Fast Cycle Expandable Polystyrene (EPS)
Fast Cycle EPS Resin Bead
Standard grade Expandable Polystyrene (EPS) is made from a raw material designed to achieve a light gram weight through a single expansion, with even lighter densities possible after multiple expansions. This material is highly versatile and can be used across a broad range of applications. It is ideal for packaging machinery and electronic products, as well as serving as a reliable packaging solution for agricultural and fishery products. In the construction sector, it is used for thermal insulation and heat preservation, enhancing building efficiency. Additionally, standard grade EPS is utilized in making fishery flotation buoys, various crafts, and decorative materials. It is also employed in food and beverage containers, lost foam casting, and the manufacture of lightweight, durable lighting equipment.
| Model | D-103 | D-104 | D-105 | D-106 |
|---|---|---|---|---|
| Bead Size (mm) | 1.00-1.60 | 0.85-1.25 | 0.70-1.00 | 0.50-0.80 |
| Foam Density (g/L) | 14-17 | 15-20 | 17-25 | 18-29 |
| Sieve Analysis Efficiency | 95% | 95% | 95% | 95% |
| Pentane Content | ＞6% | ＞6% | ＞6% | ＞6% |
| Residual Monomer | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% |
| Moisture Content | ≤0.5% | ≤0.5% | ≤0.5% | ≤0.5% |
Fast cycle grade EPS is extensively used in various sectors, particularly for electrical and ceramic packaging, as well as for products requiring low magnification.
Fast Cycle EPS Process
Fast Cycle Grade EPS material is designed for rapid processing, with lower molecular weight and foaming agent content compared to standard A series materials. This results in significantly reduced heating and maturation times, allowing for quick cooling and shaping. The short molding cycle not only saves energy but also enhances productivity. This material is environmentally friendly with low VOC emissions. It produces low-density foamed plastic products with uniform and fine cells, resulting in a bright and smooth appearance. Fast Cycle Grade EPS is ideal for batch pre-foaming machines and vacuum automatic forming machines, where it demonstrates its rapid processing capabilities effectively.
Pre Expending
EPS pre-expansion is a process used to manufacture polystyrene foam by heating polystyrene beads containing a blowing agent, causing them to expand. During this process, the beads soften at temperatures around 90℃, the blowing agent vaporizes and generates gas, which leads to the beads expanding several times their original volume.
| Main steam pressure (Kg/cm²) | 5-6 |
| Steam pressure for pre-expanding (Kg/cm²) | 1.0-1.2 |
| Temperature in vessel (℃) | 108-110 |
| Feedstock (KG) | 14-16 |
| Heating time (s) | 40-45 |
| Density (g/L) | 10.5-13.5 |
Aging
During the pre-expansion process, the blowing agent evaporates within the beads, and the incorporated blowing agent and water vapor condense into a liquid after exiting the expander. This liquid then dissolves into the styrene monomer, creating a vacuum inside the beads. Therefore, to achieve pressure balance inside and outside the beads, which grants EPS good flexibility and perfect shape, the beads should be stored in a well-ventilated silo for a certain period of time, allowing air to enter the beads.
| Aging Time | 3-4 Hours |
Molding Processing
After aging, fill the EPS into a sealed mold. Inject steam directly into the mold through its holes for a very brief period. As the beads are heated, the blowing agent within them evaporates, causing the beads to soften and expand. These expanded beads fill the entire space of the mold and fuse together due to the confines of the mold. Subsequently, cool and shape the material. The molded products are completed once the mold is released.
| Main steam pressure (Kg/cm²) | 5-7 |
| Air pressure (Kg/cm²) | 5-7 |
| Cooling water pressure (Kg/cm²) | 3.5-5 |
| Penetrating pressure (Kg/cm²) | 0.5-0.65 |
| Molding pressure (Kg/cm²) | 0.5-0.63 |
| Mold fixing pressure (Kg/cm²) | 0.4-0.5 |
| Mold moving pressure (Kg/cm²) | 0.35-0.45 |
| Penetrating heating time (s) | 11-15 |
| Molding heating time (s) | 6-10 |
| Heat preserving time (s) | 5 |
| water cooling time (s) | 5-15 |
| Draining time (s) | 2-5 |
| Sealed time (s) | 5-12 |
| Cycle time (s) | 100-120 |
EPS Packing
EPS resin beads are available in two packaging options: 25 kilograms per bag and 850 kilograms per bag. A 20-foot container can accommodate up to 17 tons, while a 40-foot container can hold up to 25.2 tons.
