NO126260B - - Google Patents

Description

Textured synthetic fibers as fluff material.

The general principles of the flocking technique, with which the most diverse textile raft structures are produced in a specific way, but also flock yarns, have been known for some years. Flocking means, as is well known, the application of cut fibers on a substrate which, depending on the intended purpose of use, is chosen in particular each time. For the production of textile raft structures, woven fabrics of the most diverse types, but also paper, plastic foils, foams and other raft structures are suitable as a flocking basis. The flocking process itself can, for example, be carried out after the previous preparation of the fibers according to the electrostatic method, as the use of a flocking adhesive applied to the substrate, which can also be an adhesive foil, gives the fibers the permanent adhesiveness to the used substrate. In principle, all fully synthetic fibres, such as polyamide fibres, polyester fibres, polyacrylonitrile fibres, etc., but also the semi-synthetic fibers of previously formed macromolecules such as viscose fibres, copper cellulose fibres, cellulose acetate fibres, egg white fibres.

When the production of flocked products was taken up, however, major difficulties arose very quickly, which even resulted in the near disappearance of lot carpets on the market. The reasons were the cratering, "leopard" and other erroneous effects occurring with such textile raft structures, the cause of which, among other things, was assumed by the fiber bundle itself or the precision with which it was cut.

The investigations carried out so far have shown that the lint produced by cutting fiber bundles from spinning cables is only suitable for straight and evenly cut fibers of exactly the same length. If a completely uniform cut length is not ensured, the longer flocks straighten up during the flocking process and act on the surroundings as a lightning conductor. An electrically neutral zone occurs in the vicinity of the created longer flocks, into which no further flocks can be shot. This results in so-called crater formation. For this reason, it was also unavoidable to separate the unavoidably formed over-long fibers from the flock material that comes into use.

In order for the fibers to move undisturbed along the streamlines and strike vertically on the base material to be flocked, it has also hitherto been considered necessary that they are almost stretched. From this last requirement derives the hitherto strictly observed principle in the technique for the production of flock products to only use fiber flock which is produced from endless non-textured threads.

Admittedly, in British patent no. 1,043,429 and US patent no. 3,377,232 it is proposed to use fibers with a potential ripple as fluff materials for the production of fluff products. These fibres, however, before and during the electrostatic flocking process have a straight shape, their latent ripple is only induced by special post-treatment operations after the electrostatic flocking on the finished fleece product. The fibers used here are distinctly special fibers and the subsequent development of their curling, which can only take place in a discontinuous manner, is of course as cumbersome as the production of the eleven fibers.

The invention now relates to the use of textured, synthetic fibers as fluff materials for the production of fluff-enriched products by means of electrostatic flocking, with which one can produce all the various fluff products manufactured up to now in very good quality.

"Synthetic fibres" are hereby understood to mean fully synthetic as well as fibrous substances produced by chemical reaction on formed macromolecules. By "textured fibres" within the scope of the invention is meant fibers whose physical properties during the spinning process or by thermal and /or mechanical finishing has been changed (cf. Koch. Satlow "Grosses Textillexikon", Deutsche Verlags-Anstalt Stuttgart (1966), volume 2, pages 487-494).

Depending on the purpose of the fleece product, the textured fibers can usually be processed in staple lengths from 0.3 to 12 mm, preferably 1 to 6 mm (the length of the stretched fibers) and titers from approx. 3.5 to 20 it. Likewise, as with the non-textured fibers used up to now, it is possible to carry out the flocking not only with the help of an electrostatic field, but also by mechanical or combined mechanical methods.

The effect to be achieved according to the invention is all the more surprising as textured fibers that arise from cutting textured spinning cables have a high volume and their very complex structure made them appear unsuitable in and of themselves for the flocking technique after the previous results according to the technique condition.

In summary, the use of textured synthetic fibers as fleece materials for the production of fleece products results in the following advantages: Level effects such as crater and leopard effects no longer appear in the finished products. The until now inevitable prospect of too long fibers from the flocking process is eliminated, important properties that relate to the finished product's usability are improved considerably, and finally a further area of application is also opened up for the very young branch of the chemical fiber industry of the textured yarns.

It has been shown that, within the scope of the invention, it is particularly advantageous to use fibers cut from synthetic fiber bundles. The improvement that can be achieved in this way relates in particular to the properties that are essential for the stress on the construction product, such as e.g. permanent bending and frictional strength as well as the change in the optical impression after loading.

The use according to the invention of textured synthetic fibers as fluff material shall be explained in more detail with the help of the following examples:

Example 1.

A twisted crimped polycaprolactam wire cable with a total titer of 5 million den (single thread titer 20 den, crimp number/cm = 10-17, crimp contraction 20%) is cut into 2.5 mm long fibers. The material is not sifted for formed fibers that are too long. In a pot, the fibers are now subjected to a preparation. "LEOMIN KP" serves as a preparation agent

(Parbwerke Hoechst AG), consisting of 33 wt% stearyl triethylene tetramine, 54.5 wt% water, 1.5 wt% butanol, 7.0 wt% salt and 4.0 wt% sodium stearic acid. The concentration of the preparation in the aqueous bath amounts to 20 g/l of water. Furthermore, 15 g/l of water is also added with common salt. The aqueous solution's pH value is "f- 7, 5-After being drained, the thus prepared material is dried at 60-80°C in a drying oven and then conditioned in a climate chamber for 24 hours at a temperature of 20°C and 65% relative The subsequently measured surface resistance, measured in a multimegometer, lies in the particularly favorable area for further processing of

0.02 . 10 9 - 0.06 . 10 9 ohms. The fiber material is loosened on a shaking machine and is now usable for flocking.

An electrostatically flocked 3>0 mm PVC foam cased fabric in the usual way in a thickness of 130-150 g fiber flock/m 2 , on which a polyurethane-solvent adhesive has previously been applied with the help of an ironing machine with a squeegee device "ACRAFLOC

CL" (Farbenfabriken Bayer AG), after drying in a drying channel, had the following properties: a) Walking stick effect (following the bending of the fiber tips when walking): beginning of surface change after 30,415

movements.

b) Tumble test: after 20,000 revolutions hardly changed.

c) Wheelchair test: scrubbed to the base material after 45,719 trips

along and across.

The walking stick effect refers to the use damage observed in flock carpets and flock goods, which manifests itself as bending of the flock fibers in the upper third, especially due to the stress of shoe heels. A converted Schopper-Gewebe-Scheuerpriifer with a grooved metal stamp plate instead of sandpaper served as a test device.

The tumbling test simulates putting on rubber heels

the carpet. The test apparatus consists of a drum laid out with the carpet test, with a 500 g heavy 4-foot, which amounts to 2,500 revolutions per hour.

In the wheelchair test, the carpet's stress on the ground is simulated

of office chair casters. A trolley, equipped with office chair casters of approx. 60 x 40 cm size, which is driven by crank drive, a linear movement on a carpet sample. The examinations are carried out under the following conditions:

Sample speed: 5,000 strokes per hour (one revolution is

two strokes).

Stroke length: 40 cm.

Pulley load: 20 kp.

Example 2.

The course of the procedure mentioned in example 1 was re-

taken in an identical manner with the only exception that the same textured polycaprolactam cable was now cut into 3 mm long fibers. It besieged

ked with 3.0 mm PVC foam laminated fabric has the following properties:

a) Walking stick effect: beginning of the surface change after 26,730 movements. b) Tumble test: after 20,000 revolutions hardly changed.

c) Wheelchair test: scrubbed to the base material after 7,682 trips

lengthwise and 35,282 trips across.

Comparative example.

According to the procedure described in example 1

a non-textured polycaprolactam cable with the same titer was cut on one occasion into 2.5 mm (1), on the other occasion into 3 mm (2) long fibers, however, as usual, the excessively long fibers were separated by sieving.

The same fabric was then flocked in the same way as in examples 1 and 2. The pile results have the following characteristics:

a) Walking stick effect: (1) onset of surface change after

(2) 7.00 - 8.000 movements.

b) Tumbling test: (1) strongly felted ugly surface after

(2) 20,000 revolutions.

c) Wheelchair test: (1) scrubbed to the ground after 1,000 trips

(2) longitudinally and transversely.

Example 3.

A torsion crimped polyethylene glycol terephthalate wire cable produced in the usual way by the false twist method with a total titer of 5 million den (single thread titer 5 den, crimp contraction . 20-25%) is cut into 0.3 - 0.5 mm long fibers . The subsequent preparation, drying and conditioning of the fibers was carried out analogously to example 1. As a flocking substrate, this time a rubber profile serving as a vehicle sliding guide element was used, which was flocked at a density of approx. 30 g fiber flock/m 2 electrostatic. For the permanent adhesion of the flock fibers previously applied to the substrate in the usual way, the adhesive was prepared according to the following recipe: 100 parts by weight "ACRAFLOC LU" (a polyester produced by Farbenfabriken Bayer AG), 60 parts by weight "IMPRAFIX BE" (an accelerator serving 10% -ig solution of an organic nitrogen derivative in combination with an organic metal compound in ethylene chloride/ethyl acetate.Manufacturer: Farbenfabriken Bayer AG). 60 parts by weight "IMPRAFIX TH" (a net-forming 75% solution of a polyfunctional aromatic isocyanate in ethyl acetate. Manufactures:

Farbenfabriken Bayer AG).

75 parts by weight methylene chloride

75 parts by weight of benzene.

After drying in a drying channel, the thus flocked rubber profile has a significantly softer and more resilient surface compared to a rubber profile flocked with non-textured polyethylene glycol terephthalate fibre. This means that shocks and vibrations are better dampened by the disks.

Example 4.-

A torsion crimped polyamide 66 wire cable with a total titer of 5 million den (single thread titer 3.4 den, crimp contraction 18-20%) is cut into 0.3 - 0.5 mm long fibers produced by the false twist method in the usual way. The subsequent preparation, drying and conditioning of the fibers was carried out analogously to example 1.

Electrostatically flocked became a PVC foil. The density of the applied fluff was 30 g/m 2. The lok glue, which was previously applied to the substrate in the usual way, was prepared according to the following recipe.

100 parts by weight "ACRAFLOC LD" (30% solution of an isocyanate-modified polyester. Manufactures:

Farbenfabriken Bayer AG).

5 parts by weight "IMPRAFIX TH" (net former based on a polyfunctional aromatic isocyanate. Produces:

Farbenfabriken Bayer AG).

6 parts by weight of adhesive agent "TN" (70%, medium-viscosity polyester solution in ethyl acetate/methyl chloride. Manufacturer: Farbenfabriken Bayer

AG).

Despite the low amount of wool used, an optically dense surface of uniform nature was produced, i.e. without leopard and crater effects.

Example 5.

A torsion crimped polycaprolactam wire cable produced by the false twist method with a total titer of 5 million den (single thread titer 20 den, crimp contraction 20%) is cut into 3 mm long fibers. The subsequent preparation, drying and conditioning of the fibers and their electrostatic flocking in a density of 130-

150 g fiber flock/m 2 on a 3.0 mm PVC foam cased fabric using the common polyurethane solvent adhesive "ACRAFLOC LD" as well as the associated mesh former based on a polyfunctional aromatic isocyanate "IMPRAFIX TH" (manufactured by Farbenfabriken Bayer AG ) is carried out analogously to example 1.

After drying in a drying channel, the mechanical property improvements of the thus produced fleece product were in relation to one that had been produced using non-textured polycaprolactam fibers in the same order of magnitude as in example 1. Example 6.

A torsion crimped polyacrylonitrile wire cable produced by the false twist method with a total titer of 5 million den (single thread titer 3 den, crimp contraction approx. h0%) is cut into 0.3 -

0.5 mm long fibres. The subsequent preparation, drying and conditioning of the fibers is carried out analogously to example 1.

■ For the production of an upholstery fabric, a cotton fabric was flocked electrostatically at a density of 30 g fiber flock/m 2. For permanent adhesion of the fleece fibers previously applied to the substrate in the usual way, the adhesive was prepared according to the following recipe: 100 parts by weight "ACRAFLOC WL" (40% aqueous, plasticizer-free dispersion of a self-crosslinking acrylic ester mixture polymer. Manufactures:

Farbenfabriken Bayer AG).

5 parts by weight "CASSURIT MLP"

liquid (alkyl etherified methylol melamine.

Produced by Cassella Farbwerke Mainkur

AG).

10 parts by weight dibutyl phthalate.

15 parts by weight alginates as thickener.

After drying in a drying channel, the fleece product produced in this way excelled with an optically dense surface of uniform nature, i.e. without leopard and crater effects.

The listed adhesive recipes which do not differ from those used by the manufacturer of the fleece products of non-textured fibers and which are also highly variable, do not fall within the scope of the invention.

Claims (2)

1, Use of textured, synthetic fibers as fluff material for the production of fluff-enriched products by means of electrostatic flocking. 2. Use as stated in claim 1 of synthetic fibers cut from twisted crimped wire cables.