Hand lay-up technique is the simplest method of composite processing. The infrastructural requirement for this method is also minimal. The processing steps are quite simple.
First of all, a release gel is sprayed on the mold surface to avoid the sticking of polymer to the surface.
Reinforcement in the form of woven mats or chopped strand mats are cut as per the mold size and placed at the surface of mold after.
Then thermosetting polymer in liquid form is mixed thoroughly in suitable proportion with a prescribed hardner (curing agent) and poured onto the surface of mat already placed in the mold.
The polymer is uniformly spread with the help of brush. Second layer of mat is then placed on the polymer surface and a roller is moved with a mild pressure on the mat-polymer layer to remove any air trapped as well as the excess polymer present.
The process is repeated for each layer of polymer and mat, till the required layers are stacked.
After curing either at room temperature or at some specific temperature, mold is opened and the developed composite part is taken out and further processed.
The schematic of hand lay-up is shown below:
Capital and infrastructural reuirement is less as compared to other methods. Production rate is less and high volume fraction of reinforcement is difficult to achieve in the processed composites.
Copyright © . EPP Composites Pvt Ltd.