Patent
Shaped polyethylene articles of intermediate molecular weight and high modulus
TLDR
In this article, a polyethylene extrusion process is described, in which polymers from about 200,000 to about 4,000,000 are extruded through an aperature at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel.Abstract:
Solutions of intermediate molecular weight polymers from about 200,000 to about 4,000,000, such as polyethylene, in a relatively non-volatile solvent are extruded through an aperature at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel. The first gels are extracted with a volatile solvent to form a second gel, and the second gel is dried to form a low porosity xerogel. Stretching occurs with any one or more of the first gel, second gel or xerogel. The polyethylene products produced by our process include products having a molecular weight between about 200,000 and about 4,000,000 a tenacity of at least about 13 grams/denier, a modulus of at least about 350 gram/denier, a porosity of less than 10% by volume, a crystalline orientation function of at least about 0.95, and a main melting temperature of at least about 140° C.read more
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High tenacity, high modulus filament
TL;DR: In this paper, a ballistic resistant composite panel is provided comprising a polyethylene multi-filament yarn having a tenacity of at least about 35 g/d, a modulus and a work-to-break of 65 J/g wherein the yarn has greater than about 60 % of a high strain orthorhombic crystalline component and a monoclinic component greater than 2 % of the crystalline content.
Patent
Very low creep, ultra high moduls, low shrink, high tenacity polyolefin fiber having good strength retention at high temperatures and method to produce such fiber
James Jay Dunbar,Sheldon Kavesh,Dusan C. Prevorsek,Thomas Yiu-Tai Tam,Gene C. Weedon,Robert C Wincklhofer +5 more
TL;DR: In this paper, a polyethylene fiber is poststretched at a temperature between about 135° and 160° C. The poststretching can be in multiple stages and/or with previous annealing.
Patent
Process for making high-performance polyethylene multifilament yarn
Joseph Arnold Paul Maria Simmelink,Jacobus Johannes Mencke,Martinus Johannes Nicolaas Jacobs,Roeloef Marissen +3 more
TL;DR: In this article, a process for making highperformance polyethylene multi-filament yarn comprising the steps of making a solution of ultra-high molar mass polymethylene in a solvent, spinning of the solution through a spinplate containing a plurality of spinholes into an air-gap to form fluid filaments, while applying a draw ratio DRfluid, cooling the fluid filament to form solvent-containing gel filaments; removing at least partly the solvent from the filaments and drawing the filament in at least one step before, during and/or after said solvent
Patent
Impact resistant helmet
Hsin Lang Li,Dusan C. Prevorsek +1 more
TL;DR: In this paper, an improved impact resistant composite and helmet made thereof is presented, which consists of a plurality of unidirectional coplanar fibers embedded in a polymeric matrix.
Patent
Composite and article using short length fibers
TL;DR: In this paper, an improved prepreg layer, a multilayer composite based on the improved pre-prepreg layer and an article made from the multi-layer composite is presented.
References
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Patent
High tenacity, high modulus polyethylene and polypropylene fibers and intermediates therefore
TL;DR: In this article, a solution of ultrahigh molecular weight polymers such as polyethylene in a relatively nonvolatile solvent is extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length.
Patent
Ballistic-resistant article
TL;DR: In this article, it was shown that polyethylene and polypropylene fibers of 15, 20, 25, 30 or more g/denier tenacity and 300, 500, 1,000, 1.500 or more tensile modulus impart exceptional ballistic resistance to the articles in spite of the melting points.
Patent
Producing high tenacity, high modulus crystalline article such as fiber or film
TL;DR: In this paper, a solution of ultrahigh molecular weight polymers such as polyethylene in a relatively nonvolatile solvent is extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length.
Journal ArticleDOI
Maximum strength and drawing mechanism of hot drawn high molecular-weight polyethylene
B. Kalb,Albert J. Pennings +1 more
TL;DR: In this paper, an investigation of the hot drawing of high molecular weight polyethylene fibres containing a substantial amount of solvent, and of fibres with a porous structure that were dried after solution spinning, was conducted.
Patent
High strength and modulus polyvinyl alcohol fibers and method of their preparation
TL;DR: In this article, polyvinyl alcohol of molecular weight over 500,000 (i.e. 1,500,000 to 2,500000) is spun as a dilute solution (2-15%) in a relatively nonvolatile solvent such as glycerin.