Effect Of Manufacturing Variability Research Articles

Study on the Pre-Heated Temperatures and Injection Pressures of the RTM Process

The objective of this research was to investigate the effects of manufactur ing variables (injection pressure, pre-heated temperature and vacuum assistance) on resin transfer molding (RTM). Specimens were made of 40 plies of TGFC-7628 cloth fiberglass mats or 12 plies of TGFW-600 woven roving fiberglass mats under different process condi tions. The fiber volume contents of the specimens were 50.3 % or 45% in the experiments. The flexural strengths of all the finished products tested by the method of three point bend ing were compared to each other to understand the influences of each process variable on the RTM products. Both the pre-heated temperatures and the injection pressure were found to affect the quality of the RTM product.

Effect of Some Manufacturing Variables on the Leakage Defect of Blue Cheese1,2

Effect of certain manufacturing variables on the leakage (water-exuding defect of 60-day-old Blue cheese was examined by a split-plot experimental design. The variables on a pilot-plant scale were starter culture, the treatment of cream or milk for whitening, amounts and types of nonfat dry milk fortification of vat milk, amount of salt added to the curd at hooping, temperature during overnight drainage in hoops, and type of coating used over the cheese during curing. Chemical analyses of cheeses for pH, salt, milk fat, and proteolysis index were made after 24 hr and (or) 60 days after manufacture. Flavor evaluations were made after 60 days.Statistical analyses of the data showed that the starter culture, rate of salt addition, temperature of overnight drainage, and the whitening treatment for the cream were highly significant in influencing the leakage tendency of 60-day-old Blue cheese. No statistical correlation, however, was obtained between any of the manufacturing variables and the flavor scores of cheeses.