Brake Forming KYDEX® Thermoplastic Sheet
For information applicable to KYDEX® FST please refer to 300 series technical briefs.
INTRODUCTION
KYDEX® sheet can be brake formed with ordinary sheet metal cornice brakes. Brake forming is limited to 3.18mm (0.125”) thicknesses or less.
The clearance between the brake arm and the brake finger should be equal to the thickness of the KYDEX® sheet being brake formed. The radius of the brake fingers should be equal to or greater than the thickness of the KYDEX® sheet. It should be brake formed at a temperature of greater than 23°C (75°F) to prevent cracking. Care must be taken during forming operation not the shear the material. Because the KYDEX® sheet has a tendency to spring back, the sheet must be over bent to obtain the final angle necessary to give a 90-degree bend in unrestrained material. The amount of over bend needed should be adjusted to fit the requirements of each fabricator because of such variables as dwell time in the brake, the temperature of the KYDEX® sheet, and the elapsed time after bending.
All blanks should be cut with the same sheet orientation to insure uniform outside curvature from part to part. The internal radius at the bend should be at least equal to the thickness of the KYDEX® sheet. Bending to sharper internal radii stretches the material excessively. When greater definition is desired, KYDEX® however, it is possible to strip heat the sheet and then brake form along the heated line. Dwell times in the brake will be much longer when this is done.
Brake formed parts are highly stressed and are unsuitable for applications in which they will be exposed to high service temperatures. The outer surface of the part may show some stress whitening in the brake formed area. To remove this stress, a flameless heat source should be passed over the line, but please KYDEX® note that care must be taken to avoid causing localized distortions in the sheet.
| Brake Finger Radius (KYDEX® Sheet Thickness) | Sharp | 1.60mm (0.063”) | 3.18mm (0.125”) |
|---|---|---|---|
| 0.17mm (0.028”) | 35 | 50 | 85 |
| 1.02mm (0.040”) | 35 | 45 | 70 |
| 1.52mm (0.060”) | 35 | 35 | 60 |
| 2.03mm (0.080”) | NR | 35 | 50 |
| 2.36mm (0.093”) | NR | NR | 50 |
| 3.18mm (0.125”) | NR | NR | 45 |
Degree overbend past 90 degrees * NR = Not Recommended * Ten Seconds Holding time in brake
Because we cannot anticipate or control the many different conditions under which this information and our products may be used, we do not guarantee the applicability of the accuracy of this information or the suitability of our products in any given situation. Users should conduct their own tests to determine the suitability of each product for their particular purposes. Data in the physical property table represents typical values and are to serve only as a guide for engineering design. Results are obtained from specimens under ideal laboratory conditions. Right to change physical properties as a result of technical progress is reserved. THE PRODUCTS DISCUSSED ARE SOLD WITHOUT WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE, EITHER EXPRESSED OR IMPLIED, EXCEPT AS PROVIDED IN OUR STANDARD TERMS AND CONDITIONS OF SALE. Buyer assumes all responsibility for loss or damage arising from the handling and use of our products, whether done in accordance with directions or not. In no event shall the supplier or the manufacturer be liable for incidental or consequential damages. Also, statements concerning the possible use of our products are not intended as recommendations to use our products in the infringement of any patent. Consult local code and regulatory agencies for specific requirements regarding code compliance, transporting, processing, recycling and disposal of our product. Product not intended for use as a heat resistant surface. Texture, product grade and other conditions may cause variations in appearance.
This information supersedes all previously published data.