Hand lamination
Most used of manufacturing techniques. After mould preparation, wet material is hand laid and impregnated with resin. Air bubbles are released from laminate with help of special rollers. After curing, the part can be taken out of mould and trimmed. Pros – fast production and low cost. Cons – Because of high resin concentration(60-70%) in the laminate, has low mechanical resistance. Quality of the laminate depends on DIMA.
Vacuum infusion
Intended for high quality and mechanical resistance. To produce laminate which is lighter and with better mehanical properties, amount of resin in laminate must be reduced preferably to 25-30%. Process starts with mould laying in dry material and covered with plastic film. With help of vaccum the resin is sucked through the layers of laminate imregnating it. Cons – slow manufacturing process. Pros – High quality products with good mechanical properties (resin content ~40%). Beetter adjustment of resin/material ratio.
Pre-preg technology
Pre-preg is the newest and greatest solution in composite industries at the moment. Material has been impregnated with epoxy resin beforehand and has the concentration of 30% resin. These fibers are kept frozen, because of material bonding under temperature and pressure. To manufacture parts out of this material an autoclave is required. Pros – Best quality and resin to fiber ratio of laminate. Cons – higher cost of manufacturing.
Silicone vacuum bagging
Silicone vacuum bagging is a technique employed to create mechanical pressure on a laminate during its cure cycle. Pressurizing a composite lamination serves several functions. First, it removes trapped air between layers. Second, it compacts the fiber layers for efficient force transmission among fiber bundles and prevents shifting of fiber orientation during cure. Third, it reduces humidity. Finally, and most important, the vacuum bagging technique optimizes the fiber-to-resin ratio in the composite part. These advantages have for years enabled aerospace and racing industries to maximize the physical properties of advanced composite materials such as carbon, aramid, and epoxy.
