EP1387627B1 - Method for producing a touch-and-close fastener element - Google Patents

Abstract

The invention relates to a method for producing a touch-and-close fastener element comprising a multitude of hook means, which are provided with a support as one piece and in the shape of stems with hook heads located at the ends thereof. Each of the hook heads is provided, at least in part, with an addition head part made of an additional material. A fastener system is produced from the respective head part being made from a duroplastic molding compound serving as the additional material. The fastener system can withstand a high temperature and mechanical stresses and lead to improved adhesion values and peel strength values during use.

Description

The invention relates to a method for producing an adhesive closure part according to the feature configuration of the preamble of claim 1.

From DE 196 46 318 A1 a method for producing a fastener part is known with a plurality of integrally formed with a carrier tape hooking means in the form of thickened stems, said thickenings form the Verhakungsköpfe. In the known method, a thermoplastic material is preferably supplied in a plastic or liquid state, a gap between a pressure roller and a forming roller, wherein the forming roller is provided with outwardly and inwardly open cavities and both rollers are driven in opposite directions, so that the carrier tape in Gap is formed between the rollers. The entangling means, however, are produced in the cavities of the mentioned Siebformwalze. The head shape of the interlocking heads can then be further shaped by a subsequent calendering process. The Verhakungsköpfe thus produced can be circular, cylindrical, plate-like Form heads or the heads are in the form of a plate-like Vielekkes, such as a hexagon formed. If the Verhakungsköpfe consist of a conventional plastic material, such as polyester od. Like., They are particularly sensitive to heat input (heat) and they can also od by scratching. Like. Be damaged so that they are no longer functional.

The hooking heads produced in this way are now used for hooking with the usual Verhakungsschlingen or loops of a corresponding adhesive closure member, which is realized in the pertinent hooking between Verhakungsmitteln and Verhakungsschlaufen both assignable adhesive fastener parts as a whole the re-releasable mechanical adhesive closure. The entanglement occurs in that the loops or loops of the corresponding adhesive fastener part engage under the projections formed between the underside of the hooking heads and the assignable stems which carry such Verhakungsköpfe at its free end, the stems turn integral part of the carrier or carrier tape are. The fact that the hooking heads are formed at its free end or along its surface as a small plate body, however, it happens that during the Verhakungsvorganges the loops of the Verhakungsköpfen down and thus flattened with the result that they are for a successful Verhakungsvorgang not available at all. The same applies to the case that the per se otherwise supersized loops or loop fabric is already flattened from the outset on the associated carrier tape, so that in this respect get the Verhakungsköpfe the other adhesive closure part under hook then difficulties. In these cases, the characteristic of adhesive closures Peel strength values greatly reduced and a detention correspondingly difficult.

In order to counter this effectively, it has already been proposed in the prior art to act so favorably on the head shapes or the head design of the interlocking heads that the described disadvantages are at least partially compensated. Thus, WO 98/57565 shows a known manufacturing method for comparable adhesive closures, in which the stems connected in one piece with the carrier are fed to a narrowing shaping gap, wherein a shaping roller with a closed cylindrical outer periphery flatly presses the stems ends to form hooking heads. The thus produced circular plate-like hooking heads are then provided at their free end, ie along their upper side, with cuts and notches, which means that in the region of the exit points of the cuts or notches in the head material this is weakened so that a kind of earing occurs and The reduced in the material Zipfelstellen are such a way to form a kind of hinge point that they slide past the upright loops or loops and then make the entanglement in the spring back to the initial state. In this way, the peel strength values and thus the adhesion of the corresponding adhesive closure parts to each other can be markedly improved, with the process to be carried out in a multi-stage process being complex and thus cost-intensive. If one applies the known method in very small-building Verhakungsmitteln, which is referred to in the jargon with "micro-closures", this known method, however, hardly applicable because when introducing the notches or incisions in the head material this then intersected and becomes unusable. Also, the head material is again sensitive to heat and scratching.

In another generic method according to EP 0 894 448 A1, by contrast, it has already been proposed to provide the respective hooking head at its free end with an additional head part of an acrylate-comprising adhesive in order to improve the adhesive effect and the peel strength values. The known head parts consist essentially of a so-called. "Hot-melt" pressure-sensitive adhesive, which is composed of acrylate-based. The pertinent adhesive for the head parts should ensure that it arrives in addition to an arrest of the head parts with the loop or loop material due to the adhesive effect also leads to a better attachment of said components of the fastener parts itself. However, it has been found that due to the adhesive property of the patch headers, the loops or loops are simply connected in an adhesive manner with the fastener part with the Verhakungsmitteln and hooking with the Verhakungsmitteln even in the form of Verhakungsköpfe not decisive takes place, so that the arrest essentially determined by the adhesive used itself and not by the choice of the respective Verhakungsmittels. So you may even od in a by baby powder, baby oil. Like. Polluted loop or loop material of the corresponding adhesive closure part for an attachment to the adhesive closure part with the hooking these thanks to the hot-melt adhesive can still use; alone is such an adhesive rather realized than an arrest on the Verhakungsmittel in the form of Verhakungsköpfe itself. Since the arrest thus essentially comes about through the adhesive, but are the achievable so adhesive or

Peel strength values are not considered sufficient. Also, the adhesive headboard can not protect the actual hooking head from heat.

From DE 199 52 417 A1 a further generic method for producing an adhesive closure part is known, with a plurality of hooking means formed with a carrier on one of its two sides, for example in the form of hooks, loops, mushrooms or the like, wherein on the opposite side an adhesive agent is applied. Characterized in that on the side of the carrier with the hooking means at least partially a silicone-containing release layer is applied and cured in the form of silicone acrylate, an adhesive closure member with adhesive means to the effect further improved that can be completely dispensed with the otherwise usual covering material for the adhesive agent.

Characterized in that, according to the characterizing part of claim 1, the thermosetting molding compound as the respective head part for the assignable hooking head forms a protective cap in hemispherical shape completely covers the Verhakungskopf on its top, each assignable hooking head is provided with a hard protective layer, so that the otherwise sensitive Plastic material of Verhakungskopfes is protected accordingly from heat and mechanical damage. It is surprising that the forming a kind of protective cap head made of a thermoset even with a very large heat exposure, which can be several 100 ° C, can ensure the function of the underlying Verhakungskopfes. The thermosetting dimensionally stable thermosetting molding compound is beyond that on its surface so hard that mechanically introduced harmful forces, such as those resulting from scratching, are held by the head so that the actual Verhakungskopf is not damaged. Consequently, also over the header as

Duroplast ensures a high adhesive effect for the adhesive closure part, even under the aforementioned harmful effects.

The head parts, which form a firm connection with the interlocking means can be formed with their protective effect such that they each form a kind of anchor surface, which facilitate the passage of the fastener closure parts, the passage of the loop or loop material at the actual interlocking head, with the result that the Slings or loops do not come to rest on the head material, but then pass this passing by for a Verhakungsvorgang to the fullest available. The latter also applies to the case that the corresponding adhesive closure part itself is provided with hooking means in the form of hooking heads or od of thread-like connecting means. The like. Is constructed. Consequently, there is a marked increase in the adhesive effect or the peel strength values, which also applies in the case where the corresponding entangling means are contaminated by powder or oil or as loop, thread or loop fabric in lying contact on the carrier tape of the corresponding adhesive closure part for the later entanglement are available. Due to the hard thermosetting molding compound, the pending passing through the head part is favored, which in turn leads to good adhesion values for the respective adhesive closure, and this effect also occurs when the hooking heads or the hooking means are geometrically extremely small in order to form a micro-fastener.

In a preferred embodiment of the method according to the invention, it has proved to be favorable to select materials as the starting material for the adhesion-promoting part, such as polyester, polyolefin, polyamide, elastomers and, in particular, thermoplastic urethanes or optionally as far as compatible, mixtures of these materials. Furthermore, crosslinkable acrylates can be used.

In a further, particularly preferred embodiment of the method according to the invention, the interlocking heads are pretreated at least on their tops facing away from the stems in such a way that reactive groups, such as OH groups, are formed, which increase the surface energy with the result that the subsequently applied thermoset filler material is better with the hooking heads enter into a fixed connection. In particular, pretreatments include processes such as heat input by means of flame treatment, but also corona and plasma processes or the application of electrical or electromagetic radiation and corresponding fields. Furthermore, it has proven to be beneficial to fluorinate the tops, resulting in particularly favorable subsequent arrest results with the head parts of thermosetting molding compounds.

In a further preferred embodiment of the method according to the invention, the thermosetting molding composition used is an acrylate material, in particular urethane diacrylate. In addition to a photoinitiator, a reactive solvent can be used with which the viscosity of the acrylate material can be adjusted for the subsequent application process on the Verhakungsköpfe.

In a particularly preferred embodiment of the method according to the invention, the materials forming the head parts are applied to the hooking heads via an applicator roll or by means of another application device. In this way, the head part shape can be obtained cost-effectively.

In a further preferred embodiment of the method according to the invention, the application roller is moved in opposite directions to a conveying roller, which serves to transport the one adhesive closure part, wherein the applicator roll is fed between the application roller and a counter-rotating driven counter-roller of the head parts forming material. As a result, the process can be operated continuously and the application gap between the conveying roller and the applicator roller is selected such that virtually exerting force and thus exerting no additional pressure on the Verhakungsköpfe the respective head part is applied. It is surprising that in the pertinent embodiment and ultimately also due to the surface energy of the acrylate material headboards can be applied to the plate-like interlocking heads, which form quasi a hemispherical shape, which is particularly favorable for the later penetration of Verhakungsmittel in the assignable loop or loop material.

In a further preferred embodiment of the method according to the invention for producing the one adhesive closure part plastic in a plastic or liquid state, a gap between a pressure roller and a forming roller is supplied, which is provided to form the stems and Verhakungsköpfe with sieve-like cavities and thus with the pressure roller a Gap forms that in their opposite direction of rotation of the carrier is formed in the gap. In this way, can be cost-effective to provide a fastener part with the Verhakungsmitteln for later order with the headboards.

In a further preferred embodiment of the method according to the invention, UV light is used to cure the material forming the head parts on the hooking heads. If cold light used is, there is the possibility to stop the manufacturing process, without being damaged by the energy input during curing, the heads of the closure material. Comparable can also be achieved if it is carried out using the ultraviolet light during the curing process in a chamber with inert gas, such as nitrogen.

Fig. 1

ein bekanntes Herstellverfahren zum Herstellen eines Haftverschlußteils als Ausgangsmaterial für das spätere Aufbringen der Kopfteile auf den Verhakungsköpfen;

Fig. 2

das erfindungsgemäße Verfahren zum Aufbringen der Kopfteile auf das nach der Fig.1 hergestellte Ausgangsverschlußmaterial;

Fig. 3 und 4

das nach der Fig.1 erhaltene Verschlußmaterial bzw. das nach der Fig.2 erhaltene mit aufgesetzten kappenartigen Kopfteilen.

In the following the method according to the invention will be explained in more detail with reference to the drawing. This show in principle and not to scale representation of the

Fig. 1

a known manufacturing method for producing a Haftverschlußteils as a starting material for the subsequent application of the head parts on the hooking heads;

Fig. 2

the inventive method for applying the head parts to the starting closure material prepared according to Figure 1;

3 and 4

the closure material obtained according to the Fig.1 or the obtained according to the Fig.2 with mounted cap-like headboards.

FIG. 1 shows a molding roll designated as a whole by 10, on which a wire 12 is mounted. The screen 12 of the forming roller 10 has on its entire circumference cavities 14 which have been etched by means of a galvanic process in a conventional manner. These cavities 14 may have a substantially cylindrical basic shape, as is the case according to FIG. But it can also etched any other forms be, depending on how the geometrical configuration of the interlocking heads is desired. For the sake of simplicity, not all cavities 14 are shown in FIG. 1, but only a section of a multiplicity of cavities, which, moreover, do not only extend within the plane of the drawing, but also perpendicular thereto in a multiplicity of further planes, not illustrated in greater detail.

To produce the one adhesive closure part 16 in a single operation, a plastic material in a conventional manner in the plastic or liquid state by means of a feeder 18 in the form of an extruder the gap 20 between a pressure roller 22 and the forming roller 10 is supplied. As the arrow representations in Fig.1 occupy, the pressure roller 22 and the forming roller 10 are driven in opposite directions, so that the released from the extruder plastic can penetrate into the gap 20 and thereby flow into the underlying cavities 14. In this case, a carrier 24 forms in the gap 20, which can be designed in the manner of a band or a larger foil surface. With this carrier 24 then formed in the cavities 14, designated as a whole with 26 interlocking means are integrally connected. The pertinent hooking means 26 consist of individual stems 28 (see Fig. 3), at whose free end the plate-like interlocking heads 30 are present. In order to form the head shapes, the hooking heads 30 can also be subjected to a so-called calendering process (not shown in detail) after the shaping according to the illustration according to FIG. 1, in which a calendering roll takes over the alignment of the upper sides of the hooking heads 30. Depending on the cross-sectional shapes of the cavities 14, the hooking heads can form cylindrical, but also polygonal, in particular hexagonal or octagonal outer contours (not shown). Depending on the shaping process have the Verhakungsköpfe In addition, on their free upper side cavities or depressions 32.

It is customary to form the carrier 24 in a thickness of 0.05 mm to 0.3 mm, preferably between 0.1 mm to 0.2 mm, wherein the number of entangling means depending on the application, 50 to 500 hooking heads per cm ² usually provides. The starting material for the adhesive closure part 16 may be materials such as polyester, polyolefin, polyamide, elastomers and thermoplastic urethanes or mixtures thereof. Furthermore, crosslinkable acrylates can be used.

The adhesive closure material obtained according to FIG. 1 is reproduced in an enlarged view in FIG. Now, if the fastener member 16 (not shown) to form a non-illustrated conventional adhesive fastener with the loop or loop material of a corresponding adhesive closure member connected, it is obvious that individual loops or loops on the top of the plate-like head material according to Fig.3 lie come and then no longer available for a Verhakungsvorgang available by the single loop or loop engages the respective associated Verhakungskopf 30 on its underside 34 and thus makes the entanglement. To improve this initial state is now the method of the invention. In order to improve the adhesion with the mentioned loops or loops of a non-illustrated corresponding adhesive closure member is provided by the method according to the invention that the interlocking heads are provided with an additional head 36 of a material subsequently, which consists of a thermosetting molding material.

The respective head part 36 is thus formed from a non-adhesive and dimensionally stable thermosetting material (thermosetting resin). The heat-resistant hard and lubricious thermoset material ensures on the one hand the protection of the actual Verhakungsköpfe from damage from the environment and on the other hand, the Verhakungsmaterial of the other corresponding adhesive closure member, for example in the form of loops or loops slide past the thermosetting head part, which facilitates the Verhakungsvorgang and such a high Adhesive forces and peel strength values leads, since due to the slidable design of the thermoset material, the interlocking material of the corresponding adhesive closure part no longer comes to rest on the headboards.

In order to achieve a good adhesion between the hooking heads 30 and the head parts 36, the formation of reactive groups, such as, for example, OH groups, is carried out on the respective free upper sides of the interlocking heads 30, which leads to an increase in the surface energy, with the result that the thermoset head parts 36 firmly connect to the hooking heads 30. In this case, it may be provided, in particular, to suspend the free upper sides of the interlocking heads 30 with a thermal treatment method, such as flaming. Furthermore, plasma processes or so-called corona processes can be used. Another possibility is to fluorinate the hooking heads 30.

1. 1. 60 Teile EBECRYL EB 483S (hartes, oligomeres Urethan Diacrylat);
2. 2. 30 Teile EBECRYL EB 230 (weiches, oligomeres Urethan Diacrylat);
3. 3. 8 Teile reaktives Lösungsmittel, beispielsweise HDDA (monomeres Diacrylat) und
4. 4. 2 Teile Photoinitiator, beispielsweise DAROCURE DC 1173.

As a thermosetting molding composition, an acrylate material, in particular in the form of urethane diacrylate, can be used, wherein a reactive solvent can be added to adjust the viscosity. In addition, the curing process for the thermosetting molding composition can be controlled, in particular accelerated, by means of a photoinitiator. A possible Recipe is as follows, with the usual, sometimes trademarked trade names are given:

1. 1. 60 parts EBECRYL EB 483S (hard, oligomeric urethane diacrylate);
2. 2. 30 parts EBECRYL EB 230 (soft, oligomeric urethane diacrylate);
3. 3. 8 parts of reactive solvent, for example HDDA (monomeric diacrylate) and
4. 4. 2 parts of photoinitiator, for example DAROCURE DC 1173.

The materials forming the head parts 36 are, as shown in particular in FIG. 2, applied to the interlocking heads 30 via an application roller 38. The pertinent applicator roller 38 is moved in opposite directions to a conveying roller 40, which serves to transport the one adhesive closure member 16, wherein the head 36 is formed material of Aüftragwalze 38 is supplied between the applicator roll 38 and a counter-rotating roller 42 driven in the same direction. Since the acrylate material has a similar consistency and viscosity as honey, it forms a kind of application bath 44 between the application roller 38 and the counter-roller 42 and can there successively discharged from the applicator roller 38 and passed to the adhesive closure member 16. The application bath 44 can, as indicated by the arrow in FIG. 2, be refilled in accordance with the quantities withdrawn by a feeding device (not shown).

The design of the gap between applicator roller 38 and conveyor roller 40 including the rotational speeds of these rollers and their substantially equal diameter is chosen such that no additional pressure on the Verhakungsköpfe 30 is formed, as far as the acrylate material is applied over the applicator roll 38. The surface tension, in particular of the acrylate material, is then chosen such that a kind of drop formation is achieved with the result that, as shown in particular Fig.4 illustrates the head portions 36 hemispherical caps. For better illustration, the head parts 36 are shown hatched in Figure 4; In reality, however, can be seen on the subsequently finished closure material hardly a difference between the subsequently applied head parts 36 and the starting material of a fastener part 16, as it results after the preparation according to the Fig.2.

If a loop or a loop of the corresponding adhesive fastener strikes the end caps of the head parts 36, they can not come to rest there, but slide laterally off the rounded surfaces until they reach the region of the undersides 34 of the interlocking heads 30 and snag there securely , In this way, a kind of penetration aid is provided, which leads to improved adhesion and peel strength values, so that the entanglement is improved even if the loops are no longer erect in the corresponding adhesive closure part, but already in lying contact with the top of the carrier are. Due to the good sliding property of the selected hard thermoset material, the pertinent sliding process but at least partially also when the head part 36 is formed as a flat plate (not shown).

To cure the pertinent head portions 36 is a curing device 46, which is provided for example with a UV lamp 48. The UV light can also be used in the form of a cold light or the like.

If the Verhakungsköpfe 30 on their upper side, the recesses 32, penetrates into the cavities additionally thermoset molding compound of the head parts 36, which is the arrest with the Verhakungsmitteln 26 yet further improved. Even in the event that the loop or loop material is dirty, coated for example with baby powder, the pertinent sliding is not affected by the pollution, so that even in such cases, a significantly improved adhesion to known solutions is achieved.

Claims (9)

1. Method for producing an adhesive closure part (16) with a multitude of hook-up means (26) in the form of stalks (28) comprising hook-up heads (30) at their ends and forming a single piece together with a carrier tape (24), whereby the hook-up heads (30) are each equipped with an additional head part (36) consisting of an additional material at least in part, whereby the relevant head part (36) is formed from a duroplastic form mass as the additional material, characterised in that the duroplastic form mass of the relevant head part (36) forms a protective cap with a semi-spherical shape for the associated hook-up head (30), which completely covers the upper surface of the hook-up head.
2. Method according to Claim 1, characterised in that polyester, polyolefin, polyamide, elastomers, as well as thermoplastic urethane or mixtures of the same are used as the base material for an adhesive closure part (16).
3. Method according to Claim 1 or 2, characterised in that the hook-up heads (30) are pretreated at least on their surfaces that face away from the stalks (28), for example with an open flame, with a corona or plasma process, with electric or electromagnetic rays and fields, or by means of fluoridation.
4. Method according to one of the Claims 1 to 3, characterised in that an acrylate, especially urethane diacrylate, serves as the duroplastic form mass.
5. Method according to one of the Claims 1 to 4, characterised in that the duroplastic form mass is equipped with a photo initiator and/or with a reactive solvent.
6. Method according to one of the Claims 1 to 5, characterised in that the additional materials forming the head parts (36) are applied to the hook-up heads (30) by means of an application cylinder (38).
7. Method according to Claim 6, characterised in that the application cylinder (38) is moved in the opposite direction to a conveying cylinder (40) serving to transport one of the adhesive closure parts (16), and in that the additional material of the application cylinder (38) forming the head parts (36) is supplied between the application cylinder (38) and the counter cylinder (42) being driven in the same direction.
8. Method according to one of the Claims 1 to 7, characterised in that a plastic material is supplied into a gap (20) between a pressure cylinder (22) and a forming cylinder (14) in a plastic or liquid condition for producing one adhesive closure part (16), being equipped with sieve-like hollows (14) for forming the stalks (28) and the hook-up heads (30), and forming the gap (20) with the pressure cylinder (22) in this way, so that the carrier (24) is formed in the gap (20) during rotation of the same in the opposite direction.
9. Method according to one of the Claims 1 to 8, characterised in that energy is supplied to the hook-up heads (30) for curing the additional materials forming the head parts (36), for example in the form of UV radiation and/or in the form of heat.

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