# US 11,306,415 B2 · Process for producing a non-woven fabric

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- Number: US 11,306,415 B2
- Document ID: US11306415B2
- Status: Granted
- Kind: B2
- Application number: 16/307,516
- Filed: 2017-04-19
- Published: 2020-01-09
- Granted: 2022-04-19
- Earliest claimed: 2016-07-22
- Assignees: ExxonMobil Chemical Patents Inc.
- Applicants: ExxonMobil Chemical Patents Inc.
- Inventors: William M. Ferry; Luis A. Sotomayor; Gregory E. Keys
- Web page: https://patentgrep.com/patent/US11306415B2

## CPC

- D01F 6/06: from polypropylene
- B32B 5/022: {Non-woven fabric}
- B32B 5/028: {Net structure, e.g. spaced apart filaments bonded at the crossing points}
- B32B 5/08: the fibres or filaments of a layer being of different substances {, e.g. conjugate fibres, mixture of different fibres}
- B32B 5/26: another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)}
- B32B 25/10: next to a fibrous or filamentary layer
- B32B 25/12: comprising natural rubber
- B32B 25/14: comprising {synthetic rubber copolymers (B32B25/18 and B32B25/20 take precedence)}
- B32B 25/16: comprising polydienes {homopolymers} or poly-halodienes {homopolymers (B32B25/12 takes precedence)}
- B32B 25/18: comprising butyl or halobutyl rubber
- B32B 25/20: comprising silicone rubber
- B32B 27/12: next to a fibrous or filamentary layer
- B32B 27/285: {comprising polyethers}
- B32B 27/306: {comprising vinyl acetate or vinyl alcohol (co)polymers}
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 27/34: comprising polyamides
- B32B 27/40: comprising polyurethanes
- D01D 5/08: Melt spinning methods {(D01D5/0023 takes precedence)}
- D01F 6/30: comprising olefins as the major constituent
- D01F 6/46: of polyolefins
- D04H 3/007: Addition polymers
- D04H 3/14: with bonds between thermoplastic yarns or filaments produced by welding
- B32B 2260/023: Two or more layers
- B32B 2260/046: Synthetic resin
- B32B 2262/0207: Elastomeric fibres
- B32B 2262/023: Aromatic vinyl resin, e.g. styrenic (co)polymers
- B32B 2262/0238: Vinyl halide, e.g. PVC, PVDC, PVF, PVDF
- B32B 2262/0253: Polyolefin fibres
- B32B 2262/0261: Polyamide fibres
- B32B 2262/0284: Polyethylene terephthalate [PET] or polybutylene terephthalate [PBT]
- B32B 2262/0292: Polyurethane fibres
- B32B 2262/04: Cellulosic plastic fibres, e.g. rayon
- B32B 2262/062: Cellulose fibres, e.g. cotton
- B32B 2262/067: Wood fibres
- B32B 2262/12: Conjugate fibres, e.g. core/sheath or side-by-side
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2274/00: Thermoplastic elastomer material
- B32B 2307/51: Elastic
- B32B 2307/54: Yield strength; Tensile strength
- B32B 2307/736: Shrinkable
- B32B 2432/00: Cleaning articles, e.g. mops or wipes
- B32B 2437/00: Clothing
- B32B 2535/00: Medical equipment, e.g. bandage, prostheses or catheter
- B32B 2555/02: Diapers or napkins
- D01D 5/0985: {by means of a flowing gas (e.g. melt-blowing)}
- D10B 2321/022: polypropylene
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B)
- D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES

## Abstract

A process for producing a nonwoven fabric comprising forming a polymer composition comprising a primary polypropylene and at least one secondary polyolefin; in a spunbond process, forming fibers then fabric from the polymer composition; and exposing the fabric to an heating environment within a range from 50° C. to 250° C.

## Claims

### Claim 1

A process for producing a nonwoven fabric comprising:
a) forming a polymer composition comprising a primary polypropylene and at least one secondary polyolefin;
b) in a spunbond process, forming fibers then fabric from the polymer composition;
c) exposing the fabric to a cooling environment to a temperature below 50° C.; and
d) exposing the fabric to a heating environment within a range from 50° C. to 250° C.

### Claim 2 (depends on 1)

The process of claim 1, wherein the cooling environment comprises cooling air.

### Claim 3 (depends on 1)

The process of claim 1, wherein the primary polypropylene has a molecular weight distribution (MWD) of less than 5.5 and a melt flow rate within a range from 1 to 500 g/10 min (ASTM D1238, 2.16 kg, 230° C.).

### Claim 4 (depends on 1)

The process of claim 1, wherein the primary polypropylene is present in a polymer composition within a range from 98 to 50 wt %, based on the weight of the polymer composition, and the secondary polyolefin is present within a range from 2 to 50 wt %, based on the weight of the polymer composition.

### Claim 5 (depends on 1)

The process of claim 1, wherein the secondary polyolefin is a propylene-based elastomer having at least 60 wt % propylene-derived structural units and 3 to 25 wt % ethylene-derived structural units, based on weight of the propylene-based elastomer, and a heat of fusion of less than 80 J/g.

### Claim 6 (depends on 1)

The process of claim 1, wherein the secondary polyolefin is an ethylene-based polymer derived from ethylene and optionally one or more C3 to C20 α-olefin comonomers, wherein the ethylene-based polymer has a density within a range from 0.900 to 0.945 g/cm3, a melt index (MI), I2.16, within a range from 0.1 to 15 g/10 min, a MWD within a range from 1.5 to 5.5, and a melt index ratio (MIR), I21.6/I2.16, within a range from 10 to 100.

### Claim 7 (depends on 1)

The process of claim 1, wherein the fibers have a thermal shrinkage at least 5% higher than the thermal shrinkage of the primary polypropylene alone, as determined in accordance with ASTM D2259.

### Claim 8 (depends on 1)

The process of claim 1, wherein the fibers have a thermal shrinkage at least 20% higher than the thermal shrinkage of the primary polypropylene alone, as determined in accordance with ASTM D2259.

### Claim 9 (depends on 1)

The process of claim 1, wherein the fibers have a thermal shrinkage of more than 10, as determined in accordance with ASTM D2259, after being spun at a spinning speed of 2500 m/min.

### Claim 10 (depends on 1)

The process of claim 1, wherein the fibers have a thermal shrinkage of more than 20, as determined in accordance with ASTM D2259, after being spun at a spinning speed of 3500 m/min.

### Claim 11 (depends on 1)

The process of claim 1, wherein the fibers have an average diameter of less than 20 μm, or a denier (g/9000 m) of less than 2.

### Claim 12 (depends on 1)

The process of claim 1, wherein the primary polypropylene is produced by using a Ziegler-Natta catalyst system.

### Claim 13 (depends on 1)

The process of claim 1, wherein the primary polypropylene has a MWD within a range from 3 to 4.5, as determined by GPC.

### Claim 14 (depends on 1)

The process of claim 1, wherein the primary polypropylene has a melt flow rate within a range from 10 to 250 g/10 min, as determined in accordance with ASTM 1238, 2.16 kg at 230° C.