IL32187A - Manufacture of articles made of synthetic stone - Google Patents

Description

Manufaoture of articles made of synthetic etone JOHN LIONEL HILLS THIS INVENTION relates to a method of making articles of synthetic stone whereby a predetermined pattern may be obtained at the surface of such articles More particularly the invention relates to the manufacture of articles made of synthetic stone and which have curved such as a bath or wash hand basin Synthetic stone articles are generally formed by moulding powdered stone mixed in suitable portions with compatible synthetic patterns being formed by use of different pigments in the resins or by using differently coloured chips particularly the articles have curved surfaces it is often difficult to obtain the desired pattern or to reproduce a certain It is accordingly the object of this invention to provide a method of such articles which enables a desired pattern to be obtained on the surface of the In accordance with this invention there is provided a method of a synthetic stone article which comprises forming a pattern with at least two differently coloured viscous mixtures of synthetic resin and powdered stone on flexible sheet applying the sheet material to a mould so that the surface of the mixture thereon contacts and adheres to the surface of the removing the sheet material from the mixture deposited on the mould and allowing the mixtures to Further features of this invention provide for the mix on the sheet material to be placed on the male member of a mould and for the mould to be sequently enclosed by a female mould member and for the cavity between the moulds to be filled with a fluent synthetic resin matrix The invention is diagramatically illustrated in the accompanying drawings as applied to the manufacture of a In the drawings 1 illustrates the method of forming the pattern on the flexible sheets 2 illustrates the application of the membranes to the male mould 3 illustrates the fitting of the female and is a plan view of the moulded As shown in 1 sheets 1 are laid in line aligned and transversely overlapped on a table Ribbons of fluent synthetic stone mixture are then poured in lines over the at least two differently coloured mixtures being used as indicated by the full lines 3 and dotted lines The table 2 is then vibrated by means of a vibrator so that the ribbons flow towards each other to form a continuous covering over the overlapped sheets 1 but still having a veined or streaked pattern resulting from the original pouring of the adjacent differently coloured ribbons of the synthetic stone mixture on the sheets The sheets 1 are now lifted one by inverted and applied to the surface of a male member 6 of a mould as in the sheets being applied in the same alignment as they ginally had on the table as indicated by dotted The mixture on the sheets is thereby transferred to the surface of the male member this being assisted by passing rollers lightly over the surfaces of the After each transfer the corresponding sheet 1 is stripped from the surface of the male mould which is vibrated on the supporting table basically for removal of any air bubbles and also to allow closure of small interstices which may have been left due to adherence of the mixture to the sheets when they were stripped from the Thereafter as shown in 3 the female mould member 7 is fitted over the male mould member an the inters ace between the moulds filled with a fluent synthetic stone During this filling operation vibration is continued to remove air consolidate the matrix and in particular to cause the matrix to flow into any interstices which were not closed by original vibration of the male The matrix may be poured in through a gate in the top of the female but preferably to avoid any trapping of pouring is the matrix mixture being introduced through the inlets The mixture is then allowed to set and after removed from the moulds to produce the bath shown in The sheets 1 should have a smooth surface so that the synthetic resin mixture does not adhere too firmly thereto and to ensure this the sheets may be treated with a release The sheets may consist of synthetic resin film but strong waxed paper has been found to be The sheets 1 where be shaped to facilitate the application thereof to parts of the male mould such as at the ends and the portion around a drain outlet They may also be printed so as to enable the ribbons of the resin mixture to be applied in a definite For as shown in 1 a whorl pattern 11 is shown printed on the sheet 12 if could result in the corresponding pattern 11 being reproduced in the normally visible surface of the finished article as shown in While it is considered desirable to duce generally similar patterns it is not considered desirable to reproduce identical It will be appreciated that the pattern of the exposed surface of the mixture on the sheets as shown in 1 will be substantially the same as that in the finished Accordingly at this stage and while the viscous resin is still sufficiently fluent the pattern of the exposed surface may be manually varied to meet any aesthetic requirements but in particular to duce variations in the regularity of the basic The resin mixtures used to form the basic pattern may be conventional mixtures of synthetic resin such as polyester resin with conventional curing agents which are varied depending on ambient ture and humidity and handling which depends on the type and size of article being To control the flow of material again normally able thixotropic agents may be and the stone dust filler and pigments or colouring materials used r o co It is preferred to use a matrix mixture substantially identical to patterned material so that it will form a homogeneous structure The colour of the matrix is preferably white or of a lighter colour than that used to form ribbons that it will tend to blend with the ribbons when it flows through interstices in or between the ribbons as above While the invention has been described with the application of two differently coloured ribbons of plastic material to the sheets more than two differently coloured ribbons may be The moulds may be made of any providing a suitably smooth surface so that no finishing operations on the normally visible surface of the mouldings are insufficientOCRQuality

Claims (3)

1. A method of manu acturing a synthetic stone article which comprises forming a pattern with at least two differently coloured viscous mixtures of synthetic resin and powdered stone on flexible sheet material, applying the sheet material to a mould so that the surface of the mixture thereon contacts and adheres to the surface of the mould, removing the sheet material from the mixture deposited on the mould surface, and allowing the mixtures to set.

2. A method as claimed in claim 1 in which the said pattern is formed on the sheet material by applying the said mixtures in the form of generally parallel adjacent ribbons.

3. A method as claimed in claims 1 and 2 in which the sheet material is in the form of generally aligned overlapping sheets .which are individually applied to the moulds with general maintenance of the alignment of the patterns on the sheet. * k , A method as claimed in any of the preceding claims in which the sheet material is vibrated on a table after application of the said mixtures thereto. 5. A method as claimed in any of the preceding claims in which the sheet material is applied to a male member of a mould, the latter then enclosed by a female member of the mould to define a cavity between said members, and the cavity then filled with a synthetic resin matrix mixture. 6. A method as claimed in claim 5 in which the mould members are vibrated to effect a flow of the matrix mixture applied to the male mould member. 7 · A method of manufacturing a synthetic stone article substantially as described with reference to the accompanying drawings. For the Appncftn s DR. REINHOLD CCSW¾fc P«TttB