MX2010012469A - Two-component injection moulded dispenser part. - Google Patents

Abstract

The invention relates to a dispenser part (20), comprising a first injection moulded plastic component part (17) with an associated first mating surface along a first edge; a second injection moulded plastic component part (18) having an associated second mating surface; a seam (21) formed by said first mating surface and said second mating surface during injection moulding for joining said first component part and said second component part to define a dispenser part. A transverse cross section of the seam comprises at least one step and at least one contact surface intermediate an inner and an outer surface of the dispenser part.

Description

PART OF DESPACHADOR MOLDED BY INJECTION OF TWO COMPONENTS TECHNICAL FIELD The present invention relates to dispensers having an external cover or containing a similar dispenser part comprising at least two selected components within a range of plastic materials, said components can be attached along a extending seam from a first side edge to a second side edge of the dispenser part.

ANTECEDENTS OF THE TECHNIQUE In many types of dispensers, for various reasons, it is often desirable to offer a dispenser part wherein at least one outer surface, a wrapper or a similar dispenser part is made of two similar or different plastic materials. For example, it is possible to make a selection of the dispatcher part to be transparent in order to facilitate the revision of the level of a consumable product contained within the dispenser. A second section can be manufactured from an opaque material in order to hide a mechanism for dispensing, in order to allow the monitoring of the filling level and offer a dispenser with an aesthetically pleasing appearance.

When a dispatcher of this type is manufactured, the first The component is usually injection molded in a first mold and transferred to a second mold for attachment with a subsequently injected component. A dispenser part manufactured in this way can present distortion problems of at least the first component, as well as of the seam, in particular at or near the regions of the side edges. The component parts are usually butt-bound and even with local reinforcements, the seam may not have sufficient strength to withstand the forces to which it can be expected to be exposed. For example, the front of the dispenser may be exposed to an accidental or intentional point load such as, for example, an impact force caused by an object or a person striking the dispenser. A weak seam can cause the dispenser part forming the cover to crack along at least a portion of the front surface, requiring the replacement of the dispenser part.

Various methods for manufacturing injection molded products are known from various documents of the prior art. WO 98/02361 relates to a known overmolding process, wherein a first component (a preform) is injected into a first mold. The preform is then transferred to a second mold, where a second material is injected and overmoulded in the preform to form a finished product, where the materials are joined along a continuous circular seam. Johannaber / Michaeli "Handbuch Sprizgiessen, 6-Sonderverfahren der Spritzgiesstechnologie", Cari Hanser Verlag, Munich, DE, is an overmolded by injection manual. Selected pages of this manual refer to overmolding methods. JP 03-120022 shows a conventional overmolding process in which two components are placed in a mold and joined by injection molding an additional material in a space between said components.

The object of the present invention is to provide an improved dispenser part for solving the aforementioned problems with regard to the distortion of the dispenser part and the strength of the seam.

DISCLOSURE OF THE INVENTION The aforementioned problems have been solved by a dispatcher party, as for example an entire dispatcher or a part of a dispatcher, in accordance with the appended claims.

The invention relates to dispenser parts, in particular dispensers or dispenser parts for consumable materials in restaurants, bathrooms or the like. Dispatchers of this type can be contemplated for rolls or stacks of paper or other cleaning materials, or for washing substances such as, for example, liquid hand cream, soap or other detergents.

In subsequent text, terms such as front, back, inner and outer are defined in relation to a visible external front or lateral surface of the dispatcher itself or, if appropriate, a surface of a dispatcher part which is in a dispenser whose Surface faces the user. In addition, the term "seam" is used as a general term defining any suitable seam or joint for joining two component parts comprising plastic material in a single dispenser part. In general, the term "dispatcher part" is used to refer to an entire dispatcher as well as a structural part of a dispatcher. In the latter case, a structural part may comprise a visible external cover, or a portion thereof, or a structural portion of the dispenser located within an outer cover. Also, the term "component part" is used to refer to each injection molded component that is joined with one or more additional component parts to form a dispenser part.

According to a preferred embodiment, the invention relates to a dispenser part comprising at least two component parts each joined by a seam having a particular configuration. The sewing is arranged preferred, but not necessarily, to extend from a first lateral edge to a second lateral edge of the dispensing part. When reference is made to a "dispatcher part" in the subsequent text, this term refers to a single-part dispenser or an internal part, an outer wrapper, or an outer cover of a dispenser for cleaning / toweling. paper, coreless rolls, plastic or paper rates, liquid / cream soap, or similar dispensers. The front part, shell or cover may comprise two component parts made of the same plastic material or different plastic materials in any desired combination of opaque, semi-opaque, semitransparent or transparent form. The component parts that make up the dispenser part may also have functionally different properties, wherein the component parts may comprise a cover attached to a cutting device. The dispenser part is advantageously manufactured using a method described below. However, the invention is not limited to visible component parts, since a seam in accordance with the present invention may also be suitable for dispenser parts mounted internally in such dispensers.

A preferred method for manufacturing the dispenser part includes the use of a single mold and the production of the dispenser part using a molding process by injection of two components. The two component injection molding process includes performing a first step of injection molding to produce at least a first part in said mold, retaining the at least one part in the mold, and performing a second molding step by injection to produce at least a second part in said mold and to complete the dispenser part. The mold is located in a first position during the first injection step, and is then moved or rotated to a second position where the second injection step and the subsequent cooling is carried out. In its simplest form, the method is used to manufacture a dispatcher part with a single first and second part. Said dispenser part may comprise a first upper part of a first material, which is transparent, and a second lower part of a second material, which is opaque. However, numerous variations are possible within the scope of the present invention. For example, a dispenser part in the form of a front cover may comprise a first transparent part, which extends horizontally through a central portion of the dispenser part, and second upper and lower opaque portions, or vice versa. According to the present invention, when the dispenser part comprises more than a first part and a second part, all the first parts are molded in the first step of injection molding and all the second parts are molded in the second step of injection molding.

A first edge of the at least one first part and a second injected edge of the at least one second part join to form said seam during the second injection molding step. Each first edge of the at least one first part is molded to form at least one step in a transverse direction to the first edge. The at least one step is preferred, but not necessarily, molded along each first edge from the first side edge to the second side edge of the first component part.

For each first part, the at least one step can be molded to form a first contact surface at right angles relative to an internal or external surface of the dispenser part, and a second contact surface extending towards the first edge. Accordingly, the second contact surface is arranged to extend between the inner and outer surfaces both in the transverse direction and in the longitudinal direction of the seam. The second contact surface can be molded to form a high contact increase means along the seam, preferably along the entire length of the seam.

The high contact increase means will melt upon contact with the injected material during the second injection molding step.

In this context, the longitudinal direction of the seam is defined as the direction of the front edge of the respective component part where they are joined by the seam, or the general direction of the front edge if the edge is not linear. The transverse direction of the seam at a particular location is defined as the direction at right angles relative to said front edge in the plane of the dispenser portion at said location.

Each first edge of the first component part can be injection molded to form at least two steps. This can be achieved by molding the first edge to form a third contact surface at right angles to an external surface or an internal surface of the dispenser part. For example, in its simplest form, the seam may comprise a first contact surface at right angles to an external surface of the dispenser part, and a second contact surface extending to the first edge. The seam is completed by a third contact surface at right angles with an internal surface of the dispensing part.

In accordance with an example, the method includes molding the means of high contact increase to form at least one additional step on the second contact surface, between the first contact surface and the second contact surface. The height of the steps can be selected according to the thickness of the dispenser wall adjacent to the seam and can be selected for example within a range of 0.05 to 3 mm. The steps have preferential, but not necessarily, the same height. For example, in a seam connecting a transparent part with an opaque part, the first step adjacent the outer surface of the dispenser part is preferably, but not necessarily, larger than the additional steps. This offers a different line separating the two parts and facilitates the filling of the mold adjacent to the edge of the first part during the second step of injection molding. An opaque material having a first thicker step adjacent to the seam will also prevent this portion of the dispenser part from becoming partially transparent. For example, a dispenser wall can have a constant total thickness of 1-6 mm, preferably 2.5-4.5 mm, adjacent a first step provided adjacent to the external surface and a first step provided adjacent to the inner surface can have, each one, a height of 0.2-1 mm. These first and second steps can be separated by numerous additional intermediate steps with a height of 0.05-1 mm. The intermediate steps are preferred, but not necessarily, of the same height. The spacing bet each adjacent step may be a distance equal to or greater than the height of the smallest of said steps. Each corner of said additional steps will melt during the second step of injection molding.

The steps may extend continuously or intermittently over the entire length of the seam. If the steps are fixed intermittently, then the sum of all the intermittent sections provided with steps must have a total length not less than half the length of the seam. The spacing bet adjacent staggered sections can be constant or variable. Preferably, the stepped sections must coincide with non-planar sections of the seam, such as, for example, corners, of sections that may be subjected to impact loading.

According to an alternative example, the method includes molding said high contact increase means to form at least one suitable projection. In a manner similar to the example above, each first edge of the first component part can be injection molded so as to form at least two steps. The seam may comprise a first contact surface at right angles to an external surface of the dispenser part, and a second contact surface extending towards the first edge. The seam is completed by a third contact surface at right angles with an inner surface of the dispenser part. In this example, the height of the first and third contact surfaces can be equal to or approximately equal to half the thickness of the dispenser wall adjacent to the seam. The high contact increase means can form at least one projection on the length of the seam as, for example, one or more planar projections extending at right angles from the second contact surface along the seam .

Alternatively, the high contact increase means can form multiple individual projections in at least one regular or irregular line along the seam. The projections may also have a regular or intermittent distribution over the entire second contact surface, wherein a greater concentration of projections is provided along portions of the seam subjected to relatively large forces during an impact. These projections can be in the form of circular, rectangular or triangular columns, or they can be hemispherical, conical, pyramidal or V-shaped projections. The projections can have a height of up to approximately half the height of the first step, or the first contact surface. The larger cross-sectional dimension of a projection, measured at the base of a projection of this type in the plane of the second contact surface, can be up to twice its height.

The projections may extend continuously or intermittently over the entire length of the seam. If the projections are arranged intermittently, then the sum of all intermittent sections provided with projections must have a total length not less than half the length of the seam. The spacing bet adjacent sections provided with projections can be constant or variable. Preferably, the sections provided with projections must coincide with non-planar sections of the seam, such as corners, of sections that can be subjected to impact loading.

According to a further example, the method includes molding the high contact increase means to form extended ridges. In a manner similar to the alternative example above, each first edge of the first component part can be injection molded to form at least two steps of equal height. In this example, the height of the first contact surface and the third contact surface can be equal to or approximately equal to half the thickness of the dispenser wall adjacent to the seam. The high contact increase means can form at least one ridge on the length of the seam. Said ridge may have a V-shaped cross section in the transverse direction of the seam. Alternatively, multiple parallel ridges having a V-shaped cross section can be provided.

The crests may extend continuously or intermittently over the entire length of the seam. If the crests are intermittently placed, then the sum of all the intermittent sections provided with ridges must have a total length not less than half the length of the seam. The spacing between adjacent sections provided with ridges can be constant or variable. Preferably, the sections provided with ridges must coincide with non-planar sections of the seam such as, for example, corners of sections that may be subjected to impact loading.

In the examples above, the at least one projection or ridge can have a height of up to half the thickness of the first contact surface, as measured from the base of the projection to the external surface of the dispenser part finished in an address at right angles relative to said external surface. The projections can have the same height or heights different The seam described in all the aforementioned examples may have a transverse width extending over a distance of up to five times the thickness of the thinnest of the first and second parts, in a transverse direction relative to the direction of the seam between the component parts in the plane of said component parts.

If the first part comprises a transparent material, the steps are formed to reduce the thickness of each first edge towards the internal surface of the first part. The second part may comprise an opaque material and the opposite edge of the second part may be used to hide the high contact increase means of the seam between the component parts. According to an example, the first part and the second part can have the same thickness on both sides of the seam and through it. According to a further example, the thickness of the wall of the first part can be gradually increased in the edge direction of the first part adjacent to the seam.

In order to achieve a desired strength, each corner of said steps, or each projection, is arranged to melt during the second step of injection molding. It has been found that, by providing steps formed by corners substantially at right angles over the entire length of the seam, the formation of a strong homogeneous seam is achieved. When the melted material injected during the second injection molding step reaches the solidified edge of the first part, the corners or projections facilitate the melting of the first part and second part. In order to ensure this, the temperature of the material to be injected and / or the temperature of a mold or of both molds can be controlled to achieve the desired result. For example, the temperature of the material injected at least during the second injection molding step can be selected such that it is higher than the injection temperature recommended for the particular material. As the second material flows through the mold to the first part, its temperature will gradually lower. However, since the initial temperature at the beginning of the injection is greater than the normal temperature, the temperature of the second melted material will still be sufficient to melt the edge of the first solidified part. The temperature of the first part can be controlled by adjusting the cooling of the mold. The first part is retained in the mold after the first step of injection molding, in order to maintain the shape of the first part as it begins to cool and to maintain the first part at an elevated temperature until The second step of injection molding is finished. The finished dispenser part can then be cooled and removed from the mold.

In combination with a choice of compatible resin materials and suitable injection temperatures for the first material and the second material, a seam in accordance with that described above will have improved impact resistance compared to the prior art seams manufactured by conventional methods. Impact resistance can be defined as the energy required to fracture a sample subjected to shock loading, as for example in the case of an impact test. Alternative terms are impact energy, impact value, impact resistance, and energy absorption.

As indicated above, the invention relates to a dispenser part manufactured by the method described above. The dispenser part comprises at least two parts joined by a seam extending from a first seam side to a second seam side of the dispenser part. The seam joining the respective first and second parts has an impact resistance at least equal to the impact resistance of any of the first and second portions adjacent to the seam. In practice, this means that when it is subjected to an impact in the area In the general seam, the dispenser part will fracture first on one side of the seam or parallel to the seam, but not on the seam itself or along the seam. The invention also relates to a component part of a dispenser part manufactured by said method. The component part is an intermediate product arranged to be manufactured during a first step of injection molding, wherein the first edge of the at least one first part comprises numerous different steps. These steps have been described in the text above.

The dispenser part may comprise two or more injection molded components joined by a seam having a predetermined strength. This can be achieved by a dispenser part comprising a first part of injection molded plastic component having a first associated coupling surface; a second part of injection molded plastic component having a second associated coupling surface; and a seam formed by said first coupling surface and said second coupling surface during injection molding to join said first component part and said second component part for the purpose of defining a dispenser part. The strength of the resulting seam is preferably equal to or greater than the strength of at least said first component part. of molded plastic and said second part of molded plastic component. The impact resistance of the resulting seam is preferably equal to or greater than the strength of at least one of said first part and said second part of molded plastic component.

The first coupling surface and the second coupling surface are generally non-planar, in that the seam extends from a first side edge in a first side wall of the dispenser part, through at least part of the front surface, and in a second side edge in a second side wall of the dispenser part.

In order to achieve the desired strength, the dispenser part must be injection molded using materials that have suitable properties for this purpose. According to an example, each of said first component part and said second component part is selected from the group consisting of plastic material of acrylonitrile butadiene styrene (ABS). According to a second example, the first component part is an ABS plastic material and said second component part is a plastic material of methyl methacrylate-ABS (MABS). According to the desired properties or according to the desired use of the dispenser part, the first component part can be an opaque ABS plastic material, and the second component part can be a transparent MABS plastic material. The thickness in cross section of the dispenser part in said seam can be within a range comprised between 1 mm and 6 MI, preferably between 2.5 and 4.5 mm.

As stated above, the first part of plastic component and the second part of plastic component can be molded from the group selected from ABS plastic material. Alternatively, a polycarbonate plastic material can be used, even though such materials have a lower resistance to scratches. Similar to ABS / MABS plastic materials, said polycarbonate plastic material can be either transparent or opaque.

The resistance of the dispenser portion through the seam should be such that, upon bending, the seam has a peak load of at least 35 MPa, preferably greater than 40 MPa, more preferably greater than 50 MPa. A comparison between a number of seams according to the present invention and a conventional seam will be described in detail below. According to an example, the cross section of the seam may comprise at least one step or projection over the entire length of the seam, in accordance with what is described above.

The dispatcher part may also comprise two or more injection molded components joined by a continuous seam extending from one side of the dispensing part to the other. This can be achieved through a dispenser part comprising a first part of injection molded plastic component with a first associated coupling surface; a second part of injection molded plastic component having a second associated coupling surface; a seam formed by said first coupling surface and said second coupling surface during injection molding to join said first component part with said second component part for the purpose of defining a dispensing part, and part of component comprising a front surface, a first side surface and a second side surface, each having an edge opposite the front surface. The resulting seam is arranged to extend from the edge associated with the first side surface to the edge associated with the second side surface of the dispenser part. In this case, the first coupling surface and the second coupling surface are generally non-planar.

In order to achieve a non-planar seam that connects two components from a first free edge to a second free edge, the dispenser part must be injection molded using materials that have properties suitable for this purpose. In addition to the strength of the seam, it is desirable to use materials that do not break when subjected to an impact on or near the seam.

According to an example, each of said first component part and said second component part is selected from the group consisting of a plastic material of acrylonitrile butadiene styrene (ABS). According to a second example, the first component part is a plastic material of the ABS type and said second component part is a plastic material of methyl methacrylate-ABS (MABS). According to the desired properties or according to the desired use of the dispenser part, the first component part can be an opaque ABS type plastic material, and the second component part can be a transparent MABS plastic material. The transverse thickness of the dispenser part in said seam can be within a range between 1 and 6 mm, preferably between 2.5 and 4.5 mm.

The seam must be able to withstand an impact of at least 10 Joules, but preferably 15 Joules, without cracking at its free edges or along non-planar areas. A suitable method for testing the seams according to the present invention, as well as conventional seams, will be described in detail below. In accordance with an example, A cross section of the seam may comprise at least one step over the entire length of the seam.

An object of the invention is to provide a dispenser part comprising two or more injection molded components joined by a seam having an appropriate shape to provide predetermined strength and resistance to impacts. This can be achieved through a dispenser part comprising at least a first part of injection molded plastic component with a first associated coupling surface; at least a second part of injection molded plastic component having a second associated coupling surface; a seam formed by said first coupling surface and said second coupling surface during injection molding to join said first component part and said second component part to define a dispenser part. A cross section of the seam comprises an intermediate contact surface between an inner surface and an outer surface of the dispenser part. According to a preferred embodiment, the invention relates to a dispenser part comprising at least two parts joined by a seam extending from a first lateral edge, through a front surface and up to a second lateral edge of the Dispatcher part. The dispatcher part can understand more than a first part of component and second part of component, each injected during a first step of injection molding and a second step of injection molding, respectively. Accordingly, each first component part may comprise one or two contact surfaces according to the shape and / or design of the dispenser part.

Each contact surface is arranged to extend over the length of the seam and at least one contact surface can have a cross-sectional extension of up to five times the thickness of at least one of the first or second component portion adjacent to the seam . Alternatively, the contact surface may have a transverse extension between 3 and 5 times, the thickness of at least one of the first or second component parts adjacent to the seam. The transverse extension of the contact surface can be defined as the total length of the splice between the first component part and the second component part at right angles relative to the seam parallel to the external surface of the dispenser part. Said at least one component is preferably the thinnest of the first component part and second component part. Alternatively, it may also be the component having a constant thickness up to the seam, in its transverse direction. The seam can have a maximum thickness that is equal or greater than the thickness of at least one of the first component part or second component part adjacent to the seam. The maximum thickness can be 1.2 to 1.5 times the thickness of said component parts.

Preferably, but not necessarily, the cross section of the seam comprises a first adjacent step and at substantially right angles relative to the outer surface of the dispenser part. The at least one step extends along each first edge from the first side edge to the second side edge. Each of said at least one step may form a first contact surface at right angles to an inner surface or an outer surface of the dispenser part, and a second contact surface extending to the first edge. The at least one step is preferably molded along each first edge from the first side edge to the second side edge of the first component part.

Here, the second contact surface is arranged to extend between the internal and external surfaces both in the transverse direction and in the longitudinal direction of the seam. The second contact surface can be molded to form a high contact increase means along the seam, preferably along the entire length of the seam. The means of high contact increase is It will melt upon contact with the material injected during the second step of injection molding.

Each first edge of the first component part can be injection molded to form at least two steps. This can be achieved by molding the first edge to form a third contact surface at right angles relative to an external surface or an internal surface of the dispenser part. For example, in its simplest form, the seam may comprise a first contact surface at right angles to an external surface of the dispenser part, and a second contact surface extending to the first edge. The seam is completed by means of a third contact surface at right angles relative to an internal surface of the dispenser part.

According to one example, the method includes molding the high contact increase means to form at least one additional step on the second contact surface between the first contact surface and the third contact surface. The height of the steps can be selected according to the thickness of the dispenser wall adjacent to the seam. This thickness is preferably measured at right angles to the front surface of the thinnest of the component parts immediately before sewing. The height of the additional steps can selected, for example, within a range between 0.05 and 2 mm. The steps preferably, but not necessarily, have the same height. For example, in a seam connecting a transparent part and an opaque part, the first step adjacent the outer surface of the dispenser part is preferably, but not necessarily, larger than the additional steps. This provides a distinct line separating the two parts and facilitates the filling of the mold adjacent to the edge of the first part during the second injection molding step.

An opaque material having a first thicker step adjacent to the seam will also prevent this portion of the part of a dispenser from becoming partially transparent. For example, a dispenser wall or a dispenser part may have a constant total thickness of 1-6, preferably 2.5-4.5 mm, adjacent to the seam. A first step provided adjacent the outer surface and a first step provided adjacent to the inner surface can each have a height of 0.2-1 mm. This first step and this second step can be separated by several additional, intermediate steps of a height of 0.05-1 mm. The intermediate steps are preferred, but not necessarily, of equal height. The separation between each adjacent step may be a distance equal to or greater than the height of the smallest of said steps. Each corner of said additional steps will melt during the second step of injection molding.

According to an alternative example, the method includes molding said high contact increase means to form at least one suitable projection. In a manner similar to the example above, each first edge of the first component part can be injection molded to form at least two steps. The high contact increase means can form at least one projection on the length of the seam as, for example, one or more planar projections extending at right angles relative to the second contact surface along the seam .

Alternatively, the high contact increase means can form multiple individual projections in at least one regular or irregular line along the seam. The projections can also be distributed regularly over the entire second contact surface. These projections can have a circular, rectangular or triangular shape, or they can be hemispheric, conical, pyramidal, or V-shaped projections.

According to a further example, the method includes molding the high contact increase means to form extended ridges. Similar to the example above, each first The edge of the first component part can be injection molded to form at least two steps. The high contact increase means can form at least one ridge along the seam. Said ridge may have a V-shaped cross section in the transverse direction of the seam. Alternatively, multiple parallel ridges having a V-shaped cross section can be provided.

In the examples above, the at least one projection or ridge can have a height of up to half the thickness of the first contact surface, in accordance with what is measured from the base of the projection to the external surface of the dispenser part. terminated in a direction at right angles relative to said outer surface. The projections may have the same height or may have different heights.

The seam described in all the examples above may have a cross-sectional width extending over a distance of up to 5 times the thickness of the thinnest of the first and second parts, in a transverse direction relative to the direction of the seam between the seams. component parts in the plane of said component parts.

If the first part comprises a transparent material, the steps are formed in order to reduce the thickness of each first edge towards the internal surface of the first one. part. The second part may comprise an opaque material and the opposite edge of the second part may be used to hide the high contact increase means of the seam between the component parts. According to an example, the first part and the second part can have the same thickness on either side and through the seam. According to a further example, the thickness of the wall of the first part can be gradually increased in the direction of the edge of the first part adjacent to the seam.

According to a further example, the thickness of the first component part can be arranged to gradually increase in a transverse direction towards the seam. The maximum thickness of the seam can be up to 1.5 times the thickness of the second component part adjacent to the seam. A leading end of the first component part is arranged to extend beyond the seam in the transverse direction of said seam. Subsequently, the leading end of the first component part may comprise a lip extending toward an inner surface of the second component part. In this way, the total length of the contact surface in accordance with what is defined above can be extended. This lip may be suitably rounded or angular to said inner surface.

A dispenser part according to that described above may comprise a first component part and a second component part, each having a front surface, and a first lateral surface and a second lateral surface, each having an opposite edge with respect to to the common front surface. A seam in accordance with the present invention can be arranged so as to extend from the edge associated with the first side surface to the edge associated with the second side surface.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail with reference to the appended figures. It will be understood that the drawings are only for the purpose of illustrating the present invention but are not intended to define the limits of the invention, for which reference will be made to the appended claims. It will further be understood that the drawings are not necessarily drawn to scale, and that, unless otherwise indicated, they are for the sole purpose of schematically illustrating the structures and procedures defined herein.

Figures 1A-B show a schematic illustration of an arrangement for carrying out a molding process for manufacturing a dispenser part in accordance with the present invention; Figure 2 shows a schematic illustration of a dispenser part manufactured through the process according to the present invention; Figure 3 shows a schematic illustration of a prior art seam; Figures 4A-D show a schematic illustration of cross sections through numerous alternative seams according to the invention; Figure 5 shows an enlarged view of the seam of Figure 4A; Figure 6 shows a schematic enlarged section of a first dispenser part provided with multiple steps according to a first example; Figure 7 shows a schematic enlarged section of a first dispenser part provided with projections according to a second example; Figure 8 shows a schematic enlarged section of a first dispenser part provided with a ridge according to a third example; Figure 9 shows a schematic enlarged section of a first dispenser part provided with intermittent ridges according to a fourth example; Figure 10 shows a schematic illustration of a dispenser part provided with intermittent ridges as shown in Figure 9; Figure 11 shows a schematic illustration of a dispenser part provided with a stepped edge as shown in Figure 6; Figures 12A-C show illustrations of cross sections through various seams in accordance with the present invention; Figure 13 shows a first example of a dispenser comprising a dispenser part according to the present invention; Figure 14 shows a second example of a dispenser comprising a dispenser part according to the present invention; Figure 15 shows a third example of a dispenser comprising a dispenser part according to the present invention; Figure 16 shows a fourth example of a dispenser comprising a dispenser part in accordance with the present invention.

MODALITIES OF THE INVENTION Figures 1A and IB show a schematic illustration of an arrangement for performing a two component injection molding process for manufacturing a dispenser part in accordance with the present invention.

In this example, the process uses two injection units 11, 12 and a rotary mold M designed for injection One-part sequential using two different materials. In the subsequent text, the process will be described for the injection of a transparent material and an opaque material, but it is applicable for any combination of transparent and / or colored materials. The mold M used in this example is a two-cavity mold. The mold M is kept closed in a first cavity position which is shown in Figure 1A and is heated to a predetermined operating temperature. The first material which is usually the material having the highest injection temperature is injected from the first injection unit 11 through a system of primary pipes 13 into a first cavity 15 to form a first component 17. In this example, the first material is a transparent or translucent resin. During the first injection, the mold volume that will be occupied by the second material is closed relative to the primary pipe system. The mold is open and a core plate is rotated 180 °, as indicated by arrow A in the second cavity position shown in Figure IB, after which the mold is closed. A secondary pipe system 14 is connected to the volume to be filled and the second material is injected from the second injection unit 12 into the second cavity 16 to form a second component 18. In this example, the second material is a opaque resin. After sufficient cooling of the injected dispenser part 17, 18, the mold is opened and the dispenser part is ejected.

Figure 2 shows a schematic illustration of a dispatcher part 20 manufactured through the process indicated above. Dispatcher part 20 is fabricated from two component parts 17, 18 injected during the process shown in Figures 1A-B. Said component parts 17, 18 are joined along a seam 21, which extends from a side edge 22 to a second side edge 23 of the dispenser part 20. Figure 2 further indicates the location of gate 24 for the primary pipe system 13 and the corresponding gate location 25 for the secondary pipe system 14.

One factor to be taken into account during the process is the relative melting temperature of the two materials. As indicated above, the material having the highest injection temperature is usually injected first. To ensure that the temperature of the second material is sufficient to melt at least partially a corresponding edge of the first material, the injection temperature of the second material can be increased. The increased temperature may be higher than the injection temperature recommended by the manufacturer, but not higher than the material degradation temperature.

In the example above, the first material was a transparent resin tested at two different injection temperatures. The second material was an opaque resin injected at the same temperature in both tests. These tests are described with additional details below.

Additional factors are the mold wall temperature, the injection speed, the time lapse between injections, and the temperature of part of the injected component. For example, the mold wall temperature is controlled to maintain the first component part at a desired temperature during rotation of the first component in the second injection position. In this way, the edge of the first component will not cause the second injected material to cool before the corresponding edges have melted together. The temperature of both components can also be maintained during consecutive injections in order to reduce the distortion of the dispenser part during subsequent cooling of the complete dispenser part. Since each injection station is fed through an independent injection unit, injection speeds and pressures can be controlled and adapted exactly for each injected material.

In addition to the tool design, additional considerations are the wall thickness of the injected component, the surface structure of the part from the primary pipe system to avoid ventilation problems, the tool surface and demoulding temperature, the gate location for optimal adhesion between the component parts according to the flow path, and the way how the part it will be extracted from the mold, causing the application of a force on the adhesion area between the component parts.

In order to increase the adhesion between the contacting edges of the two materials, the seam has a particular configuration. A prior art seam, as shown in Figure 3, fabricated by joining the two identical materials was used as a reference sample. The prior art sample was subjected to a comparison test using samples comprising several alternative seams in accordance with the present invention and a sample comprising a length of a homogeneous opaque material of the same thickness as the reference sample. The seams according to the present invention are shown in Figures 4A-4D. The test will be described with additional details below.

Figure 3 shows a schematic illustration of a prior art seam between a first transparent component part 31 and a second opaque component part 32. The first part of component 31 and the second part of component 32 have the same wall thickness and are butt-joined by a flat, straight seam 33.

Figures 4A-D show a schematic illustration of cross sections through various alternative seams in accordance with the present invention. Figure 4A shows a first transparent component part 41a and a second opaque component part 42a. The first component part 41a and the second component part 42a have the same wall thickness of 3 mm and are butt-joined by a seam 43a comprising several steps. The seam extends over a distance 2.5 times greater than the thickness of the second component part 42a, in a transverse direction relative to the direction of the seam 43a between the component parts. The front surfaces of the respectively joined component parts are completely flush with each other along the seam. In the region of the seam, the leading edge of the second component part 42a is arranged to join the first component part 41a in order to hide the seam 43a. The seam 43a will be described with further details below (see Figure 5). In Figures 4A-D, the steps are shown as distinct steps with corners at right angles for clarity. However, in the finished seam between two injection molded components, at least the corners of the Contact surfaces have melted to form a molten seam. In order to achieve a desired strength, each corner of said steps is arranged to melt during the second step of injection molding. It has been found that by providing steps formed by corners substantially at right angles over the entire length of the seam, the formation of a strong homogenous seam is achieved. When the melted material injected during the second injection step reaches the solidified edge of the first part, the corners facilitate the melting together of the first part and the second part. To ensure this, the temperature of the material to be injected and / or the mold temperature can be controlled to achieve the desired result. Figure 4B shows a first part of transparent component 41b and a second part of opaque component 42b. The first component part 41b and the second component part 42b are butt-joined by a seam 43b comprising several steps. The seam extends over a distance of 2.5 times the thickness of the second component part 42b, in a transverse direction relative to the direction of the seam 43b between the component parts. The first component part 41b has a wall thickness arranged to increase in the direction of the second component part 42b. To avoid a visible increase of the first transparent component 41b, the wall thickness is gradually increased from 3mm to 4mm over a distance of 65mm from the front edge of the first component 41b. The increase in wall thickness is located on the inner or rear surface of the first component part 41b. The second component part 42b has a constant wall thickness of 3 mm. The front surfaces of the respective joined component parts are completely flush with each other along the seam. In the region of the seam, a leading edge of the first component part 41b is equipped with a lip 44b placed to join the second component part 42b in order to reinforce and hide the seam 43b. The size of the splice in the transverse direction of the seam is up to the thickness of the dispenser part. The thickness of the lip 44b is gradually reduced to zero, for example, by a rounded section shown in Figure 4B. The part of the wall having an increased thickness extends beyond the end of the stepped portion of the seam 43b and is then rounded towards the inner surface of the second component part 42b.

Figure 4C shows a first part of transparent component 41c and a second part of opaque component 42c. The first component part 41c and the second component part 42c are butted together by means of a seam 43c comprising numerous steps. The seam extends over a distance 2.5 times the thickness of the second component part 42c, in a transverse direction relative to the direction of the seam 43c between the component parts. The first component part 41c has a wall thickness arranged to increase in the direction of the second component part 42c. To reduce a visible increase in the first transparent component part 41c, the wall thickness is gradually increased in said transverse direction. The wall thickness is increased from 3 mm to 4 mm over a distance of 15 mm from the front edge of the first component 41c. The second component 42c has a constant wall thickness of 3 mm. The front surfaces of the respective joined component parts are completely flush with each other along the seam. In the region of the seam, a leading edge of the first component part 41c is equipped with a lip 44c arranged to splice the second component part 42c to reinforce and hide the seam 43c. The size of the splice in the transverse direction of the seam is up to the thickness of the dispenser part. The thickness of the lip 44c is gradually reduced to zero, for example, by a rounded section shown in Figure 4C. The wall having an increased thickness extends beyond the end of the stepped portion of the seam 43c and it is then rounded towards the internal surface of the second component part 42c.

Figure 4D shows a first part of transparent component 41d and a second part of opaque component 42d. The first component part 41d and the second component part 42d are butt-joined by a seam 43d comprising numerous steps. The seam extends over a distance 2.5 times greater than the thickness of the second component part 42d, in a transverse direction relative to the direction of the seam 43d between the component parts. The first component 4 Id has a wall thickness that increases in the direction of the second component part 42d. To avoid a visible increase in the first transparent component 41d, the wall thickness is gradually increased and parallel to the angle of the seam in said transverse direction. The wall thickness is increased from 3mm to 4mm from a position on the inner surface immediately opposite the leading edge of the second component part 42b where it comes into contact with the first component 41d. The second component 42d has a constant wall thickness of 3 mm. The front surfaces of the respective joined component parts are fully gripped therebetween along the seam. In the region of the seam, a leading edge of the first component part 41d is equipped with a lip 44d arranged to join the second part of component 42d in order to reinforce and hide the seams 43d. The size of the splice in the transverse direction of the seam is up to the thickness of the dispenser part. The thickness of the lip 44d is gradually reduced to zero, for example, by a rounded section shown in Figure 4D. The part of the wall having an increased thickness extends parallel and beyond the end of the stepped portion of the seam 43d and is then rounded towards the inner surface of the second component part 42d.

Figures 4B-4D show a seam with a splice, wherein an edge portion or a lip 44b, 44c, 44d in a dispenser part extends beyond the transverse extent of the seam. The lip 44b, 44c, 44d partially connects the back surface in the opposite dispenser portion to reinforce the seam. Comparative bending and impact tests have shown that a splice of this type will offer only a limited improvement of the seam strength at bending. Nevertheless, a noticeable positive effect was observed during the impact test. Accordingly, in order to further improve the impact resistance of a dispenser part, a splice region in accordance with what is written above can be provided along a portion of the seam that It will probably be subjected to an impact. An example of a portion of this type may be the front surface of an outer cover of a paper towel dispenser in a bath.

Figure 5 shows an enlarged view of the seam of Figure 4A, comprising a first transparent component part 41a and a second opaque component part 42a. The front edge of the first component part 41a is injection molded to form numerous distinct steps 44, 45, 46. The height of the steps is selected according to the thickness of the dispenser wall adjacent to the seam 43a. In this example, the wall thickness of the dispenser adjacent to the seam is 3 mm, and the height of the steps is selected based on this measurement. For example, in a seam 43a connecting a transparent portion 41a and an opaque portion 42a, a first step 44 adjacent the outer surface 47 of the dispenser portion has been selected larger than a number of intermediate steps 45. This provides a different line separating the two parts 41a, 42a and facilitating the filling of the mold adjacent the edge of the first part 41a during the second injection molding step, n the first highest step 46 adjacent to the seam 43a will also prevent this portion from the dispatcher part becomes partially transparent. Similarly, a step end 46 adjacent to the inner surface 48 of the dispenser part has been selected larger than the intermediate steps 45 to facilitate the filling of the mold adjacent the edge of the first part 41a. In the latter case, the steps 44, 46 provided adjacent the outer surface and the inner surface 47, 48 each received a height of 0.2 mm. For a dispenser wall having a constant total thickness of 2 mm, these first external steps may be separated by numerous intermediate steps of 0.05-0.1 mm. In this case, the intermediate steps have a height equal to 0.05 mm. Figure 6 shows a schematic enlarged section of a component part provided with multiple steps as shown in accordance with a first example. This component part corresponds to the first component part 41a shown in Figure 5. As described above, the front edge of the first component part 41a is injection molded in order to form a number of distinct steps 44, 45 , 46 during a first step of injection molding according to the invention. A first step 44 adjacent the outer surface 47 of the component part has a height greater than a number of intermediate steps 45. Similarly, a final step 46 adjacent to the inner surface 48 of the component part has been selected from larger than the intermediate steps 45 to facilitate the filling of the mold adjacent to the edge of the first component part la. The first component apart 41a will be attached to the second component part 41b (see Figure 5) during the second injection molding step.

Figure 7 shows a schematic enlarged section of the first component part 51 provided with projections 52 in accordance with a second example. According to this example, a contact surface 53 is provided with a high contact increase means in the form of numerous conical projections 52. In a similar manner to the previous example, the front edge of the first component part 51 is injection molded. to form at least two steps 54, 56. A first step 54 adjacent an external surface 57 of the component part has a height corresponding to half the thickness of the first component part 51. In Figure 7, the High contact increase means forms two rows 55a, 55b of conical projections 52 over the length of the front edge. Alternatively, the multiple individual projections may be placed in at least one regular or irregular line along the seam. The projections can also be distributed regularly over the entire second contact surface. The front edge with its associated projections 52, contact surfaces 53 and steps 54, 56 subsequently forming part of a seam between the first component part 51 and a second part of injection molded component (not shown) to form a dispenser part.

Figure 8 shows a schematic enlarged section of a first component 61 provided with a ridge 62 in accordance with a third example. According to this example, a contact surface 63 is provided with a high contact increase means in the form of a ridge 62 extending parallel to a front edge of the first component part 61. In a manner similar to the example above, the front edge of the first component part 61 is injection molded to form two steps 64, 66 at the outset. A first step 64 adjacent an external surface 67 of the component part has a height corresponding to half the thickness of the first component part 61. In Figure 8, the high contact increase means forms a single V-shaped crest 62 over the length of the front edge. Alternatively, the ridge may have an I-shaped or U-shaped cross section or a rectangular cross-sectional direction of the front edge. In addition, multiple parallel ridges can be provided. The front edge with its associated projections 62, contact surface 63 and steps 64, 66 will subsequently be part of the sewing between the first component part 61 and a second part of the injection molded component (not shown) to form a dispenser part.

Figure 9 shows a schematic enlarged section of a first component part 71 provided with intermittent ridges 72a, 72b in accordance with a fourth example. According to this example, a contact surface 73 is provided with high contact increase means in the form of a flat, rectangular or I-shaped ridge 72a, 72b extending parallel to a front edge of the first component part 71. Similarly to the example above, the front edge of the first component part 71 is injection molded to form at least two steps 74, 76. A first step 74 adjacent an outer surface 77 of the component part has a height which corresponds to half the thickness of the first component part 51. In Figure 9, the high contact increase means forms an intermittent I-shaped peak 62, said crest is provided to reinforce selected portions along the edge frontal. Alternatively, the ridge may have a V-shaped or U-shaped cross section in the transverse direction of the front edge. In addition, multiple parallel ridges may be provided, said intermittent ridges may be staggered. The front edge with its associated projections 72a, 72b, contact surfaces 73 and steps 74, 76 will subsequently form part of a seam between the first component part 71 and a second part of injection molded component (not shown) to form a dispenser part.

In the examples above, as shown in Figures 6-9, the at least one projection or ridge may have a height of up to half the thickness of the first step, in accordance with that measured from the base of the projection or crest, in the plane of the first contact surface, to the outer surface of the dispenser part in a direction at right angles relative to said external surface. The projections / ridges may have the same height or different heights. Also, the resultant seam described in the examples above can be extended over the distance of up to five times the thickness of the thinnest of the first part and of the second part, in a direction transverse to the direction of the seam between the component parts. . For example, in Figure 6, the width of the resulting seam corresponds to the distance between the first step 44 and the second step 46 in accordance with that measured at right angles to the front edge.

Figure 10 shows a schematic illustration of a component part 71 provided with intermittent ridges 72a, 72b, 72c, 72d, 72e as illustrated in Figure 9. As indicated schematically in Figure 10, the crests are located in areas where it is anticipated that the deformation caused by the external load will be relatively large. For example, numerous crests 72a, 72b, 72c are located closer together between them along a section A of a middle or front surface of the component part 71, which is likely to receive impact load. The crests 72a, 72b, 72c can be placed closer together or they can be made to be longer in this section. An impact load on the front surface will also increase the deformation in a corner section B of the component part 71, requiring a reinforcement ridge 72b in each of said sections B. The component part 71 also comprises a section of free lateral edge C that can be subjected to deformation caused by impact loading and forces induced in the material during cooling of the injection molded dispenser part. Accordingly, each lateral edge section C is provided with a reinforcing crest 72e. Note that the ridges in Figure 10 are not drawn to scale, for reasons of clarity.

Figure 11 shows a schematic illustration of the component part 41a provided with a stepped edge 80 comprising numerous distinct steps 44, 45, 46, as shown in FIG. shown in Figure 6. In Figure 11, it can be seen how the stepped edge 80 extends continuously from a side edge 81 of the component part 41a to a second side edge 82.

Figures 12A-12C show illustrations of actual photographs of cross-sectional samples through a number of dispenser parts corresponding to the schematic cross sections illustrated in Figures 4A-4C. In Figures 12A-12C, the dispenser parts have been cut in a transverse direction of the seam between the first component part and the second component part. Accordingly, Figure 12A, which corresponds to Figure 4A, shows a first part of transparent component 41a and a second part of opaque component 42b. The first component part 41a and the second component part 42a have the same wall thickness of 3 mm and are butt-joined by a seam 43a comprising several steps. As can be seen from the Figure, the contact surfaces have been joined and the corners of the different steps have been fused to form rounded surfaces and fused with the second component part 42a during the second injection molding step.

FIGS. 12B and 12C show a transparent first component part 41b, 41c and a second opaque component part 42b, 42c. The first and second parts of component 41b, 42b; 41c, 42c are butt-joined by a seam 43b, 43c comprising numerous steps. The seam extends over a distance 2.5 times greater than the thickness of the second component part 42b, 42c in a transverse direction relative to the direction of the seam 43b, 43c between the component parts. The first component part 41b, 41c has a wall thickness arranged to increase in the direction of the second component part 42b, 42c. A leading edge of the first component part 41b, 41c is equipped with a lip 44b, 44c arranged to splice the second component part 42b, 42c in order to reinforce and hide the seam 43b, 43c. As shown in Figure 12A, the contact surfaces have been joined and the corners of the distinct steps have been fused to form rounded surfaces and fused with the second component part 42b, 42c during the second injection molding step.

Unlike the prior art solution as shown in Figure 3, the seam between two component parts can withstand an impact test by subjecting the dispenser part to a 15 Joule impact. This test is described with additional details below. When subjected to an impact load greater than the impact load used in said test, the dispenser part will crack adjacently parallel to the seam.

Figure 13 shows a first example of a dispenser comprising a dispenser part in accordance with the present invention. In this example, a dispatcher part 90 is formed by a first transparent component part 91 and a second opaque component part 92. The first component part 91 and the second component part 92 are joined by a seam 93 extending from a first side edge 94 to a second side edge 95 of the dispenser part 90. The component parts 91, 92 may be joined through any of the seams described in relation to Figures 6-9. The dispenser portion 90 is removably attached to a rear dispenser section 96 for the purpose of forming a dispenser housing 97. The rear dispenser section 96 is arranged to be mounted on a vertical surface such as, for example, a wall. In this example, the dispenser housing 97 is contemplated for a dispenser for stacking paper towels or the like that are removed through a dispenser opening 98 on a lower surface of the dispenser.

Figure 14 shows a second example of a dispenser comprising a dispenser part according to the present invention. In this example, a dispatcher part 100 is formed of a first transparent component part 101 and a second opaque component part 102. The first component part 101 and second component part 102 are joined by a seam 103 extending from a first side edge 104 to a second side edge 105 located along a lower boundary section of the dispenser part 100 The component parts 101, 102 may be joined through any of the seams described in relation to Figures 6-9. The dispenser part 100 is removably attached on a rear dispenser section 106, so as to form a dispenser housing 107. The rear dispenser section 106 is arranged to be mounted on a vertical surface such as, for example, a wall. In this example, the dispenser housing 107 is contemplated for a dispenser for a roll of paper or the like that is removed through a dispenser opening 108 in a lower surface of the dispenser. Figure 15 shows a third example of a dispenser comprising a dispenser part according to the present invention. In this example, a dispenser part 110 is formed through a first central transparent component part 111 and second upper and lower opaque component parts 112a, 112b. The first component part 111 and the second component parts 112a, 112b are joined by seams 113a and 113b, respectively. Both seams 113a, 113b extend in parallel shape from a first side edge 114 to a second side edge 115 of the dispenser part 110. The component parts 111, 112a, 112b may be joined through any of the seams described in relation to Figures 6-9. The dispenser portion 110 is releasably attached to a rear dispenser section 116 for the purpose of forming a dispenser housing 117. The rear dispenser section 116 is arranged to be mounted on a vertical surface, such as a wall. In this example, the dispenser housing 117 is contemplated for a dispenser for a stack of paper towels or the like, which are removed through a dispenser opening 118 in a lower surface of the dispenser.

Figure 16 shows a fourth example of a dispenser comprising a dispenser part according to the present invention. The Figure shows a bottom perspective view of a one-piece or one-part type dispenser, in this case a cantilever type dispenser. In accordance with the present invention, the dispenser part comprises a bracket 120 for containing or supporting a bag or box of cleaners B (indicated in lines of dashes and dots). The bracket 120 comprises transparent first component parts 121a, 121b on both sides of the bracket 120, and a second part of component 122 opaque rear and bottom only. The first component parts 121a, 121b and the second component part 122 are joined by seams 123a and 123b, respectively. Both of the seams 123a, 123b extend from a first side edge 124a, 124b at the rear of the bracket to a second side edge 125a, 125b adjacent to the front of the bracket 120. The component parts 121a, 121b, 122 can be joined together through any of the seams described in relation to Figures 6-9. The bracket 120 is provided with a rear section 126 (not shown) that allows its attachment to a wall or a similar vertical surface. In this example, the bracket 120 is contemplated for a dispenser for a box B containing a stack of paper towels or the like, which are removed through a dispenser opening 128 on a lower surface of the dispenser.

A one-part cantilever dispenser can be manufactured from at least two plastic component parts, which have two or more different colors or a combination of transparent, frosted or opaque sections. A similar cantilever dispenser can be used for soap dispensers comprising a one piece bracket in which a soap refill bottle will be contained or on which a bottle of soap refill will be supported. In the latter case, the refill bottle it can be manufactured in such a way as to have the appearance of a "bell" or an external cover as it is used in available types of soap dispensers. In other words, the filling (ie, the soap bottle) will take the place of one of the dispenser's part (ie, the bell). In such cases, the cantilever type dispenser forms a one-part dispenser defined as part of the dispenser according to the present invention.

When the materials are selected, it must be determined that the resins used are generally compatible, without antagonistic effects between resins. Suitable materials for use in the aforementioned method are acrylonitrile butadiene styrene (ABS) plastics and / or methyl methacrylate-ABS plastics (MABS). However, these materials are provided by way of example only and the invention is not limited to these materials. The materials tested in the examples below are Terlux® TR2802 MABS (BASF Corp.) or Polylux® C2 MABS (A. Schulman GmbH) for the first transparent part and Polyman® M / MI A40 ABS (A. Schulman GmbH) for the second part. opaque part.

A comparative bending test was performed using a selection of the materials mentioned above for the seams as described in relation to Figures 3 and 4A-D. The test used complies with ISO 178: 2001. Test samples in the form of five individual strips with the Following dimensions: 1 cm by 10 cm were cut from numerous injection molded components. Seam configurations included a prior art seam, shown in Figure 3, as a reference sample, the seams shown in Figures 4A-D, and a sample comprising a length of a homogeneous opaque material having the same thickness than the reference sample. As indicated in Table 1, all of the samples except one containing seams were fabricated by joining two same materials. The samples were kept at each free end subjected to a force applied to the seam. During this test the maximum load (MPa) and the breaking load (MPa) were recorded. In Table 1, the samples 1A-1C represent a seam in accordance with the reference seam of Figure 3, wherein the samples comprise different materials joined at different injection temperatures. Similarly, the samples 2A-2B represent a seam according to the seam of Figure 4A, while the samples 3-5 represent the seams according to Figures 4B-D, respectively. The sample 6 comprises a length of a homogeneous opaque material with the same thickness as the reference sample.

In order to improve the properties of the seam between two component parts it is also discovered that a Proper selection of injection temperatures during the first step of injection molding and / or second step of injection molding had a positive effect.

According to an example, a dispenser part was produced, which contained Polylux® C2 MABS (A. Schulman GmbH) for the first transparent part and Polyman® M / I A40 ABS (A. Schulman GmbH) for the second opaque part of the dispatcher part. The injection temperature, or barrel, was modified for the first step of injection molding. According to a catalog of materials comprising technical data for said plastic materials supplied by A. Schulman GmbH; "Schulamid" ®; page 28; (3rd edition May 2006), it can be seen that the recommended injection temperature for Polylux® C2 MABS is 200-240 ° C.

When the two-component injection molding process was carried out in accordance with the present invention, for the first injection molding step an injection temperature of 260-290 °, preferably 280 ° C, was used for the first component part. transparent. Combined with the seaming configuration, as shown in Figures 4A-D, in particular Figure 4A, a subsequent test showed that the injection temperature was increased during the first injection step, which resulted in improved structural strength of the seam joining the component parts.

Table 1 - Bending test As can be seen from Table 1, samples 2A and 2B representing the seam shown in Figure 4A will provide an adhesion between the two component parts that is equal to or better than that offered by sample 6, which comprises a length of a homogeneous opaque material. The test also shows that the stitching resistance in samples 2A and 2B is almost double compared to the reference sample, regardless of the material or the injection temperature.

During testing, it was discovered that samples 3-5, despite having a seam with substantially the same configuration, they exhibited a tendency to rupture adjacent to the rounded end section of the transparent component parts where it joins the opaque component part. It would seem that the end section created a weakened section at this point. Despite this, the strength of the samples 3-5 remains equal to or greater than the resistance of the reference samples 1A-1C.

An additional test carried out was an impact test that simulates an external force applied to a part of the dispenser formed as a front cover in the region of the seam. A suitable test developed for this purpose involves suspending a weight fixed on a pivoted arm, said weight being released to strike a limited area of a front surface of a dispenser cover mounted on a fixed surface or on a bracket for attaching the dispenser on a wall. This test simulates a dispatcher hit with a predetermined force by an object or a person.

In accordance with one example, the test used a weight of 13 kg fixed on an arm of a length of 0.75 m. The part of the weight arranged to impact on a front surface of the dispenser part had an area corresponding to the average area of a fist of a male adult human being, which corresponds to a flat rectangular area of approximately 63 cm2 (7). x 9 cm). He The arm to which the weight was held was pivoted from a vertical position to a horizontal position, through an arc of approximately 34 °, and released. This angle can be selected and adjusted to provide a desired repeatable impact energy. The impact energy absorbed by the dispatcher part by using the test settings described above is considered to correspond to a value of 15 Joules (J). During the test, dispatcher parts were subjected to impacts of 10 and 15 J, respectively. The lowest value was selected as the minimum acceptable level, and the highest value was selected as the preferable level for impact resistance without cracking.

Many combinations of material were tested and rejected because at least one of the component parts was destroyed by the impact. Combinations of additional materials were tested and rejected due to cracking or separation of the seam between the component parts.

After performing a significant number of tests to determine the strength of various seam configurations and material combinations, it was determined that a combination of ABS materials or ABS and MABS materials resulted in a seam having the desired properties. In addition to finishing properties Suitable surface coatings for example to gloss and scratch resistance, an injection molded part comprising a seam in accordance with the present invention had the desired strength and strength to impact test without cracking. Examples of such materials are Polylux® C2 MABS (A. Schulman GmbH) for the first transparent part and Polyman® M / MI A40 ABS (A. Schulman GmbH) for the second opaque part of the dispenser part.

The tool design that was used in the described example is a rotating plate. It comprises a two-station tool that rotates in the vertical (or horizontal) direction. The rotating plate is held in a first position in a first injection station for the injection of the first material. It then rotates in a second position in a second injection station for the injection of second material.

An alternative tool design is a core retraction. In a core retraction, a sliding core is closed first and the first material is injected. The sliding core is then opened and the second material is injected.

The injection is not limited to the examples above but may be varied freely within the scope of the appended claims. For example, in the examples above a combination of transparent and opaque materials is described. In addition, combinations of one or more colored and / or transparent materials can be used. Also, the examples describe a single seam extending horizontally or at an angle through the front surface of the dispenser part. Alternative solutions may comprise one or more vertically arranged seams or to enclose a single corner. The seam does not have to be located along a straight line, as described above, but may also have a curved, wavy or irregularly shaped line.

Claims (31)

1. CLAIMS 1. A dispenser part comprising at least two component parts (17, 18; 31, 32; 41a, 42a) each joined by a seam (21; 33; 43a), said dispenser part comprises a first component part plastic (17; 31; 41a) injection molded with a first coupling surface associated along a first edge; a second part of plastic component (18; 32; 42a) injection molded having a second associated coupling surface; the seal formed by said first coupling surface and said second coupling surface during injection molding to join said first component part (17; 31; 41a) and said second component part (18; 32; 42a) to define a part of dispenser (20) characterized in that a cross section of the seam (21; 33; 43a) comprises at least one step (44, 45, 46) and at least one intermediate contact surface between an external surface and a inner surface (47, 48) of the dispenser part (20). A dispenser part according to claim 1, characterized in that each contact surface extends over the length of the seam (21; 33; 43a). 3. A dispenser part according to claim 1 or 2, characterized in that the surface of contact has a transverse extension of up to 5 times the thickness of at least one component part (17, 18, 31, 32, 41a, 42a) adjacent to the seam (21; 33; 43a). . A dispenser part according to claim 3, characterized in that the contact surface has a transverse extension between 3 and 5 times the thickness of at least one component part (17, 18; 31, 32; 41a, 42a) adjacent to the seam (21; 33; 43a). 5. A dispenser part according to any of claims 1-4, characterized in that the cross section of the seam (21; 33; 43a) comprises a first step (44) adjacent to the external surface of the dispenser part (20) . 6. A dispenser part according to claim 5, characterized in that the first step (44) comprises a first contact surface at right angles to the external surface of the dispenser part and a second attached contact surface extending to the first edge. 7. A dispenser part according to claim 5 or 6, characterized in that the cross section of the seam (21; 33; 43a) comprises a second step (46) adjacent to the internal surface of the dispenser part. 8. A dispatcher part in accordance with the claim 7, characterized in that the second step (46) comprises a third contact surface at right angles to the inner surface of the dispenser part (20), said third contact surface coinciding with the first edge of the first part of component (17; 31; 41a). 9. A dispenser part according to claim 7 or 8, characterized in that the first step and the second step (44, 46) have a height equal to or less than half the thickness of at least one part of the component adjacent to the seam. , said steps are joined by the second contact surface. 10. A dispenser part according to any of claims 7-9, characterized in that the first step and the second step (44, 46) have a height between 1/6 and 1/2 the thickness of at least one component part adjacent to the seam. 11. A dispenser part according to any of claims 6-10, characterized in that the second contact surface comprises a means of increasing contact along the seam (21; 33; 43a). 12. A dispenser part according to claim 11, characterized in that the high contact increase means is arranged to melt during the injection molding of the second part of component. 13. A dispenser part according to claim 11 or 12, characterized in that the high contact increase means comprises at least one additional step (45). 14. A dispenser part according to claim 13, characterized in that each additional step has a height of 0.05 to 1 mm. 15. A dispenser part according to claim 13 or 14, characterized in that the high contact increase means comprises steps having an equal height. 16. A dispenser part according to any of claims 13-15, characterized in that, in cross section, the at least one additional step (45) has a height that is equal to or less than the height of the first step (4). 17. A dispenser part according to any of claims 13-16, characterized in that the additional steps (45) have a height between 1/20 and 1/3 of the thickness of at least one part of the component adjacent to the seam. 18. A dispenser part according to any of claims 13-17, characterized in that, in transverse direction, each adjacent step is separated by a distance equal to or greater than the height of the smallest of said steps. 19. A dispenser part according to claim 11, characterized in that the high contact increase means comprises at least one projection along the seam (21; 33; 43a). 20. A dispenser part according to claim 19, characterized in that the high contact increase means comprises at least one flat projection extending at right angles relative to the second contact surface along the seam. 21. A dispenser part according to claim 19, characterized in that the high contact increase means comprises multiple individual projections along the seam. 22. A dispenser part according to claim 11, characterized in that the high contact increase means comprises at least one crest along the seam. 23. A dispenser part according to claim 22, characterized in that the high contact increase means comprises multiple parallel ridges having a V-shaped cross-section. 24. A dispenser part according to claim 22, characterized in that the at least one ridge has a V-shaped cross section. 25. A dispenser part according to any of claims 19-24, characterized in that it has a projection or ridge that has a height of up to half the thickness of the second contact surface. 26. A dispenser part according to any of claims 19-25, characterized in that the projections have the same height or different heights. 27. A dispenser part according to any of claims 1-26, characterized in that the thickness of the first component part (17; 31; 41a) is arranged to gradually increase in the transverse direction toward the seam (21; 33; 43a) . 28. A dispenser part according to any of claims 1-27, characterized in that the maximum thickness of the seam is 1.5 times the thickness of the second component part adjacent to the seam. 29. A dispenser part according to any of claims 1-28, characterized in that, in the transverse direction of the seam, a leading end of the first component part (17; 31; 41a) is arranged to extend beyond the Intermediate contact surface of an external surface and internal surface (47, 48) of the dispatcher part (20). 30. A dispenser part according to claim 29, characterized in that the front end of the first component part (17; 31; 41a) comprises a lip extending towards an internal surface of the second component part (18; 32; 42a). 31. A dispenser part according to any of claims 1-30, wherein each first part, component and second component part (17, 18; 31, 32; 41a, 42a) comprising a front surface, a first surface side and a second side surface, each having an opposite edge relative to a front surface, characterized in that the seam is arranged to extend from the edge (22) associated with the first side surface to the edge (23) associated with the second. lateral surface.