Patent ID: 8211342
Filing Date: 2012-07-03
Classification: B29C,B29K,Y10T

Abstract:
1. A process for producing a non-fibrous ultra high molecular weight polyethylene tape comprising: providing an ultra high molecular weight polyethylene (UHMWPE) powder having a viscosity-average molecular weight of at least 2,000,000; compression molding said polyethylene powder at a temperature lower than the melting point of said polyethylene powder to form a friable polyethylene sheet; calendering and shearing said friable polyethylene sheet between nip rolls to form a partially oriented polyethylene sheet; drawing said partially oriented polyethylene sheet to form a polyethylene tape having a modulus of at least 1,400 grams per denier; said drawing of said partially oriented polyethylene sheet includes a first stage drawing and a second stage drawing; said first stage drawing includes a draw ratio where at the exit of said draw unit the total draw ratio of the compacted, calendered and partially oriented polyethylene sheet is between 14:1 and 24:1; and said second stage drawing includes a draw ratio of at least 7:1 applied to said partially oriented polyethylene sheet.