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US 12,637,789 B2Granted
Polyethylene yarn of high tenacity having high dimensional stability and method for manufacturing the same
AssigneeKolon Industries, Inc.
InventorsSin-Ho Lee, Il Chung, Young-Soo Lee, Min-Woo Nam
Life of this patent
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Abstract
The present disclosure relates to a polyethylene yarn and a method for manufacturing the same. In the present disclosure, there are provided a polyethylene yarn having excellent dimensional stability and high tenacity, and a method for manufacturing the above polyethylene yarn more efficiently.
Claims5
A polyethylene yarn comprising 40 to 500 filaments having fineness of 10 denier or less,
- wherein the polyethylene yarn has total fineness of 80 to 5000 denier, tenacity of 12.5 to 16.5 g/d, and a maximum thermal shrinkage stress of 0.250 to 0.325 g/d, and
- the filaments comprise a polyethylene made of polyethylene chips having a weight average molecular weight (Mw) of equal to or higher than 170,000 and lower than 180,000 g/mol, a polydispersity index (PDI) of 6.0 to 7.5, crystallinity of 65 to 85%, a melting temperature (Tm) of 130 to 140° C., a density of 0.93 to 0.97 g/cm3, and a melt index (MI) of 0.4 to 0.6 g/10 min,
- wherein the filaments further contain a fluorine-based polymer in an amount such that the polyethylene yarn contains 500 to 1000 ppm of fluorine,
- wherein the polyethylene yarn has a crystallite size on a (110) plane of 120 to 190 Å and a crystallite size on a (200) plane of 90 to 150 Å, when measured using the Scherrer equation from XRD data.
1 more element
A method for manufacturing a polyethylene yarn, comprising:
- (i) a preparation step of providing a melt for spinning containing a polyethylene having a weight average molecular weight (Mw) of equal to or higher than 170,000 and lower than 180,00 g/mol, a polydispersity index (PDI) of 6.0 to 7.5, crystallinity of 65 to 85%, a melting temperature (Tm) of 130 to 140° C., a density of 0.93 to 0.97 g/cm3, and a melt index (MI) of 0.4 to 0.6 g/10 min;
- (ii) a spinning step of obtaining filaments by extruding the melt through a spinneret having 40 to 500 holes;
- (iii) a quenching step of quenching the filaments;
- (iv) a drawing step of multi-stage drawing a multifilament composed of the quenched filaments at a total draw ratio of 11 to 23 times using a multi-stage drawing zone comprising a plurality of godet rollers set at a temperature of 40 to 140° C.;
- and
- (v) a take-up step of taking up the multi-stage drawn multifilament,
- wherein the multifilament is continuously transferred to the multi-stage drawing zone without being separately taken up and then drawn,
- wherein the multifilament is directly in contact with the plurality of godet rollers to be drawn and thermally fixed in the drawing step,
- wherein the filaments further contain a fluorine-based polymer in an amount such that the polyethylene yarn contains 500 to 1000 ppm of fluorine.
6 more elements
Dependencies are inferred from the claim text.