SI8812227A8 - Process for making fibrous article, suitable for storing and handling - Google Patents

Description

There was a need for a technologically advanced process for the production of a new fiber knit, suitable for storage and handling, derived from cellulosic fibers and thermoplastic fibers, especially polyester fibers and / or natural fibers of plant origin, giving homogeneous fixed cross-section knit fibers and which can be performed with low power consumption. In addition, the manufacture of uniformly fixed workpieces should be ensured from this fiber knitter. The state of the art

(DE-A-32 39 732) It is known to form a suitable knitter of fibers of the type described above, by making a fibrous fleece made of cellulose fibers and thermoplastic fibers and under the given conditions of further thermoplastic materials or duroplastic binder. it is heated by softening the thermoplastic fibers to their point of adhesion, thereby securing the fibers at the jointing points with each other and keeping the knit j _{from the} fibers pre-attached.

In When reinforcing the fiber fleece by tightening thermoplastic fibers, a fiber fleece with a cross-section is strongly different in nature, especially since the fiber fleece on the surface layers was most strongly heated. If the adhesive of the center layers is to be secured, it is no longer guaranteed that the surface layers will still have a fibrous structure and that the fiber knit hoops are flexible enough for further handling.

In the case of fiber knitters according to DE-A-32 39 732, the binders of fibers are solely responsible for the hardening of the fiber knitter, so that uniform hardening cannot be ensured. In particular, there may be areas where the binders are in insufficient quantity so that the workpiece does not have the same strength at each site.

The process for the manufacture of fiber knitwear is further known from DE-B-1 054 146. According to this document, a mixture of cellulose fibers and synthetic fibers is processed into fiber fleece, which is hardened by the application of adhesive agents and subsequent drying and compression. In doing so, they adhere to one another at the points of contact of the fiber of the surface layers so that the fibrous fleece is stabilized and can be subjected to further processing.

This known process comprises the disadvantages that are evident in the fact that the application of bonding agents to the surface of the fleece fleece is complicated and that it requires further drying. In addition, the fiber fleece across the cross-section has very different strength properties, since the impregnation of the fiber fleece with the adhesive is only provided through its surface layers. Absorption completely requires even more demanding post-treatment, where the fiber fleece that has not yet dried must be treated with due care. The compression workpiece is secured according to DE-B-1 054 4-16 by injecting artificial resin powder into a press cavity forming a fiber knit. In order to obtain a uniformly fixed workpiece, it is necessary to introduce artificial resin powder into the press in an evenly thick layer, which can be very difficult to accomplish in complex workpiece shapes, if any.

Description of solution to a technical problem with implementation examples

The problem according to the invention is solved by the combined use of the following measures:

- that the pulp fibers are impregnated with a duroplastic binder solution, preferably a phenolic resin solution,}

and dried,

- that the dried pulp fibers are mixed dry with thermoplastic fibers such as polyester fibers and / or natural fibers of vegetable origin,

- to form a fleece from a mixture of cellulosic fibers and · moplastic fibers and / or natural fibers of plant origin, and

- to secure the shaped fleece to the needle-needle machine.

If further processing of the knitting fibers is carried out with a particularly strong transformation of the knitting fibers, then a mixture of cellulosic fibers and terraoplastic fibers and / or natural fibers of vegetable origin is deposited on a thin thermoplastic carrier fleece.

Particularly uniform knitting of fibers may be advantageously made by forming a fleece of impregnated cellulose fibers and a fleece of thermoplastic fibers and / or natural fibers of vegetable origin, these runes being mixed in a drum, from which a further fleece is formed, and bent on a thin support fleece made of thermoplastic fibers.

According to the invention, a fiber braid, preferably for the manufacture of heat and pressure formed articles, with cellulose fibers, thermoplastic fibers and / or natural fibers of vegetable origin and plastic-based duroplastic binder, is characterized by the fact that cellulose fibers impregnated with a duroplastic binder solution and bonded to thermoplastic fibers and / or natural fibers of plant origin by means of mechanical grouting without precipitation.

For particularly high loads of fiber knitting, cellulosic fibers and thermoplastic fibers and / or natural fibers of plant origin are additionally mechanically coupled to a thin thermoplastic fiber carrier web.

An object made from a braid of fibers according to the invention using heat and pressure, characterized in that the cellulosic fibers, thermoplastic fibers and / or natural fibers of plant origin are lodged in and bonded to the hardened melt of the duroplastic binder.

Preferably, the cellulose fibers are interwoven with a carrier fleece and a hardened melt of duroplastic binder, which makes the article particularly strong and very stress-resistant. An object of this type also has great stability in the dimension and value of the flexural pressure.

The process of the invention is described in more detail below on the basis of the accompanying drawing, illustrating FIG. 1 and 2 each for a process for the production of fiber knitwear. In FIG. 3 is shown from knitting if an object in an oblique design is made of fibers according to the invention. FIG. 4 shows a cross-sectional view of this object, taken along line IV-IV of FIG. 3. FIG. 5 shows a detailed section through this object in large magnification.

In accordance with FIG. 1 is processed by chipping 1 by baking in the baking tray 2 into cellulose fibers 3 · These are impregnated with wax 4 and a solution of 5 phenolic resin. The impregnated cellulose fibers 6 are then dried in a tube dryer 7 and pressed into bales 9 in a press 8.

Thermoplastic fibers 10, namely polyester fibers, are disintegrated from bales 11 of polyester fibers and transported via an intermediate bunker 12 to a fiber binder 13. Fiber shaker 13 shakes polyester fibers 10 onto conveyor belt 14. To this position, polyester fibers are filled with the help of two further shakers 15, 16 cellulose fibers, which are formed by disintegration of bales 9.

The sandwich thus formed is pre-mixed in the mixer 17 and further mixed in the fine mixer 18. The mixture 19 is transported to a fleece-laying machine 20 in which a pre-defined fibrous fleece 21 is formed. This fibrous fleece 21 is applied to a thin polyester fleece 22, thereby rocking in the needle machine 23. The knit fabric made in this way 24 is then cut into a cutting device 25 and cut into a predefined format and stacked 26.

Fibrous fleece can be handled very well and is nonetheless soft and flexible so that it does not present any problems in further processing into a pressed object if natural fibers of plant origin (eg cotton) are used instead of thermoplastic fibers 10 or used such natural fibers mixed with thermoplastic fibers also produce a soft and flexible fibrous fleece.

Correspondingly in FIG. 2 shows the preparation of chips 1 into impregnated cellulose fibers 6 and polyester fibers 10 in the same manner as in FIG. 1 to the process described; the formation of fibrous fleece, however, is different. The cellulose fibers 6 are guided through a conveyor belt 14 into a fleece laying machine 20. The polyester fibers 10 arrive via conveyor belt 27 into their own fleece laying machine 28. In this way, separate fibrous runes 29, 30 are formed from both cellulosic fibers and polyester fibers.

The two fibrous runes 29, 30 are brought together and mixed in the drum 31. From this mixture, the fleece 21 is re-applied to the thin polyester fleece 22. In the next needle machine, the fiber fleece 21 is jiggled with thin polyester fleece 22. again creating a well-handled knit fabric 24 that can also be sufficiently reshaped.

Fiber knitters 24 are made by pressing objects using heat and pressure. Such an object 32 is shown e.g. in FIG. 3 and 4. Represents a passenger car door trim. As can be seen from FIG.

4, this cover has 32 doors over the entire cross-section of approximately the same wall thickness.

In FIG. 5 is a detailed enlargement of the cross-section through object 32. The cellulose fibers 6 lodged in the solidified melt 33 of the duroplastic binder are seen. The outer restriction of the object 32 is formed on one side 34 from a carrier fleece 22 of thermoplastic fibers 35, which is not mechanically coupled to cellulose fibers 6 only, but the cellulose fibers 6 are impregnated and interwoven with carrier fleece 22 and a hardened melt 33 of a duroplastic binder, which it burst into a support roll 22 in a compression-rigid, molding-capable and form-stable formation.

The hardened binder also contains 36 or more thermoplastic fibers. natural fibers, if used in addition to, or in place of, thermoplastic fibers 36.

Claims (2)

A process for the manufacture of fiber knitwear suitable for storage and handling, formed from cellulosic fibers and thermoplastic fibers, in particular polyester fibers, and / or natural fibers of vegetable origin, containing a plastics-based duroplastic binder, capable of being operable heat and pressure, and upon hardening of the duroplastic binder, in a later stage of the process, it is compressed into form-stable workpieces, characterized in that the cellulose fibers are impregnated with wax and phenolic resin after separation and then dried, after which these fibers are formed by scattering into a fibrous fleece with 5 to 20 g / m ² , with a proportion of 65 to 60 wt% of natural fibers of vegetable origin in the knitting machine. %, artificial resins 5 to 15% by weight, solid phenolic resins 10 to 20% by weight and solid wax 1 to 2% by weight. Method according to claim 1, characterized in that the proportion of natural fibers of vegetable origin with a thickness of more than 1.0 mm is 20 to 40% by weight, with a thickness of less than 0.2 mm, 40 to 60% by weight and a thickness of 4 1.0 X 0.2 10 to 30%. For Kiihnsdorfer Holzfasermattenwerk Pacht- und Betriebsgesellschaft m.b.H .: 20614-Χ-89 / ΚΑ