Pick the paste resin grade for each coated layer: a high-K, low-viscosity grade for the wear layer or top coat, a low-to-medium-K foaming grade for the chemically blown layer, and a very-low-viscosity grade with high filler tolerance for the base coat or compact layer. Flooring, wallpaper and synthetic leather all follow this split, so one product usually takes two or three different grades.
The three products differ in where each layer sits on the K scale. General wallpaper foam grades sit lowest, synthetic-leather layers sit higher, and automotive leather adds a low-fogging requirement to every layer. The coating method then narrows the shortlist to the grades whose viscosity behaviour your coater can run.
Why the Grade Follows the Layer
A paste grade is chosen per layer because each layer needs different properties from the resin. The top coat has to resist abrasion, staining and water uptake and stay clear, which needs high molecular weight. The foam layer has to gel and expand evenly with a fine cell structure, and the base coat has to stay fluid under a heavy filler load.
Floor tiles and other dry-blend products are a different case: SCGC lists suspension resins, not paste grades, for floor tile, and a suspension grade cannot stand in on a coating line.
Paste Resin Grades for Vinyl Flooring
Cushion vinyl flooring takes three grade types: a high-K grade for the transparent top coat, a foaming grade for the printed foam layer, and a very-low-viscosity, filler-tolerant grade for the base coat.
Wear Layer and Top Coat
The flooring top coat takes a high-molecular-weight homopolymer that still gives a low-viscosity, near-Newtonian paste. Kaneka’s flooring top-coat grade PSH-985 has a K-value of 94, and SCGC lists its high-molecular-weight grade PC750 for the flooring top layer.
Within the top-coat group, pick by finish. Westlake Vinnolit sorts its top-coat grades into glossy (P 70, P 80), silk-matt (E 70 TT, E 80 TT) and matt (MP 8058).
From our own range, Formolon PR-1060 is a K 80 grade we supply for vinyl floor wear layers. PVC paste resin Grade D, at K 78, gives a matte finish for high-wear sports floors.
Foam and Print Layer
The chemically foamed print layer takes a low-to-medium-K grade that gives a low or low-to-medium viscosity paste and foams fast and evenly into fine cells. The grades are also rated for printability with inhibitor inks, which chemical embossing of the pattern depends on.
Kaneka lists PSM-162 (K 70) and PSL-180 (K 66) for the flooring foam layer. Our Formolon PR-450 is a K 65 grade made for chemical foaming, and PVC paste resin Grade A (K 66) goes into sports-floor foam layers.
Some resin vendor pages recommend high-viscosity grades for foamed layers, but the flooring foam grades Vinnolit and Kaneka list are low or low-to-medium viscosity.
Base Coat and Backing
The base coat takes a grade rated for very low viscosity and very high filler tolerance, with a K-value that is not the lowest of the three layers. Vinnolit rates its base-coat grades P 4472 and MP 7151 as Newtonian and suitable for contact gelation, and P 4472 for no plate-out on the pregelling cylinder.
The back-side foam under the base coat runs on foaming grades: Vinnolit lists one set of grades for both back-side and print foam.
Paste Resin Grades for Wallpaper
Wallpaper takes a fine foaming grade for foamed (screen-printed or chemically embossed) and hot-embossed paper, and a very-low-viscosity, filler-tolerant grade for compact paper. Across these processes, wallpaper grades are also rated for high whiteness and for filler tolerance.
Our PVC paste resin Grade B (K 65) is made for wallpaper, and Formolon PR-450 (K 65) serves wall covering.
Foamed and Chemically Embossed Wallpaper
Rotary-screen foamed wallpaper takes a very fine, low-coarse-content foaming grade of low to medium K, and chemically embossed wallpaper can take a higher-K grade. Vinnolit’s E 69 ST, a K 68 grade with 0.1% retained on a 0.063 mm screen, is recommended for foamed wallcoverings made by rotary screen printing.
The paste also has to suit the screen. Kaneka’s rotary-screen wallpaper grade PSM-271R (K 69) is rated for low high-shear viscosity with high thixotropy.
Kaneka names its K 77 grades PSH-161 and PSH-31 for chemically embossed wallpaper.
Hot-Embossed Wallpaper
Hot-embossed wallpaper takes a low-K foaming grade rated for very high whiteness, a foam structure that takes the emboss, and fast gelling. Vinnolit’s E 68 CT (K 68) is built for this process: very low paste viscosity even at high filler loads, high gelling speed, and matt films of very high whiteness.
SCGC’s hot-embossing grade PF621 has a K-value of 62.9 and is rated for low viscosity at high filler loadings. Kaneka’s PSL-685 (K 64) is rated to prevent cell bonding and surface scaling during embossing.
Compact Wallpaper
Compact wallpaper takes a very-low-viscosity, near-Newtonian grade with high filler tolerance and long storage stability. Vinnolit lists P 4472 and MP 7151 for compact wallpaper, the same two grades it lists for the flooring base coat, and rates MP 7151 for thin, highly filled coats on high-speed reverse-roll and rotary-screen lines.
For a matt compact surface, producers move to a higher-K grade. Vinnolit’s P 5078 (K 78) is a medium-viscosity grade for compact vinyl wall coverings, and Kaneka names its matt grades PSH-945 and PSH-947 for the wallpaper base coat.
Paste Resin Grades for Synthetic Leather
PVC synthetic leather takes a high-K, high-strength grade for the top layer, a medium-K foaming grade for the intermediate layer, and a low-viscosity grade that bonds to textile for the adhesive layer. Automotive leather adds low fogging and thermoforming stability to each layer.
Top Layer
The leather top layer takes a high-molecular-weight homopolymer rated for high physical strength at low viscosity. SCGC’s PG740 (K 74.4) is listed for the synthetic-leather top layer, and its PG770 (K 79.3) for a high-strength top layer.
Our Formolon PR-1060 (K 80) is a high-molecular-weight grade we supply for coated fabrics. Automotive leather adds a fogging requirement, with the limit set in each carmaker’s material specification. The PR-1060 data sheet specifies a fogging value of ≤ 3 mg/10 g PVC under DIN 75201-B.
Foam Layer
The leather foam layer takes a medium-molecular-weight foaming grade. SCGC’s leather foam grades PF682 and PG680 have K-values of 69.9 and 69.2. Our Formolon PR-450 (K 65) also serves casting leather.
For thermoformed automotive leather, the foam has to stay stable when the sheet is vacuum-formed. Vinnolit’s E 75 SK (K 74) is rated for thermally and mechanically stable foams while classified low to medium viscosity.
Adhesive Layer
The adhesive layer takes a low-viscosity grade that bonds to the textile and works with bonding agents. Vinnolit names its K 74 grade E 74 CC for the automotive adhesive layer as well as the foam and top coat, and lists MP 7151 for textile coating for its good adhesion to fabrics at low viscosity. SCGC lists PG680 for the leather adhesive layer.
A vinyl chloride/vinyl acetate copolymer is the other route. Formolon PR-640, a copolymer with 5–6% vinyl acetate, gels at a lower temperature than homopolymer pastes and bonds to fabrics at low temperature without a separate primer step.
How the Coating Method Narrows the Choice
The coating method narrows the choice to grades whose paste suits the shear rate and coat weight it runs. Each method takes a different kind of paste:
- Knife over roll: handles viscous pastes and unmilled grades; Vinnolit’s MP 8058 top-coat grade runs on knife or reverse-roll coaters but is not suited to thin coats or rotary screens.
- Reverse roll: runs thin coats at high speed, which needs a low-viscosity, near-Newtonian paste; Vinnolit rates P 4472 for coatings under 100 µm at high speed on reverse-roll coaters and rotary screens.
- Rotary screen: needs fine, milled particles with little coarse content, plus either very low viscosity or high thixotropy with low high-shear viscosity.
- Fabric coating: needs a pseudoplastic paste that limits strike-through; Formosa Plastics USA rates its F-KVH and F-KVF grades for fabric coating where minimum strike-through is essential.
A blending or extender resin can bring a grade’s viscosity into the method’s range: Vinnolit offers EXT and C 65 V for this, and Kaneka offers PBM-B5F. Producers’ viscosity figures use different test methods and plasticizer ratios, so confirm the shortlisted grade on a trial with your production plastisol formulation and coater.