Browse Prior Art Database

High Performance SuperLite Sheet

IP.com Disclosure Number: IPCOM000009046D
Publication Date: 2002-Aug-02
Document File: 7 page(s) / 119K

Publishing Venue

The IP.com Prior Art Database

Abstract

SuperLite thermoplastic composite sheets, made by a modified paper making process, are a highly adaptable form of chopped glass reinforced resin that may be easily molded over a wide range of density to provide the required balance of properties for a host of applications. Relatively high glass fiber content is used to effect lofting, the tendency of the product to form a porous, low density structure with excellent insulating and flammability characteristics, depending on the particular resin, temperature and glass fiber content and molding pressure. Relatively high glass fiber content and low melt viscosity resin at the intended use or processing temperature are paired to maximize lofting. The resulting network tends to exhibit superior sound dampening properties, thermal insulation and fire performance without the use of halogen or heavy metal salts, while also providing high mechanical properties in a relatively easily moldable form. Resins such as polyetherimide (PEI) and polyphenylene sulphide (PPS) provide a superior balance of properties with outstanding flame resistance, stiffness, temperature capability and chemical resistance.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 25% of the total text.

High Performance SuperLiteÒ[1] Sheet

Introduction

SuperLiteÒ thermoplastic composite sheets, made by a modified paper making process, are a highly adaptable form of chopped glass reinforced resin that may be easily molded over a wide range of density to provide the required balance of properties for a host of applications. Relatively high glass fiber content is used to effect “lofting”, the tendency of the product to form a porous, low density structure with excellent insulating and flammability characteristics, depending on the particular resin, temperature and glass fiber content and molding pressure. Relatively high glass fiber content and low melt viscosity resin at the intended use or processing temperature are paired to maximize lofting. The resulting network tends to exhibit superior sound dampening properties, thermal insulation and fire performance without the use of halogen or heavy metal salts, while also providing high mechanical properties in a relatively easily moldable form. Resins such as polyetherimide (PEI) and polyphenylene sulphide (PPS) provide a superior balance of properties with outstanding flame resistance, stiffness, temperature capability and chemical resistance.

Resin Choices

Any resin that can be processed as a wet slurry may be used as the matrix in these lofted structures. Lofting is due to glass fibers that are generally orientated in the “Z” direction, being bent during compression and locked into a highly strained configuration by the cooled resin. When the resin is reheated and reaches a sufficiently low viscosity to no longer be able to constrain the fiber, the fiber will straighten, expanding into the “Z” direction. The higher the glass content and the lower the melt viscosity the more rapidly the structure will loft. The maximum lofting will be nearly the same for both highly viscous and very fluid melts given sufficient time to loft.

Resins exhibit very different burning characteristics depending on their chemical makeup, the amount of heat they are exposed to, the temperature they attain, as well as their physical form and availability of oxygen. Many neat resins produce high volumes of heavy, dark smoke, while others produce very little smoke and release relatively small amounts of energy or toxic chemicals. When any of these same resins are used in lofted structures, they tend to burn cleaner, producing lower smoke levels and releasing even less energy. The high glass fiber levels also aid in the fire resistance of those resins that are not inherently flame resistant by reducing or even eliminating dripping of the burning resin, further improving their fire resistance rating.

The lofted structures protect the substrate by insulating it from the flame, while permitting gaseous degradation products to escape and burn more completely, rather than build up and causing flairs and heavy smoke. The escaping gases also take away energy thereby cooling the substrate.

Trim and scrap may be made into useful arti...