Sheet molding compound mechanical properties

A.2.4 Discontinuous-Fiber-Reinforced Polymer-Matrix Composites Sheet Molding Compound. Of the parameters influencing the mechanical properties in short-fiber-reinforced polymer-matrix composites, fiber composition, matrix composition, fiber geometry, and manufacturing method will be elaborated upon here. 

The relevant properties of these materials for the torsional-mechanical analysis are listed in Table 8.11. On the basis of specific elastic modulus and specific shear modulus, the best materials are the graphite-fiber-reinforced epoxy resin, followed by either of the alloys, then the Kevlar fiber-reinforced epoxy. The chopped glass sheet molding compound is obviously not a good choice. 

Low-density SMC In 2007, Yamaha announced the devdopment of NanoXcd, a low-density sheet molding compound to be used in their WaveRunner line of personal watercraft. Nanoclays enable the reduction of fiberglass and other bulking (clay) components content, thus lowering the SMC specific gravity by about 25% (from about 1.9 to 1.5) without sacrificing mechanical properties [16]. 

J. J. Magrans and J. Ferrarini, Unique Electrical and Mechanical Properties of ITP SMC, 24th Annual Technical Conference, R-P/C Institute, SPI, P.1, Section 2-E (1979). Sheet molding compounds. ITP process. Electrical and Mechanical Properties. 

Glass-Reinforced Composites. These composites are prepared from SMC and by liquid injection molding, (LIM). Phenolic resins are usually not amenable to LIM because of the volatiles generated. However, a resin suitable to LIM has been prepared (107). The properties of the 60% glass-mat-reinforced product obtained from this resin were compared to conventional isophthalic polyester and vinyl ester sheet-molding compounds at equivalent glass loading the mechanical... 

Polymeric materials have very many applications in today s world.These applications frequently depend on the details of the processing procedures as well as the physical and mechanical properties of the materials involved. As an example, the processing of sheet molding compounds (SMC) will be developed. 

Ease of cure, easy removal of parts from mold surfaces, and wide availabiHty have made polyesters the first choice for many fiber-reinforced composite molders. Sheet mol ding compound, filament winding, hand lay-up, spray up, and pultmsion are all weU adapted to the use of polyesters. Choosing the best polyester resin and processing technique is often a challenge. The polyester must be a type that is weU adapted to the processing method and must have the final mechanical properties requked by the part appHcation. Table 1 Hsts the deskable properties for a number of fiber-reinforced composite fabrication methods. 

UP resins can be compounded with different additives and filling materials to improve and enhance the physical and mechanical properties. The added material must be uniformly distributed within the resin. The compound is then molded to the desired shape by several techniques such as bulk molding, transfer molding, or sheet molding. 

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