摘要:
An improved process for flash-spinning plexifilamentary film-fibril strands from fiber-forming polyolefins is provided. A polyolefin is mixed to form a solution of 18 to 33 percent polyolefin by weight of the solution, 42 to 73 perceny methylene chloride by weight of the solution and 9 to 25 percent carbon dioxide by weight of the solution. The mixture is then flash-spun into substantially dry plexifilamentary strands.
摘要:
Solutions for flash-spinning substantially dry plexifilamentary film-fibril strands from fiber-forming polyolefins. The solutions comprise a mixture of 18 to 33 percent polyolefin by weight of the solution, 42 to 73 percent methylene chloride by weight of the solution and 9 to 25 percent carbon dioxide by weight of the solution.
摘要:
The invention relates to nonwoven fabrics containing polymeric multiple component fibers which include a core component and a plurality of wing components attached to the core. The polymeric core component has an elasticity that is greater than the elasticity of at least one of the wing polymeric components. The fibers assume a spiral twist configuration in which the plurality of wings substantially spiral about the core. In a preferred embodiment, the nonwoven fabrics have elastic stretch and recovery properties with a textile-like hand.
摘要:
This invention relates to flash spinning copolymers which provide softness and quietness to nonwoven sheet structures formed of plexifilamentary film-fibril material. In particular, flash spinning polyethylene with an ethylene copolymer provides a substantial improvement in softness and quietness.
摘要:
Controlled porosity composite sheets comprising a melt-blown polypropylene fiber web having a spunbonded polypropylene fiber sheet laminated to at least one side thereof are made by calendering an assembly of the component webs in such a manner that, when a two-layer composite sheet is made, the web of melt-blown fibers is in contact with a metal roll heated to 140.degree.-170.degree. C. operating against an unheated resilient roll; and, when a three-layer composite sheet is made, the spunbonded web in contact with the heated metal roll has a dtex per fiber value of less than 6.These composite sheets have a Gurley-Hill porosity of about 5-75 seconds, excellent mechanical and tear strengths, high water vapor penetration rate, and low liquid water permeability. They are particularly suitable for making housewrap sheets and sheets for sterile packaging. In the sterile packaging field, they are significantly better than medical paper used for the same purpose.
摘要:
A diffuse reflective article is provided including a diffuse reflector of light positioned within a structure defining an optical cavity. The diffuse reflector is a nonwoven sheet containing a plurality of inter-fiber and intra-fiber pores of optimal light scattering dimension. Also provided is an optical display, including: (i) a structure defining an optical cavity; (ii) a light source positioned within the optical cavity; (iii) a display panel through which light from the light source passes; and (iv) a diffuse reflector positioned within the optical cavity for reflecting light from the light source toward the display panel, wherein the diffuse reflector is a nonwoven sheet containing a plurality of inter-fiber and intra-fiber pores of optimal light scattering dimension.
摘要:
A process for the preparation of plexifilamentary film-fibril strands of synthetic fiber-forming polymer comprises the steps of generating a spin fluid and flash-spinning the spin fluid to form plexifilamentary film-fibril strands of the synthetic fiber-forming polymer. The spin fluid consists essentially of (a) 5 to 30 wt. % of a synthetic fiber-forming polymer, (b) a primary spin agent selected from the group consisting of hydrocarbons with 4 to 7 carbon atoms, and chlorinated, brominated and fluorinated compounds, and (c) a co-spin agent co-spin agent selected from the group consisting essentially of fluorinated organic compounds containing 4 to 8 carbon atoms and a double bond, and having an atmospheric boiling point of less than 100° C. The co-spin agent is present in the spin fluid in an amount sufficient to raise the cloud point pressure of the spin fluid by at least 50 pounds per square inch (345 kPa). A spin fluid used in the process of the invention is also provided.
摘要:
A diffuse reflective article is provided including a diffuse reflector of light positioned within a structure defining an optical cavity. The diffuse reflector is a nonwoven sheet containing a plurality of inter-fiber and intra-fiber pores of optimal light scattering dimension. Also provided is an optical display, including: (i) a structure defining an optical cavity; (ii) a light source positioned within the optical cavity; (iii) a display panel through which light from the light source passes; and (iv) a diffuse reflector positioned within the optical cavity for reflecting light from the light source toward the display panel, wherein the diffuse reflector is a nonwoven sheet containing a plurality of inter-fiber and intra-fiber pores of optimal light scattering dimension.
摘要:
A process for producing plexifilamentary products by spinning from a spin fluid of a polyolefin dissolved in a primary spin agent selected from the group consisting of 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,1,3-trichloro-2,2,3,3-tetrafluoropropane and isomers thereof; 1,2-dichloro-3,3,3-trifluoropropane and isomers thereof; and 1,2-dichloro-1-fluoroethylene; and a co-spin agent; and also a spin fluid of a polyolefin dissolved in a primary spin agent selected from the group consisting of 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,1,3-trichloro-2,2,3,3-tetrafluoropropene and isomers thereof; 1,2-dichloro-3,3,30-trifluoropropane and isomers thereof; and 1,2-dichloro-1-fluoroethylene; and a co-spin agent.
摘要:
A spinning process using azeotropic compounds as spin agents having essentially zero ozone depletion potential and that are either non-flammable or of very low flammability.