Shrink films

Hi-Shrink tapes start shrinking at 70°C and reach their maximum shrinkage at 150°C. Therefore, these tapes are applied for maximum compression force when you need it as your resin begins to flow.
 This allows additional compression to be given to the layers, eliminating the formation of air voids on the walls of the product and gives a good final surface. The Hi-Shrink line of tapes are tapes for 
various applications: up to 170°C in polyester materials, up to 230°C with ETFE release film, and up to 400°C in their polyamide products.

The technical data provided by product is for informational purposes only. Testing to determine whether a material is suitable or not must be done by the end user. 
We cannot guarantee performance in end use. Unless otherwise indicated, percentage shrinkage data was obtained within 15 minutes at 150°C.
We reserve the right to a tolerance of ± 3% in product shrinkage percentage.

Important formula:

How to calculate the compression force per product:

2×T×WP=D

How to count the number of layers of tape referring to wrap per inch:

Factors affecting the compression force on your product:

Examples of using materials

The following are a number of case studies that show customer problems in their manufacturing processes and how these problems have been solved with our products

Aerospace thermal insulation skin

Industry

Aerospace sector, composites

Application

The company manufactures epoxy/glass and phenol/glass insulating skins that are used as a thermal shield over metal duct systems.

Problem

The company used cellophane film and PVA film to wrap the parts and provide compression during the curing cycle. 
To wrap each piece, the production required two different wrapping operations - one with cellophane and one with PVA. 
The cellophane used as a release liner under the PVA layer adhered to the epoxy/glass prepreg after curing. 
The customer immersed each product in water for 24 hours to soften the cellophane layer, 
and a subsequent production step was required - cleaning the remaining cellophane from the product.

Our company“s proposed solution

Hi-Shrink Heat Shrink Tape 210R (Thickness.002", 10% Shrink, Polyester Shrink Tape with Release Layer)

Implementation

The customer was able to reduce the number of wrapping steps to a single operation as they were able to achieve
 adequate compression of the part with just one layer of Our film compared to the previous two layers (cellophane and PVA).
 Because PTFE release tapes are easy to peel off after post-curing, Dunstone's Hi-Shrink tapes allowed the customer to completely 
eliminate the need to soak all parts in water overnight, increasing productivity.

Composite poles

Industry

Infrastructure.

Application

The company manufactures epoxy/glass composite poles using a filament winding process.

Problem

The company has not previously used film to wrap sections of composite poles prior to curing. As a result, 
they had a surface containing irregularities, with air voids, and the quality was inconsistent from product to product.

Our company's proposed solution

Hi-Shrink 210R (thickness.002", shrinkage 10%, polyester shrink film with release layer)

Implementation

After applying the last layer of polyester veil to achieve surface finish, the customer spirals 2.0" wide Hi-Shrink tapes 
along the entire length of the product. during curing, as the post sections do not rotate in the oven during curing.
The PTFE release layer makes it easy to remove the tape after curing and gives a smooth, quality product surface.

Pipeline of the artificial climate system (ECS)

Industry

Aerospace sector, composites.

Application

Lightweight piping used to supply air to climate control systems in commercial aircraft.
Problem

 Composite pipelines laid on a gypsum core require external compression during the curing process to prevent voids from
 forming on the pipeline walls. The manufacturer's current manufacturing process is to use cellophane film wound under high
 tension to achieve sufficient sealing. After curing the product at 120°C, the cellophane stuck to the prepreg of phenolic resin 
and glass materials, making the peeling process difficult and increasing the production time of the product. In addition to being 
difficult to remove, cellophane is not a shrinkable film, resulting in wrinkling of the outer prepreg layer on the product.

Our company's proposed solution

Heat shrink tape Hi-Shrink 220 with release layer

Implementation

Replacing the cellophane with 220R tape allowed operators to wind the film in the same way but with less tension during wrapping.

Shrink characteristics

Replacement of Tedlar material on high voltage electrical winding

Industry

High voltage motors and generators

Application

The company uses DuPont's Tedlar release film between the mica tape impregnated with resin on the wall of the generator and the tooling on the heated press.

Problem

The company had difficulty supplying DuPontfilm with Tedlar film.

Our company's proposed solution

Hi-Shrink 212HT shrink tape was used as a replacement for Tedlar film.

Implementation

The customer was able to use Hi-Shrink 212HT shrink tape as the first layer of release film instead of the Tedlar release film they had
 previously used. Hi-Shrink 212HT Heat Shrink Tape is a thick fluoropolymer film that peels off without any release coat. The customer also can use
 Hi-Shrink 220S as a second layer over 212HT. The 220S tape provides additional compression to ensure even corner radii on high voltage windings.

Aerospace composite stringers and stiffeners

Industry

Aerospace sector, composites

Application

Silicone chambers with a separating layer with a shrink tube, replacing the manual winding process
Problem

 Long composite tubular structures, 20-40' long, required inflatable silicone bladders to be placed 
inside the product on a rig. The chambers had to be wrapped by hand with ETFE release film before 
the carbon fiber prepreg was laid. The manual winding process is quite laborious and as a result, the separation film
 was not applied uniformly along the entire length of the product, with the formation of whips and the use of adhesive 
tapes to fix the film, and all this led to a set of undesirable thickness between the tooling and the composite product.
 Uneven layers of release film can cause the release film to shrink on the cured composite article, making it difficult to
 remove from the inner diameter of the cured part.

Our company's proposed solution

Heat shrink tube LST-ET

Implementation

LST heat shrink tubing used in the chamber prep process allowed the manufacturer to prepare more parts
 in less time, reducing the time required to assemble the entire structure by autoclave. LST-ET tubing shrinks quickly 
without wrinkling. Compared to other tubular heat shrink materials,  LST-ET tubing has a constant thickness,
 resulting in uniform shrinkage throughout the product.