Method and device for fibrillating easily fibrillated cellulose fibres, particularly tencel fibres

The invention relates to a method and an apparatus according to the preamble of the independent claims.

Fibrilatable cellulose fibers, in particular Lyocell fibers (such as Tencel fibers) are very successful due to good coloring and wearability, and a variety of equipment options and methods for influencing the "handle" of increasing popularity.

"Lyocell" fibers are produced in a solvent-spinning process cellulose fibers whose shell is cleavable by mechanical impact so that project from the mantle surface fibrils.

Customary in lyocell fibers it is initiating fibrillation in the rope treatment. Factors which influence the tendency to fibrillation in particular: pH, temperature and mechanical action. Moreover, cellulase enzymes are often used to promote fibrillation. Cellulase enzymes are protein substances that are capable of reducing cellulose. A cellulase enzyme consisting of a plurality of different enzyme components. The 4 most important are: endo, exocellulase, cellobiohydrolase and cellobiase. The action of exocellulases results in soluble glucose directly from cellulose. The other components engage systematically to the cellulose chains, by arbitrarily dividing the formation of cellobiose to glucose soluble.

Theoretically, the fibrillation of lyocell fibers also initiate only by mechanical treatment, in particular by wet friction. The addition of enzyme is an additional promotion and control of the process. Furthermore, enzyme processes are used to weaken after a first fibrillation the long fibrils and remove. This process is described in detail in "ITB finishing, 2/94, p 5; R. Breier, finishing lyocell fibers, man-made fibers / textiles, 44./96 vintage, November / -December 1994, p 812;. Lyocell fibers: preparation, properties, fields of application in chemical fiber / textile industry, 43./95 vintage, Oct. 1993, p 745. I. Marini, Lenzing lyocell fibers in fibers / textiles, 43./95 vintage, November 1993. S. 878th

In practice, the fibrillation is usually introduced at the strand and treatment carried out batchwise. Known fibrillation require many hours of treatment. In contrast to so far assumed that in the classical form of Finish of Tencel fabric (treatment "open-wide") no fibrillation occurs.

However, the invention proposes to carry out the fibrillation of fibrillatable cellulose fibers such as Lyocell, in particular Tencel fibers containing fabrics with a broad goods. According to the invention this can be achieved is if the wide web acted upon by a high velocity liquid stream and accelerated by this and thrown to the stream of liquid against a baffle and if the acceleration and spin operation is repeated, are cleaved to surface areas of the fibers and form fibrils.

As is known, can be influenced by enzyme treatment, temperature and pH adjustment fibrillation. The invention can be used to fibrillate goods primarily and in a subsequent enzyme process to remove as in a known manner, the long fibrils by enzyme treatment. The inventive method can also be used for the secondary fibrillation, so that is a Fibrillierungsprozess which is a first fibrillation, a subsequent treatment for the reduction to long fibrils and possibly other equipment connected to steps.

it when the web accumulated at a department store and is withdrawn from the high velocity fluid is particularly advantageous. The lying loose in such goods storage goods can be particularly well entrained and accelerated by the high velocity fluid.

It is particularly advantageous on, is when the web sequentially entrained in the opposite direction of such a liquid stream and flung against baffles. For example it is possible to promote in a crack-goods by the liquid flow to hurl against an impact surface to collect the goods in a department store, then reverse the liquid flow in the direction and the goods in the opposite direction through the gap to accelerate and spin against a arranged on the other side of the gap second baffle and there to collect the goods again in a department store. Goods would thus "forward and backward" conveyed alternately through the guide gap. Case, if the time period for the promotion in "forward" direction is longer than the time period for the promotion in the opposite direction, a resulting "forward" funding. In one direction example can take six seconds are promoted, then switches and funded for five seconds in the opposite direction. Afterward conveyed back six seconds forward and backward five seconds, etc .. Thus promoted the product is handled at about ten acceleration processes, where they jewei is thrown against a baffle plate ls.

Specifically recommended accordingly arranging two goods store, where the goods are respectively loosely accumulated after being thrown against a baffle. From such goods store can then be transported away, the corresponding desired subsets, while the remainder for another treatment cycle, ie acceleration in the opposite direction is again available.

Such treatment cycles with wechselweisem acceleration and spin of the goods against baffles leads to particularly good grip properties. Of course, it would be conceivable to promote the product in only one direction through an arrangement and to repeat the process in the opposite direction by treating the desired quantity of goods.

Particularly good results can be achieved if the web at a rate of at least 8 m / sec. preferably to a speed of 9 m / sec. to 15 m / sec. is accelerated.

This can be achieved especially when the velocity of the liquid jet (preferably a water jet) in the conveying gap approximately 12 to 20 m / sec., Preferably about 15 m / sec. is.

The inventive method for fibrillating contained in a textile web of cellulose fibers, in particular Lyocell fibers (such as Tencel fibers) can be particularly advantageous with a device to carry out, in a wide supplied web is accelerated in a flow-through of a liquid guide gap when the guide gap is bounded at least on one side by a nozzle member having a supply channel for the liquid and having on two opposite sides of one hand to guide gap narrowing exit slit and a valve element for alternately closing one of the outlet column.

Particularly uniform and good acceleration can be achieved when exit slots are provided for the liquid in the two surfaces of the guide slot, so that the product is exposed on both the top side and on its underside of acceleration through the liquid.

Instead of an exit gap for the liquid can of course also buy several exit slots provide and provided it is favorable flow values ​​with them. In practice, it has proven particularly useful when each exit slit tapers towards the guide slot and when the flow axis of the exit gap is preferably inclined approximately at an angle α of 10 ° to 20 ° of about 15 ° to the guide gap plane.

The invention is explained in the following in embodiments with reference to the drawings. Show it<dl id="dl0001" compact="compact"><dt>Fig. 1</dt><dd>a schematic representation of a fibrillated Tencel fiber as an example of a fibrillated cellulose fiber,</dd><dt>FIG. 2</dt><dd>the schematic representation of a fabric run with the features of the invention,</dd><dt>Fig. 3</dt><dd>a sectional representation through a guide gap for accelerating the web with the characteristics of the invention, and </dd><dt>Fig. 4</dt><dd>the partial representation of the guide slot of FIG. 3 in a view from the direction "A" according to FIG. 3.</dd></dl>

Fig. 1 shows schematically a Tencel fiber 1 projecting from fibrils which second The Tencel fiber 1 is a component of a tissue, not shown, that one according to the invention was subjected to treatment.

As shown schematically in Fig. 2, a web 3 of an apparatus for fibrillating 4 is fed via a feed roller 5 by a conveyor device not shown. The feed roller 5 continuously promotes the web in a goods storage 6. From there, the web passes through the guide gap 3 7 an acceleration device. 8

The guide gap 7 is defined by an upper and a lower guide rail 9a and 9b limited. In the lower guide track two exit slots 10 are provided laterally, each one of the column through valve means 11 is closed. In the embodiment shown in FIG. 2 the exit slit 10a is closed while the outlet gap 10 b is opened while shown as closed during the embodiment of FIG. 3 of the exit slit 10 b. The exit slit of water occurs at a rate of about 15 m / sec. from which is supplied from a supply 12th The outlet from the column 10 b flowing water pulls the web 3 with, speeding them up and hurls it against an impact surface 13, whereby the web 3 and the fibers constituting the web 3, to mechanical strain. Of the impact surface 13, the web falls down in a goods storage 17, from which they can be transported away by conveying rollers 14 and 15. FIG.

To 3 repeatedly exposing the web of the treatment described, the valve can be means to move laterally so that alternately the exit slots 10a or the outlet slots 10 b is closed. Depending on through which the liquid exits outlet gap at high speed, the material web 3 is thrown against the impact surface 13 or the baffle 16 either. The reciprocal spin causes particularly uniform and effective for the handle of the product mechanical treatment of the web.

Fig. 3 shows an embodiment where a guide gap is 7 at both the upper side and on the underside of the web 3 with outlet columns 10 a, 10 b, respectively. Accordingly, two valve means 11 are provided, which close when the operating state shown, the outlet slots 10 b, so that the liquid is supplied to the exit slots 10 a and the goods x promoted and accelerated in the direction of the arrow.

Fig. 4 shows in a cutout plan view showing the guide gap 7 as shown in FIG. 3, through which the web is transported through the 3-funded high speed water. The exit slots 10a and 10b are indicated by dashed lines on both sides. (As noted above, in the exemplary embodiment shown in FIG. 2 only on the underside of the guide slot 7 an outlet opening 10 a provided).

By the number of treatment steps (spin on an impact surface), the regulation of the impact velocity, by unilateral or mutual treating can be influenced with the invention, the degree of fibrillation and thus also the surface condition and the handle of the goods. Upstream or downstream and enzyme treatment steps can be used to influence the fibrillation addition.

Especially in an arrangement according to FIG. 3, in which both the top of the guide slot 7 and on the underside of the guide slot 7 exit slits 10 a and 10 b are provided for the liquid, can be not only "open wide" goods but also tubular fabric treat, if desired. This leads to more economic results, which, surprisingly, a surface treatment in the interior of the hose occurs, although this does not come directly into contact with the baffle. Treatment generally consists of three components: (1) substance-baffle; (2) Substance-water; (3) fabric material.

The force with which the wet product is thrown against the baffles depends Evidently on both the speed of the conveying fluid and the length of the acceleration path, any braking actions and the mass of the wet goods at the moment of impact. Typically occur upon impact forces per centimeter fabric width on the order of magnitude 2.5 to 9 Newton. Preferably, the values ​​between 5 and 9 Newtons per cm. This leads to particularly good Fibrillierungsergebnissen.

Particularly effective is the invention when used with tissues (in particular Tencel fibers) made entirely of fibrillatable cellulose fibers, such as "Lyocell" fibers. but it is also possible to treat fabrics consisting of mixed fibers or blended fabrics.