| 摘要 |
A process for flash-spinning a web of plexifilamentary film-fibril strands of synthetic fiber-forming polymer and laying down the web to form a nonwoven batt material therefrom is provided. The process includes the the step of generating a spin fluid consisting essentially of synthetic fiber-forming polymer and a spin agent, wherein the spin agent is comprised of at least 80% by weight, based on the total weight of the spin agent, of hydrocarbons comprised substantially exclusively of carbon and hydrogen atoms. The hydrocarbons are comprised of at least 25% by weight of unsaturated hydrocarbons having 4-8 carbon atoms. The process further includes the steps of flash-spinning the spin fluid at a pressure that is greater than the autogenous pressure of the spin fluid into a spin cell maintained at lower pressure to form a web of plexifilamentary film-fibril strands of said synthetic fiber-forming polymer, applying an electrostatic charge to the web by passing the web through an electric corona, and laying the web onto a grounded surface to form a batt of plexifilamentary film-fibril strands that is suitable for being consolidated into a sheet. |
