# US 5,700,556 A · Granules of fiber-reinforced thermoplastic > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,556 A - Document ID: US5700556A - Status: Granted - Kind: A - Application number: 08/476,067 - Filed: 1995-06-07 - Granted: 1997-12-23 - Earliest claimed: 1993-02-19 - Assignees: Hoechst Aktiengesellschaft - Inventors: Detlef Skaletz; Horst Heckel; Bruno Wagner; Joachim Heydweiller - Web page: https://patentgrep.com/patent/US5700556A ## CPC - C08K 7/14: Glass - B29B 9/14: fibre-reinforced - B29K 2023/12: {PP, i.e. polypropylene} - B29K 2105/101: {Oriented} - Y10T 428/24994: Fiber embedded in or on the surface of a polymeric matrix - Y10T 428/249942: Fibers are aligned substantially parallel - Y10T 428/249945: Carbon or carbonaceous fiber - Y10T 428/249946: Glass fiber - Y10T 428/249947: Polymeric fiber - Y10T 428/249949: Two or more chemically different fibers - Y10T 428/2971: Impregnation - Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.] - Y10T 428/2998: including synthetic resin or polymer - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - B29B: PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In granules of fiber-reinforced thermoplastic material, a multiplicity of individual filaments of the reinforcing fiber (e.g. glass) are arranged in parallel in a matrix of the thermoplastic material (e.g. polypropylene). The fiber length corresponds to the granule length and is in the range from 3 mm to 8 mm. The melt viscosity of the thermoplastic material is above 100 Pa.s, the diameter of the granules (measured perpendicular to the fiber direction) is 1.7 to 5 mm and the ratio diameter:length of the granules is 0.4 to 1.66. ## Claims ### Claim 1 A granule composed of fiber-reinforced thermoplastic material, in which a multiplicity of individual reinforcing fibers are arranged in parallel in a matrix of the thermoplastic material, and the fiber length corresponds to the granule length and is in the range from 3 mm to 8 mm, the reinforcing fibers having been wetted in a pultrusion process with a thermoplastic melt wherein the melt viscosity of the thermoplastic material is above 100 Pa.s at processing temperature, the diameter of the granule (measured perpendicular to the fiber direction) is 1.7 to 5 mm and the ratio diameter:length of the granule is 0.4 to 1.66. ### Claim 2 (depends on 1) The granule as claimed in claim 1, wherein the reinforcing fibers are comprised of glass. ### Claim 3 (depends on 1) The granule as claimed in claim 1, wherein the thermoplastic material is comprised of polypropylene. ### Claim 4 (depends on 1) The granule as claimed in claim 1, wherein the proportion of reinforcing fibers in the granule is 3 to 67% by volume. ### Claim 5 (depends on 1) The granule as claimed in claim 1, wherein the reinforcing fibers have diameters of 7 to 30 micrometers. ### Claim 6 (depends on 1) The granule as claimed in claim 1, wherein the reinforcing fibers are comprised of glass, carbon, aramid, steel or synthetic fibers. ### Claim 7 (depends on 1) The granule of claim 1, wherein said thermoplastic material contains at least one polymer selected from the group consisting of polypropylene, polyamides, polyoxymethylene, polyethylene, polyurethane, polyphenylene sulfide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyaryl ether ketones and mixtures thereof. ### Claim 8 (depends on 1) A method of making granules of fiber-reinforced thermoplastic material, in which a multiplicity of individual reinforcing fibers are arranged in parallel in a matrix of thermoplastic material as claimed in claim 1, comprising the steps of: (a) arranging a plurality of individual filaments in parallel and under tension to form a filament ribbon; (b) wetting the filament ribbon with molten thermoplastic polymer to form impregnated pultruded strands; (c) comminuting the impregnated pultruded strands to produce composite granules wherein the tension is in the range from 20 to 80% of the tensile strength of the filament ribbon. ### Claim 9 (depends on 8) The method as claimed in claim 8, wherein the filament ribbon has a drawing tension of 5N to 50N per 4,000 individual filaments. ### Claim 10 (depends on 8) The method as claimed in claim 8, wherein the reinforcing fibers are comprised of glass, carbon, aramid, steel or synthetic fibers. ### Claim 11 (depends on 10) The method as claimed in claim 10, wherein the reinforcing fibers are comprised of glass. ### Claim 12 (depends on 8) The method as claimed in claim 8, wherein the thermoplastic material is comprised of polypropylene. ### Claim 13 (depends on 8) The method as claimed in claim 8, wherein the proportion of reinforcing fibers in the granule is 3 to 67% by volume. ### Claim 14 (depends on 8) The method as claimed in claim 8, wherein the individual filaments have diameters of 7 to 30 micrometers. ### Claim 15 (depends on 8) The method as claimed in claim 8, wherein during step (b), the filament ribbon is drawn over at least two heated spreader surfaces. ### Claim 16 (depends on 15) The method as claimed in claim 15, wherein the filament ribbon has a drawing tension during drawing off of the impregnated pultruded strand from the melt higher than the drawing tension during entry into the first spreader surface. ### Claim 17 (depends on 16) The method as claimed in claim 16, wherein the drawing tension during drawing off is at least 50N per 4,000 filaments. ### Claim 18 (depends on 8) The method of claim 8, wherein during step (b) the filament ribbon is drawn through the molten thermoplastic at a speed greater than about 3 m/min. ### Claim 19 (depends on 8) A fiber-reinforced granule made by the method according to claim 8.