WO1983001942A1

WO1983001942A1 - Production of hollow-ware

Info

Publication number: WO1983001942A1
Application number: PCT/AU1982/000206
Authority: WO
Inventors: Peter John Crisp
Original assignee: Peter John Crisp
Priority date: 1981-12-04
Filing date: 1982-12-06
Publication date: 1983-06-09
Also published as: EP0108064A1

Abstract

The production of unique articles of hollow-ware is achieved by the provision of a tubular basket (10A) composed of a liner (9) of heat-resistive sheet material enclosed by a flexible heat-resistive meshed cone (12), and a frame (5) supporting the basket above a surface (7), whereby with the introduction of heat responsive mouldable material (14) to, or in, the basket and the application of heat thereto the mouldable material (14) while being held in one part by the basket (10A) slumps in another part onto the surface (7) to form hollow-ware having a base and side walls.

Description

"PRODUCTION OF HOLLO -WARE" This invention relates to the production of hollow-ware and more particularly to the forming of glass vessels. BACKGROUND ART

Presently employed techniques for forming glass hollow-ware involve a highly skilled blowing art and a glass moulding process, the latter being suited generally for mass production. Glass products resulting from these and other processes have a sameness in that uniformity of design and wall thickness and texture are adhered to. There is a substantial public demand for uniqueness in the design of glass-ware_f and designs resembling the features of artifacts are eagerly sought. Some of these features are the "meaty" look of the article and peculiarity in texture which are extremely difficult to produce at a reasonable price by known processes.

DISCLOSURE OF INVENTION It is the principal object of this invention to provide a means and process for producing hollow-ware of unique appearance capable of selection by an operator. To this end the invention in one general form provides apparatus used in the production of hollow-ware, comprising a base, a frame supported on the base, and an apertured support basket suspended or supported over the base from the frame, said basket having a lining of heat-resistive sheet material surrounded by a flexible heat-resistive mesh, whereby mouldable material for the walls of the hollow-ware is locatable over or within the apertured basket to close said aperture so that the mouldable material during heating in an oven slumps through said aperture towards said base to form a selected shape of hollow-ware.

The invention also envisages the provision of a novel process for producing such hollow-ware, and novel products resulting from such process.

BRIEF DESCRIPTION OF DRAWINGS The following description should be read with reference to the accompanying drawings, in which: Figs. 1 and 2 show in side elevation and perspective one form of apparatus according to the invention;

Fig. 1A is an enlarged side elevation of a glass stack as shown in Figs, i and 2; and

Figs. 3 and 4 show in side elevation and plan another form of basket to be used with the apparatus. BEST MODES OF CARRYING OUT THE INVENTION Preferred embodiments will now be described with reference to apparatus capable of performing the method of the invention. An understanding of the following description will make it readily apparent in what manner the process is to be performed.. It will be seen that articles of glass-ware, or articles formed from other mouldable material, are formed without the need for an encompassing mould, and automatically to an external shape which can be controlled and selected by an operator.

Figs. 1 and 2 show a first embodiment of a tubular basket 10 supported on a metal or ceramic frame 5 composed of upright posts 6 mounted in respective corners of a rectangular kiln shelf base 7 and terminating in an upper open rectangular framework 8. The upper surface of the base 7 may be lined with a glass insulation paper or other suitable liner. The flexible upright tubular basket 10 is either suspended or supported within or by the rectangular framework 8 above the surface of the base 7. Figs. 3 and 4 show two views of a second embodiment of a basket 10A which may be used to obtain a different form of product.

The basket 10A, according to the latter embodiment, includes a lining of glass insulation paper 9 provided either as a single sheet, or multiple overlapping sheets, folded over the framework 8 into an inverted open-ended cone 11 and confined to this shape by an encircling flexible mesh of metal, preferably formed as a knitted or interwoven Nikrome wire cone 12. Nikrome wire is chosen because of its property of withstanding high temperatures without distortion, but other appropriate materials may be utilised.

Suspension or support of the basket 10A within the framework 8 may be by Nikrome tie wires interconnecting th wire mesh with respective side members 13 of the rectangular framework 8. At the upper end 15 of the baske 10A both the lining sheet 9 and surrounding wire terminate in an outwardly folded skirt 17 of relatively short length Any selected number and quality of glass pieces such as discs arrayed in a stack 14 are introduced through the upper end 15 of the cone 11 formed by the wrapped glas insulation paper 9, and are of such a diameter that they become an interference fit within the cone 11. The upper end 15 of the cone 11 above the stack 14 of glass discs ma be at least partly filled with an expanding material 16, such as sand or other material, possessing a fluid mass of granular or liquid substance. In some instances where thi glass discs are intended to be formed into a large diameter vessel with thin wall structure the expanding material 16 need not be used. As will be explained hereafter the quality and diameter of the glass discs, and the quantity of sand introduced to the conical basket 10A and the spacing of the basket 10A from the base 7 will be determined by the operator according to the glass-ware intended to be produced. In some instances other mouldable material than glass can be used. In some other instances it has been found also that the basket 10A will suffice even if the cone 11 is omitted and an aperture only provided centrally in a planar form of support basket which seats upon the framework 8. In that form the stack 14 of discs will be placed to cover the aperture.

According to the first embodiment of the basket 10 shown in Figs. 1 and 2, the outwardly folded skirt 17A is of extended length to encircle the inner cone 11 and the upper posts 6. That form of basket 10 is especially suited for the creation of hollow-ware with outwardly and downwardly flared ornate rims such as occur on many vases. Figs. 1 and 2 show the preparation for production of such a vessel. A first laminated glass disc stack 14A provided with additional rectangular peripheral glass pieces 18 is laid over the basket 10 and is of small diameter to the outer diameter of the skirt 17A. A second laminated glas disc stack 14B is placed upon a pile of sand 19, or other such granular material, formed upon the upper surface of the base 7. Of course the cone 11 may be replaced by a central aperture (not shown) at the framework 8. When placed in a kiln and heated the hollow central column of the vessel will be formed by slumping of the softened glass through the basket 10 and it will become welded to the upper surface of the glass stack 14B which has slumped over the pile of sand 19 to form a base with a central depression. The outer periphery of the stack 14A will, by surface friction with the skirt 17A, be restrained from slumping too far and will form an ornate downwardly flared rim.

INDUSTRIAL APPLICABILITY In the performance of the process of this invention the apparatus is introduced into a heating kiln where the temperature of the basket 10 and its contents will rise to between 720°C and 900°C whereat the glass discs (or other mouldable material) , under the weight of the overlying sand (or its own weight if no expanding material 16 is used) , sag or slump towards the surface of the base. As a result the glass is formed into a core vessel containing sand. A flat base to the glass-ware is formed by contact with the base surface and distension of the wall of the vessel then occurs due to the weight of the contained sand. It will be appreciated that as the glass is drawn by its own weight, or the weight of the sand, down to the base surface the glass walls of the vessel are exposed to more heat thus providing for distension of the vessel walls. The forming operation may be halted at any instance by the operator opening the kiln door. From observations of the process, using a soda type glass, it would seem that from 720°C to 760°C the glass discs in the stack 14 within the basket fuse together and slightly slump towards the lower open end of the basket 10. Between 760 C and 830°C the glass gradually slumps through the bottom of the basket 10 and continues at a substantially regular rate to about half the distance to the floor of the kiln shelf base. When the temperature rises between

OM 830°C and 860°C final slumping to the base surface 7 occurs at an accelerated rate and initially thereafter an enlarged base portion of the glass vessel commences to for of flask-like shape. Distension of the wall of the vessel progressively from the lower end continues at an accelerating rate requiring the operator's attention so that it may be arrested at a selected shape by opening of the kiln door, or other means for quickly cooling the interior of the kiln. Although only one manner of controlling the vessel shape has been described, many refinements may be made to the apparatus, such as the shaping of the surface of the kiln shelf base 7 and the conical angle of the overhead basket 10, all of which can be controlled and determined according to a predicted shape of the finished glass-ware.

It should be noted that the arrangement of discs or segments of glass in this lamination process also determines the shape of the resulting hollow-ware form. Fig. 1A shows one such arrangement where the stack 14 comprises four laminated sheets 20 of glass, or other suitable material such as thermoplastics, which may be separated by layers of coloured or other foreign material 21, with pieces of glass 22 adhered to the top surface of the stack 14 to create desirable surface texture on the finished product.

When the formed glass-ware has cooled and annealed it may be removed from the basket, if necessary, by cutting the lower margin of the wire mesh to allow the mouth of the vessel to be drawn through the lower end of the basket 10. It will be a simple matter to repair the break in the mesh before commencing production of further articles of glass-ware.

Considerable flexibility in the production of glass-ware is provided by the arrangement of the glass discs within the basket 10. Colouring of the finished ware involves an artistic aspect of the process. For example, striations in the vessel wall may be obtained by the glass discs being cut into a grid pattern (as shown in Fig. 4) and laminated with adjacent flat discs. Enamels may be brushed into the grid pattern where they will remain during the slumping action of the glass. Furthermore, surface texture of the vessel can be determined by placing between or around the glass discs glass fractions or splinters. A very attractive striated stalagmite-like effect can be obtained in this way. Many other unusual effects in the finished vessel can be obtained by the choice of glass discs and the combination therewith of other substances. Whereas a preferred embodiment has been described in the foregoing passages it should be understood that other forms, refinements and modifications are feasible within the scope of this invention. For example, any suitable heat-resistive sheet material may be utilised in place of the glass insulation paper 9 (commercially known as high fibre insulation paper) , and many knitted or woven patterns of wire to provide the flexible enclosing mesh on the basket may be utilised.

Claims

CLAIMS 1. Apparatus for the production of hollow-ware, comprising a base, a frame supported on the base, and an apertured support basket suspended or supported over the base from the frame, said basket having a lining of heat-resistive sheet material surrounded by a flexible heat-resistive mesh, whereby mouldable material for the walls of the hollow-ware is locatable over or within the apertured basket to close said aperture so that the mouldable material during heating in an oven slumps through said aperture towards said base to form a selected shape of hollow-ware.

2. Apparatus according to claim 1, wherein said basket is an upright tube with its upper end folded outwardly and downwardly to form a skirt and is suspended or supported at the area of the foled.

3. Apparatus according to claim 2, wherein said aperture in said basket is located at the lower end of an inverted conical portion thereof.

4. Apparatus according to any one of the preceding claims, wherein said mouldable material comprises laminated discs.

5. Apparatus according to any one of the preceding claims, wherein said lining is of glass insulation paper, and said mesh is of Nikrome wire.

6. A method for producing unique articles of hollow-ware comprising placing a laminated sheet of heat-sensitive mouldable material over an aperture in a heat resistive basket comprising a liner of sheet material and an enclosing flexible mesh, applying heat to said material so that a central portion thereof slumps through said aperture to strike a lower flat surface for the formation of a base upon said article, and terminating said application of heat when a selected distended wall formation of said article has been attained.

7. The method of claim 6, wherein a quantity of a fluid mass of granular or liquid substance is placed upon said mouldable material over said aperture before said application of heat.

8. The method of claim 6 or 7, wherein the sheet of mouldable material is in the form of a disc of a diameter exceeding the diameter of the aperture so that with the application of heat an outer peripheral portion of the disc slumps downwardly outside the basket to form an outwardly and downwardly flared rim for the said article.

9. A unique article of hollow-ware produced by the method of any one of claims 6 to 8.

10. A method of producing an article of hollow-ware substantially as hereinbefore described with reference to Figs. 1 and 2, or Figs. 3 and 4 of the accompanying drawings.