Abstract: An apparatus and method for setting and maintaining the setpoints of a plurality of product variables for a continuous fibrous glass product on a production line. A computer may be programmed to establish and maintain the setpoints in response to feedback signals representing the actual values of the product variables. In order to minimize lost time and waste material when a job change requires the generation of new setpoints, the computer is programmed to drive the present values of the setpoints to new values for the new product by incrementing each setpoint in sequence until the new values are attained. The initiation of the drive for each setpoint is based on the movement of the product down the line so as to minimize the amount of material sacrificed between the end of the old product and the beginning of the new product.

Abstract: A programmed method for the preparation of an intermediate polyester resin is disclosed. The process is monitored and controlled by a supervisory on line computer which supervises the three phases of the process: the charging phase; the temperature elevation phase and the cooking phase. During the critical temperature elevation phase the supervisory program assures that a runaway exothermic chemical reaction does not occur. This is accomplished by periodically reading batch temperature and comparing it with an emperically determined temperature time curve stored within the program. Heat input or removal is then ordered depending upon the relationship of the batch temperature and the temperature time curve.