DE1761117A1 - Felt for paper machines - Google Patents

Description

A 372 Albany Felt Company, 1373 Broadway, Albany, N.Y., USA Felt for paper machines

When producing paper on paper machines, there are different Types of felts used to shape, press and dry the paper web. These fi ^ .ze are normally either as flat material or: .n endlessly woven in a known manner. In the finished felt, the yarn, that runs in the direction of the machine, i.e. in the direction of movement of the felt, ala L-yarn (length yarn) and the yarn, that runs across the machine is called X-yarn (cross yarn). If the fabric is flat woven, so will the warp L-yarn and the weft daa X-yarn. If the fabric is endless, the warp becomes the X-yarn and the weft becomes the L-yarn, since the fabric is woven as a tube and the endless fila by cutting off a piece of the tube and is obtained by turning u «$> O °.

A basic requirement for a fabric that is to be used satisfactorily in a paper machine is that it has a high degree of runnability. This term is intended to mean that there * tissue longitudinally feat enough iat to the Maachinenspannung su able to accommodate that it iat longitudinally flexible, auaauhalten to daa constant bending when it comes to dia rolls

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is performed so that it is stiff in its plane in the transverse direction is to withstand the forces that strive to deform the tissue in its plane and to create folds » which can result from misalignment or from bending of the rollers, and that there will eventually be diagonal deformations resists, which lead to the formation of wrinkles when the deformation becomes severe enough.

In addition to the above properties, the fabric is required have further properties that depend on the desired end product in the particular application case, by Selection of specific yarns (multifadon yarns, monofilament yarns, Staple fibers) and gamma t he lall or combinations from this and the selection of certain fcebaren these can be desired Properties can be achieved. In achieving these desired properties and in the selection of the The designer is often limited by the need for yarn and weave to have a high degree of runnability necessary is. This then leads to a compromise among the actual properties. To achieve the desired Properties in the longitudinal direction are required to achieve the desired properties in other criteria Transverse direction. The strength and flexibility in the longitudinal direction can be achieved better than stiffness in the transverse direction and dl is special if d «r

Designer in terms of the choice of yarn structure

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the claims is limited ₉ are placed on the tissue with respect to its function on the paper machine as regards the preparation of the final product.

The invention has the task of creating a felt for paper machines to create high tensile and compressive forces can accommodate in the transverse direction without bending or wrinkling occurs. The invention Felt is characterized by a tightly woven, multi-layered ~

Fabric, since it has transverse yarns, which consist of yarns with the desired properties, which are reinforced by twisting with yarns with higher mechanical tensile and compressive fastness. By using a multi-layer fabric, the transverse yarns are advanced out of the neutral axis, so that when the fabric is bent around its axis parallel to the longitudinal yarns, tensile or compressive forces arise in them, which result in the Counteracting bending. In a force that strives to bend the fabric in the transverse direction, M applies pressure to the transverse yarn layers on one "side" of the neutral axis and tension on the transverse yarn layers on the other side. The Komitruktlon gives the fabric a high resistance g «g <in bending forces. The transverse yarn thus consists of yarns which are selected according to the function of the fabric in the paper machine and which are pre-strengthened in such a way that the tensile and compressive strength of the transverse yarn is increased. Because tissue is so formed

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that the transverse yarns in the finished fabric are essentially straight are. The cross yarns are usually made by their density of the tissue is firmly held in the tissue structure. If necessary, chemical treatment of the fabric can be provided to increase the binding of the transverse yarns au.

Further features of the invention emerge from the sub-tests *

The invention is illustrated below by way of example with reference to FIG On the drawing. Ea shows Fig. 1 is a section through ain tissue parallel to the longitudinal

yarn, and
FIG. 2 shows a section through the Gawaba of FIG. 1 parallel to the quartz yarn.

The example of the example shown is in fiIs for paper machines, who is able to withstand the high temperatures that occurred in the dry zone of the paper machine.

The longitudinal or warp yarns 10, 20, 30 and ko consist of 1200 denier two-ply multi-thread Nomex yarn (Nomex is a trademark of DuPont regiatriartaa for a polyamide fiber). This yarn can withstand high temperatures and also has sufficient fitness and flexibility properties. The warp yarns are made with cross yarns

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connected to a two-layer fabric, as shown in the figures can be seen.

Since the fabric is a multilayer fabric, the transverse or weft yarns 50 and 6u are offset from the neutral axis A, as can be seen from FIG. This offset enables tensile and compressive forces to develop in the transverse threads 50 and 60 upon flexing of the fabric, thereby resisting flexing and providing good guidance and ™

Runnability is achieved.

A material MUST be used in the transverse yarns which is heat-resistant and has the desired surface properties. One such material is asbestos. However, aesthetics alone do not have sufficient rigidity, usi can be used as cross yarns in a Pils for paper machines. For this reason, two-strand Aebest yarns with a weight of approx. 2.5 m / g USi ”in Monel wire 0.2 mm in diameter were twisted in order to give the transverse yarns good compressive and tensile strength.

To obtain a firm structure, it is necessary that the transverse yarns feat be held in the fabric structure. This is achieved by the diohta of the tissue and / or by the fact that the tissue is held in place by a prior treatment and is solidified. For beetiawte application · fall-Ie the tight tissue is sufficient. In other use cases

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chemical treatments are provided »which are common knowledge are ο

For example, the fungus was treated as follows after weaving: A resoreinal formaldehyde resin was applied in amounts of 5 to 10% by weight of the fungus by conventional means and dried at temperatures between 99 and 105 ° C for 10 to 20 minutes. This is followed by a hardening process at temperatures of 176 ° to 184 ° C for 10 to 20 minutes. Then, an elastomer, polyacrylic SB was, in amounts up au $ 50 dea Oeeaaitgevlchtea sugefttgt _(the dia flexibility and WiderstandafählgkeIt gaff · "Abautstrag adapted to the requirements.

Urethane hares can also be used with sweetening and svar preventive tissue in amounts of $ 5 to $ 10 that Dry weight the original tissue. After drying asked 93 ° ble 99 ° C can be done at 176 ° to 18 ° C for 15 to 25 minutes long to be treated.

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Claims (6)

Claims s tarn mss m es: s sss se ss ε ssb s sssces 1. Mushroom for paper machines, characterized by a tightly woven, multi-layer fabric which has transverse yarns (50, 6ü) which consists of yarns with the desired properties, which are reinforced by twisting with yarns with higher mechanical tensile and compressive strength. 2. Felt according to claim 1, characterized that the longitudinal yarn (10, 20, 30, ** 0) flexible and the transverse yarns (50, 6θ) ie essentially rigid are. 3. FiIs according to claim 1, characterized in that the Cross yarns (50, 60) in the fabric structure due to the density of the tissue are held. K » Felt according to claim I _1, characterized in that the transverse yarns (50, 60) are held in place in the fabric structure by binding to the longitudinal yarns (10, 20, 30, ko) . 5 «Felt according to claim 1, characterized in that the longitudinal yarns (10, 20, 30, ko) consist of multi-thread polyanide yarn and the transverse yarns (50, 6o) are asbestos yarns twisted around Mona1 wire, and that the fabric "is in two-layer fabric. 109816/0862 -i- 6. FiIs according to claim k, characterized in that the longitudinal and transverse yarns are varbundan through hardened resorcinol Fomaldahydhars aiitaliiaadar. 7 · FiIs according to claim k, daduroh yakannsaiohnet that the · long · and quar yarns duroh auagahltrtat ·· Vrathan-Üars / Hiitainaiidar Tarbund'in «iod. 109816/0882 BATH ORIGINAL