Choosing the best expandable polystyrene machine depends largely on the volume of expandable polystyrene (EPS) packaging material needed per hour and the budget constraints for purchasing such a machine. Higher-end expandable polystyrene machine designs are completely computer controlled and can manage the entire production cycle. This includes opening and closing the molds as well as filling them. The EPS foam is also steamed, stabilized, and cooled, as well as cut and ejected automatically.
Many expandable polystyrene machines meant for factory packaging lines are built in China, and conform to International Standardization Organization (ISO) 9001 standards. Some machines also come with a weighing feature at the end of the EPS production line so that the blocks of foam can be better tracked as inventory. The larger and more expensive the machine, the larger the blocks of polystyrene foam it is capable of producing as well. Heavy duty models have expansion chambers that are 3.5 feet by 3.6 feet by 5.6 feet in size (1.07 meters x 1.1 meters x 1.7 meters) or larger.
The faster the machine works and the bigger the size of foam block it can produce per cycle, the more it also tends to weigh. Cycle times can range from 60 to 130 seconds per block, and shipping weight to have the machine delivered from a supplier in China is anywhere from 11,464 to 14,330 pounds (5,200 to 6,500 kilograms). Though the machines run on 5 to 10 kilowatts of electrical power for their hydraulic, vacuum, and hopper pumps, they are designed for low energy consumption. This is done through precise computer control of everything from the steam pressure used to make the foam to the vacuum condensation systems used.
Smaller expandable polystyrene machine models also exist, where the main production capabilities are broken down into individual machines. This includes the process of a pre-expander, the EPS block molding machine, an EPS cutting machine, and auxiliary equipment to process the foam afterward. A stand-alone pre-expander requires the manual feeding of raw material into the processing chamber, after which steam is turned on. A fully-integrated expandable polystyrene machine, however, weighs the EPS beads before and during processing so that exact amounts of foam are produced.
Another feature to consider when purchasing an expandable polystyrene machine is the reverse process for waste material. Since polystyrene is a thermoplastic that can be melted and reshaped without losing molecular cohesion, insulation machines that generate foam often goes hand-in-hand with expanded polystyrene machines that take old foam and recycle it into new EPS blocks. Expanded polystyrene machines generally have the same range of features and costs for breaking down the foam as do those that create it in the first place.