Multi-level embossed cellular surface covering and process for producing same

Claim 1

A process for forming a decorative, cellular, resinous surface covering having a multi-level embossed wear surface, comprising (a) producing a printable porous substrate; (b) pre-selecting a plurality of thermoplastic resins having different molecular weights which ultimately result in differences in their melt viscosities during a subsequent heating step; (c) using said pre-selected resins as binders to form a plurality of thermoplastic resinous inks, at least one of said inks having a binder of a different molecular weight and therefore a different melt viscosity than that of another of said inks, the molecular weight differential between said resins being sufficient to produce a distinguishable embossed appearance in the final product by the effect of the melt viscosity difference; (d) producing design areas in said porous substrate by applying the resinous inks to selected portions thereof in amounts and fluid viscosities predetermined to result in at least partial penetration through the thickness of the substrate at the points of application, said inks and said substrate comprising a composite structure which further includes a blowing agent; and (e) finally heating the composite structure to fuse the resin and decompose the blowing agent, whereby the differences in the melt viscosities of the pre-selected resins used in the inks affect the expansion of the ink-containing portions of the structure by the blowing agent in varying degrees, thus producing multi-level embossed cellular design areas on the final product.