Dunstone Co., Inc.

United States

Dunstone's core product line, our Hi-Shrink Tapes are unique in that they allow the user to control the amount of compressive force applied to the underlying part during the cure process.Some non-shrinking films, such as cellophane, nylon, or polypropylene (OPP), are commonly used to overwrap composite parts to provide compression during cure. They are wrapped, under high tension before the part enters the curing oven. However, these films will relax as the temperature of the cure cycle increases, at the same time that the resin in the composite part begins to drop in viscosity and flow. This is the exact opposite of what you need to ensure good resin flow, and a void free cure.Dunstone Hi-Shrink Tapes will begin to shrink at 70°C, and reach maximum shrink force in the 120°C to 160°C range. Therefore, our tapes will apply the maximum amount of compressive force right when you need it, as your resin begins to flow. This allows for additional ply compaction, elimination of air voids in the part walls, and gives a nice, resin-rich surface finish.The family of Hi-Shrink Tapes is geared to suit applications up to 180°C with ETFE and PETTedlar® films, and up to 400°C with our polyimide shrink product.

Hi-Shrink FEP Tubing is designed for tooling applications where the outer tool surface is required to be covered with a release film prior to part lay-up. Typically, hand taping of large, uniform cross sectional tools is time consuming and costly, especially in the Aerospace industry. Hi-Shrink FEP tubing helps reduce tool prep and part lay-up time by allowing operators to ‘sleeve’ the tool with the release film tubing. Application of heat initiates tube shrinkage and results in a tight, uniform film covering on the tool surface.

Non-Shrink Tapes are used to help consolidate parts where only slight compaction is needed. The compaction provided by Dunstone non-shrink tapes is achieved only through the tension applied during the actual taping of the part.

Non-Shrink Tapes are used to help consolidate parts where only slight compaction is needed. The compaction provided by Dunstone non-shrink tapes is achieved only through the tension applied during the actual taping of the part.