GB2317361A

GB2317361A - Container and method for manufacture thereof from husk material

Info

Publication number: GB2317361A
Application number: GB9619439A
Authority: GB
Inventors: Fu-Ming Huang
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-09-11
Filing date: 1996-09-18
Publication date: 1998-03-25
Anticipated expiration: 2016-09-18
Also published as: CA2185316A1; CA2185316C; JP3295606B2; GB9619439D0; DE19637659C2; FR2753689B3; BR9603879A; DE19637659A1; JPH10109304A; FR2753689A1; GB2317361B

Abstract

A method for manufacturing a container from husk material comprises the steps of comminuting the husk material into powder form in comminuter 21; mixing 31 the powder with an edible adhesive in the presence of steam to form a paste 32 from which a blank 320, which may be folded to form a laminate 321, is formed; shaping the blank between mould parts 51,52; re-shaping the part-formed product between mould parts 61,62 to fill any cracks formed during the first shaping operation; optionally shape-fixing the formed product at elevated temperature between mould parts 71,72; drying under heater 82; applying 90 a surface coating and finally drying under second heater 101.

Description

2317361 CONTAINER AND THE METHOD FOR MANUFACTURING SAME

FIELD OF THE INVENTION

The present invention relates to a method for manufacturing containers, especially food containers, from husks, such as rice husk, and also relates to a bio-degradable container made of husks.

BACKGROUND OF THE INVENTION

Containers, especially food containers, such as bowls and cups, have been widely used in human society. In a modern society, disposable food containers have been very prevailing for they do not need to be cleaned af ter use and do not transmit disease between individuals. The disposable food containers are usually made of paper material or synthetic materials, such as polypropylene and polystyrene foam. The drawbacks of paper container is that the manufacturing of the paper containers consumes a great quantity of pulp which is obtained by cutting down trees and thus causing a damage to the earth environment. As to the synthetic materials mentioned above, they are usually not suitable for making food containers for they release toxicant material when heated by cooked hot foods, such as hot soup or hot coffee. Furthermore, such synthetic materials, basically, are not biodegradable. In other words, they will last almost forever after being discarded. This is even a more severe environmental problem, as compared to cutting trees.

To overcome the above problems, food containers made of edible and biodegradable materials have been developed, such as food containers made of corn starches. A major drawback associated with corn starch containers is that it is quite in- economic to use the edible corn starch to make disposable container while there are people starved to death.

1 It is therefore desirable to provide a food container that is environment compatible and non-toxicant to human body to overcome the above-mentioned problems.

OBJECTS OF THE INVENTION 5 Therefore, the principal object of the present invention is to provide a container which is made of husk so as to make a complete utilization of the waste husk and which does not cause any damage to environment and human body. Another object of the present invention is to provide a method for manufacturing containers from husk which overcomes the drawbacks of prior art resulting from lacking fibrous material in the husk.

A further object of the present invention is to provide a food container which does not contain toxicant material and is completely bio-degradable.

The present invention will be better understood from the following description of a preferred procedure for making the container in accordance with the present invention, with reference to the attached drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is block diagram showing the process of making container in accordance with the present invention; Figure 2 is a schematic side elevational view showing the apparatus and process for making the container in accordance with the present invention; Figure 3 is a schematic side elevational view showing a portion of a multiple-folded blank used to form the container in accordance with the present invention; Figure 4 is a cross-sectional view showing a portion of a container made in accordance with the present invention after the step of primary shaping; Figure 5 is a view similar to Figure 4, showing the container after secondary shaping step; and 2 Figure 6 is a schematic side elevational view showing a variation of forming the blank for making the container.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the drawings and in particular to Figures 1 and 2, wherein a method for manufacturing container from husk in accordance with the present invention is shown, the method comprises the steps of comminuting 20, mixing 30, blank forming 40, primary shaping 50, secondary shaping 60, shape-fixing 70, first drying 80, surface treating 90 and second drying 100 These steps will now be further described.

In accordance with the present invention, the raw material used to manufacture the containers, which is indicated at 10 in Figure 1, comprises husks, preferably rice husk, which is fed into a comminuting device 21 and comminuted to powder form. Such powders may have different sizes to meet the needs of different applications. This is the comminuting step 20.

The powder material is then supplied to a mixing device 31 to mix with a suitable amount of edible adhesive which may be any know edible, non-toxicant adhesive. In the mixture, the powder material takes 88-92% and the adhesive 12-8% in weight. Steam having a pressure of 7 lb/cm2 is introduced into the mixing device 31 to mix with the mixture after the powder material and the adhesive are completely mixed. The mixture is stirred at a desired speed to completely mix with the steam and a paste-like material 32 is formed. This is the mixing step 30.

The paste 32 is then fed into a collection hopper 41 to be supplied to the blank-forming step 40. The blank-forming step 40 comprises using a conveyor, preferably a belt conveyor 43 to which the paste 32 is supplied from the hopper 41, to move the paste 32 through a pair of rollers 42 so as to have the paste 32 rolled into a sheet or thin plate like blank 320 having a predetermined thickness, preferably 0.7 mm. A 3 folding device 44 is provided along the conveyor 43 to fold the blank 320 into a multiple-folded lamination 321, which preferably has four folds, see Figure 3.

The conveyor 43 then moves the laminated blank 321 into the primary shaping step 50. The primary shaping step 50 comprises a male die member 51 and a mated female die member 52 which are movable relative to each other to performing pressing operation on the laminated blank 321 with a pressure of 150-180 Kg/cm2 to form a primary semi-product 322.

Further referring to Figures 4 and 5, since the husk powder hardly contains any fibrous material, the primary semiproduct 322 that is formed by the primary shaping step 50 often breaks at angled portions of the female die member 52, such as those indicated at 521 and 522, so that cracks 3222 and 32221, see Figure 4, are formed on the primary semiproduct 322 with only a portion of the thickness of the blank 321, such as those indicated at 3223 and 3224, remaining unbroken. It is thus desired to have the primary semi-product 322 undergo a secondary shaping operation 60 to eliminate the cracks.

The female die member 52 of the primary shaping step 50 comprises a release member 521 which releases and supports the primary semiproduct 322 from the female die member 52. The primary semi-product 322 is then transferred by being supported by the release member 521 to the secondary shaping step 60 which comprises a male die member 61 and a mated female die member 62 to press the primary semi-product 322 by the die members 61 and 62 with an instantaneous heating to approximate 100C so as to form a completely shaped container product 323, which is also referred to as secondary semiproduct having a shape completely the same as the desired final product.

In the secondary shaping (pressing) operation 60, the pressure applied to the primary semi-product 322 by the die members 61 and 62 forces the paste material of the primary 4 semi-product 322 to f low and f ill into the cracks 3221 and 3222 so as to form a smooth and continuous surface as indicated at 3231 and 3232 in Figure 5.

The secondary semi-product 323 so formed may still be soft and possesses no desired rigidity. To solve such a problem, the secondary semi-product 323 is carried by a release member 621 associated with the female die member 62 of the secondary shaping operation 60 to the shape-f ixing step 70 to undergo a shape-fixation operation which is done with a male die member 71 and a female die member 72 to apply pressure to the secondary semi-product 323 again with an instantaneous heating to approximately 1000C. This substantially increases the mechanical strength of the product.

The product 323, after being shape-fixed, is moved by a second conveyor 81 to undergo the first drying step 80 which is done by making use of heating device 82 to dry the product by means of heat radiation at approximately 60-80C. The so dried product is then moved into a surface treating device 91 to be coated with a non-toxicant, edible surface coating in the surface treatment step 90 to serve as a protective coating to the container. Thereafter, a second drying step 100 is taken to dry the surface coating of the product with a second heat drying device 101 at a temperature of approximately 180 200C so as to obtain the final product 110.

It can be seen from the above description that the present invention fully makes use of waste material to manufacture container 110 by comminuting the waste material to powder form and mixing the powder with suitable adhesive to provide a paste. The paste then undergoes blank-forming and folding operation to provide a blank of multiple-folded lamination having a loose structure which allows the paste to fill into the cracks that are formed on the semi-product at the primary shaping operation when it is subject to a secondary shaping operation with instantaneous heating to approximately 1OCC. This effectively eliminates the cracks that of ten occur in the prior art. Thereaf ter, a surface coating is applied to the semi-product which after being dried, allows the final product to endure high temperature liquid within quite a period (approximately 2-40 hours) without dissolution.

In Figure 6, a variation of the present invention is shown wherein the rollers 42 are eliminated so that the paste 32, without being rolled, forms a thick blank, as compared to that is rolled by the rollers 42. Such a thick blank may be directly supplied to the primary shaping step 50 for manufacturing containers of larger sizes.

Thus, the present invention provides the following advantages:

(1) The present invention solves the problem in the prior art that containers made of husks are not capable to contain high temperature liquid for a long while.

(2) The present invention solves the problem in the prior art that containers made of husks cannot be suitably shaped as desired without any crack.

(3) The present invention provides a container that does not generate toxicant material in high temperature and can be disposed in a completely environment compilable manner.

(4) The present invention provides a container that is water dissoluble.

(5) The present invention provides a container which will completely decompose once a crack is formed and gets in contact with water.

Although the best model for carrying out the present invention has been described, it is apparent that changes and modifications in the best model can be carried out without departing from the scope of the invention which is intended to be limited only by the appended claims.

6 CLATAS 1 1. A method for manufacturing container of a given shape 2 from husk, comprising the following steps:

3 (1) comminuting the husk into powder form; 4 (2) mixing the husk powder with an adhesive in a pre-determined ratio to provide a paste; 6 (3) forming a blank from the paste; 7 (4) shaping a product from the blank with die 8 assembly; 9 (5) drying the shaped product; (6) applying a surface coating to the shaped product 11 to form a protective coating; and 12 (7) drying the surface coating to provide a final 13 product of the container.

Claims

1

2. The method as claimed in Claim 1, wherein the shaping

2 step comprises a primary shaping step for shaping the 3 blank to provide a semi-product and a re-shaping step for 4 further shaping the semi-product to provide the shaped product.

1

3. The method as claimed in Claim 1, wherein the adhesive 2 used in the mixing step comprises an edible, non-toxicant 3 adhesive.

1

4. The method as claimed in Claim 1, wherein the blank 2 forming step comprises the steps of forming a paste sheet 3 having a pre-determined thickness and folding the paste 4 sheet to overlap itself a number of times to provide a multiple-folded lamination.

1

5. The method as claimed in Claim 4, wherein the thickness 2 of the paste sheet is 0.7 mm.

7 1

6. The method as claimed in Claim 4, wherein the lamination 2 of paste sheet comprises four folds.

1

7. The method as claimed in Claim 4, wherein the lamination 2 comprises a loose structure so as to allow the paste 3 material of the sheets of the lamination to flow and fill 4 into cracks that are formed on the product in the shaping step and thus providing a smooth surface of the shaped 6 product.

1

8. The method as claimed in Claim 1, wherein the surface 2 coating comprises an edible, non-toxicant and water 3 dissoluble material.

1

9. The method as claimed in Claim 1, wherein the mixing step 2 comprises a further step of introducing steam of a pre 3 determined pressure into the paste.

1

10. The method as claimed in Claim 9, wherein the pre- 2 2 determined steam pressure is 7 lb/cm 1

11. The method as claimed in Claim 1, wherein the ratio of 2 the husk powder to the adhesive is 88-92% to 12-8% in 3 weight.

1

12. The method as claimed in Claim 1, further comprising a 2 shape-fixation step selectively performed after the 3 shaping step to strengthen the product.

1

13. The method as claimed in Claim 12, wherein the shape 2 fixation step is carried out with an instantaneous 3 heating to approximately 100C.

8 1

14. The method as claimed in Claim 2, further comprising a 2 shape-fixation step selectively performed after the 3 secondary shaping step to strengthen the product.

1

15. The method as claimed in Claim 14, wherein the shape 2 fixation step is carried out with an instantaneous 3 heating to approximately 1OCC.

1

16. The method as claimed in Claim 1, wherein the die 2 assembly that carries out the shaping step comprises a 3 male die member and a female die member movable relative 4 to each other to press the blank with a pre-determined pressure.

1

17. The method as claimed in Claim 16, wherein the pressure 2 2 is between 150-180 Kg/cm 1

18. The method as claimed in Claim 2, wherein the re-shaping 2 step is carried out at a temperature of approximately 3 iooc.

1

19. The method as claimed in Claim 1, wherein the drying of 2 the shaped product is carried out at a temperature of 60 3 800C.

1

20. The method as claimed in Claim 1, wherein the drying of 2 the surface coating is carried out at a temperature of 3 180-200C.

1

21. The method as claimed in Claim 1, wherein blank forming 2 step is carried by passing the paste through between a 3 pair of rollers.

9