Due to its high strength to weight ratio, corrosion resistance, and low cost. Sheet Molding Compound (SMC) production offers great potential for growth in the automotive and trucking industry. Much attention is now being given to improving the economy of SMC compression molding by reducing the cycle time required to produce acceptable parts in steady production.; One of the fastest growing applications of Sheet Molding Compound (SMC) compression molding panels is the manufacture of truck body panels. Due to their large size, the molding forces developed are substantial and have a major influence in the molding cycle. The relevant process models for SMC flow are reviewed and a procedure is developed that can be used to obtain the closing force and calculate the needed material parameters. Experiments were done using commercially made SMC varying quantities of glass, filler, and thickener to verify the validity of this model and the compression force was predicted for commercially made automotive hoods.; It was found that glass and filler had a significant impact on the material parameters. When the amount of glass was increased, both material parameters m/δn and η increased. Similar trends were seen when increasing the amount of filler. For the thickener used in this research (magnesium oxide), it was found that it had minimal effect on the material parameters. Molding conditions and initial SMC charge configurations were also varied to see their effects on molding force and material parameters. Initial charge dimensions and volume as well as mold closing speed showed no effect on material parameters, while molding temperature showed a minimal effect.; Material parameters were calculated for each SMC composition. These parameters were used to predict the compression force for the Corvette hood and Fiero hood. These predictions were compared with actual Corvette and Fiero hoods manufactured in industry. They predicted the commercially made parts quite well.
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机译：由于其具有高的强度重量比，耐腐蚀性和低成本。片状模塑料（SMC）的生产为汽车和卡车行业的增长提供了巨大的潜力。现在，通过减少在稳定生产中生产合格零件所需的循环时间，人们越来越关注改善SMC压铸的经济性。片状模塑料（SMC）压模板发展最快的应用之一是卡车车身板的制造。由于它们的大尺寸，形成的模制力很大，并且在模制周期中具有重大影响。审查了SMC流动的相关过程模型，并开发了可用于获得闭合力并计算所需材料参数的程序。使用市售SMC制成的各种玻璃，填料和增稠剂进行了实验，以验证该模型的有效性，并预测了市售汽车引擎盖的压缩力。发现玻璃和填料对材料参数有显着影响。当玻璃量增加时，材料参数m /δ n 和η均增加。当增加填料量时，可以看到类似的趋势。对于本研究中使用的增稠剂（氧化镁），发现它对材料参数的影响最小。成型条件和初始SMC装料配置也有所变化，以查看它们对成型力和材料参数的影响。初始装料尺寸和体积以及合模速度对材料参数没有影响，而成型温度则影响很小。计算每种SMC组成的材料参数。这些参数用于预测Corvette引擎盖和Fiero引擎盖的压缩力。将这些预测结果与实际生产的Corvette和Fiero油烟机进行了比较。他们预测商业化零件相当好。
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