초록 ▼

A non-porous sheet for bonding to honeycomb-type core structures to be machined on a vacuum chuck includes a woven fiberglass fabric impregnated with a nonporous epoxy-thermoplastic resin having a low melting temperature. The epoxy-thermoplastic resin comprises a blend of bisphenol-A based epoxy and

A non-porous sheet for bonding to honeycomb-type core structures to be machined on a vacuum chuck includes a woven fiberglass fabric impregnated with a nonporous epoxy-thermoplastic resin having a low melting temperature. The epoxy-thermoplastic resin comprises a blend of bisphenol-A based epoxy and phenoxy thermoplastic. The nonporous sheet is exposed to a relatively low temperature for about five minutes to soften the epoxy-thermoplastic resin. A core structure is placed on the softened sheet and the sheet is allowed to cool to ambient temperature to adhere the non-porous sheet to the core. The core and sheet assembly can then be placed on the surface of a vacuum chuck associated with a machine tool for a subsequent machining operation of the core structure. When the machining operation is finished, the nonporous sheet is easily removed from the core structure by heating the core and sheet assembly slightly above ambient temperature and then peeling off the sheet from the core for reuse. In this manner, the core is not damaged and little or no residue is left on the core from the sheet.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A nonporous sheet material for temporary or permanent bonding to a work piece, the sheet material comprising:a porous fabric impregnated with a resin blend in sufficient quantity t

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] A nonporous sheet material for temporary or permanent bonding to a work piece, the sheet material comprising:a porous fabric impregnated with a resin blend in sufficient quantity to render the fabric nonporous, the resin blend comprising a blend of epoxy and thermoplastic resins; the epoxy resin being present in the blend in the range of about 35 to about 65 percent by weight and the thermoplastic resin being present in the blend in the range of about 65 to about 35 percent by weight, and the thermoplastic and epoxy resins are selected such that the resin blend softens at a temperature in the range of about 100.degree. F. to about 300.degree. F.;wherein the nonporous, reusable sheet material can be bonded to the structure by heating the sheet material to a temperature within the temperature range to soften the resin, placing the sheet material and structure in mutual contact, and then cooling the sheet material to ambient temperature.