Methods for molding articles which include a hinged starch-bound cellular matrix

• US 5,776,388 A
• Filed: 06/10/1996
• Issued: 07/07/1998
• Est. Priority Date: 02/07/1994
• Status: Expired due to Term

• Current Assignee: Earthshell Spe, LLC
• Original Assignee: E. Khashoggi Industries, LLC
• Inventors: Andersen, Per Just, Hodson, Simon K.
• Primary Examiner(s): Kuhns, Allan R.
• Application Number:
  US08/661,224
• Time in Patent Office: 757 Days
• Field of Search: 264/45.5, 264/51, 264/53, 264/129, 264/327
• US Class Current: 264/45.5
• 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: B27N 3/002 characterised by the type of binder compositions of macromolecular compounds C08L
• CPC Class Codes: B27N 3/007 and at least partly composed of recycled material
• 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 23/0081 Embedding aggregates to obtain particular properties
• 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 2043/5841 for accommodating variation in mould spacing or cavity volume during moulding
• CPC Class Codes: B29C 33/04 using liquids, gas or steam tyre moulds with incorporated heating or cooling means using liquids, gas or steam B29D30/0601
• CPC Class Codes: B29C 33/10 with incorporated venting means
• CPC Class Codes: B29C 33/20 Opening, closing or clamping
• CPC Class Codes: B29C 33/36 continuously movable in one direction, e.g. in a closed circuit B29C49/0021 takes precedence
• CPC Class Codes: B29C 39/003 characterised by the choice of material
• CPC Class Codes: B29C 39/42 Casting under special conditions, e.g. vacuum
• 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 43/06 : continuously movable in one direction, e.g. mounted on chains, belts
• CPC Class Codes: B29C 43/08 : with circular movement , e.g. mounted on rolls, turntables
• CPC Class Codes: B29C 43/34 : Feeding the material to the mould or the compression means B29C43/085 takes precedence
• CPC Class Codes: B29C 43/36 : Moulds for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29C 44/0407 : by regulating the temperature of the mould or parts thereof, e.g. cold mould walls inhibiting foaming of an outer layer
• CPC Class Codes: B29C 44/3402 : Details of processes or apparatus for reducing environmental damage or for working-up compositions comprising inert blowing agents or biodegradable components
• CPC Class Codes: B29C 45/0013 : using fillers dispersed in the moulding material, e.g. metal particles
• CPC Class Codes: B29C 49/0005 : characterised by the material
• CPC Class Codes: B29C 51/002 : characterised by the choice of material
• CPC Class Codes: B29C 55/18 : by squeezing between surfaces, e.g. rollers
• CPC Class Codes: B29C 67/202 : comprising elimination of a solid or a liquid ingredient
• 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 70/025 : with particular filler
• CPC Class Codes: B29C 70/12 : using fibres of short length, e.g. in the form of a mat non-woven fabrics per se D04H1/00
• 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 2105/0064 : Latex, emulsion or dispersion
• CPC Class Codes: B29K 2105/04 : cellular or porous
• CPC Class Codes: B29K 2105/06 : containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2105/16 : Fillers
• CPC Class Codes: B29K 2995/0059 : Degradable
• 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: 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 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 5/14 : characterised by a layer differing constitutionally or physically in different parts, e.g. denser near its faces
• CPC Class Codes: B32B 5/18 : characterised by features of a layer of foamed material
• 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 65/466 : Bio- or photodegradable packaging materials
• CPC Class Codes: C04B 14/46 : Rock wool ; Ceramic or silicate fibres C04B14/40, C04B14/42 take precedence
• CPC Class Codes: C04B 2111/00094 : Sag-resistant materials
• CPC Class Codes: C04B 2111/0062 : Gypsum-paper board like materials
• CPC Class Codes: C04B 26/28 : Polysaccharides or derivatives thereof
• CPC Class Codes: C08J 2201/0504 : the liquid phase being aqueous
• CPC Class Codes: C08J 2303/00 : Characterised by the use of starch, amylose or amylopectin or of their derivatives or degradation products
• 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: C08J 9/0085 : Use of fibrous compounding ingredients C08J9/0076 takes precedence
• CPC Class Codes: C08J 9/12 : by a physical blowing agent
• CPC Class Codes: C08J 9/28 : by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: C08J 9/365 : Coating
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• 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: E05D 1/02 : made of one piece
• CPC Class Codes: E05Y 2999/00 : Subject-matter not otherwise provided for in this subclass
• CPC Class Codes: Y02W 90/10 : Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics

Abstract

Methods and systems for forming hinged starch-bound matrices. Starch-based compositions are molded between heated molds in order to form a cellular matrix and also to remove the water from the starch-based compositions in order to form a binding matrix of solidified starch. The molding apparatus is configured to form one or more creases within the hinge area in order to define one or more lines upon which the hinge will bend. The molding apparatus is also configured such that the region of the mold corresponding to the inner surface of the hinge area will transfer heat more slowly to the inner hinge surface, resulting in reduced thickness of the skin of the inner hinge. This increases the collapsibility, or ability of the inner surface of the hinge to fold or buckle, during the bending action. This in turn reduces the bending radius of hinge such that the hinging action exerts less strain on the outer surface of the hinge. The inner surface of the hinge may optionally be treated with glycerin or other polyols to soften the inner surface. The outer surface of the hinge may optionally be coated with an elastomeric material, such as polyvinyl alcohol, in order to strengthen the outer surface and reduce its tendency to fracture during the hinging action.

Claims

1. A method for manufacturing an article having a starch-bound cellular matrix, the method comprising:

molding an aqueous starch-based mixture into a desired shape of the article under elevated temperature in order to remove a substantial portion of the water from the mixture by evaporation and thereby form the starch-bound cellular matrix of the article, the molding step including forming a hinge structure within the article, the hinge structure comprising an interior skin portion, an exterior skin portion, and an interior cellular core disposed between the interior skin portion and the exterior skin portion, the interior cellular core having a density less than the densities of the interior and exterior skin portions; and

demolding the article after the article has achieved form stability.

2. A method for manufacturing an article as defined in claim 1, wherein the molding step includes forming at least one depression in the interior skin portion of the hinge structure.

3. A method for manufacturing an article as defined in claim 1, wherein the molding step results in the interior skin portion having a thickness that is less than the thickness of the exterior skin portion.

4. A method for manufacturing an article as defined in claim 1, wherein the molding step imparts less heat per unit time to the interior skin portion of the hinge structure than to the exterior skin portion of the hinge structure such that the interior skin portion is formed having a thickness that is less than the thickness of the exterior skin portion.

5. A method for manufacturing an article having a starch-bound cellular matrix, the method comprising:

molding an aqueous starch-based mixture into a desired shape of the article under elevated temperature in order to remove a substantial portion of the water from the mixture by evaporation, thereby forming the starch-bound cellular matrix of the article, the molding step including forming a hinge structure within the article, wherein the hinge structure comprises an interior skin portion, an exterior skin portion, an interior cellular core disposed between the interior skin portion and the exterior skin portion, and at least one depression in the interior skin portion, the molding step resulting in the interior skin portion of the hinge structure having a thickness that is less than the thickness of the exterior skin portion of the hinge structure; and

demolding the article after the article has achieved form stability.

6. A method for manufacturing an article as defined in claim 5, wherein the molding step imparts less heat per unit time to the interior skin portion of the hinge structure than to the exterior skin portion of the hinge structure such that the interior skin portion is formed having a thickness that is less than the thickness of the exterior skin portion.

7. A method for manufacturing an article as defined in claim 5, wherein the molding step is carried out using a heated mold apparatus.

8. A method for manufacturing an article as defined in claim 7, wherein the heated mold apparatus includes a molding strip corresponding to the interior skin portion of the hinge structure and having reduced heat diffusivity compared to the rest of the mold apparatus.

9. A method for manufacturing an article as defined in claim 5, wherein the molding step yields a multiple hinge having at least two depressions in the interior skin portion of the hinge structure.

10. A method for manufacturing an article as defined in claim 5, wherein the molding step results in the exterior skin portion of the hinge structure having at least one bending initiation groove.

11. A method for manufacturing an article as defined in claim 5, further including the step of treating the interior skin portion of the hinge structure with a polyol.

12. A method for manufacturing an article as defined in claim 11, wherein the polyol is applied by means of an aqueous polyol solution.

13. A method for manufacturing an article as defined in claim 11, wherein the polyol comprises glycerin.

14. A method for manufacturing an article as defined in claim 11, wherein the polyol is selected from the group consisting of polyethylene glycol, propylene glycol, polypropylene glycol, sorbitol, and mixtures of the foregoing.

15. A method for manufacturing an article as defined in claim 5, further including the step of applying an elastomeric coating to the exterior skin portion of the hinge structure.

16. A method for manufacturing an article as defined in claim 15, wherein the elastomeric coating comprises polyvinyl alcohol.

17. A method for manufacturing an article as defined in claim 15, wherein the elastomeric coating is selected from the group consisting of polylactic acid, natural latex, derivatives of the foregoing, and mixtures of the foregoing.

18. A method for manufacturing an article having a starch-bound cellular matrix, the method comprising:

molding an aqueous starch-based mixture into a desired shape of the article under elevated temperature in order to remove a substantial portion of the water from the mixture by evaporation, thereby forming the starch-bound cellular matrix of the article, the molding step including forming a hinge structure within the article, wherein the hinge structure comprises an interior skin portion, an exterior skin portion, an interior cellular core disposed between the interior skin portion and the exterior skin portion, and at least one depression in the interior skin portion, the molding step imparting less heat per unit time to the interior skin portion of the hinge structure than to the exterior skin portion of the hinge structure such that the interior skin portion is formed having a thickness that is less than the thickness of the exterior skin portion; and

demolding the article after the article has achieved form stability.

19. A method for manufacturing an article as defined in claim 18, wherein the molding step yields a multiple hinge having at least two depressions in the interior skin portion of the hinge structure.

20. A method for manufacturing an article as defined in claim 18, wherein the molding step results in the exterior skin portion of the hinge structure having at least one bending initiation groove.

21. A method for manufacturing an article as defined in claim 18, further including the step of treating the interior skin portion of the hinge structure with a polyol.

22. A method for manufacturing an article as defined in claim 21, wherein the polyol is applied by means of an aqueous polyol solution.

23. A method for manufacturing an article as defined in claim 21, wherein the polyol comprises glycerin.

24. A method for manufacturing an article as defined in claim 21, wherein the polyol is selected from the group consisting of polyethylene glycol, propylene glycol, polypropylene glycol, sorbitol, and mixtures of the foregoing.

25. A method for manufacturing an article as defined in claim 18, further including the step of applying an elastomeric coating to the exterior skin portion of the hinge structure.

26. A method for manufacturing an article as defined in claim 25, wherein the elastomeric coating comprises polyvinyl alcohol.

27. A method for manufacturing an article as defined in claim 25, wherein the elastomeric coating is selected from the group consisting of polylactic acid, natural latex, derivatives of the foregoing, and mixtures of the foregoing.

28. A method for manufacturing an article as defined in claim 18, further including the step of applying a wax-based coating material to the article.

29. A method for manufacturing an article as defined in claim 18, wherein the molding step yields a clam shell container.

30. A method for manufacturing an article having a starch-bound cellular matrix, the method comprising:

molding an aqueous starch-based mixture within a heated mold apparatus into a desired shape of the article under elevated temperature in order to remove a substantial portion of the water from the mixture by evaporation, thereby forming the starch-bound cellular matrix of the article, the heated mold forming a hinge structure within the article, wherein the hinge structure comprises an interior skin portion, an exterior skin portion, an interior cellular core disposed between the interior skin portion and the exterior skin portion, and at least one depression in the interior skin portion, the heated mold being configured such that it imparts less heat per unit time to the interior skin portion of the hinge structure than to the exterior skin portion of the hinge structure such that the interior skin portion is formed having a thickness that is less than the thickness of the exterior skin portion; and

demolding the article after the article has achieved form stability.

31. A method for manufacturing an article as defined in claim 30, wherein the molding step yields a multiple hinge having at least two depressions in the interior skin portion of the hinge structure.

32. A method for manufacturing an article as defined in claim 30, wherein the molding step results in the exterior skin portion of the hinge structure having at least one bending initiation groove.

33. A method for manufacturing an article as defined in claim 30, further including the step of treating the interior skin portion of the hinge structure with a polyol.

34. A method for manufacturing an article as defined in claim 33, wherein the polyol is applied by means of an aqueous polyol solution.

35. A method for manufacturing an article as defined in claim 33, wherein the polyol comprises glycerin.

36. A method for manufacturing an article as defined in claim 33, wherein the polyol is selected from the group consisting of polyethylene glycol, propylene glycol, polypropylene glycol, sorbitol, and mixtures of the foregoing.

37. A method for manufacturing an article as defined in claim 30, further including the step of applying an elastomeric coating to the exterior skin portion of the hinge structure.

38. A method for manufacturing an article as defined in claim 37, wherein the elastomeric coating comprises polyvinyl alcohol.

39. A method for manufacturing an article as defined in claim 37, wherein the elastomeric coating is selected from the group consisting of polylactic acid, natural latex, derivatives of the foregoing, and mixtures of the foregoing.

40. A method for manufacturing an article as defined in claim 30, further including the step of applying a wax-based coating material to the article.

41. A method for manufacturing an article as defined in claim 30, wherein the molding step yields a clam shell container.