Operating Principle Of EPS Pre-expansion Machine

The operating principle of the EPS pre-expansion machine is mainly based on the following steps:

Raw Material Preparation: Expandable polystyrene (EPS) raw material granules are fed into the pre-expansion machine through a reducer, screw feeder, and other feeding devices.

Steam Heating: Steam is introduced into the pre-expansion machine from the bottom to heat and pre-expand the raw material. The heated raw material granules increase in volume, forming pre-foamed beads.

Precise Metering: An electronic scale is installed in the feeding device to accurately measure the weight of the raw material each time it is fed. Simultaneously, a photoelectric level sensor strictly controls the volume of the pre-expanded beads before discharge.

Pre-expansion Ratio Control: The pre-expansion ratio is determined by measuring the feed rate and the volume of the foamed material. Steam pressure and air pressure do not directly affect the pre-expansion ratio, making it easy to control and ensuring stability and reliability.

Curing Treatment: When the pre-expanded granules reach a certain density, the conveying device transports them to a fluidized bed for curing under normal pressure before conveying them to the silo.

Molded products: Cured EPS pre-expanded material is supplied to molding machines to form various shapes of foam packaging products, such as bicycle helmets, car seat cushions, slippers, shockproof materials, sound insulation materials, etc.