FUNDAMENTALS OF FIBERGLASS
Introduction Composites are materials made up of two individual components who's combined physical strength exceeds the properties of either of them individually. The reinforced plastic compostie consists of a fibrous reinforcing network embedded in the cured resin matrix. The thermosetting type resin is a plastic that cures from a liquid to a solid through a chemical reaction of its two components. Once this reaction occurs, the material can not be reformed. A typical thermosetting epoxy resin has a tensile strength below 10,000 psi and is quite brittle. when such a resin is reinforced with glass fibers the resulting composite can have a tensile strength between 45,000-50,000 psi. It also becomes extremely resistant to impact damage. This high strength for the relatively low weight is the fundamental reason that fiberglass composites are popular. Another significant reason is their tailorability. Since the reinforcement can be added in any direction, layers can be built up which are perfectly oriented with the stress the part is to encounter. This saves additional weight by removing unnecessary material from areas with little stress. Other reasons for composite popularity are how easily these materials can be formed into complex shapes, that they have superior resistance to most environments and they can be used by most individuals without a major investment in equipment. Fiberglass is only one type of reinforcement. Other common types are carbon fiber and Kevlar (R). These will be explained shortly in greater detail where their importance and variety can be covered adequately.
Brief Glossary Of Composite Terms The process you've taken the time to read is what I've done for over 20 years. I am currently unemployed. Consider me for any fiberglass project. My experience is in all aspects of automotive and marine fiberglass restoration, repair, and refinishing. I am available to consult and/or be contracted for your fiberglass repair needs whether it's a small or large job. Contact me for work at ddsnnn2009@cox.net if this information has been helpful you can make a donatation to me below via PayPal. 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 compostie part, molded or otherwise. A current example would be: "The part tested was a 10-ply vacuum bagged laminate". LAMINATION SCHEDULE: A list of the individual layers and orientation of the plies used to construct a composite part. 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. Specialized casting resins are necessary which generate less heat during their cure and thus create less distoration 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 polyrethane foam and them 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. CONCLUSION: This guide is intended to help the beginner conceptualize the fiberglass composite process.           |
