Process for making fibrous web having inelastic extensibility
AssigneeUni-Charm Corporation
InventorsToshio Kobayashi, Hiroki Goda, Kazunari Isogai, Satoshi Mitsuno
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Abstract
Component thermoplastic synthetic fiber having inelastic extensibility as well as fiber diameter of 5-20 μm constituting a fibrous web is obtained by melt spinning a mixture of two or more thermoplastic synthetic resins each having a number-average molecular weight in a range of 20000-150000 at a draft ratio of 200-2300. In the case of the mixture consisting of at least two types of thermoplastic synthetic resin Ra, Rb having number-average molecular weights Ma, Mb, respectively, wherein a ratio Ma/Mb is 1.1 or higher, Ra is of 20-80 wt %, Rb is of 80-20 wt % and a sum of Ra and Rb makes up 50-100 wt % of the mixture.
Claims4
A process for making a fibrous web having inelastic extensibility generally comprising the steps of:
- providing a thermoplastic synthetic resin;
- melt spinning continuous inelastically extensible fibers from the thermoplastic synthetic resin through a plurality of nozzles;
- and
- accumulating the inelastically extensible continuous fibers on continuously running belt,
- said thermoplastic synthetic resin comprising a mixture of at least two different types of thermoplastic synthetic resins each having number-average molecular weight of 20000-150000, said mixture including:
- a first thermoplastic synthetic resin which comprises 20-90 wt. % of the inelastically extensible fibers and has a number-avenge molecular weight M1;
- and
- a second thermoplastic synthetic resin which comprises 80-10 wt. % of the inelastically extensible fibers and has a number-average molecular weight M2,
- said mixture being prepared so that a sum of said first thermoplastic synthetic resin and said second thermoplastic synthetic resin makes up 50-100 wt % of said mixture and a number-average molecular weight ratio of said first thermoplastic synthetic resin to said second thermoplastic synthetic resin is 1.1 or higher,
- said melt spinning comprising using a draft ratio of 200-2300 so that said continuous inelastically extensible fibers each have a fiber diameter of 5-20 μm.
Dependencies are inferred from the claim text.