DE29824979U1 - Synthetic monofilaments for brush bristles or papermaking fourdriniers/blankets - Google Patents

Abstract

The synthetic monofilament material is a mixture of polyamide and polyurethane. The monofilament is composed of 1-30% or 1-10% of polyurethane, and sufficient polyamide to give 100%. The pref. polyamide content is polyamide 6 and/or polyamide 66 and/or polyamide 610 and/or polyamide 612.

Description

The invention relates to monofilament synthetic fibers based on polyamide.

Monofilament synthetic fibers made of polyamide, especially made of polyamide 6 and polyamide 66 are known (e.g. Hansjürgen Saechtling: plastic pocket book, 22nd edition 1983, page 286 ff., Carl Hanser Verlag, Munich). These monofilaments are used, for example, for the production of brushes and used for the production of fabrics and screens for paper machines. Since such monofilaments in use are particularly strong mechanical and are chemically stressed, there is a tendency to such synthetic fibers based on polyamide with regard to their mechanical and chemical To improve properties.

For this purpose, a monofilament synthetic fiber made of polyamide and polypropylene has become known ( EP 0 658 640 A1 ), which has significantly better properties than pure synthetic fibers made of polyamide. In particular, water absorption is reduced and chemical resistance is increased. In addition, the mechanical stiffness, both dry and wet, is increased and a longer brush life is achieved under high loads. However, it has been found that such a monofilament synthetic fiber is also in need of improvement, particularly with regard to its use in the manufacture of fabrics for paper machine clothing.

The object of the invention is a Specify synthetic fiber based on polyamide, which compared to synthetic fibers made of pure polyamide better properties with regard to abrasion resistance and has dimensional stability, is nevertheless sufficiently flexible.

This object is achieved with a monofilament synthetic fiber of the type mentioned at the beginning by a mixture made of polyamide and polyurethane.

It was surprisingly found that by adding 1 to 10% polyurethane ad 100% polyamide Synthetic fibers made of polyamide significantly improved in many properties can be. The addition of polyurethane increases the flexibility of the monofilament and thus also of the finished fabric formed from it. This allows larger tissues due to the higher Suppleness better in the individual, with rotating rollers stocked Feed paper machine sectors. It also turned out that the abrasion caused by the contact between the tissues and the drive rollers in the paper machine, essentially is reduced.

It also turned out that in the needle process, e.g. in the production of a wet felt, the splicing of the monofilament is prevented by the addition of polyurethane can be. With such a needle process it is namely on there is inevitable that a number of monofilaments in the tissue is damaged by the retracting needles. Still has found that with a fabric from a monofilament according to the invention Synthetic fiber significantly better noise reduction on the paper machine is achievable.

A monofilament according to the invention Synthetic fiber can be after the usual Manufacture extrusion spinning process. Commodity Trockenlufttrockner ensure in advance that that the raw material mixture, which is fed to the extruder, does not have too high a moisture content. As an extruder both single and twin screws come with and without degassing for use. The rest Plant parts correspond to those for the technical conditions necessary for standard monofilament production.

Polyamides, for example, can be used as polyamides 6 and / or polyamide 66 and / or polyamide 610 and / or polyamide 612 be used.

The is particularly preferred monofi le according to the invention Synthetic fiber for the production of fabrics or sieves, in particular for paper machine clothing. These paper machine clothing can be inside the paper machine both in the wire section and in the press section as well as in the Insert dryer section.

The invention is illustrated below of embodiments explained in more detail:

example 1

It first became a state of the art appropriate synthetic fiber made of pure polyamide 6 examined, namely with a thread diameter of 0.2 mm. This thread diameter was therefore examined because in the wet felt area in paper machines such thread diameter often is used. This synthetic fiber is hereinafter referred to as synthetic fiber I designated.

Example 2

In contrast, a monofilament according to the invention Synthetic fiber with the following composition examined: 90% polyamide, 10% polyurethane, this fiber is subsequently called synthetic fiber II designated. It also had a diameter of 0.2 mm.

Both synthetic fibers were first subjected to a physical test. The results are in shown in Table 1 below:

Table 1 (physical test):

Recognizable compared to known ones Synthetic fibers made of polaymid (synthetic fiber I) through the synthetic fiber according to the invention II the stiffness essential, namely reduce by an average of 15%.

In addition, a scrubbing test (dry) performed once at constant speed and once at constant time Results are shown in Tables 2 and 3.

Table 2 (abrasion test (dry) -speed constant):

Table 3 (abrasion test (dry) time constant):

Tables 2 and 3 show clearly recognize that opposite known synthetic fibers made of polyamide with an artificial fiber according to the invention the abrasion considerably, namely can be reduced by at least 50%.

Of course, the invention is not on the illustrated embodiments limited. In particular, a synthetic fiber based on polyamide 66 is also included Suitable polyurethane additive or other polyamides in connection with Polyurethane.

Claims (2)

Monofilament synthetic fiber based on polyamide, consisting of a Mixture of polyamide and polyurethane with 1 - 10% polyurethane and ad 100 % Polyamide. Monofilament synthetic fiber according to claim 1, characterized by a Use of polyamide 6 and / or polyamide 66 and / or polyamide 610 and / or polyamide 612.