Flash spun plexifilamentary strands and sheets

Patent metadata

Field	Value
Publication number	US-10329692-B2
Application number	US-201514796350-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Jul 10, 2015
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A flash-spun plexifilamentary fiber strand having a BET surface area of less than 12 m2/g, a crush value of at least 0.9 mm/g wherein said fiber strand comprises predominantly fibers formed from polyethylene, said fibers having a total crystallinity index of less than 55%, and sheets made thereof.

First claim

We claim:

1. A thermally or mechanically consolidated sheet comprising a flash-spun plexifilamentary fiber strand comprising fibers having a total crystallinity index of less than or equal to 55%, the flash-spun plexifilamentary fiber strand having a BET surface area of less than or equal to 12 m 2 /g and a crush value of greater than or equal to 0.9 mm/g,
wherein said fiber strand comprises predominantly said fibers, and said fibers are formed from homopolymers of ethylene and have a monoclinic and orthorhombic structure as determined by X-ray characterization and a crystallinity index of the monoclinic structures is higher than 1%;
the sheet resulting from a flash spinning process utilizing a spin agent medium comprising a mixture of i) and ii), wherein
i) is dichloromethane or trans-1,2-dichloroethylene; and
ii) is 2,3-dihydrodecafluoropentane, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexane, or a hydrofluoroether.

2. The sheet of claim 1 wherein said fibers have a total crystallinity index of less than or equal to 52%.

3. A multilayer structure comprising a multiplicity of two or more sheets wherein at least one sheet is a sheet according to claim 1 .

Assignees

• Du Pont

Inventors

• Meerveld Jan Van
• Schmitz Corneille
• Mathieu Joseph
• Brabbs Noel Stephen
• Skoplyak Orest
• Lemoine Christine
• Rebouillat Serge

Classifications

• D01D10/00

  Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected (finishing D02J) · CPC title

• D01D5/11

  Flash-spinning · CPC title

• D01F6/04 Primary

  from polyolefins · CPC title

• D10B2321/021

  polyethylene · CPC title

• D04H1/724

  forming webs during fibre formation, e.g. flash-spinning · CPC title