PREFORM UNIT

This is a gas fired preform curing system.  In this process, the unit has four preform screens, one at each station, that rotate through the process.  At the first station, the fiber and binder is applied, at the second the preform is cured, at the third it is allowed to cool an at the fourth it is removed from the screen. 

The entire process is automated to the extent that all of the timing is controlled by a PLC as well as the oven temperature an fiber/binder application.

This process has been used for over 50 years and is well proven as a standard in the composites industry.

The preform process is relatively simple.  After the fibers are applied to the preform screen with a binder, they must be cured.  About 400 degrees is normally required.  Where lighter colored preforms are desired, the temperature and curing time are held down somewhat.  In general, loose preforms will mold better than stiff dense ones.  Where a deep draw is involved, stiff, dense preforms are necessary. 

 

Curing time will vary from one to a few minutes depending upon the size and thickness of the part.  On a larger thick part, the curing time can be reduced by allowing the fan to pull air through the part for a few seconds before rotating it into the curing oven.  This will remove some of the water.  It is necessary to use a mold release on the screens to prevent fiber sticking. 

 

In the rendering above, a robot with the fiber cutter and binder sprayer on the arm, is programmed to deposit the wetted out fiber on the preform screen, in this case a boat hull.  The curing of the fiber can be accomplished in several ways; gas fired oven, infrared heat lights or an ultraviolet curing system.  The  artist’s rendering depicts an ultraviolet curing station.

Brenner International

Designers and Builders of Specialized Machinery for the Composites Industry

Designers and Builders of Specialized Machinery for the Composites Industry