Method of producing a soft, nonwoven web
AssigneeKimberly-Clark Corporation
InventorRobert E. Weber
Life of this patent
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Abstract
A soft, nonwoven web is produced by adding directly to a thermoplastic polymer at the time of extrusion a lubricating agent having an HLB number in the range of 8 to 20 and a molecular weight in the range of from 200 to 4000. The lubricating agent is uniformly distributed into the polymer as extruded into filaments. The filaments are collected to form a web and then subjected to heat treatment in the range of from 180-260.degree. F. for at least about 1-7 seconds. The lubricating agent migrates to the surface of the fibers producing a release effect and preventing secondary bonding from occurring. After pattern bonding to provide spaced areas of high intensity bonds, the result is a soft, strong nonwoven web having particular utility as a liner for disposable diapers and catamenial devices.
Claims8
A method of making a soft, nonwoven web comprising the steps of,
- mixing with a thermoplastic polymer 0.1% to 3.0% of a semi-compatible lubricating agent having a molecular weight in the range of from about 200 to about 4000 and an HLB number in the range of from about 8 to about 20;
- extruding said mixture to form filaments;
- collecting said filaments into a web;
- pattern bonding said web to produce areas of relative high and low bond intensity;
- and
- heating said bonded web to a temperature in the range of from about 180.degree. F to 260.degree. F to cause said agent to migrate to the filament surfaces and substantially release said low intensity bonds.
A method of forming a soft, nonwoven web comprising the steps of,
- uniformly mixing with a polyolefin 0.1 to 3.0% by weight of a semi-compatible surfactant lubricating agent having a molecular weight in the range of from about 200 to about 4000 and an HLB number in the range of from about 8 to about 20;
- extruding said mixture to form filaments;
- collecting said filaments into a web;
- pattern bonding said web to produce 50 to 3200 high intensity bond areas per square inch including 5 to 50% of the total web area and low bond intensity areas outside of said compacted areas;
- and
- heating said bonded web to a temperature in the range of from about 180.degree. F to 260.degree. F to cause said agent to migrate to the surfaces of said filaments to the extent that 0.05 to 1.0% of the lubricating agent can be measured on the filament surfaces and said low intensity bonds are substantially released.
Dependencies are inferred from the claim text.