WO2009076920A1

WO2009076920A1 - Method and device for bonding textile material

Info

Publication number: WO2009076920A1
Application number: PCT/DE2008/001889
Authority: WO
Inventors: Erwin Glawion
Original assignee: Fleissner Gmbh
Priority date: 2007-12-18
Filing date: 2008-11-14
Publication date: 2009-06-25
Also published as: WO2009076920A8

Abstract

The invention relates to a method for bonding textile material, which comprises consolidated fibres in the form of fibre bundles, filaments or the like, wherein a molten thermoplastic hotmelt adhesive is applied to one side of the textile material. The invention envisages the use of a hotmelt adhesive which, on account of its low viscosity, penetrates into the consolidated fibres or the fibre bundles at the intended processing temperature by capillary action.

Description

Method and device for solidifying textile material

The invention relates to a method and a device for

Implementation of the method for solidifying textile material according to the preamble of the method or device claim.

In the production of a carpet in the tufting process, the fibers forming the pile are introduced into a carrier layer, and the pile naps or pile loops on the back of the carpet subsequently have to be fixed. For this it is known to coat the back with latex material. Furthermore, it is known to apply a plastic to fix the anchoring of the tufts on the back of the carpet. It is also possible to attach another layer as a second back to the back. A method for the backcoating of a carpet is known from 10 2005 060 450 A1.

From WO99 / 35327 a multilayer carpet back construction is known. In one of the layers, heat-expandable microspheres are incorporated in a thermoplastic material.

DE 198 60 256 A1 describes the structure and function of a twin-screw extruder, which can be used in the present invention.

The object of the present invention is to further develop a known method and a corresponding device. This object is achieved by the features of the method or device claim. Advantageous developments of the invention will become apparent from the dependent claims.

According to the invention, it is provided that a hot-melt adhesive is used which has such a low viscosity in the processing state that it can only penetrate through the capillary action into the fiber material of at least part of the textile material which is preferably present in bundles or at least partially compacted , Preferably, the viscosity of the molten thermoplastic hot melt adhesive is less than 5 Pas. The hot melt adhesive is thus brought to a temperature at which it has the intended for penetration into the fiber material viscosity.

Depending on the type of fiber (density of the bundle of threads, yarn or type of thread), the temperature curve (course of the temperature over time) of the adhesive is controlled so that it completely into the fiber bundles, the threads of the fabric by thermal post-processing of the applied hot melt adhesive can penetrate. The thermal post-treatment / post-treatment can be influenced by appropriate control of a belt furnace (setting of the individual heating zone sections), by radiant heaters (infrared radiators) or combinations thereof. The temperature post-treatment can also be carried out in a belt dryer or a flat tensioning frame or in a drum dryer or a round clamping frame.

The invention is preferably applicable for the consolidation of pile loops in a back of the carpet. It can be done as well

Woven carpets or other fabrics but also densified nonwovens and composite composites with the adhesive application of the invention or solidify. By selecting the Properties of the adhesive as a function of the fiber material can be realized with the invention a variety of applications.

Thus, it is possible to use in a fabric consisting of weft and warp threads of different fiber material, an adhesive that penetrates at the intended temperature in the one type of fiber, in the other, however, does not or only superficially surrounds.

As a hot melt adhesive, a liquid to be processed plastic can be used, which is applied liquified to processing temperature. Preferably, the hotmelt adhesive is provided in the form of granules and processed by means of a heated twin screw extruder. The extruder melts and processes the plastic granulate.

The advantage of the twin-screw extruder lies in the fact that, especially at the processing temperature, low-viscosity adhesives can be processed with a good degree of efficiency, ie with high delivery rates. The addition of aggregates is also particularly advantageous with a twin-screw extruder.

By one or more feed pumps downstream of the extruder, the liquefied hot-melt adhesive is fed to an application device and then applied to the material web to be processed.

According to a preferred embodiment of the invention, it is further provided that the hot-melt adhesive is applied in the molten state via a nozzle which extends over the entire width of the material or of the carpet backing. It is also advantageous that the nozzle is designed as a slot nozzle and has an outlet gap, so that the adhesive is applied across the width of this nozzle.

It is also advantageous that the exit slit has an exit slit thickness (distance of the lips of the exit slit) between 0.2 and 2 mm.

It is also possible to use a plastic to be applied in powder form, which is liquefied after application by heat input and thus penetrates into the fiber bundles, the compacted fiber regions.

It is furthermore advantageous if the application takes place with a basis weight of between 50 and 500 g per m ² .

Advantageously, the invention, if the textile material is subjected to a corona treatment before applying a hot melt adhesive, by which the wettability of the material is positively influenced by the adhesive.

Furthermore, it is advantageous that the textile material and preferably the back of the carpet or the woven carpet is heated before the application of the hot melt adhesive.

Preferably, the hot melt application takes place in a region in which the textile material or the carpet is conveyed fixed by a tenter. It can be provided that the fixation is carried out by the clamping frame in direct connection to the hot melt adhesive application.

According to a particularly preferred embodiment of the invention, provision can be made for the hot melt adhesive or the starting material of the hotmelt adhesive (the granulate) to be admixed. Substances are mixed. This is done in an advantageous manner by supplying the intended substances within the twin-screw extruder. This causes by the mechanical work of the rotating screw, the melting of the plastic granules while mixing in the intended additives.

As an additive can be provided according to an embodiment of the invention, a the properties of the hot melt adhesive not influencing extender. Primarily the processing properties of the hot melt adhesive should not be adversely affected. The use of a cost effective extender makes it possible to reduce the proportion of hot melt adhesive and thus to reduce the cost of the coating as a whole. At the same time, a designated minimum order per area can be achieved. By means of a suitable additive (high density), it is also possible to increase the basis weight of the coating and thus of the coated goods, even given a given coating volume (layer thickness). Particularly in the case of carpets (carpet), a high weight per unit area increases the quality.

It can be used powdered calcium carbonate (chalk) or aluminum hydroxide. The use of aluminum hydroxide gives the additional advantage of a flame retardant effect (flame retardant) by the hot melt application.

Through the use or the additional admixture of electrically conductive substances, in particular in the form of short fiber elements, the coated web material can be prepared against static charges. This is particularly advantageous in the case of web material in the field of carpet flooring. As fibers, portions of carbon fibers can be used. It can also be provided that expandable gas-filled microspheres are used as an additive by the action of heat, the activation temperature of which is preferably above the melting temperature of the hot-melt adhesive. The activation of the microspheres then takes place by a heat treatment of the coated web at a temperature at which the microspheres are activated. This can be done by a downstream of the hot melt adhesive band furnace.

The activation temperature of the microspheres admixed as an additive may also be selected such that they are already activated in the region of the slot nozzle during application to the material web, and the hotmelt adhesive is thus applied in the form of a foam.

As a further development measure, provision is made for a further layer in the form of a woven fabric, a nonwoven or a second backing to be applied to the textile material or the backing prior to solidification of the molten thermoplastic hot melt adhesive.

In this case, it is advantageous if a hot melt adhesive is used for solidifying the textile material or the carpet, the properties of which are optimally adapted to the hardening effect to be achieved. The melt adhesive temperature selected for penetration into the fiber bundles in conjunction with the thermal aftertreatment described above thus effects the fastest possible penetration of the adhesive into the structure. For the application of a further layer or the second back, another adhesive is now used, the function of which is to fix the further layer or the second back. This additional adhesive can therefore have a significantly higher viscosity, since this only needs to be applied to the threads or pile loops penetrated by the first adhesive. zen, but does not have to penetrate it.

The equipment of a carpet by means of a second back offers the possibility here that a mixture of a further thermoplastic hot melt adhesive and heat-expandable gas-filled microspheres is applied to the secondary backing and the first still molten thermoplastic hot melt adhesive. These microspheres are foamed directly by another heat treatment and cooled together.

As a device according to the invention it is provided that adjoins the device for the hot melt adhesive application means for heating and / or cooling at least the back of the textile material or the carpet. If the textile material or the back side of a carpet still undergoes a heat treatment after the hot melt application, the time in which the hot adhesive, which has been heated by heating to a low-viscosity state, can penetrate into the fiber material of the threads or pile loops is increased.

The textile material or the carpet is preferably conveyed by means of a tenter through the furnace and / or the cooling section. This measure is particularly advantageous if a shrinkage of the textile material or of the carpet is to be expected by a subsequent to the hot melt application heat treatment or by the application of adhesive itself.

The invention is particularly advantageous if the device for hot melt adhesive application in the region of the guidance of the textile material or of the carpet is arranged by the tensioning ram or if the material or the rug is directly in contact with it. At the end of the hot melt application is taken over by the clamping frame.

Furthermore, the explanation of embodiments with reference to the drawings.

FIG. 1 shows a first embodiment of the invention, in which a carpet 1 processed in a preceding inking station, not shown, is guided over a drying drum 2 with a round clamping frame. A device C for corona treatment is arranged upstream of a slot nozzle 5. Via the slot nozzle 5 is applied to the back of the carpet 1 to a designated temperature heated thermoplastic (hot melt adhesive). The slot nozzle is assigned to a region in which the carpet 1 is conveyed vertically upwards. The hotmelt adhesive has such a low viscosity at the appropriately selected processing temperature that it can penetrate into the fibers of the pile loops by virtue of the capillary action.

Immediately following the hot melt application 5, the carpet 1 is conveyed after being deflected by a cooling section 14. The transport of the carpet 1 through the cooling section 14 is effected either by means of a circulating belt or, if shrinkage of the carpet 1 can not be ruled out by the temperature effect of the hot melt adhesive application 5, by means of a tentering frame 17. Depending on the air permeability of the carpet 1, the cooling takes place by means of blown air and / or air sucked through the carpet material.

Subsequent to the cooling section 14, the web of the carpet 1 passes through a goods storage 15 with a plurality of movably mounted deflection rollers, before the carpet 1 is received on a winder 16. FIG. 15 shows the hotmelt adhesive application 5 designed as a slot nozzle, to which a hot melt adhesive prepared by a heated twin-screw extruder 26 is fed via a feed pump 29. Depending on the width of the slot 5, one or more distributors together with feed pumps are arranged here.

The twin-screw extruder 26 is assigned a storage container 27 for charging with the hot-melt adhesive material present as granules. Furthermore, a further storage container 28 is provided, via which the twin-screw extruder 26 an additive can be supplied. In the twin-screw extruder 26, the granules of the hot melt adhesive are melted and mixed with the additive present as powder and supplied.

The arrangement described here (FIG. 15) can also be used in the other embodiments described below.

In the embodiment according to FIG. 2, the carpet 1 is guided over a drying drum 2 with round clamping frames as described above. A hot melt adhesive application on the back of the carpet 1 takes place via a slot die. A secondary backing 9 arranged on a roll 8 is placed on the back of the carpet 1 covered with the hot melt adhesive and applied by the pressure of the pressure roll 9 ironed this. The occupied with the secondary backing carpet 1 is conveyed through a circulating belt or a tenter through a belt furnace 6 with subsequent cooling section 14. In the belt furnace 6 as well as in the cooling section 14, the heating or cooling of the carpet-second backbone composite takes place by means of blowing or blowing air. In the belt furnace, a heat treatment can be carried out by means of infrared radiators. As in the exemplary embodiment according to FIG. 1, the web of the carpet 1 passes through a goods store 15 with a plurality of movably mounted deflection rollers before the carpet 1 is received on a winder 16.

In FIG. 3, a carpet 1 rolled up on a roll 3 is provided. The carpet 1 thus has ambient temperature. By means of infrared heating, the back of the carpet 1 is preheated. In the upwardly directed conveying region of the carpet 1, two slot nozzles 5, 7 are arranged successively, through which preferably two differently viscous hot melt adhesives are applied to the back of the carpet. Preferably, by means of the slot nozzle 5, the application of a low-viscosity hot melt adhesive, which is able to penetrate into the fibers of the pile loops due to its low viscosity at the processing temperature. Via the second slot nozzle 7, a higher-viscosity hot-melt adhesive is applied, which serves to fix a second backing provided on a roll 8 and placed on the back side of the carpet 1 via a pressure roller 9. Subsequently, carpet 1 with applied secondary backing pass through a belt furnace 6 and a cooling section 14 on a circulating belt 17 or a tenter frame.

The embodiment according to FIG. 4 is also based on a carpet 1 provided on a roll 3, which has an ambient temperature. The rear side of the carpet 1 is preheated by means of infrared heating 4, via a slit nozzle 5 arranged in the upwardly directed part of the carpet support, a hot melt application is effected in a temperature range which gives the hotmelt adhesive a viscosity which is so low that the latter becomes moist due to the capillary action Polschlingen penetrates. Via a circulating belt 17 or fixed by a tenter frame, the carpet 1 passes through a belt furnace 6 with the hot melt adhesive applied on the back. This application of heat prevents too rapid a cooling of the applied melt fabric, which thus has a greater contact time with the fibers penetrate the pile loops.

A further preferably higher-viscosity hot melt adhesive is applied via a slot nozzle arranged downstream of the belt furnace in order to directly impose a secondary backing provided on a roll 8 via a pressure roller 9 on the back side of the carpet 1. Before the carpet 1 is fed together with applied second back on the goods storage 15 the winder 16, the carpet 1 is still running over a cooling section 14th

The embodiment of the invention according to FIG. 5 corresponds to that of FIG. 4. Here, however, microspheres expandable by the action of heat are applied to the outside of the secondary backing following application of the secondary backing via the pressure roller 9 via a spreading application. By means of infrared heating 12, the unexpanded microspheres 11 are expanded - the outer side of the second back undergoes a damping layer through these expanded microspheres 13, which also results in a skid resistance.

Figures 6 a) - c) show a fiber bundle 18 with a glue application according to the prior art. The bundle of fibers 18 is applied from the side of the adhesive application (from above) with a quantity of adhesive 19. The adhesive 19 encloses the fiber bundle 18 either completely (FIG. 6 c) or only partially (FIG. 6 b), depending on the quantity applied. By the property of the used

Adhesive 19 and the nature of the order encloses this, however, the fiber bundle 18 only externally - according to the schematic diagram of Fig. 6 b) and 6 c), only the outer fibers 18 are fixed. Done over the adhesive 19 a fixation with, for example, another layer of material, so transferred just at a partial sheathing of the outer fibers 18 (Fig. 6 b)) the forces unfavorable to the overall fiber composite (the thread). The inner fibers are not sticky and can easily be released from the composite.

According to the invention it is provided that an adhesive 20 is used, which penetrates into the composite of the fibers 18 (the fiber bundle) due to its viscous properties in connection with the intended processing. According to the order dosage

(Slot nozzle 5, 7) and the thermal loading after the adhesive application - control of belt furnace 6, cooling section 14 and other in the embodiments of Figure 1-5 not shown facilities - arise in the figures 7a) - 7c) in principle illustrated situations. According to FIG. 7 a), a relatively small application of adhesive was selected, the adhesive 20 has completely penetrated into the bundle of fibers 18 (similar to an impregnation). The fiber bundle 18 (the thread) thus substantially retains its original structure on the outer surface, but is reinforced and stiffened by the adhesive 20 in its interior. As a result, a significantly increased tensile and abrasion resistance can be achieved.

According to FIG. 7b), the amount of adhesive in the metering is selected such that the adhesive 20 surrounds the fiber bundle 18 even in a small layer thickness on its outer surface. This provides, in addition to reinforcement and stiffening, a kind of protective layer around the complete bundle 18. The outer structure of the fiber bundle 18 (the filament) is maintained, which is e.g. may be necessary in view of appropriate steps in the finishing.

A very high adhesive application results in a complete encapsulation of the fiber bundle 18. This is shown in principle in Figure 7 c). This complete encapsulation of the fiber bundle 18 thus results in an optimum Male prerequisite for a bond of the fiber bundle 18, for example, with another layer (secondary backing).

FIGS. 8a) -c) show, in principle, three phases of the adhesive application according to the invention. FIG. 8 a) shows the situation directly after the adhesive application. Corresponding to the thermal aftertreatment (e.g., belt furnace, infrared radiator), the adhesive 20 penetrates from the application side into the fiber composite 18 (Fig. 8b) until finally the fully penetrated situation according to Fig. 8c) is reached. The amount of adhesive application, the application temperature, the processing speed and the type and strength of the thermal post-processing are adapted to the properties of the adhesive and the type of fibers, the fiber composite, the thread.

FIG. 9a), b) and c) each show a pile loop 21 in a carrier layer 22 of a carpet. To consolidate the backing 22, an adhesive 20 is applied, wherein an amount of adhesive that is too small (FIG. 9 a) results in only internal hardening of the fibers 18 of the pile loops 21. An adhesion of the pile loops 21 to the carrier layer 22 is carried out only to a very small extent. Fig. 9b) shows the ideal situation that can be achieved by the method according to the invention. The fiber composite of the pile loop 21 is completely saturated, at the same time the pile loop 21 is bonded to the support layer 22 (the back of the carpet). If the application of adhesive is too high, the applied adhesive 20 also penetrates the carrier layer 22 as far as the visible side, which in particular can lead to an optical impairment.

FIG. 10 shows a cross section through a fiber bundle 18, which is penetrated by hotmelt adhesive 20 in the manner described above. By applying a second adhesive 23, as has been described in particular with reference to FIGS. 3 to 5, the basis for applying a second back 24 is thus created, which is shown in FIG. 11 is shown. To fix the second back 24 so an adhesive 23 can be used, which is optimally adapted in its properties to this task.

Figures 12 and 13 show a further application of the method according to the invention. In principle, a fabric 25 consisting of weft and warp threads of a fabric or fabric is shown. Webteppichs. The adhesive application results in a penetration of the adhesive into the warp and weft threads (the fiber bundles of the respective threads), which results in impregnation and solidification of the fabric (FIG. 12). By applying a further adhesive 13, a further solidification of the fabric 25 can be achieved. The order of the further adhesive 23 can also serve to apply a further layer (fabric, nonwoven fabric).

In order to estimate how quickly an adhesive of given viscosity (at the processing temperature) penetrates into the fiber bundles, the threads of the fabric, the physical relationship can be used for the rise height resulting from the capillary forces as well as the suction speed. The following applies:

Suction speed: climbing height:

V = KT exactly

r Capillary radius in mm H Steighhe. "mmx Rising height in mr Capillary radius in mm η Viscosity in Ns / m ² Θ Wetting angle σ Surface tension- 'in N / m σ Surface tension • in N / mp Density in kg / m ³ p Density in kg / m ³ g gravitational acceleration (10 m / g ² ) g gravitational acceleration (10 m / g ² )

The capillary radius r here is the radius of the effectively resulting capillary between the fibers in a fiber bundle, in a thread. The time required for complete penetration is thus lower for a lower viscosity adhesive than for a higher viscosity adhesive. The thermal aftertreatment (exposure time) of a hot melt adhesive which penetrates the fiber bundles quickly and the threads is therefore lower than with a high-viscosity adhesive. Accordingly, the processing line is to be dimensioned. The suitability of a fiber bundle or a fabric for impregnation with the corresponding adhesives can be determined by a simple rapid test. For this purpose, immerse the tissue or fiber bundle in water and determined after a minute, the height of rise of the water in the tissue or fiber bundle. If it is more than 3 mm, the fiber bundle or fabric is suitable for impregnation according to the invention.

FIG. 14 shows the dependence of the viscosity of three different thermoplastic hot melt adhesives SKi, SK2 and SK3 on the temperature. The viscosity range below 5 Pas, which is relevant according to the present invention, is highlighted dark.

SKi is a very low-viscosity hot-melt adhesive which has a very low viscosity in the region of the processing temperature and has good penetration properties, but also remains very soft at normal temperature, ie in the cured state, and therefore does not give stable solidification.

SK2 is a hot-melt adhesive that has a viscosity of less than 5 Pas in the processing temperature range, but has sufficient hardness in the cured state for stable solidification.

SK3 is an ideal hot melt adhesive for applying, fixing a second layer, a second back. Its high viscosity also penetrates the processing temperature range of the hot-melt adhesive SK2 this only to a very small extent by the fabric of a carpet backing layer, so that disturbing phenomena on the visible side of the carpet can be excluded. Therefore, the careful selection of a suitable hot-melt adhesive and the corresponding adjustment of the processing parameters are always required to fulfill a specific task.

LIST OF REFERENCE NUMBERS

1 carpet

2 drying drums (with round clamping frame)

3 roll (unwinder carpet 1)

4 infrared heating

5 slot nozzle

6 band furnace

7 slot nozzle

8 roll (unwinder secondary backing)

9 pressure roller

10 scattering order (microspheres)

11 microspheres (not expanded)

12 infrared heating

13 microspheres (expanded)

14 cooling section

15 goods storage

16 winder

17 conveyor belt / tensioning frame (chain)

18 fiber / fiber bundles / thread

19 glue

20 glue

21 pole loop

22 carrier layer / carpet backing

23 glue

24 second back

25 tissue

26 twin-screw extruder

27 stock granules (hot glue)

28 stock additive

29 feed pump

Claims

claims

1. A method for solidifying textile material, in particular a carpet backing or a woven fabric, wherein the textile material comprises compressed fibers in the form of fiber bundles, threads or the like, wherein on one side of the textile material, a molten thermoplastic hot melt adhesive is applied, characterized by the use of a hot-melt adhesive which penetrates at the intended processing temperature due to its low viscosity by the capillary action into the compacted fibers or fiber bundles.

2. The method according to claim 1, characterized in that the product is warmed up before the order of the hot melt adhesive.

3. The method according to claim 1 or 2, characterized in that the goods before the application of the hot melt adhesive is subjected to a Corona treatment.

4. The method according to claim 1, 2 or 3, characterized in that the goods after the application of the hot melt adhesive undergoes a temperature treatment.

5. The method according to any one of the preceding claims, characterized in that before the solidification of the molten thermoplastic hot melt adhesive, a further layer is applied.

6. The method according to any one of the preceding claims, characterized in that after application of the first hot melt adhesive, a further adhesive for fixing a further layer is applied.

7. The method according to claim 1, characterized in that fiber bundles or tissue are used, in which the height of rise of water in the fiber bundles or the tissue is at least 3 mm within the first minute.

8. The method according to claim 5, characterized in that a mixture of a further thermoplastic hot melt adhesive and heat-expandable gas-filled microspheres is applied to the second layer and the first still molten thermoplastic hot melt adhesive.

9. The method according to claim 8, characterized in that these microspheres are foamed directly by a further heat treatment and then cooled together.

10.Verfahren according to any one of the preceding claims, characterized in that the hot melt adhesive before application to the textile material, an additive is admixed, by which the processability of the hot melt adhesive and / or the optical properties of the coating and / or the electrical properties of Coating and / or the basis weight of the coating can be influenced.

11.Verfahren according to claim 10, characterized in that the aggregate has heat-expandable gas-filled microspheres.

12. An apparatus for carrying out the method according to claim 1, comprising means for applying a hotmelt adhesive to a side of a textile material which comprises compressed fibers in the form of fiber bundles, threads or the like, characterized by the means (5) for application of hot melt adhesive immediately downstream of a device for heat treatment (6) and / or a cooling section (14).

13. The apparatus according to claim 12, characterized by, the means for heat treatment (6) and / or the cooling section (14) is associated with a clamping frame.

14. The apparatus according to claim 12, characterized by, the means (5) for the application of hot melt adhesive is arranged in an area in which the goods (1) in a clamping frame (17) is held.

15. The apparatus according to claim 12, characterized by, the means (5) for applying hot melt adhesive is immediately downstream of the clamping frame (17).

16. Device according to one of claims 12 - 15, characterized by the means (5) for the application of hot melt adhesive is assigned a further application device (7) for applying an adhesive with a different viscosity.

17. Device according to one of claims 12-16, characterized by, the device (5) for applying hot melt adhesive is a device for heating the goods (1), preferably an infrared heating (4) vorgebrdnet.

18. Device according to one of claims 12 - 17, characterized by, the means (5) for the application of hot melt adhesive is a device for placing a further layer (8) arranged downstream.

19. The apparatus according to claim 18, characterized by, the means for placing the further layer (8) is a

Device (7) upstream of the order of a further hot melt adhesive.

20. The apparatus of claim 18 or 19, characterized by, between the means (5) for applying hot melt adhesive and the means for placing the further layer (8), a furnace (6) is arranged. 2. I device according to claim 20, characterized by, the means for applying a second layer (8) is a

Means (10) downstream of the order of thermally activated microspheres (11).

22. The apparatus according to claim 21, characterized by, the means (10) for the application of thermally activated microspheres (11) is a device for heating the back of the goods (1), preferably an infrared heating (12) arranged downstream.

23. The apparatus according to claim 12, characterized by, the means (5) for applying hot melt is arranged upstream of a corona treatment device.

24. The device according to claim 12, characterized by, the means (5) for the application of liquid hot melt adhesive is preceded by a twin-screw extruder.