A manufacturer of drive-belts wishes to conduct some investigations with a view to improving
the life of his products. His manufacturing process involves injecting rubber into moulds
containing reinforcing fibre preforms. He is interested in understanding what effects the
following variables have on belt life so that he can maximise the running life of his belts.
• cure time (10, 20, 30 or 40 minutes)
• cure temperature (110 °C, 120 °C, 130 °C, 140 °C)
• injection pressure (0.5 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa)
• geometry of the weave of the preforms (three different options, I, II, III)
(a) Explain how an experiment could be used to obtain results noting how many treatments
would be used in this array, writing the first nine rows of the experiment matrix, and
what response model could be found from such an experiment.