Process of making dimensionally stable nonwoven fibrous webs

Patent metadata

Field	Value
Publication number	US-9416485-B2
Application number	US-201414231175-A
Country	US
Kind code	B2
Filing date	Mar 31, 2014
Priority date	Dec 17, 2009
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Dimensionally stable nonwoven fibrous webs include a multiplicity of continuous fibers formed from one or more thermoplastic polyesters and polypropylene in an amount greater than 0% and no more than 10% by weight of the web. The webs have at least one dimension which decreases by no greater than 10% in the plane of the web when heated to a temperature above a glass transition temperature of the fibers. A spunbond process may be used to produce substantially continuous fibers that exhibit molecular orientation. A meltblown process may be used to produce discontinuous fibers that do not exhibit molecular orientation. In some embodiments, the fibers comprise a viscosity modifier and/or an anionic surfactant. The webs may be used as articles for filtration, sound absorption, thermal insulation, surface cleaning, cellular growth support, drug delivery, personal hygiene, medical apparel, or wound dressing.

First claim

The invention claimed is:

1. A method of making a web comprising:
forming a mixture comprising:
one or more thermoplastic polyesters selected from aliphatic polyesters and aromatic polyesters,
polypropylene in an amount greater than 0% and no more than 10% by weight of the mixture; and
a viscosity modifier selected from the group consisting of alkyl carboxylates, alkenyl carboxylates, aralkyl carboxylates, alkylethoxylated carboxylates, aralkylethoxylated carboxylates, alkyl lactylates, alkenyl lactylates, and mixtures thereof

simulataneously forming a plurality of fibers from the mixture; and
collecting at least a portion of the fibers to form a web, wherein the web has at least one dimension which decreases by no greater than 10% in the plane of the web when the web is heated to a temperature above a glass transition temperature of the fibers but below the melting temperature when measured in an unrestrained condition.

2. The method of claim 1 , wherein the web is formed using a melt-blowing, spun-bonding, or melt-spinning process.

3. The method of claim 1 , wherein the thermoplastic polyester and the viscosity modifier are mixed prior to the web forming process.

4. The method of claim 1 , further comprising the step of extruding the polyester blended with the viscosity modifier.

5. The method of claim 1 , wherein the mixing of the polyester and the viscosity modifier comprises extruding the polyester and the viscosity modifier.

6. The method of claim 1 , further comprising post heating the web.

7. The method of claim 1 , wherein the web is formed using melt-spinning, filament extrusion, electrospinning, gas jet fibrillation or combinations thereof.

8. The method of claim 1 , wherein the fibers do not exhibit molecular orientation.

9. The method of claim 1 , wherein the mixture is a melt-processable mixture.

10. The method of claim 1 , wherein the web is in the form of a surgical drape, surgical gown, sterilization wrap, or wound contact material.

Assignees

• 3M Innovative Properties Co

Inventors

• Moore Eric M
• Stelter John D
• Berrigan Michael R
• Porbeni Francis E
• Scholz Matthew T
• Landgrebe Kevin D
• Karls Korey W
• Fennessey Sian F
• Jennen Jay M

Classifications

• B29L2031/731

  Filamentary material, i.e. comprised of a single element, e.g. filaments, strands, threads, fibres (cables B29L2031/707) · CPC title

• D01F6/92

  of polyesters · CPC title

• B29C48/12

  Articles with an irregular circumference when viewed in cross-section, e.g. window profiles · CPC title

• Y10T442/68

  Melt-blown nonwoven fabric · CPC title

• B29C48/0017

  combined with blow-moulding or thermoforming · CPC title