Patent GB-739802-A (GB)
Title: Improvements relating to the production of decorated articles by moulding from thermosetting synthetic resins
IPC: B29C43/18
Filed: 1951-03-13
Abstract: 739,802. Moulding decorated articles from thermosetting plastics. HAYWARD, L. H. March 4, 1952 [March 13, 1951], No. 6088/51. Class 87 (2). Relates to a method of producing a decorated article by compression - moulding thermosetting synthetic resin powder, in which a thin wafer of absorbent paper impregnated with thermosetting synthetic resin and bearing a design in printing inks or other media is applied to a part of the surface of the article when the article has been moulded substantially to its final shape but before its curing has been completed, the curing being thereafter completed with compression so that the wafer becomes embedded in the surface of the article. According to the invention the wafer is mechanically guided to engage the surface of the article. Fig. 1 shows a beaker A being made in a hydraulic press including a mould B, a pressing die C and a plunger B<2> which is disposed in the mould wall and the inner end of which conforms to the mould surface. In operation, the plunger is locked in its inner position, the beaker is initially shaped, the plunger is completely withdrawn from the mould, a paper wafer having a design printed on one side of it is applied to the head of the plunger, and the plunger is reinserted in the mould and pressed fully home to apply the wafer to the surface of the partly moulded article. Curing under heat and pressure is then completed. In a modified apparatus, Figs. 2-4 (not shown), there are two moulds, one having the plunger B<2> and one not having it; first the article is partly moulded in the mould having the plunger, then the wafer is applied as in Fig. 1, then the partly-moulded article having the wafer applied thereto is discharged from the mould and put into the second (plain) mould, where curing is completed. These two moulds are mounted on a horizontal turntable, and are brought in turn beneath the upper die C. In another modification, Fig. 5, the article is partly moulded in a wafer-applying mould B and finally cured in a mould B<3>, both moulds being formed in a body L journaled at L<1> in bearings L<3> carried by springs L<3>. When the die C descends to mould the article, first the springs are compressed and then the body L bottoms on the surface S, whereby strain on the bearings is prevented. The partlymoulded article is ejected from mould B by ejector B<4> operated by compressed air against its return spring B5. In the modifications of Figs. 2, 4 and 5 the wafer-applying plunger may be operated by a mechanical linkage which also turns the turntable or body L; a single pedal may control the operations automatically in correct sequence. Fig. 6 shows apparatus for making a bowl in a single mould. First the article is initially moulded, then the mould opens, then a pivoted arm P having at its end a pivoted suction cup which has taken a wafer from a pile swings inwardly and deposit's the wafer on the article. As the wafer touches the article the suction is cut off and replaced by compressed air. The arm is swung clear, the mould closes and curing is completed.. The wafers in the pile may have pips which orientate them. Composite wafers are described in Specification 739,801 may be used. Specifications 706,179 and 732,774 also are referred to.