Patent GB-1432175-A (GB)
Title: Method and means for providing a foamed plastic surface with a relief structure
IPC: B44C1/17
Filed: 1973-05-23
Abstract: 1432175 Coated products FORBO BETRIEBS AB 23 May 1973 [24 May 1972] 24526/73 Heading B2E [Also in Division B5] Means for providing foamed plastics surfaces in a relief structure design comprise a printed, non-foamable, self-supporting foil or a printed film located on a carrier material in which either (a) predetermined locations of the film or foil, corresponding to the printing pattern, contain a means which inhibits or accelerates foaming or (b) a uniform layer containing a means which inhibits or accelerates foaming is covered at predetermined locations corresponding to the printed pattern by a barrier layer material which prevents the passage of a means which inhibits and accelerates foaming. Also claimed is a method of providing a surface of a foamed plastics sheet with a relief structure the embossment of which coincides with a pattern applied to the surface thereof, which comprises (i) spacing a non-foamable foil or film having a pattern printed thereon which either (a) contains at predetermined locations, substantially coinciding with the said printed pattern a means which accelerates or accelerates foaming, or (b) is covered by a uniform layer of a means which inhibits or accelerates foaming having a pattern printed thereon of, a barrier layer which prevents through-passage of said means at predetermined locations coinciding with the printed pattern, (ii) applying the non-foamable printed foil or film to a foamable base layer, prior to foaming, and (iii) heating the composite material to the foaming temperature whereby during the foaming step the means which inhibits or accelerates the foaming migrates in accordance with the pattern printed on the film or foil into the base layer to provide the surface of the foamed layer with a relief structure coinciding with the said printed pattern and the printed foil or printed film becomes anchored to the surface of the foamed layer. In the first embodiment the non-foamable selfsupporting foil, or a film on a temporary carrier material provided with a design or pattern a printing dye is employed containing different amounts of the inhibiting or accelerating material. The foil is then applied to a pregelled foamable layer and the composite material heated until foaming and gelling occurs and a foamed plastics material provided with a relief design is obtained. A wearresistant protective layer constituted by the non-foamable material is thereby located over the printing design, and the non-foamable foil must be substantially transparent and colourless so that the printing design is visible. The non- self-supporting film is located on a temporary carrier material, such as a silicone treated paper, the film is transferred to the foamable layer before the foaming action is carried out. A further transparent layer may be applied before heating to obtain foaming is effected. In a second embodiment uniform layer of the inhibiting or accelerating means is provided on a non-foamable self-supporting film or a film located on the carrier material and a pattern is printed on this layer, with various coloured inks having different contents of a barrier layer material which prevents penetration of the inhibiting or accelerating means. Anchoring of the non foamable foil is carried out as just described. In a third embodiment a film located on a carrier material is provided with a printing design in which the individual printing dyes or inks which possess different contents of the barrier material which prevents passage of the accelerating of inhibiting means. The film therefore contains only a barrier layer material and is transferred to the foamable substrate or base in the manner just described. When the film carrier has been removed and the printed film is located on the foamable substrate or base support the surface is -treated with the inhibiting or accelerating means either with use of an applied liquid or through introduction into an appropriate gaseous atmosphere. The foamable base layer may be located upon a substrate which after foaming either remains connected with the foamed layer or may be removed therefrom. The substrate may be reinforced material such as a felt, fabric or paper or a plastic or metal foil. A layer of non-foamable transparent or translucent material may overly the patterned foamed plastic surface which is provided with a relief structure.