# US 2023/0212366 A1 · Cellulose fiber foam with paper-like skin and compression molding process for its preparation

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2023/0212366 A1
- Document ID: US20230212366A1
- Status: Published application
- Kind: A1
- Application number: 17/876,040
- Filed: 2022-07-28
- Published: 2023-07-06
- Earliest claimed: 2021-12-30
- Applicants: The United States of America, as represented by the Secretary of Agriculture
- Inventors: Gregory M. Glenn
- Web page: https://patentgrep.com/patent/US20230212366A1

## CPC

- C08J 9/0095: {Mixtures of at least two compounding ingredients belonging to different one-dot groups}
- C08J 9/0061: {characterized by the use of several polymeric components}
- C08J 9/0085: {Use of fibrous compounding ingredients (C08J9/0076 takes precedence)}
- C08J 9/009: {Use of pretreated compounding ingredients}
- C08J 9/28: by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
- C08J 9/30: by mixing gases into liquid compositions or plastisols, e.g. frothing with air
- C08J 9/34: Chemical features in the manufacture of articles consisting of a foamed macromolecular core and a macromolecular surface layer having a higher density than the core
- C08J 9/365: {Coating}
- C08L 1/02: Cellulose; Modified cellulose
- C08J 2205/05: Open cells, i.e. more than 50% of the pores are open
- C08J 2205/10: Rigid foams
- C08J 2301/02: Cellulose; Modified cellulose
- C08J 2329/04: Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
- C08J 2401/02: Cellulose; Modified cellulose
- C08J 2403/02: Starch; Degradation products thereof, e.g. dextrin
- C08J 2491/06: Waxes
- C08J 2493/02: Shellac
- C08L 2203/14: used for foams
- C08L 2205/16: Fibres; Fibrils
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Provided herein is a molded cellulose foam having a smooth, dense surface fiber layer and a low density, open-cell structure interior, a process for compression-molding fiber foam into such molded cellulose foam, articles prepared with such foam, and articles prepared by such process.

## Claims

### Claim 1

A molded cellulose foam having a smooth, dense surface fiber layer and a low density, open-cell structure interior.

### Claim 2 (depends on 1)

The molded cellulose foam of claim 1, wherein the molded cellulose foam comprises a pulped fiber component, at least one foaming agent, optionally at least one binding agent, and optionally at least one filler component;
wherein the pulped fiber component, the at least one foaming agent, the optional at least one binding agent when present, and the optional filler component when present are uniformly dispersed throughout a matrix.

### Claim 3 (depends on 2)

The molded cellulose foam of claim 2, wherein the pulped fiber component is crop waste fibers, wood, fiber crops, or combinations thereof.

### Claim 4 (depends on 2)

The molded cellulose foam of claim 2, wherein the foaming agent is an anionic, cationic, amphoteric, or nonionic surfactant, or based on synthetic, rosin, protein, or composite compounds.

### Claim 5 (depends on 2)

The molded cellulose foam of claim 2, wherein the molded cellulose foam comprises polyvinyl alcohol, a pregelatinized starch, a native starch, a chemically modified starch, carboxymethyl cellulose, a carboxymethyl cellulose derivative, hydroxymethyl cellulose, a hydroxymethyl cellulose derivative, xanthan gum, tara gum, alginate, or gelatin.

### Claim 6 (depends on 1)

The molded cellulose foam of claim 1, wherein the molded foam comprises a moisture resistant additive uniformly dispersed throughout the matrix.

### Claim 7 (depends on 6)

The molded cellulose foam of claim 6, wherein the moisture resistant additive uniformly dispersed throughout the matrix is a wax emulsion, a rosin emulsion, an alkyl ketone dimer (AKD), an alkyl succinic anhydride (ASA), or a pulverized wax.

### Claim 8 (depends on 1)

The molded cellulose foam of claim 1, wherein the molded foam comprises a moisture resistant outer coating applied as a surface moisture barrier.

### Claim 9 (depends on 8)

The molded cellulose foam of claim 8, wherein the moisture resistant outer coating is at least one of a plastic film, a wax, AKD, ASA, or a chemically modified carbohydrate.

### Claim 10 (depends on 1)

The molded cellulose foam of claim 1, wherein the molded foam is a liner, a packaging material, a shipping material, a food container, or an insulation.

### Claim 11 (depends on 10)

The molded cellulose foam of claim 10, wherein the molded foam is a thermal insulation, an acoustic insulation, or an impact insulation.

### Claim 12

A wet cellulose fiber foam press comprised of a porous upper platen, a porous lower platen, and a mold contained between the upper and lower platens.

### Claim 13 (depends on 12)

The wet cellulose fiber foam press of claim 12 wherein the mold is held rigidly in place and when overfilled with a wet foam a positive pressure is created inside the mold during compression action.

### Claim 14 (depends on 12)

The wet cellulose fiber foam press of claim 12 wherein the positive pressure created inside the mold during the compression action forces the wet foam to flow into void spaces within the mold, and forces liquid to flow through the porous platen to relieve excess pressure and form a. molded cellulose foam having a smooth, dense surface fiber layer and a low density, open-cell structure interior.

### Claim 15

A wet cellulose fiber foam press comprising:
a lower platen assembly comprising a first rigid grid through which liquid can pass set on a flat surface and at least one first perforated sheet through which only liquid can pass set on top of the first rigid grid,
a solid frame forming a molding chamber set on top of the first perforated sheet, and an upper platen assembly comprising a second perforated sheet through which liquid can pass with and at least one second rigid grid through which only liquid can pass set on top of the second perforated sheet,
wherein the molding chamber comprises a mold inserted into the molding chamber or as part of the solid frame, and
wherein the lower and/or the upper platen assembly may further comprise a first or second perforated sheet through which only liquid can pass.

### Claim 16 (depends on 15)

The wet cellulose fiber foam press of claim 15, wherein the first and/or second rigid grid is acrylic plastic, polymethyl methacrylate, polycarbonate, polypropylene, polyethylene terephthalate, polyvinyl chloride, acrylonitrile-butadiene-styrene, metal, wood, or terracotta.

### Claim 17 (depends on 15)

The wet cellulose fiber foam press of claim 15, wherein the first and/or second perforated sheet is acrylic plastic, polymethyl methacrylate, polycarbonate, polypropylene, polyethylene terephthalate, polyvinyl chloride, acrylonitrile-butadiene-styrene, metal, or silk.

### Claim 18 (depends on 15)

The wet cellulose fiber foam press of claim 15, further comprising at least one first screen through which only liquid can pass located between the first rigid grid and the first perforated sheet through which only liquid can pass, and/or a second screen through which only liquid can pass located between the second rigid grid and the second perforated sheet.

### Claim 19 (depends on 18)

The wet cellulose fiber foam press of claim 18, wherein the first and/or second screen is acrylic plastic, polymethyl methacrylate, polycarbonate, polypropylene, polyethylene terephthalate, polyvinyl chloride, acrylonitrile-butadiene-styrene.

### Claim 20 (depends on 15)

The wet cellulose fiber foam press of claim 15, wherein the solid frame is wood, metal, or plastic.

### Claim 21 (depends on 16)

A method for molding a wet fiber foam using the wet cellulose fiber foam press of claim 16 comprising:
stacking the solid frame forming a molding chamber on top of the lower platen assembly,
overfilling the molding chamber with the wet fiber foam,
lowering onto the wet fiber foam the upper platen assembly,
to create a molded fiber foam with a smooth, dense surface fiber layer and a low density, open-cell structure interior, and
optionally drying the molded fiber foam.

### Claim 22 (depends on 21)

The method of claim 21, further comprising drying the molded fiber foam.

### Claim 23 (depends on 21)

The method of claim 21, wherein the wet foam has a compressive strength greater than about 1.5 kPa.