GENERAL FUSING CONDITIONS: FUSING TECHNOLOGY The three main requirements for successful fusing are temperature, pressure and time.   Temperature: Sufficient heat must be applied to reach the temperature at which the adhesive resin softens and flows. Pressure: Sufficient pressure must be exerted so that the softened resin will be forced to penetrate the shell fabric. Time: Sufficient time allows the resin to reach its proper softening point and achieve proper flow.   WARNING! Excessive variations in temperature, pressure and/or time can cause improper fusing. FUSING EQUIPMENT There are several types of fusing equipment that will give the required temperature, pressure and time. Hand iron: Used in less critical fusing applications where fusing conditions are not crucial; usually used on small parts. In general, a hand iron is not recommended as an acceptable fusing program. Steam press: Temperature and pressure regulation is better than a hand iron, but usually not sufficient for critical fusing operations; a timer may be installed for accuracy of dwell time. Fusing press: A press specially designed for fusing features good temperature control (usually ± 5C), evenly distributed pressure capability and automatic timing controls. Conveyorized type: This type of press allows for an enclosed heat chamber reducing the heat loss; time is controlled by the speed of the conveyor. Current models have an electrical heat chamber that the fusing process. Conveyorized presses have the advantage of higher production and thereby lower labor cost as well as better temperature regulation.