EP2129254B1 - Method for the production of a part of a hook and loop fastener together with a corresponding apparatus - Google Patents

Description

The invention relates to a method for producing an adhesive closure part, comprising at least one plastic material, in which a support member having a plurality of projecting handle parts with individual head parts is connected such that at least a part of said handle parts whose free ends in touching or immersing plant with an investment side of each assignable headboard come, which are still present at least in the partially liquid or partially plasticized state during the connection process of handle parts and assignable headboards and the headboards are fully cured after the connection. The invention further relates to a device for producing an adhesive closure part with the method.

Adjacent adhesive closure parts, which are also attributed to the mechanical fastening elements, form a closure which can be repeatedly opened and closed with complementary closure parts, wherein hooks or mushroom-like closure parts interact with loop-like closure elements of another adhesive closure part to form the adhesive closure. Solutions are also known in which the same adhesive closure elements of two different adhesive closure parts interact with one another (hermaphroditic closure). The US 2003/0126724 A1 discloses a fastener closure member having a sheet-like support member and a plurality of handle parts, which are arranged as projections on the support member and each composed of a soft, elastic-flexible resin material and a hard, solid resin material. Here, each of the shaft of the stem part of the hard resin or plastic material and its upper part may be formed from the soft resin or plastic material.

Furthermore, it is through the DE 699 22 264 T2 known to supply a belt-like support member having a plurality of projecting stem parts of a forming gap between heatable forming rollers, in which an extruder over an additional shaping belt made of plastic material can be fed, which transforms the actual stem shape ends of the stem parts of the stem parts to head parts as the actual mold with Formausnehmt to a mushroom-like To obtain adhesive closure part. Since the head parts mentioned are formed in the known solution of the plastic material of the stem parts fall so far the head parts because of the low material input in the available for hooking free and thus protruding head surface of low, which adversely affects the required adhesive forces.

In contrast, the US Pat. No. 6,180,205 B1 a manufacturing method using a forming roller, in which a band-like support member is connectable to a plurality of relatively large dimensionable hook closure elements. For this purpose, the shaping roller has hook-shaped form recesses on its outer circumference, in which plastic material is pressed in through a first extruder device in order to fill the mold. Excess plastic material on the outer peripheral side of the forming roll is removed by means of a Schneidabtrageinrichtung, which is referred to in technical language as a doctor blade. The carrier part material is then applied by means of a second extruder device arranged downstream in the direction of manufacture, and with the hook-shaped closure parts during the Cooling process of the roller firmly connected. A peel roller then removes the finished closure from the former. Due to the hook geometry, this can lead to difficulties during the demolding process and, furthermore, during the production process, a relatively high proportion of plastic waste arises due to the use of said doctor blade.

By the WO 2006/099000 A2 It is also known to spray a ribbon-like conveyor on its upper strand side with droplets of plastic material, wherein the plastic material forms due to its surface tension to hemispherical shell bodies, which are then firmly connected at its top of curvature with a band-like support member to form the adhesive closure part. In further development of this solution, it is also possible to supply a band-like support member in the manner of thickened stem parts, which already carries on its upper side granular agglomerates as stem parts, on which then the half-shell-shaped head parts are placed. However, the adhesive closure part produced in this way, which is intended in particular to serve as a closure for baby and incontinence diapers, is relatively stiff and, to that extent, still leaves desires open with regard to the closure characteristic. By the US 2006/0220271 A1 a comparable solution is known, however, which provides for the production of the half-shell-shaped closure elements, a molding tool in the form of a molding roll with corresponding Formausnehmungen instead of a band. A manufacture of stem parts between the head parts and the carrier part does not take place with this known solution.

By the American patent 5,785,784 For example, a manufacturing method is known for producing a band-like carrier part on which a plurality of projecting handle parts is located. In a subsequent manufacturing step, the free ends of the stems are heated, which then become one in particular due to the surface tension of the plastic material thicken hemispherical headboard. If, in continuation of the known solution, the headers which can be produced in this way are subsequently deformed by means of a so-called calender rolling process, broadened headboard geometries are produced to that extent; but still relatively small in terms of the low material input and are only widened in the direction of the earlier rolling direction.

A method of the type mentioned is out US 2004/0134045 A1 known. In the known method for producing a Haftverschlussteils with a plurality of integrally formed with a carrier Verhakungsmitteln in the form of end interlocking heads having stem parts, the Verhakungsköpfe are at least partially provided with in each case an additional head part of a filler material. The fact that the respective additional head part is formed from a thermosetting molding material as a filler material, a Haftverschlusssystem is created, which can withstand high temperatures and mechanical stresses on the one hand and on the other with appropriate design leads to better adhesion and peel strength values.

The hooking means produced in a conventional manner consist of individual handle parts, at whose free ends plate-like interlocking heads are present. The materials forming the additional headers are applied to the hooking heads via an applicator roll. The typically used acrylate material has a similar consistency and viscosity as honey and forms a kind of application bath between the applicator roll and a counter-roller and can be passed from there successively from the applicator roll to the adhesive closure part. The surface tension of the acrylate material is selected to provide some form of drop formation with the result that the headers form hemispherical caps on the hooking heads. For curing of the additional head parts forming additional material is expediently Energy is supplied to the hooking heads, for example in the form of UV radiation and / or in the form of heat.

Based on this prior art, the invention has the object to further improve the known solutions while maintaining their advantages, especially at low production costs to provide a functionally reliable adhesive closure, which is adjustable in its wide behavior of its behavior. This object is achieved by a method having the features of patent claim 1 and a device having the features of claim 4.

The method according to the invention serves to produce an adhesive closure part, preferably consisting of at least one plastic material, characterized in that head part material is provided in a molding tool having a multiplicity of individual mold recesses configured in accordance with the respective head geometry, and in that the free ends of the stem parts when approached on or at the time of introduction into the mold recesses touch the at least partially liquid or partially plasticized plant sides of the head parts and / or immerse in the head part material.

By the subsequent placement of separately manufactured head parts on the free end side of the assignable handle parts can be combined in a wide range of different material components of handle parts with headboards and also different geometries for head and / or the handle parts can be defined. Due to the large number of possible combinations, a multiplicity of technical parameters can thus be set for the adhesive closure part produced in this way. The inventive method is also reliable in the application and cost feasible.

As particularly economical to carry out the method, a device has been found in which for the individual head parts a mold is present with a variety of mold cavities corresponding to the respective head geometry and with a feeder for the already finished support member with the handle parts whose free Ends are inserted by means of the feed device in the mold recesses.

A particularly functional and mechanically robust adhesive closure part results then, provided that stem and head parts consist of different plastic materials, in particular the stem parts are formed from a thermoplastic material and the head parts made of acrylate. The relatively hard acrylate material for the respective head part allows a robust Unterhakungsmöglichkeit for the loops of a corresponding adhesive closure part, so that an adhesive closure constructed in this way allows very high adhesion and peel strength values.

Further advantageous embodiments of the solution according to the invention are the subject of the other dependent claims.

Fig. 1

einen Teil der erfindungsgemäßen Herstellvorrichtung; und

Fig. 2 und 3

in Seitenansicht verschiedene Ausführungsformen des herstellbaren Haftverschlussteils.

In the following, the solution according to the invention is explained in more detail using an exemplary embodiment according to the drawing. This show in principle and not to scale representation of the

Fig. 1

a part of the manufacturing device according to the invention; and

FIGS. 2 and 3

in side view, various embodiments of the producible adhesive closure part.

In the following, the inventive method is based on the manufacturing device according to the Fig. 1 explained in more detail. The inventive method is used to produce a designated as a whole with 10 adhesive closure part, in which a band-shaped support member 12 is connected to a plurality of projecting stem parts 14 with individual head parts 16 such that at least a portion of said stem parts 14 whose free ends 18 in touching or immersion plant come with a plant side 20 of each assignable head part 16. When using the method according to the invention it is provided that during the actual connection process of handle parts 14 with the assignable head parts 16, these are still present at least in partially liquid or teilplastifiziertem state and the head parts 16 are completely cured after the connection. The free ends 18 of the handle parts 14 thus touch the still at least partially liquid Anlageseiten 20 of the head parts 16 or even dive preferably in the headboard material in order to ensure the compound in the later cured state of the head parts 16 can.

For the shaping of the individual head parts 16, a mold designated as a whole with 22 is provided with a plurality of individual mold recesses 24, which correspond in terms of their design to the respective head geometry. The mold recesses 24 are part of a circulating in the manner of a conveyor belt forming belt 26, wherein the mold recesses 24 of the upper run are filled with plastic material and the lower run substantially the empty mold recesses 24 leads. The mold recesses 24 are in turn in the transverse and longitudinal direction of the forming belt 24 - in regular or irregular distribution - multiple available.

Furthermore, a feed device designated as a whole by 28 is provided for the already finished carrier part 12 with the handle parts 14, the free ends 18 of which can be introduced into the mold recesses 24 by means of the feed device 28. For this purpose, the feed device 28 has a kind of supply roll 30, from which the stem part closure material can be unwound. About appropriate Pulleys 32, the strip material can perform the mold 22 and the complete adhesive product is at the end on a designated 34 transport roller for further transport wound. For the sake of simplicity, the individual transport and management facilities were omitted; likewise, the heating and cooling devices for the manufacturing device are not shown. However, the transport direction of the mold 22 and feed device 28 is represented by the arrow 36.

As the presentation after the Fig. 1 Further, the mold recesses 24 are open to the outside, so freely accessible from there, wherein for filling the mold recesses 24 of the mold 22, a filling device 38 is used, which, without being specified, may be a conventional extruder application device; however, preferably represents a droplet applicator that does not completely fill the mold recesses 24 to the free edge with plastic material without the mold recesses 24 overflowing. However, the filling device 38 may also be designed in the manner of a doctoring device for the plastic material, with excess plastic material being removable from the upper side of the strip by means of the so-called doctor blade device (not shown).

To produce the firm connection between the handle parts 14 and the head parts 16 again serves a unspecified curing device 40, which is preferably arranged at the end of the connection process, and shortly before the point, as seen in the direction of arrow 36, the finished adhesive product the mold 22 away in the direction of the transport roller 34 is removed. Depending on the plastic material used in each case, the curing device 40 may be a common heat source, but also a UV emitter and the like. If an acrylate material is used for the head parts 16, the curing device 40 is preferably a UV radiation source.

Adhesive closure parts, produced by the method shown using the device described, are enlarged in the FIGS. 2 and 3 reproduced, wherein the head parts 16 as shown in the Fig. 2 are designed to be substantially flat towards their free end side, which allows them to form very narrow or thin-lipped with respect to their environmental edge; unlike the closure solution after the Fig. 3 in which the top side of the head part 16 shown is curved in a convex manner, so that this head part 16 ends towards the surrounding edge 42 with a thicker wall than the solution according to FIG Fig. 2 , Both solutions have in common that the head part 16 consists of an acrylate material, whereas the stem part preferably consists of a thermoplastic material, in particular of polyamide, polypropylene or polyethylene. Other material combinations are possible here.

It is surprising to a person of ordinary skill in the field of closure technology that, for mushroom top closure systems, he can connect any desired head parts 16 to any stem part material 14 in order to be able to offer functional adhesive closures in a wide range of applications. How the particular Fig. 2 shows, not all stem parts 14 need to be provided with a head part 16 and in special cases it would also be possible to provide two and more stem parts 14 with only one head part 16 end (not shown). Furthermore, it would be possible, depending on the design of the mold recesses 24, to provide closure systems which, for example, control the head geometries of the closure elements of Fig. 2 and Fig. 3 combine according to specifiable patterns. Incidentally, it has been shown that very smooth and hard head parts 16 can be obtained with the method according to the invention, which protects the closure as a whole and leads to very long-lasting adhesive closure subsystems.

Depending on the depth of the used mold recesses 24 of the molding tool 22 can also be realized if necessary, different lengths for the stem parts 14, so that then the head parts 16 in different heights in relation to the ribbon-like support member 12 ends. The carrier part 12 itself can also consist of a multi-extrusion layer arrangement or have a film-like, elastically extensible character. The said head parts 16 can form spherically shaped, outwardly smooth shell bodies seen from above; but here are also realizations in polygonal shape, especially in hexagonal shape possible. By using acrylate material for the head parts 16, these also form a kind of edge protection towards their environmental edge 42, which in turn benefits the longevity of the overall closure.

Claims (5)

1. A method for producing an adhesive fastener part (10) made of at least one plastic material,

   - wherein a backing part (12) with a plurality of projecting stem parts (14) is connected to individual head parts (16) such that in at least some of said stem parts (14) the free ends (18) of the latter are in contiguous or embedded contact with a contact side (20) of the respectively assignable head part (16),

   - during the process of connecting the stem parts (14) and the assignable head parts (16) the latter still being at least in the partially liquid or partially plasticised state and the head parts (16) only being completely cured after connection,

   - characterised in that the head part material is prepared in a moulding tool (22) that has a plurality of individual mould recesses (24) configured according to the respective head geometry, and

   - that the free ends (18) of the stem parts (14) come into contact with the still at least partially liquid or partially plasticised contact sides (20) of the head parts (16) and/or are embedded in the head part material when moved towards or introduced into the mould recesses (24).
2. The method according to Claim 1, characterised in that stem parts (14) and head parts (16) are made of plastic materials that are different from one another.
3. The method according to Claim 2, characterised in that the stem parts (14) are formed from a thermoplastic and the head parts (16) are made of acrylate material.
4. An apparatus for producing an adhesive fastener part by means of a method according to any of Claims 1 to 3, a backing part (12) with a plurality of projecting stem parts (14) being able to be connected to individual head parts (16) such that in at least some of said stem parts (14) the free ends (18) of the latter are in contiguous or embedded contact with a contact side (20) of the respectively assignable head part (16), and during the process of connecting the stem parts (14) and the assignable head parts (16) the latter still being at least in the partially liquid or partially plasticised state and the head parts (16) only being able to be completely cured after connection to a curing device (40), characterised in that the head part material can be provided by a filling device (38) in a moulding tool (22) that has a plurality of individual mould recesses (24) configured according to the respective head geometry, that the free ends (18) of the stem parts (14) can come into contact with the still at least partially liquid or partially plasticised contact sides (20) of the head parts (16) and/or the free ends (18) of the stem parts (14) can be embedded in the head part material when moved towards or introduced into the mould recesses (24), and that for the individual head parts (16) the moulding tool (22) is provided with the plurality of mould recesses (24) which correspond to the respective head geometry, and with a supply device (28) for the already finished backing part (12) with the stem parts (14) the free ends (18) of which can be introduced into the mould recesses (24) by means of the supply device (28).
5. The apparatus according to Claim 4, characterised in that the moulding tool (22) is formed by a revolving moulding belt (26) which includes the mould recesses (24) which are freely accessible from the outside.

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