Patent application number | Description | Published |
20080290549 | Process for the preparation of polymer yarns from ultra high Molecular weight homopolymers or copolymers, polymer yarns,molded polymer parts, and the use of polymer yarns - A process for the preparation of polymer yarns from ultra high molecular weight homopolymers or copolymers, wherein the process includes the following steps:
| 11-27-2008 |
20080290550 | Process for the preparation of polymer yarns from ultra high molecular weight homopolymers or copolymers, polymer yarns, molded polymer parts, and the use of polymer yarns - A process for the preparation of polymer yarns from ultra high molecular weight homopolymers or copolymers, wherein the process includes the following steps: | 11-27-2008 |
20090123748 | Process for the production of high tensile strength and low creep polymer yarns, high tensile strength and low creep polymer or copolymer yarns, and, the use of such yarns - The present invention relates to a process for the production of high tensile strength and low creep polymer yarns, wherein it comprises the following steps: (a) preparing a mixture of: (i) a first ultra high molecular weight polyolefin polymer or copolymer, (ii) a second clay nanocomposite polyolefin polymer or copolymer, and (iii) a non-polar spinning solvent, (b) feeding the resulting suspension through an extruder at a temperature of at least 180° C., causing the formation of a gel, (c) spinning the gel so obtained in a spinneret with a length to diameter ratio (L/D) of at least 15, (d) cooling the yarn to a temperature below 2° C., (e) subsequently removing the non-polar spinning solvent, and (f) drawing the yarn so obtained so as to obtain a tensile strength value of at least 18 cN/Dtex and a creep value lower than 0.07% per hour, wherein the first ultra high molecular weight polyolefin polymer or copolymer has a weight-average molecular weight higher than 2,000,000 g/mol and a polydispersivity of at least 7, and the second clay nanocomposite polyolefin polymer or copolymer is obtained via in situ polymerization of an olefin and an exfoliated layered clay, the polyolefin so obtained having a weight-average molecular weight of at least 400,000 g/mol. | 05-14-2009 |
20090163679 | Suspension polymerization process for manufacturing ultra high molecular weight polyethylene, a multimodal ultra high molecular weight polyethylene homopolymeric or copolymeric composition, a ultra high molecular weight polyethylene, and their uses - The present invention relates to a suspension polymerization process for the production of ultra high molecular weight polyethylene, wherein the operation is carried out in at least two reactors of the CSTR type (continuous stirring tank reactor), in a serial configuration, wherein the first reactor is fed with solvent, monomer and, optionally, comonomer; Ziegler-Natta type catalyst, said catalyst composition having a chloride concentration of at least 55%, based on its composition, and preferably more than 76%, chlorinated cocatalyst and chain growth regulator, said continuous stirring tank reactor being kept under a pressure between 0.1 to 2.0 MPa and temperature from 40° C. to 100° C., which contents of the first reactor are transferred to the subsequent reactor, by means of a pressure differential or through pumping, wherein said subsequent reactors are kept under a pressure between 0.1 to 2.0 MPa and temperature from 40° C. to 100° C., and fed with solvent, monomer, and, optionally, comonomer, catalyst, cocatalyst and chain growth regulator, the pressure and temperature in each of the reactors being different from one another up to the “n | 06-25-2009 |
20110256400 | PROCESS FOR THE PREPARATION OF POLYMER YARNS FROM ULTRA HIGH MOLECULAR WEIGHT HOMOPOLYMERS OR COPOLYMERS, POLYMER YARNS, MOLDED POLYMER PARTS AND THE USE OF POLYMER YARNS - Polymer yarns prepared from ultra high molecular weight homopolymers or copolymers which includes the steps of preparing a suspension of a homopolymer or copolymer and a spinning or gelling solvent, extruding the suspension with the formation of a gel, spinning the gel to obtain non-stretched filaments or yarns, cooling the non-stretched filaments or yarns, feeding the non-stretched filaments or yarns, to an extractor together with the feed of an organic extraction solvent, extracting the non-polar long chain solvent impregnated in the yarns, drying the non-stretched filament bundles or yarns, and stretching said dry yarns at a temperature in excess of 80° C. | 10-20-2011 |