Manufacture of transmission housing by contact layer technique using vaccum bag
Jakub Smoleń, Artur Cyganek, Mateusz Kozioł
Quarterly No. 1, 2019 pages 18-22
DOI:
keywords: gear housing, hand lay-up composites, vacuum bag, adaptation projects
abstract The article presents an experimental procedure for making a single product - a gear housing, by the hand lay-up technique using a vacuum bag, as part of an adaptation project. The applied technological procedure included using the original element as a model to produce a mold, the production of the mold and the production of two elements from two alternatively reinforced laminates (a chopped-strand mat and a plain-woven fabric), by the hand lay-up method. On the basis of the observations made during the technological procedures and based on evaluation of the manufactured products, it was stated that the hand lay-up lamination technique with additional use of a vacuum bag is a very good and simple method of making single products. The use of vacuum prevents the occurrence of defects typical for classic manual lamination, such as delaminations, closed air bubbles, or (especially) lack of adhesion in low-radius curved areas. It was also found that the original solution consisting in removing the semi-finished product in the form of a part of the hardened stack from the model/form and continuing the lamination of the remaining layers outside the model/form is effective. It has no visible impact on the quality of the product and significantly facilitates demolding. An important issue during the application of vacuum bag assistance is proper selection of the amount of catalyst for the resin. This should be preceded by measuring the room temperature in which the process is carried out and the time of the hand lay-up lamination process - the number of layers should be selected for the predicted resin curing time so that a proper lay-up can be prepared and the vacuum process carried out before the laminate cures. The manufactured elements require slight machining of the technological surplus, which is difficult to avoid when designing a technically simple form for a single or low- series product.