Soil-repellent monofilament for paper machine wire-cloths, production thereof and use thereof
AssigneeRhone-Poulenc Viscosuisse SA
InventorsHalim Baris, Erwin Lerch
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Abstract
The soil-repellent monofilament for paper machine wire-cloths consists of at least 85% by weight of polyethylene terephthalate having a viscosity index (V.I.) of at least 96 dl/g and an added copolymer prepared from alkenes and perfluoroalkenes having a melting point from 255.degree. to 275.degree. C. To make the soil-repellent monofilament 1.5 to 5% by weight of tetrafluoroethylene is included by addition to the polymer melt of polyethylene terephthalate prior to extrusion. The soil-repellent monofilament produced by this method has a soiling index of <2 after 5 soiling and cleaning cycles.
Claims3
Soil-repellent homogeneously structured monofilament for a paper machine wire-cloth said soil-repellent monofilament having a viscosity index of at least 96 dl/g and a homogeneous diameter from 0.2 to 0.7 mm and consisting at least 85% by weight of polyethylene terephthalate and from 1.5 to 5% by weight of a polynary copolymer prepared from at least one alkene and at least one perfluoroalkene.
Process for making a soil-repellent monofilament for a paper machine wire-cloth comprising the steps of:
- a) providing a polymer melt consisting of at least 85% by weight of polyethylene terephthalate having a viscosity index of at least 96 dI/g, and
- b) prior to extruding said soil-repellent monofilament, mixing from 1.5 to 5% by weight of a polynary copolymer prepared from at least one alkene and at least one perfluoroalkene;
- c) and extruding, cooling, Spin-finishing, drawing, relaxing and winding up said monofilament.
Dependencies are inferred from the claim text.