Sheets having a starch-based binding matrix

• US 6,083,586 A
• Filed: 02/06/1998
• Issued: 07/04/2000
• Est. Priority Date: 11/19/1993
• Status: Expired due to Fees

• Current Assignee: E. Khashoggi Industries, LLC
• Original Assignee: E. Khashoggi Industries, LLC
• Inventors: Andersen, Per Just, Christensen, Bruce J., Hodson, Simon K., Ong, Shaode
• Primary Examiner(s): Copenheaver, Blaine
• Application Number:
  US09/019,907
• Time in Patent Office: 879 Days
• Field of Search: 428/36.4, 428/36.5, 428/36.92, 428/43, 428/152, 428/182, 428/317.9, 428/532, 428/906, 206/524.3, 206/524.7, 106/206.1, 106/217.01, 106/400
• US Class Current: 428/36.4
• CPC Class Codes: B05B 1/34 designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl designed to control volume of flow B05B1/30
• CPC Class Codes: B05B 11/0037 Containers for several components B05B11/0078
• CPC Class Codes: B05C 5/0245 for applying liquid or other fluent material to a moving work of indefinite length, e.g. to a moving web B05C5/0241, B05C5/0254, B05C5/027, B05C5/0283 take precedence
• CPC Class Codes: B28B 1/00 Producing shaped prefabricated articles from the material using presses B28B3/00; shaping on moving conveyors B28B5/00; producing tubular articles B28B21/00 ; producing articles with embedded elements B28B23/00
• CPC Class Codes: B28B 1/52 specially adapted for producing articles from mixtures containing fibres, e.g. asbestos cementby wrapping on to mandrels B28B1/42
• CPC Class Codes: B28B 11/00 Apparatus or processes for treating or working the shaped or preshaped articles specially adapted for tubular articles B28B21/92; decoration or surface treatment in general B05, B44; compacting concrete in situ in connection with building E04G21/06; drying F26
• CPC Class Codes: B28B 11/003 the shaping of preshaped articles, e.g. by bending B28B11/08 takes precedence
• CPC Class Codes: B28B 23/00 Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objectsB28B21/00 takes precedence; in units for prefabricated buildings B28B7/22
• CPC Class Codes: B28B 23/0081 Embedding aggregates to obtain particular properties
• CPC Class Codes: B28B 23/0087 Lightweight aggregates for making lightweight articles
• CPC Class Codes: B28B 3/126 on material passing directly between the co-operating rollers
• CPC Class Codes: B28B 3/20 wherein the material is extruded extrusion moulding of plastics B29C48/00
• CPC Class Codes: B29C 2043/3433 using dispensing heads, e.g. extruders, placed over or apart from the moulds
• CPC Class Codes: B29C 2043/463 corrugated, patterned or embossed surface
• CPC Class Codes: B29C 2049/023 using inherent heat of the preform, i.e. 1 step blow moulding
• CPC Class Codes: B29C 2049/4608 Nitrogen
• CPC Class Codes: B29C 2791/006 Using vacuum
• CPC Class Codes: B29C 2795/007 after shaping
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 43/00 Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor by liberation of internal stresses B29C61/006
• CPC Class Codes: B29C 43/003 : characterised by the choice of material
• CPC Class Codes: B29C 43/02 : of articles of definite length, i.e. discrete articles B29C35/0227 takes precedence
• CPC Class Codes: B29C 43/08 : with circular movement , e.g. mounted on rolls, turntables
• CPC Class Codes: B29C 43/22 : of articles of indefinite length
• CPC Class Codes: B29C 43/24 : Calendering
• CPC Class Codes: B29C 43/34 : Feeding the material to the mould or the compression means B29C43/085 takes precedence
• CPC Class Codes: B29C 43/46 : Rollers
• CPC Class Codes: B29C 48/0017 : combined with blow-moulding or thermoforming
• CPC Class Codes: B29C 48/0019 : combined with shaping by flattening, folding or bending
• CPC Class Codes: B29C 48/0022 : combined with cutting
• CPC Class Codes: B29C 48/07 : Flat, e.g. panels
• CPC Class Codes: B29C 48/08 : flexible, e.g. films
• CPC Class Codes: B29C 48/15 : incorporating preformed parts or layers, e.g. extrusion moulding around inserts
• CPC Class Codes: B29C 49/0005 : characterised by the material
• CPC Class Codes: B29C 49/04 : Extrusion blow-moulding
• CPC Class Codes: B29C 49/06 : Injection blow-moulding
• CPC Class Codes: B29C 49/063 : with the parison axis held in the plane of rotation
• CPC Class Codes: B29C 49/0691 : using sheet like material, e.g. sheet blow-moulding from joined sheets
• CPC Class Codes: B29C 51/002 : characterised by the choice of material
• CPC Class Codes: B29C 51/04 : Combined thermoforming and prestretching, e.g. biaxial stretching
• CPC Class Codes: B29C 51/08 : Deep drawing or matched-mould forming, i.e. using mechanical means only
• CPC Class Codes: B29C 51/082 : by shaping between complementary mould parts
• CPC Class Codes: B29C 51/10 : Forming by pressure difference, e.g. vacuum
• CPC Class Codes: B29C 53/063 : combined with folding
• CPC Class Codes: B29C 53/58 : helically
• CPC Class Codes: B29C 55/18 : by squeezing between surfaces, e.g. rollers
• CPC Class Codes: B29C 67/24 : characterised by the choice of material
• CPC Class Codes: B29C 67/242 : Moulding mineral aggregates bonded with resin, e.g. resin concrete shaping ceramic compositions without binder or water-setting cementitious material B28B; compositions per se C04B
• CPC Class Codes: B29C 70/50 : for producing articles of indefinite length, e.g. prepregs, sheet moulding compounds [SMC] or cross moulding compounds [XMC]
• CPC Class Codes: B29C 71/0009 : using liquids, e.g. solvents, swelling agents spectacle cases, e.g. for cleaning contact lenses A45C11/04; disinfecting or sterilising contact lenses A61L12/00, using liquid substances A61L2/20; cleaning involving the use of liquid in general B08B3/00; for hydrating contact lenses B29D11/00067
• CPC Class Codes: B29K 2003/00 : Use of starch or derivatives as moulding material
• CPC Class Codes: B29K 2005/00 : Use of polysaccharides or derivatives as moulding material
• CPC Class Codes: B29L 2031/712 : Containers; Packaging elements or accessories, Packages closures therefor B29L2031/56; ink or toner cartridges B29L2031/7678; squeeze tubes B29L2023/20; suitcases B29L2031/7418
• CPC Class Codes: B29L 2031/7132 : Bowls, Cups, Glasses
• CPC Class Codes: B31B 2105/0022 : Making boxes from tubular webs or blanks, e.g. with separate bottoms, including tube or bottom forming operations
• CPC Class Codes: B31B 50/32 : in circular paths
• CPC Class Codes: B31D 1/005 : making bottoms or caps
• CPC Class Codes: B32B 13/02 : with fibres or particles being present as additives in the layer
• CPC Class Codes: B32B 27/04 : as impregnant, bonding, or embedding substance not used
• CPC Class Codes: B32B 27/20 : using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 37/12 : characterised by using adhesives
• CPC Class Codes: B32B 5/02 : characterised by structural features of a fibrous or filamentary layer layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02
• CPC Class Codes: B32B 9/00 : Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
• CPC Class Codes: B65D 2565/385 : especially suited for or with means facilitating recycling
• CPC Class Codes: B65D 43/162 : the container, the lid and the hinge being made of one piece B65D43/161 takes precedence
• CPC Class Codes: B65D 65/38 : Packaging materials of special type or form
• CPC Class Codes: B65D 65/466 : Bio- or photodegradable packaging materials
• CPC Class Codes: C04B 20/0048 : Fibrous materials
• CPC Class Codes: C04B 2111/00612 : as one or more layers of a layered structure
• CPC Class Codes: C04B 2111/00948 : for the fabrication of containers
• CPC Class Codes: C04B 24/14 : Peptides; Proteins; Derivatives thereof
• CPC Class Codes: C04B 24/26 : obtained by reactions only involving carbon-to-carbon unsaturated bonds C04B24/243 takes precedence
• CPC Class Codes: C04B 24/38 : Polysaccharides or derivatives thereof C04B24/243 takes precedence
• CPC Class Codes: C04B 24/383 : Cellulose or derivatives thereof
• CPC Class Codes: C04B 26/02 : Macromolecular compounds
• CPC Class Codes: C04B 26/28 : Polysaccharides or derivatives thereof
• CPC Class Codes: C04B 40/00 : Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability active ingredients C04B22/00 - C04B24/00; hardening of a well-defined composition C04B26/00 - C04B28/00; making porous, cellular or lightening C04B38/00; mechanical aspects B28, e.g. conditioning the materials prior to shaping B28B17/02
• CPC Class Codes: C04B 40/0071 : making use of a rise in pressure
• CPC Class Codes: C04B 40/0082 : making use of a rise in temperature, e.g. caused by an exothermic reaction
• CPC Class Codes: C04B 40/0092 : Temporary binders, mortars or concrete, i.e. materials intended to be destroyed or removed after hardening, e.g. by acid dissolution
• CPC Class Codes: C08J 2323/02 : not modified by chemical after treatment
• CPC Class Codes: C08J 5/18 : Manufacture of films or sheets
• CPC Class Codes: C08L 1/28 : Alkyl ethers
• CPC Class Codes: C08L 1/286 : substituted with acid radicals, e.g. carboxymethyl cellulose [CMC] C08L1/282 takes precedence
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 : Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 3/00 : Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
• CPC Class Codes: C08L 3/02 : Starch; Degradation products thereof, e.g. dextrin
• CPC Class Codes: C08L 5/02 : Dextran; Derivatives thereof
• CPC Class Codes: C08L 5/12 : Agar or agar-agar , i.e. mixture of agarose and agaropectin; Derivatives thereof
• CPC Class Codes: C08L 5/14 : Hemicellulose; Derivatives thereof
• CPC Class Codes: C08L 89/06 : derived from leather or skin , e.g. gelatin
• CPC Class Codes: C08L 97/02 : Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: E05D 1/02 : made of one piece
• CPC Class Codes: E05Y 2900/602 : for containers
• CPC Class Codes: Y02W 90/10 : Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics
• CPC Class Codes: Y10S 428/906 : Roll or coil
• CPC Class Codes: Y10T 428/1372 : Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/1376 : Foam or porous material containing
• CPC Class Codes: Y10T 428/249986 : Void-containing component contains also a solid fiber or solid particle
• CPC Class Codes: Y10T 428/31971 : Of carbohydrate

Abstract

Compositions and methods for manufacturing sheets having a starch-bound matrix, optionally reinforced with fibers and optionally including an inorganic mineral filler. Suitable mixtures for forming the sheets are prepared by mixing together water, unmodified and ungelatinized starch granules, a cellulosic ether, optionally fibers, and optionally an inorganic mineral filler in the correct proportions to form a sheet having desired properties. The mixtures are formed into sheets by passing them between one or more sets of heated rollers to form green sheets. The heated rollers cause the cellulosic ether to form a skin on the outer surfaces of the sheet that prevents the starch granules from causing the sheet to adhere to the rollers upon gelation of the starch. The green sheets are passed between heated rollers to gelatinize the starch granules, and then to dry the sheet by removing a substantial portion of the water by evaporation. The starch and cellulosic ether form the binding matrix of the sheets with the fibers and optional inorganic filler dispersed throughout the binding matrix. The starch-bound sheets can be cut, rolled, pressed, scored, perforated, folded, and glued to fashion articles from the sheets much like paper or paperboard. The sheets are particularly useful in the mass production of containers, such as food and beverage containers.

Claims

1. A starch-bound sheet comprising:

a binding matrix including starch and a cellulosic ether, wherein the binding matrix is formed by at least partially gelating the starch in water and then causing the starch to substantially harden by removing a substantial portion of the water by evaporation, wherein the combined concentration of the starch and cellulosic ether is greater than about 20% by weight of solids in the sheet;

fibers substantially homogeneously dispersed throughout the binding matrix and having an average aspect ratio greater than about 10;

1; and

an inorganic mineral filler included in an amount up to about 80% by weight of solids in the sheet,

wherein the starch-bound sheet has a thickness of less than about 1 cm and a density greater than about 0.5 g/cm³ and is sufficiently flexible so that it can be significantly mechanically deformed by at least one process selected from the group consisting of crimping, creping, stretching, bending, folding, rolling, convoluting, spiral winding, pressing, fluting, and corrugating without complete rupture of the sheet.

2. A sheet as defined in claim 1, wherein the starch has a concentration in a range from about 15% to about 75% by weight of total solids in the sheet.

3. A sheet as defined in claim 1, wherein the starch has a concentration in a range from about 30% to about 70% by weight of total solids in the sheet.

4. A sheet as defined in claim 1, wherein the starch has a gelation temperature and the cellulosic ether has a thermal precipitation temperature such that the gelation temperature of the starch is greater than the thermal gelation temperature of the cellulosic ether.

5. A sheet as defined in claim 1, wherein the binding matrix further includes a protein-based binder selected from the group consisting of prolamine, collagen, gelatin, glue, casein, and mixtures or derivatives thereof.

6. A sheet as defined in claim 1, wherein the binding matrix further includes a polysaccharide selected from the group consisting of alginic acid, phycocolloids, agar, gum arabic, guar gum, locust bean gum, gum karaya, gum tragacanth, and mixtures or derivatives thereof.

8. A sheet as defined in claim 1, wherein the inorganic mineral filler has a concentration in a range from about 20% to about 80% by weight of total solids in the sheet.

9. A sheet as defined in claim 1, wherein the fibers have a concentration in a range from about 3% to about 40% by weight of total solids in the sheet.

10. A sheet as defined in claim 1, wherein the sheet has a thickness of less than about 1 mm.

11. A sheet as defined in claim 1, wherein the sheet has a thickness of less than about 0.1 mm.

12. A sheet as defined in claim 1, wherein the sheet has a density greater than about 1 g/cm³.

13. A sheet as defined in claim 1, wherein the sheet is water degradable.

14. A sheet as defined in claim 1, wherein the sheet further includes a coating.

15. A sheet as defined in claim 1, wherein the sheet further includes at least one other sheet laminated thereto.

16. A sheet as defined in claim 1, wherein the sheet includes a hinge.

17. A sheet as defined in claim 16, wherein the coating is selected from the group consisting of edible oils, melamine, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyacrylates, polyamides, hydroxypropylmethylcellulose, methocel, other cellulosic ethers, polyethylene glycol, acrylics, polyurethane, polyethylene, polylactic acid, polyhydroxybutyrate-hydroxyvalerate copolymers, latexes starches, soybean protein, soybean oil, polyethylene, waxes, elastomers biodegradable polymers, sodium silicate, calcium carbonate, aluminum oxide, silicon oxide, kaolin, clay, ceramic and mixtures thereof.

18. A sheet as defined in claim 16. wherein the at least one other sheet is selected from the group consisting of starch-bound sheets, organic polymer sheets, metal foil sheets, ionomer sheets, elastomeric sheets, plastic sheets, fibrous sheets, mats, paper sheets, cellophane sheets, nylon sheets, wax sheets, hydraulically settable sheets, highly inorganically filled sheets, metallized film sheets and combinations thereof.

19. A sheet as defined in claim 1, wherein the sheet has been fashioned into a container.

20. A sheet as defined in claim 1, wherein the sheet comprises a continuous sheet that has been rolled onto a spool.

21. A sheet as defined in claim 1, wherein the fibers have a length greater than about 1.5 mm.

7. A sheet as defined in claim l, wherein the binding matrix further includes a synthetic organic binder selected from the group consisting of polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, polyvinylmethyl ether, polyacrylic acids, polyacrylic acid salts, polyvinylacrylic acids, polyvinylacrylic acid salts, polyacrylimides, polylactic acid, ethylene oxide polymers, latex, and mixtures or derivatives thereof.

22. A starch-bound sheet comprising:

a binding matrix including starch and a cellulosic ether, wherein the starch has a concentration in a range from about 5% to about 90% by weight of solids in the sheet;

fibers included in an amount of at least about 3% by weight of solids in the sheet and being substantially homogeneously dispersed throughout the binding matrix, the fibers having an average aspect ratio greater than about 10;

1; and

an inorganic mineral filler included in a range from about 0% to about 90% by weight of solids in the sheet, the starch-bound sheet having a thickness less than about 1 cm and a density greater than about 0.5 g/cm³.

23. A sheet as defined in claim 22, wherein the fibers have a concentration in a range from about 3% to about 40% by weight of total solids in the sheet.

24. A sheet as defined in claim 22, wherein the cellulosic ether has a concentration in a range from about 0.5% to about 10% by weight of total solids in the sheet.

25. A sheet as defined in claim 22, wherein the starch has a gelation temperature and the cellulosic ether has a thermal precipitation temperature such that the gelation temperature of the starch is greater than the thermal gelation temperature of the cellulosic ether.

26. An inorganically filled starch-bound sheet comprising:

a binding matrix including starch and a cellulosic ether, the starch having a concentration in a range from about 5% to about 75% by weight of solids in the sheet;

fibers substantially homogeneously dispersed throughout the binding matrix and having an aspect ratio greater than about 10;

1; and

an inorganic mineral filler included in a range from about 20% to about 90% by weight of solids in the sheet, the starch-bound sheet having a thickness less than about 1 cm and a density greater than about 0.5 g/cm³.

27. An inorganically filled starch-bound sheet as defined in claim 26, wherein the binding matrix further includes a protein-based binder selected from the group consisting of prolamine, collagen, gelatin, glue, casein, and mixtures or derivatives thereof.

28. An inorganically filled starch-bound sheet as defined in claim 26, wherein the binding matrix further includes a polysaccharide selected from the group consisting of alginic acid, phycocolloids, agar, gum arabic, guar gum, locust bean gum, gum karaya, gum tragacanth, and mixtures or derivatives thereof.

29. An inorganically filled starch-bound sheet as defined in claim 26, wherein the binding matrix further includes a synthetic organic binder selected from the group consisting of polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, polyvinylmethyl ether, polyacrylic acids, polyacrylic acid salts, polyvinylacrylic acids, polyvinylacrylic acid salts, polyacrylimides, polylactic acid, ethylene oxide polymers, latex, and mixtures or derivatives thereof.

30. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet has a thickness less than about 1 mm.

31. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet has a density greater than about 1 g/cm³.

32. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet is water degradable.

33. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet further includes a coating on at least a portion thereof.

34. An inorganically filled starch-bound sheet as defined in claim 33, wherein the coating is selected from the group consisting of edible oils, melamine, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyacrylates, polyamides, hydroxypropylmethylcellulose, methocel, other cellulosic ethers, polyethylene glycol, acrylics, polyurethane, polyethylene, polylactic acid, polyhydroxybutyrate-hydroxyvalerate copolymers, latexes, starches, soybean protein, soybean oil, polyethylene, waxes, elastomers, biodegradable polymers, sodium silicate, calcium carbonate, aluminum oxide, silicon oxide, kaolin, clay, ceramic and mixtures thereof.

35. An inorganically filled starch-bound sheet as defined in claim 33, wherein the at least one other sheet is selected from the group consisting of starch-bound sheets, organic polymer sheets, metal foil sheets, ionomer sheets, elastomeric sheets, plastic sheets, fibrous sheets, mats, paper sheets, cellophane sheets, nylon sheets, wax sheets, hydraulically settable sheets, highly inorganically filled sheets, metallized film sheets and combinations thereof.

36. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet further includes at least one other sheet laminated thereto.

37. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet includes a hinge.

38. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet is fashioned into a container.

39. An inorganically filled starch-bound sheet as defined in claim 26, wherein the sheet comprises a continuous sheet that has been rolled onto a spool.

40. A starch-bound sheet formed by passing a starch-based composition between least one set of heated rollers, the starch-bound sheet having a thickness less than about 1 cm and a density greater than about 0.5 g/cm³, the starch-based composition comprising:

(a) water;

(b) ungelatinized starch granules having a concentration in a range from about 5% to about 90% by weight of total solids in the starch-based composition, the starch granules having a gelation temperature;

(c) a cellulosic ether having a thermal precipitation temperature that is less than the gelation temperature of the starch granules;

(d) an inorganic mineral filler having a concentration in a range from about 0% to about 90% by weight of solids in the starch-based composition; and

(e) fibers substantially homogeneously dispersed throughout the starch-based composition.

41. A starch-bound sheet as defined in claim 40, wherein at least a portion of the ungelatinized starch granules in the starch-based composition become at least partially gelatinized upon formation of the starch-bound sheet.

42. A starch-bound sheet as defined in claim 40, wherein the cellulosic ether reduces adhesion between the starch-based composition and the heated rollers during formation of the starch-bound sheet.

43. A starch-bound sheet as defined in claim 40, wherein the sheet has the thickness of less than about 1 mm.

44. A starch-bound sheet as defined in claim 40, wherein the sheet has the thickness of less than about 0.1 mm.

45. A starch-bound sheet as defined in claim 40, wherein the sheet has a density greater than about 1 g/cm³.

46. A starch-bound sheet as defined in claim 40, wherein the sheet further includes a coating on at least a portion thereof.

47. A starch-bound sheet as defined in claim 46, wherein the coating is selected from the group consisting of edible oils, melamine, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyacrylates, polyamides, hydroxypropylmethylcellulose, methocel, other cellulosic ethers, polyethylene glycol, acrylics, polyurethane, polyethylene, polylactic acid, polyhydroxybutyrate-hydroxyvalerate copolymers, latexes, starches, soybean protein, soybean oil, polyethylene, waxes, elastomers, biodegradable polymers, sodium silicate, calcium carbonate, aluminum oxide, silicon oxide, kaolin, clay, ceramic and mixtures thereof.

48. A starch-bound sheet as defined in claim 40, wherein the sheet is fashioned into a container.

49. A starch-bound sheet as defined in claim 40, wherein the sheet comprises a continuous sheet that has been rolled onto a spool.

50. A starch-bound sheet as defined in claim 40, wherein the sheet further includes at least one other sheet laminated thereto.

51. A starch-bound sheet as defined in claim 50, wherein the at least one other sheet is selected from the group consisting of starch-bound sheets, organic polymer sheets, metal foil sheets, ionomer sheets, elastomeric sheets, plastic sheets, fibrous sheets, mats, paper sheets, cellophane sheets, nylon sheets, wax sheets, hydraulically settable sheets, highly inorganically filled sheets, metallized film sheets and combinations thereof.

52. A starch-bound sheet as defined in claim 40, wherein the starch-based composition further includes a hydraulically settable binder.

53. A starch-bound sheet as defined in claim 40, wherein the fibers have a concentration in a range from about 3% to about 40% by weight of total solids in the starch-based composition.

54. A starch-bound sheet formed by passing an aquoues starch-based composition between at least one set of heated rollers in order to remove a substantial portion of water by evaporation to thereby solidify the sheet, the starch-bound sheet having a thickness less than about 1 mm and a density greater than about 0.5 g/cm³ and being sufficiently flexible so that it can be significantly mechanically deformed by at least one process selected from the group consisting of crimping, creping, stretching, bending, folding, rolling, convoluting, spiral winding, pressing, fluting, and corrugating without complete rupture of the sheet, the aqueous starch-based composition comprising:

water;

substantially ungelatinized starch granules having a concentration in a range from about 5% to about 90% by weight of total solids in the starch-based composition and having a gelation temperature;

a cellulosic ether having a thermal precipitation temperature that is less than the gelation temperature of the substantially ungelatinized starch granules; and

an inorganic mineral filler having a concentration in a range from about 0% to about 90% by weight of solids in the starch-based composition.

55. An inorganically filled starch-bound sheet as defined in claim 54, further including fibers in a range from about 3% to about 40% by weight of total solids in the starch-based composition.

56. An inorganically filled starch-bound sheet formed by a process comprising the steps of:

providing an aqueous starch-based composition including water, starch, a cellulosic either, and an inorganic mineral filler, wherein the water has a concentration in a range from about 5% to about 80% by weight of the starch-based composition, wherein the inorganic mineral filler has a concentration of up to about 80% by weight of solids, and wherein the starch and cellulosic ether have a combined concentration of at least about 20% by weight of solids; and

passing the starch-based composition between at least one set of heated rollers in order to remove a substantial portion of the water by evaporation to thereby solidify the sheet, wherein the solidified sheet has a thickness of less than about 1 cm and a density greater than about 0.5 g/cm³.