# US 2025/0083403 A1 · In mold painting of lightweight core structure assembly with vehicle exterior surface finish > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0083403 A1 - Document ID: US20250083403A1 - Status: Published application - Kind: A1 - Application number: 18/806,806 - Filed: 2024-08-16 - Published: 2025-03-13 - Earliest claimed: 2023-09-07 - Assignees: Teijin Automotive Technologies, Inc. - Applicants: Teijin Automotive Technologies, Inc. - Inventors: Hugh Foran; Matthew Plauman; Evan Freeman-Gibb - Web page: https://patentgrep.com/patent/US20250083403A1 ## CPC - B32B 3/12: characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure - B29C 43/18: incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles {(B29C43/206 takes precedence)} - B29C 43/203: {Making multilayered articles} - B29C 43/56: Compression moulding under special conditions, e.g. vacuum - B32B 3/08: characterised by added members at particular parts {(layer formed of separate pieces of material which are juxtaposed side-by-side B32B3/14, B32B3/18)} - B32B 5/022: {Non-woven fabric} - B32B 5/024: {Woven fabric} - B32B 5/18: characterised by features of a layer {of} foamed material - B32B 5/245: {another layer next to it being a foam layer} - B32B 7/02: Physical, chemical or physicochemical properties - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 15/14: next to a fibrous or filamentary layer - B32B 27/12: next to a fibrous or filamentary layer - B32B 27/20: using fillers, pigments, thixotroping agents - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - B32B 27/40: comprising polyurethanes - B32B 29/02: next to a fibrous or filamentary layer - B29C 2043/561: {under vacuum conditions} - B29C 2793/0027: Cutting off - B29C 2793/009: after shaping - B29L 2031/3005: {Body finishings} - B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA - B32B 2255/26: Polymeric coating - B32B 2262/101: Glass fibres - B32B 2307/4023: on the layer surface, e.g. ink - B32B 2307/406: Bright, glossy, shiny surface - B32B 2307/41: Opaque - B32B 2307/538: Roughness - B32B 2307/7246: Water vapor barrier - B32B 2307/7376: Thickness - B32B 2605/003: Interior finishings - B32B 2607/00: Walls, panels - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A composite sandwich panel structure is provided with a lightweight core sandwiched between a high gloss surface sheet and an optically uniform painted or otherwise finished structural skin that are adhered to the lightweight core so as to reduce delamination of the formed part. The structural skin is surface finished during the formation of the sandwich panel structure and does not require any post manufacturing finishing steps such as a separate painting step or material application step. The sandwich composite structure, the high gloss surface sheet, and structural skin are adhered to the lightweight core with an adhesive or glue that is viscous when applied. The viscosity of the adhesive as applied allows for contact with the interior volume of the lightweight core to create more adhesion surface area yet without excessively running into the pores defined in the lightweight core before the adhesive cures or hardens. ## Claims ### Claim 1 A composite sandwich panel assembly, the assembly comprising: a lightweight core having a first face and a second face opposing the first face; a high gloss surface sheet adhered to the first face of the lightweight core by a first adhesive layer, the high gloss surface sheet having a high gloss surface; a structural skin adhered to the second face of the lightweight core by a second adhesive layer; and a paint layer disposed on an exposed surface of the structural skin, the layer exhibiting optical uniformity over at least 80% of the surface area of the layer. ### Claim 2 (depends on 1) The assembly of claim 1 wherein the paint layer is formed of precursors of: polyurethanes, latexes, epoxies, polyureas, polyacrylates, or block co-polymers in which any of the aforementioned constitute at least 20 percent of the total number of subunits. ### Claim 3 (depends on 1) The assembly of claim 1 wherein the paint layer imparts a color to the structural skin and the structural skin has surface texture that is not smooth or is entirely opaque across at least 80% of the surface area of the layer. ### Claim 4 (depends on 1) The assembly of claim 1 wherein the paint layer is applied to the exposed surface of the structural skin in a mold during formation of the composite sandwich panel assembly. ### Claim 5 (depends on 1) The assembly of claim 1 further comprising a veil positioned between the structural skin and the layer. ### Claim 6 (depends on 5) The assembly of claim 5 wherein the veil is pre-painted. ### Claim 7 (depends on 1) The assembly of claim 1 wherein the lightweight core is formed of at least one of: cellulosics, thermoplastic, thermoset, metal, or foam. ### Claim 8 (depends on 1) The assembly of claim 1 wherein the high gloss surface sheet is formed of any one of: sheet molding compound (SMC), thermoplastic sheet, dicyclopentadiene (DCPD), or overmolded polyurethane (PU) and optionally comprises a filler. ### Claim 9 (depends on 1) The assembly of claim 1 wherein the high gloss surface sheet has a thickness of from 0.5 to 3.5 mm and optionally has a ratio of a thickness of the high gloss surface sheet to a thickness of the lightweight core of 0.01-1:1. ### Claim 10 (depends on 1) The assembly of claim 1 wherein further comprising a cloth intermediate between the high gloss surface sheet and the lightweight core and is optionally embedded in the first adhesive paint layer and the high gloss surface sheet is an SMC that has a thickness of less than 1.5 mm and still retains the high gloss surface. ### Claim 11 (depends on 1) The assembly of claim 1 further comprising a decorative layer attached to the structural skin. ### Claim 12 (depends on 1) The assembly of claim 1 wherein the high gloss surface sheet and the structural skin are joined together to form an edge defining a moisture resistant seal and optionally includes a gasket disposed between the high gloss surface sheet and the first structural at the edge. ### Claim 13 (depends on 1) The assembly of claim 1 wherein the paint layer includes at least one of a UV stabilizer, a mica material, a phosphorescent material, a felted material, or a rubberized material felt. ### Claim 14 (depends on 1) The assembly of claim 1 wherein the lightweight core has at least one of a fastener, a duct, a conduit, or a wire, embedded at least partially therein. ### Claim 15 A process for forming a composite sandwich panel assembly, the process comprising: applying paint layer precursors to a surface of a mold in which the composite sandwich panel assembly is to be formed and allowing the paint layer precursors to at least partially cure to form a layer; positioning an exposed surface of a structural skin in the mold on the layer; joining a first face of a lightweight core to a surface of the structural skin that is opposite the paint layer with a first adhesive layer intermediate therebetween; joining a high gloss surface sheet to a second face opposing the first face of the lightweight core with a second adhesive layer intermediate therebetween to form the composite sandwich panel assembly. ### Claim 16 (depends on 15) The process of claim 15 further comprising applying a mask to the surface of the mold prior to applying the paint layer precursors to the surface of the mold. ### Claim 17 (depends on 15) The process of claim 15 further comprising vacuum molding the composite sandwich panel assembly. ### Claim 18 (depends on 15) The process of claim 15 further comprising removing excess material from the structural skin proximal to the edge. ### Claim 19 (depends on 15) The process of claim 15 wherein the composite sandwich panel assembly is formed in the mold at a temperature between 200 and 250 degrees F. or a pressure between 60 and 70 psi. ### Claim 20 (depends on 15) The process of claim 15 further comprising opening the mold at least once during formation of the composite sandwich panel assembly to vent off gases.