Monday, September 22, 2014

Fibreglass Making Process


Brief Glossary Of Composite Terms
Molding: Molding is the process of constructing a part within a mold. Typically, precut reinforcement is placed one layer at a time into the mold and saturated with resin. When the part has achieved the desired thickness and orientation, it is left to cure. When it is demolded, it will have the exact shape of the mold surface.
Laminating: Laminating originally referred to applying a thin protective coating of resin and reinforcement over a surface such as wood. The term's use has broadened to include virtually any finished composite part, molded or otherwise. A current example would be: "The part tested was a 10-ply vacuum bagged laminate."
Lamination Schedule: This is a list of the individual layers and orientation of the plies used to construct a composite part, and typically specifies the ounce-weight of the reinforcement and the weave style.
Casting: Casting refers to pouring a large mass of resin into a cavity. The cavity can be a mold when casting parts, or it can be the backside filler for a tool when making the mold itself. It is necessary to use specialized casting resins which generate less heat during their cure and thus create less distortion in the final part. Fibrous fillers can be added as needed to strengthen the casting.
Sculpting: Sculpting is usually accomplished by carving a shape out of polyurethane foam and then laminating the surface. This can be done to create a plug for the molding process, or to shape a finished part in the case of moldless construction.

Reinforcement Types, Properties, and Styles
The physical properties of composites are fiber dominant. This means that when resin and fiber are combined, their performance remains most like the individual fiber properties. For example, it is not satisfactory to merely average the tensile strengths of fabric and resin to determine the strength of a panel. Test data shows that the fibrous reinforcement is the component carrying the majority of the load. For this reason, fabric selection is critical when designing composite structures. Fabricators today choose from three common reinforcements, including fiberglass, carbon fiber, and Kevlar®. Each comes in various forms and styles, and has benefits and drawbacks that should be analyzed before starting any project.