114‧‧‧Extension 118‧‧‧Section 120‧‧‧Fiber box 122‧‧‧Bunch separator 124‧‧‧First intermediate box 126‧‧‧Tap bar 128‧‧‧Plate body 130‧‧‧ Shaped or Deflected Holes 132‧‧‧Openings 134‧‧‧Hose 136‧‧‧Strands 138‧‧‧Rolls 140‧‧‧Baffles 142‧‧‧Press Plates 144‧‧‧Blades 146‧‧‧ Hot Wire 148‧‧‧Punch 200‧‧‧Depression 202‧‧‧Bottom 206‧‧‧Back 208‧‧‧Bottom 210‧‧‧Cooling Channel 212‧‧‧Side 214‧‧‧Cold Airflow 218‧‧‧Edge 220 ‧‧‧Section 228‧‧‧Vent clearance 240‧‧‧Electric motor 242‧‧‧Spindle nut 300‧‧‧Base 302‧‧‧Hole 304‧‧‧Insert 306‧‧‧Base 320‧‧‧Transition Edge 322‧‧‧Chamfering 323‧‧‧Envelope 324‧‧‧Line 330‧‧‧Part 332‧‧‧Part 340‧‧‧Connecting piece 342‧‧‧Chamfering 350‧‧‧Gap A‧‧‧Longitudinal d ‧‧‧Maximum Wall Thickness D‧‧‧Total Thickness D1‧‧‧Diameter D2‧‧‧Diameter D3‧‧‧Diameter t‧‧‧Depth T‧‧‧Depth Y‧‧‧Arrow Z‧‧‧Depth K‧‧ ‧Shadow side

Further features and advantages of the present invention are described below with reference to the accompanying drawings. In the diagram:

Figures 1a to 1g illustrate a perspective top view and a perspective bottom view of various steps successively performed in the method of the present invention, both of which also illustrate the apparatus of the present invention;

Figure 2 illustrates an enlarged view of the perspective bottom view of the anchoring station in Figure 1e;

Figure 3 shows a cross-sectional view of the anchoring station shown in Figures 1e and 1f before the cassette and the bristle carrier are moved towards each other;

Fig. 4 shows a corresponding view of the station shown in Fig. 3 when the cartridge is in first contact with the bristle carrier;

Figures 5 and 5A show the corresponding views of the anchoring station shown in Figure 3, just after the end of the feeding movement and the end of the action time, just before the station is separated and opened;

Figure 6 illustrates a cross-sectional view of an alternative assembly station;

Figure 7 illustrates a cross-sectional view of the anchoring station illustrated in Figure 3 on which the oblique tufts of bristles are processed;

Figure 8 shows a first embodiment of an injection moulding mould and a cross-sectional view of an injection moulding half mould part according to the invention for injection moulding in the method according to the invention and in the process according to the invention Bristle carriers used in the device;

Figure 8a illustrates an enlarged detail of the area indicated by X in Figure 8 according to the first variant;

Figure 8b illustrates an enlarged detail view of the area denoted by X in Figure 8 according to the second variant;

Figure 9 illustrates a front view of the bristle carrier produced by the present invention;

Figure 10 illustrates another injection moulding mould and another injection moulding half mould part according to the invention for injection moulding used in the method according to the invention and in the apparatus according to the invention bristle carrier;

Figure 11 shows a cross-sectional view of the bristle carrier when inserted into tufts and/or individual elastic bristles;

Figure 12 illustrates a variation of the single preformed bristles used in the present invention;

Figure 13 illustrates a variant of the method of the invention and the apparatus of the invention;

Figure 14 illustrates a perspective view of a bristle carrier produced in an injection moulding half-mould part according to the invention for carrying out the method according to the invention;

Fig. 15 shows an enlarged cross-sectional view of the bristle carrier according to Fig. 14,

Fig. 16 shows an enlarged cross-sectional view of the bristle carrier according to Fig. 14 after insertion of the bristle tuft and before shaping the bristle tuft, wherein the cassette is not shown for simplicity;

Figure 17 illustrates a rather enlarged detailed cross-sectional view of the tufts of bristles and the surrounding bristle carrier after deformation, wherein the bristle carriers of different degrees of deformation are shown as variants in the left and actual half of the drawing; and

Figure 18 illustrates an enlarged perspective top view of a bristle carrier produced in an injection moulding half mould part according to the invention according to another variant.

Domestic storage information (please note in the order of storage institution, date and number) None

Foreign deposit information (please note in the order of deposit country, institution, date and number) None

100‧‧‧Injection molding half

101‧‧‧First injection molding half-mold part

102‧‧‧Injection molding half mold

104‧‧‧cavity

106‧‧‧pin

107‧‧‧Inserts

Claims (25)

A method for making a brush, the brush comprising: a bristle carrier made of thermoplastic, the bristle carrier having a front and a back and at least one anchoring opening, and a bristle carrier made of thermoplastic including a thickened fixed end At least one bristle is inserted without anchor anchoring in the anchoring opening, so that the bristle protrudes from the front surface of the bristle carrier, wherein the at least one anchoring opening is defined by an inner side, and the at least one The anchoring opening has an end side edge on the front side which surrounds the anchoring opening, characterized by the following step: a) providing the bristle carrier which has in a region of the end side edge a bristle carrier to the inner side a transition edge that is at least partially chamfered on a circumference of the transition edge, wherein the anchor opening and the transition edge are created when injection molding the bristle carrier, b) housing the at least one bristle In an accommodating opening of a tool, c) while the at least one bristle is still in the accommodating opening, push the at least one bristle into the bristle carrier by means of the thickened fixed end of the at least one bristle the anchoring apertures formed during manufacture of the bristle carrier, d) reducing the distance of the tool piece to the bristle carrier such that the tool piece contacts the bristle carrier, e) bringing the front side of the bristle carrier to a temperature which is lower than the melting temperature of the bristle material and/or the bristle carrier material, in particular up to the bristle material and/or the bristle carrier material with 85% of the corresponding melting temperature calculated in °C, f) the tool applies a pressure to the heated bristle carrier and reduces the anchor at least in an area around the end edge of the anchor opening With the cross-section of the aperture fixed, the bristle carrier is deformed in such a way that the at least one bristle is embedded and anchored in the anchor aperture, wherein in the region of the edge and the inner side the The material of the bristle carrier is pressed laterally into the anchor opening and into a region of the transition edge and against the at least one bristle, and g) increasing the distance of the tool from the bristle carrier , so as to pull out the at least one bristle from the accommodating opening. The method of claim 1, wherein the chamfer extends along the entire circumference of the transition edge. The method of claim 2, wherein the chamfer has the same cross-section along the entire circumference of the transition edge. The method of claim 2, wherein the chamfer has a different cross-section along the circumference of the transition edge. The method of claim 4, wherein the chamfer has different cross-sections along the circumference of the transition edge, the cross-sections starting from the same axial depth of the anchor opening, the depth from the Measured on the front side of the bristle carrier adjoining the chamfer. A method as claimed in any one of the preceding claims, wherein the chamfer starts in the anchoring opening at a depth of at least 0.1 mm and at most 0.5 mm, in particular at most 0.35 mm, the depth from the bristle carrier The depth of the face adjacent to the chamfer. The method of any one of claims 1 to 5, wherein the chamfer has a radial width of at least 0.1 mm and at most 0.5 mm, in particular at most 0.35 mm. A method as claimed in any one of claims 1 to 5, wherein the chamfer is formed at least partially in cross section by a chamfer and/or an arc, in particular a radius. The method of any one of claims 1 to 5, wherein adjacent anchoring openings are separated by a web provided with the chamfer at least toward one of the anchoring openings , wherein the connecting piece protrudes to the front side of the bristle carrier and forms a part of the front side. The method of any one of claims 1 to 5, wherein the front surface of the bristle carrier is a flat surface or a convex or concave curved surface. The method of any one of claims 1 to 5, wherein a plurality of anchor openings are provided, wherein at least some of the anchor openings each have a chamfer, and the chamfers of the anchor openings each have different. A method as claimed in any one of claims 1 to 5, wherein the at least one anchoring opening of the bristle carrier, in the region surrounding the end edge of the anchoring opening, in the cross section only reduces at most As small as the start of the thickened fixed end, in particular to a depth of up to 1 mm. A method as claimed in any one of claims 1 to 5, wherein the bristle carrier is compressed in such a way that the material of the bristle carrier is pressed laterally into the anchoring openings in the region of the edge and the inside and is pressed into the region of the transition edge without protruding outward beyond an envelope formed by the front face of the bristle carrier. The method of any one of claims 1 to 5, wherein the thickened fixed end has a rounded or chamfered bottom surface, and the thickened fixed end is previously introduced into the anchoring opening through the bottom surface. The method of any one of claims 1 to 5, wherein the at least one bristle tuft is previously pushed into the anchoring opening by the thickened fixed end of the at least one bristle tuft in the following manner: the thickening The thick fixed end does not contact the chamfer of the anchor opening. 5. The method of any one of claims 1 to 5, wherein the lateral dimensions of the thickened fixed end are greater than those of each associated anchor aperture in an area of the bottom of the anchor aperture of such lateral dimensions are small. The method of any one of claims 1 to 5, wherein the bristle carrier is injection molded with the at least one anchor opening, and the at least one anchor opening includes an inner side with a demolding bevel , for demolding after injection molding. 6. The method of any one of claims 1 to 5, wherein the bristles or tufts of bristles are inserted into the anchoring openings obliquely to the front face, and the chamfer is adjacent to the bristles or the bristles at the transition edge is formed larger on one side of the bundle than at the rest of the periphery of the transition edge, or where there is no chamfer on one side away from the bristles or bundles of bristles and at the transition edge in the rest of the periphery There is a chamfer on it. The method of any one of claims 1 to 5, wherein the backside of the bristle carrier is actively cooled when the pressure is applied to the bristle carrier. The method of any one of claims 1 to 5, wherein the bristle carrier has anchoring apertures, and the edges of the anchoring apertures do not have a protrusion protruding beyond the anchoring apertures This front side of the bristle carrier. A device for carrying out the method as claimed in any one of the preceding claims to manufacture a brush comprising at least one bristles or at least one tuft of bristles, the brush having a bristle carrier having at least one for of the at least one bristle or the at least one tuft of bristles Anchoring aperture, characterized in that the apparatus comprises a plurality of stations, including an injection molding station for producing the bristle carrier and a subsequent anchoring station for securing the at least one bristle in the bristle carrier , wherein on the injection molding station there is an injection molding half-mould portion having at least one pin extending into an injection molding cavity, the pin forming part of the injection molding half-mould portion, and the The pin produces the anchoring opening constructed as a blind hole, wherein the pin protrudes from a bottom face of the injection moulding half-mould part, and wherein a chamfer is constructed at a transition from the bottom face to the pin, the chamfer for forming the complementary chamfer on the bristle carrier in an area of the transition edge, and wherein the apparatus comprises a tool having at least one accommodation for the at least one bristle or the at least one bristle tuft an opening, wherein the outlet of the receiving opening is located on the end face of the tool piece facing the bristle carrier, and wherein the tool piece has a heater that at least heats a section of the end face, the heater being constructed and The end face is controlled such that it is heated to a temperature of up to 140°C, in particular up to 130°C. 21. The apparatus of claim 21, wherein the apparatus is constructed such that the tool can apply a pressure of at least 200 bar, preferably at least 400 bar, to the bristle carrier. An apparatus as claimed in claim 21 or 22, wherein the chamfer on the injection moulding half part has an axial length and a radial width at the transition between the pin and the bottom surface, the axial The length is from at least 0.1 mm to at most 0.5 mm, in particular at most 0.35 mm, the radial width is from at least 0.1 mm to at most 0.35 mm. An injection moulding half-mould part for an apparatus according to any one of claims 21 to 23 for producing a bristle carrier for carrying out a method according to any one of claims 1 to 20, which Characterized in that the injection moulding half-mould part has at least one pin protruding into an injection moulding cavity, the pin forming part of the injection moulding half-mould, and the pin creates the anchoring opening configured as a blind hole, wherein The pin protrudes from the bottom face of the injection moulding half and wherein a chamfer is formed at the transition from the bottom face to the pin for forming the bristle carrier on the bristle carrier in the region of the transition edge Complementary chamfer, wherein the chamfer on the injection molding half-mould portion has an axial length and a radial width at the transition between the pin and the bottom surface, the axial length from at least 0.1 mm to at most 0.5 mm, especially at most 0.35 mm, the radial width is from at least 0.1 mm to at most 0.35 mm. The injection moulding half-mould part of claim 24, wherein the injection moulding half-mould part has an insert made as a separate part which extends into a hole in the remaining injection moulding half-mould part and ends with The free end protrudes from the front face and thus forms the pin.

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