Abstract:
The present invention pertains to a process for manufacturing a film of ultra-high molecular weight polyolefin comprising the steps of subjecting a starting ultra-high molecular weight polyolefin with a weight average molecular weight of at least 500 000 gram/mole in powder form to a compacting step using an isobaric press, subjecting the compacted polyolefin to a rolling step and at least one stretching step under such conditions that at no point during the processing of the polymer its temperature is raised to a value above its melting point. The process allows for the manufacture of ultra-high molecular weight polyolefin films of high quality.
Abstract:
The present invention pertains to a process for manufacturing high molecular weight polyethylene fibers, comprising subjecting a polyethylene tape with a weight average molecular weight of at least 500 000 gram/mole, an Mw/Mn ratio of at most 6, and a 200/110 uniplanar orientation parameter of at least 3 to a force in the direction of the thickness of the tape over the whole width of the tape. The invention also pertains to a polyethylene fiber having an Mw of at least 500 000 gram/mole, an Mw/Mn ratio of at most 6, and a 020 uniplanar orientation value of at most 55°. The use of these fibres in various applications is also claimed. The preparation of low-linear density fibers is particularly preferred.
Abstract:
The present invention pertains to a process for manufacturing a film of ultra-high molecular weight polyolefin comprising the steps of subjecting a starting ultra-high molecular weight polyolefin with a weight average molecular weight of at least 500 000 gram/mole in powder form to a compacting step using an isobaric press, subjecting the compacted polyolefin to a rolling step and at least one stretching step under such conditions that at no point during the processing of the polymer its temperature is raised to a value above its melting point. The process allows for the manufacture of ultra-high molecular weight polyolefin films of high quality.