GB1259652A - - Google Patents

Abstract

1,259,652. Producing glass fibres. OWENSCORNING FIBERGLAS CORP. 18 Sept., 1969 [18 Sept., 1968], No. 46070/69. Heading C1M. In a method of producing glass fibres in which glass is flowed from a feeder 11 through one or more orifices 12, the environment of the zone adjacent the fibres 16 and feeder 11 is controlled e.g. by controlling the temperature of the zone and protecting it from air currents by means of liquid or gas cooled shields 28, and the effectiveness of such control is monitored and the amount of heat supplied to the feeder regulated, such that loss of environmental control results in a reduction in the amount of heat supplied to the feeder. The temperature of the feeder is regulated by detecting the temperature thereof using a thermocouple 72 connected to a controller 73, the controller comparing the actual temperature with a desired temperature and adjusting the output of a transformer 70 which supplies electric current to heat the feeder accordingly. The loss of environmental control may be detected by a rate of change detector 80 which forms part of the controller which in the event of the thermocouple indicating a rate of change of temperature exceeding a pre-determined amount, activates a switch CD thereby enabling a device 81 to bias the controller to a lower desired temperature to compensate for loss of control. The switch CD may also be activated by a limit switch activated by the pivoting of a shield 28 out of its operative position, or by means responsive to a reduction of the flow of the liquid or gas cooling medium.