EP1728902A1 - Method and apparatus for manufacturing artificial grass - Google Patents

Abstract

In a process to make artificial turf, a feed of polymer strands passes between a pair of heated galettes (11, 12) where it is tautened and texturized prior to release to a chilled galette (14) and wound onto a drum. The texturizing process takes place in a jet chamber (13) immediately prior to the chilled galette. The air jet impinges on the heated polymer strand as it emerges via a guide channel from the chamber. The guide channel has apertures through which cooling air is drawn. The wind-on speed is 100-500 m/min, and the extrusion speed is 5-35% higher than the wind-on speed. The strands are stretched by 5-20% between the two galettes. The polymer is e.g. a polyamide, polypropylene, or linear low-density polyethylene. The polymer strips are 0.5-1.5 mm wide and have a linear density of 250-1200 dtex. also claimed is a suitable artificial turf processing assembly.

Description

Technical area

The invention describes a method and an apparatus for the production of textured filament tapes for artificial grass, wherein these tapes are stretched between two heating godets and then textured and the textured filament tapes are peeled off over a cooling godet and then wound up.

State of the art

For texturing of thermoplastic polymer fibers usually the false twist method is used. Moreover, for the production of fibers for artificial grass and the Zahnradkräuseln is common.

From the textbook "Synthetic Fibers" by Franz Fourne, a draw texturing method is known in which a compression chamber is used, in which a cooling zone is provided (see page 433, Figure 4.255, right image section).

The texturing of threads by means of a stuffer box is also out DE 21 42 652 and DD 221 214 known.

For the production of crimped fibers, the knit-fixing method (Knit-Deknit method) is used. EP 0 263 566 describes the production of crimped polypropylene fibers for artificial turf using the Knit-Deknit method. However, the degree of texturing is limited in these methods.

Out DE 38 00 773 For example, there is known a method of crimping an extruded yarn in which the extruded yarn is first stretched by two heating rolls, then crimped in a texturing unit, and then cooled over a cooling drum with a certain number of turns. The texturing unit is a graft former. To cool the textured yarn, cooling air is drawn through holes located on the outside of the cooling drum.

A cooling godet or roll for treating synthetic filament or web shaped stock is also made DE 28 44 207 known.

Out DE 21 10 670 a device for continuous curling of thermoplastic threads is known in which the crimping (texturing) is carried out with a stuffer box attached tangentially to a rotary cylinder and the rotary cylinder is used for cooling. For this purpose, openings are provided after the stuffer box on the outside of the rotary cylinder through which cooling air is supplied via the cylinder and a cover plate.

Out DE 43 18 689 A method for producing low-shrink tapes is known in which flat strips, monofilaments or monofilaments of plastic stretched in a stretching station and fixed in a fuser.

Out EP 0 003 952 is the cooling of threads known, said threads formed from formed in compression chambers yarn plug and then wound on an air-permeable drum and cooled. There is a considerable distance between the stuffer box and the cooling godet.

Presentation of the invention

The object of the present invention is to provide a method and an apparatus for producing extremely crimped polymer tapes, which are suitable for use in artificial turf fields, for example for football, hockey, tennis or golf courses and are characterized by a high strength great volume and high elasticity.

This object is achieved in that the texturing of the filament tapes takes place by means of a stuffer box, wherein the filament tapes are deposited on a cooling godet immediately after the stuffer box.

Preferably, the filament ribbon leaving the stuffer box is fed approximately radially to the cooling godet.

Above the cooling godet and laterally next to the stuffer box an additional air nozzle is preferably mounted, which supports the deposition of the material on the Kühlgalette.

The stuffer box should be mounted with the smallest possible distance above the cooling godet. The deposition on the cooling godet takes place without the use of a delivery mechanism, as the texturing would be destroyed again by the use of a delivery mechanism.

On the outside of the cooling galette is a guide groove, which is provided with small openings. The radius of the guide groove is adapted to the texturing of the textured material to avoid deformation of the texturing. The cooling godet is provided with a suction which sucks air through the openings in the guide groove to cool and hold in the groove the filament ribbon deposited in the groove. As a result, rapid cooling of the material is achieved, and by an incoming crystallization, the texturing is fixed. In addition, in the Kühlgalette a standing cover installed so that the suction occurs only in that part of the circumference of the Kühlgalette, in which the thread lies in the guide groove. From the cooling godet, the filament is withdrawn through a draw-off godet.

Description of the invention

Fig. 1

shows schematically the device for carrying out the method.

Fig. 2

shows in section A - A of Fig. 1, the stuffer box and the Kühlgalette with suction.

In the present method, a polymeric material is processed in the form of tapes 10 0.5 to 1.5 mm wide and having a linear density of 250 to 1200 dtex. As the polymeric materials, for example, PA (polyamide), PP (polypropylene) or LLDPE (linear low density polyethylene) are used. The tapes 10 are fed from a gate or processed directly from the extruder coming.

For further processing, four to ten tapes 10 are bundled into a multifilament and thermally stretched over two heating godets 11 and 12 by 5% to 20%.

Subsequently, the tapes 10 are subjected to a Heißlufttexturierungsverfahren in a stuffer box 13, wherein the tapes 10 are pressed into a chamber and compressed at the Faserpfropfen formed there. This leads to a mutual buckling of the filaments. The stuffer box has a side inlet for a hot air texturing nozzle 21 and an air outlet area 23. The resulting structure is still heat set in the chamber with hot air from the texturing nozzle 21. It forms a three-dimensional, sawtooth curling structure. Commercially available compression chambers can be used in the process.

To stabilize the texturing, the swaged and crimped ribbons 10 are picked up by a cooling godet 14 immediately after texturing. The degree of texturing is limited by the speed ratio of the cooling godet 14 to the second heating godet 12.

The discharge end of the stuffer box is located as close as possible to the surface of the cooling godet 14, and the stuffer box 13 terminates only a few millimeters above the cooling godet 14. The filament ribbon 10 exiting the stuffer box 13 is directed radially onto the cooling godet 14. In addition, an air nozzle 18 is laterally attached to the stuffer box 13, which at an angle of about 45 ° to the longitudinal axis of the discharge end of the stuffer box 13 and the surface of the Kühlgalette 14 directs an air jet to the point at which the filament ribbon 10 from the stuffer box 13 exits and is placed on the cooling godet 14. This supports the laying down of the filament ribbon 10 on the cooling godet 14.

As shown in Figure 2, the Kühlgalette 14 has a suction 15. On the outside of the Kühlgalette 14, a radial guide groove 25 is arranged with small openings 26, is sucked through the air from outside to inside and ensure a sufficiently large air flow for cooling , The radius of the guide groove 25 is adapted to the textured material. The filament ribbons 10 generally lie on a circular arc of less than 360 °, e.g. one of about 180 °, on the Kühlgalette 14 at. In the Kühlgalette 14, a standing cover 19 is installed, which shields from the inside the part of the guide groove 25, on which no filament ribbon lie. As a result, an unnecessary consumption of suction air and an unnecessary reduction of the negative pressure in the cooling godet 14 is avoided.

By the suction air on the cooling godet 14, the textured tapes 10 in the desired segment of e.g. held about 180 ° on the circumference of the cooling godet 14 in the guide groove 25 and cooled. Due to the cooling, the glass point falls quickly, so that the texture of the fibers is fixed by the onset of crystallization.

The cooled tapes 10 are withdrawn from the Kühlgalette 14 by a Abzugsgalette 16 and fed to a winder.

The speed ratios of the godets are variable and can be adjusted according to the desired Texturierungsgrad. Of particular importance here is the speed ratio between the second heating godet 12 and the cooling godet 14, by which the degree of texturing is determined. The second heating godet 12 is faster than the cooling godet 14 by a factor of 1.05 to 1.20.

The speed difference between the extrusion and the winding is 5-35%, the extrusion speed being higher by a factor of 1.05 to 1.35 than the winding speed. This allows production speeds of 100 - 500 m / min. to reach.

The fibers thus obtained can now be bundled as fiber groups and anchored on dimensionally stable carrier fabric, whereby an artificial turf field is obtained with high elasticity, an optimal Wiederaufstellvermögen and high abrasion resistance.

example

Six extruded polyamide tapes 10 are stretched at 180 ° C over the two heating godets 11 and 12 with a yarn tension of 4000 g by 10%. Subsequently, the stretched ribbon 10 are compressed and crimped in the stuffer box 13 with a texturing of 5 bar and heat-set at 120 ° C texturing nozzle temperature. This results in a shrinkage of 35%. The textured tapes 10 are, supported by an air flow from the side air nozzle 18, stored with a yarn tension of 180 g at 6600 dtex on the cooling godet 14 and held by the air flow of the suction 15 in the guide groove of the cooling godet 14, cooled and transported. The temperature at the cooling godet 14 corresponds to the ambient temperature. The cooled tapes 10 are picked up by the take-off godet 16 and fed to the winding machine, the winding tension being 300 g. The difference in speed between extrusion and winding is 25%, thus compensating for shrinkback. It is a production speed of 400 m / min. reached.

LIST OF REFERENCE NUMBERS

• 10 ribbons
• 11 first heating godet
• 12 second heating godet
• 13 stuffer box
• 14 cooling godet
• 15 suction
• 16 withdrawal godet
• 18 air nozzle
• 19 standing cover
• 21 Texturing nozzle
• 23 air outlet area
• 25 guide groove
• 26 openings

Claims (10)

A method of making textured filament tapes (10) for artificial grass, wherein filament tapes (10) are stretched between two heating godets (11) and (12) and then textured, and the textured filament tapes (10) are cooled by a godet godet (14) ) and then wound, characterized in that the texturing in a stuffer box (13) and the filament ribbon (10) are deposited and cooled immediately after the texturing on the cooling godet (14). The method of claim 1, wherein the filament tapes (10) are fed approximately radially to the cooling godet (14). Method according to claim 1 or 2, wherein the laying down of the tapes (10) on the guide groove is assisted by an air nozzle (18) arranged laterally on the stuffer box (13) whose air jet is directed to the exit point of the stuffer box (13). Method according to one of claims 1 to 3, wherein air is sucked for cooling by means of an exhaust (15) through openings in the guide groove. Method according to one of claims 1 to 4, wherein the winding speed 100-500 m / min. is and the extrusion speed is 5-35% higher than the winding speed. A method according to any one of claims 1 to 5, wherein the stretch between the heating godets (11) and (12) is 5-20%. A method according to any one of claims 1 to 6, wherein the polymer material comprises the polymers polyamide, polypropylene and LLDPE (Linear Low Density Polyethylene). A method according to any one of claims 1 to 7, wherein four to ten tapes (10) are processed simultaneously and the tapes (10) have a width of 0.5-1.5 mm and a linear density of 250-1200 dtex. Apparatus for carrying out the method according to one of claims 1 to 8, having two heating godets (11, 12) for drawing the filament ribbons (10), with a texturing device (13) and with a cooling roll (14) connected downstream of the texturing device (13). , characterized in that the texturing device is a stuffer box (13) and that the cooling godet (14) is arranged at the smallest possible distance from the end of the stuffer box (13). Device according to one of claims 8 or 9, wherein the side of the stuffer box (13) an air nozzle (18) is arranged, whose air jet is directed to the exit point of the stuffer box (13).

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