# US 4,394,413 A · Flame retardant dryer fabrics > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,394,413 A - Document ID: US4394413A - Status: Granted - Kind: A - Application number: 06/232,678 - Filed: 1981-02-09 - Granted: 1983-07-19 - Earliest claimed: 1981-02-09 - Assignees: Scapa Dryers, Inc. - Inventors: William T. Westhead - Web page: https://patentgrep.com/patent/US4394413A ## CPC - D21F 1/0036: {Multi-layer screen-cloths} - Y10S 428/92: Fire or heat protection feature - Y10T 442/3049: Including strand precoated with other than free metal or alloy - Y10T 442/3203: Multi-planar warp layers - Y10T 442/3252: Including synthetic polymeric strand material - D21F: PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention is directed at modifying a resin-treated dryer fabric in such a way that its scaffolding effect is reduced or eliminated. Further, according to the teachings of the present invention, the resin used to coat the dryer fabric is itself made self-extinguishing, such that even if the fabric acts as a scaffold, the resin will not burn. Even further, a degree of flame retardancy is imparted to the base fabric in those cases where the base fabric itself is not self-extinguishing. A dryer fabric in which the woven fabric material is treated with an admixture of flame retardant material and resin, such that the flame retardant and resin are added to either the yarns of the fabric or the woven fabric at the same time. The admixture may take the form of a solution, a suspension, a colloidal suspension, a dispersion or an emulsion of flame retardant material and resin. The flame retardant material is preferably a water soluble material having an active phosphorous ingredient, preferably at the 15% level. The retardant material, in some cases, can also be a high bromide content material. ## Claims ### Claim 1 A flame retardant dryer fabric comprising: a plurality of interwoven machine direction and cross-machine direction yarns; and an admixture of resin and flame retardant coating said machine direction and cross-machine direction yarns, said resin being chosen for its known ability to provide fabric stability, wear and abrasion resistance, heat and hydrolysis resistance, resistance to chemical attack, modulus, and oil and dirt resistance; said flame retardant being compatible with said resin; and said admixture being free of nucleation and being an integral part of said fabric. ### Claim 2 (depends on 1) The dryer fabric of claim 1, wherein said flame retardant is water soluble and contains phosphorus. ### Claim 3 (depends on 1) The dryer fabric of claim 1, wherein said resin is an acrylic or epoxy resin. ### Claim 4 (depends on 1) The dryer fabric of claim 1, wherein said flame retardant is present in an amount of approximately 5-15% based upon total weight of said resin. ### Claim 5 (depends on 1) The dryer fabric of claim 1, wherein the components of the machine direction and cross-machine direction yarns are selected from the group consisting of spun synthetic yarn material, non-spun synthetic yarn material, and combinations of spun and/or non-spun synthetic yarn materials. ### Claim 6 (depends on 1) The dryer fabric of claim 1, wherein the components of the machine direction and cross-machine direction yarns comprise polyester, glass, acrylic, nylon, aramid fiber, and mixtures thereof. ### Claim 7 (depends on 1) The dryer fabric of claim 1, wherein the warp yarn of the dryer fabric comprises 100% polyester or combinations of polyester and other synthetic yarns or combinations of other synthetic yarns not including polyester, and the weft yarn of the dryer fabric comprises glass/synthetic yarn, polyester, or glass. ### Claim 8 A flame retardant dryer fabric comprising a woven fabric including a plurality of machine direction yarns, each of said machine direction yarns being coated with a first admixture of both a first resin and a first flame retardant, and a plurality of cross-machine direction yarns, each of said cross-machine direction yarns being coated with a second admixture of a second resin and a second flame retardant, said coatings being applied prior to weaving said yarns into said dryer fabric. ### Claim 9 (depends on 8) The dryer fabric of claim 8, wherein said first and second resins are of the same resin material, said resins being chosen for their known ability to provide fabric stability, wear and abrasive resistance, heat and hydrolysis resistance, resistance to chemical attack, modulus, and oil and dirt resistance. ### Claim 10 (depends on 9) The dryer fabric of claim 9, wherein said resin material is acrylic or epoxy. ### Claim 11 (depends on 8) The dryer fabric of claim 8, wherein said first and second flame retardants are of the same flame retardant material, said flame retardants being compatible with their respective resins; said admixtures being free of nucleation, said flame retardant acting to soften said resin; and said admixture increasing the flexibility of said dryer fabric. ### Claim 12 (depends on 8) The dryer fabric of claim 8, wherein each of said first and second flame retardants are present in an amount of approximately 5-15% based upon total weight of their respective resins. ### Claim 13 (depends on 8) The dryer fabric of claim 8, wherein at least one of said admixtures further comprises at least one dyestuff. ### Claim 14 (depends on 9) The dryer fabric of claim 9, wherein each of said admixtures includes a resin solids concentration in the range of 5-9%, where percent is based upon the liquid resin mix. ### Claim 15 (depends on 8) The dryer fabric of claim 8, wherein at least one of said flame retardants is a complex phosphonate ester. ### Claim 16 (depends on 15) The dryer fabric of claim 15, wherein 15% phosphorus is present in said complex phosphonate ester. ### Claim 17 (depends on 8) The dryer fabric of claim 8, wherein at least one of said flame retardants is a compound having tightly cross-linked organic benzene rings, and having a high bromine content. ### Claim 18 (depends on 17) The dryer fabric of claim 17, wherein said compound contains at least 83% bromine and 0% phosphorus. ### Claim 19 (depends on 8) The dryer fabric of claim 8, wherein the components of the machine direction and cross-machine direction yarns are selected from the group consisting of spun synthetic yarn material, non-spun synthetic yarn material, and combinations of spun and/or non-spun synthetic yarn materials. ### Claim 20 (depends on 8) The dryer fabric of claim 8, wherein the components of the machine direction and cross-machine direction yarns comprise polyester, glass, acrylic, nylon, aramid fiber, and mixtures thereof. ### Claim 21 (depends on 8) The dryer fabric of claim 8, wherein the warp yarn of the dryer fabric comprises polyester or combinations of synthetic yarns, and the weft yarn of the dryer fabric comprises glass/synthetic yarn, polyester, or glass. ### Claim 22 (depends on 1) The dryer fabric of claim 1, wherein said flame retardant acts to soften said resin, and said admixture increases the flexibility of said fabric over that exhibited by said fabric without the addition of said flame retardant. ### Claim 23 (depends on 9) The dryer fabric of claim 9, further comprising a third admixture of both a third resin and a third flame retardant. ### Claim 24 (depends on 23) The dryer fabric of claim 23, wherein said third resin material is acrylic or epoxy, chosen for its known ability to provide fabric stability, wear and abrasion resistance, heat and hydrolysis resistance, resistance to chemical attack, modulus, and oil and dirt resistance; and wherein said third flame retardant is chosen so as to be compatible with said resin; said admixture being free of nucleation.