Use the regression models for molecular weight and viscosity to answer the following questions.

(a) Construct a response surface contour plot for molecular weight. In what direction would you adjust the process variables to increase molecular weight?

(b) Construct a response surface contour plot for viscosity. In what direction would you adjust the process variables to decrease viscosity?

(c) What operating conditions would you recommend if it was necessary to produce a product with molecular weight between 2400 and 2500, and the lowest possible viscosity?

Problem 6-26

An experiment was conducted on a chemical process that produces a polymer. The four factors studied were temperature (A), catalyst concentration (B), time (C), and pressure (D). Two responses, molecular weight and viscosity, were observed. The design matrix and response data are shown below:

Transcribed Image Text:

Actual Run Factor Levels Run Molecular Number Order А В с D Weight Viscosity Low (-) High (+) 1 18 2400 1400 A (°C) 100 120 2 9. 2410 1500 B (%) 4 8 C (min) 20 D (psi) 60 3 13 2315 1520 30 4 2510 1630 75 5 3 2615 1380 11 2625 1525 7 14 2400 1500 8 17 2750 1620 2400 1400 10 7 2390 1525 11 2 2300 1500 12 10 2520 1500 13 4 2625 1420 14 19 2630 1490 15 15 2500 1500 16 20 + 2710 1600 17 1 2515 1500 18 2500 1460 19 16 2400 1525 20 12 0 0 2475 1500 + + + + + + + O + + + + + + + + 1