EPS, commonly known as Styrofoam, is about 98% air. This makes it incredibly bulky and expensive to transport and landfill, even though the actual amount of plastic is small.
The machine’s genius lies in its ability to remove the air and transform the bulky foam into a dense, manageable, and valuable raw material. This is achieved through two primary methods:
1. The Mechanism of Efficient Compression
EPS recycling machines use one of two core technologies to achieve dramatic volume reduction:
A. Cold Compaction (or Screw Press)
This method uses immense physical force to compress the EPS. Think of it like a giant, powerful garlic press.
- Versnipperen: The machine’s hopper first feeds the large, bulky EPS pieces (like packaging or containers) into a shredder. This breaks them down into smaller, more manageable flakes.
- Voeding: The flakes fall into a chamber with a large, powerful screw.
- Verdichting: The screw auger pushes the flakes forward with tremendous pressure. This force physically squeezes the air out from between the polystyrene beads.
- Extrusie: The de-aired, compacted material is forced out of an extrusion port, forming a dense, solid block or log. The friction from the pressure can generate some heat, but it doesn’t actively melt the material.
- Efficiency Metric: A cold compactor can achieve a compression ratio of up to 50:1. This means 50 truckloads of loose EPS can be reduced to fit into just one truckload of compacted blocks.
- Uitvoer: Solid, dense blocks of compressed EPS.
B. Hot Melt Densification
This method uses heat to melt the EPS, which releases the trapped air and allows for even greater density.
- Versnipperen: Just like in cold compaction, the process starts with shredding the EPS into small flakes.
- Smelten en extruderen: The flakes are fed into a heated chamber. The heat melts the polystyrene into a thick, viscous paste. As it melts, all the air is released. A screw then pushes this molten plastic through a die.
- Cooling and Solidifying: The extruded “sausage” of molten plastic is cooled by air or water, solidifying into a hard, dense ingot that resembles a plastic brick.
- Efficiency Metric: A hot melt densifier is even more efficient, achieving a compression ratio of up to 90:1.
- Uitvoer: Hard, solid plastic ingots, often called “purged” material. These are heavier and denser than cold-compacted blocks.
2. How This Efficiency Enables Reuse
The compression process is the critical first step that makes reuse economically viable. Without it, EPS recycling is often too expensive to be practical. Here’s how the machine enables a circular economy for this material:
1. Creates a Valuable, Transportable Commodity
The machine transforms what was essentially a costly waste product into a valuable raw material. A truckload of loose, dirty EPS might cost money to dispose of. In contrast, a pallet of dense EPS blocks or ingots has a market value and can be sold to manufacturers. This economic incentive is the primary driver for recycling.
2. Reduces Transportation and Storage Costs
By reducing the volume by 50 to 90 times, the machine drastically cuts the cost of shipping the material to a processing facility. A company can store months’ worth of waste in a small corner of a warehouse instead of filling multiple dumpsters daily.
3. Prepares the Material for Manufacturing
The dense blocks and ingots are the ideal form for the next stage of recycling. They are:
- Easy to handle and stack.
- Consistent in density.
- Ready to be re-processed.
4. The Reuse and Remanufacturing Process
The compressed EPS blocks or ingots are sold to specialized recycling companies or manufacturers who then:
- Grind them into small pellets.
- Melt the pellets and mix them with other additives if needed.
- Extrude or mold the recycled plastic into new, durable products.
Common products made from recycled EPS include:
- Picture frames and architectural moldings
- Park benches and outdoor decking
- Coat hangers and pens
- Hard insulation boards for construction
- Flower pots and seedling trays
Samenvatting
An EPS recycling machine achieves efficiency by:
- Solving the Core Problem: Using either high-pressure cold compaction of hot melt densification to remove the 98% air content from the foam.
- Achieving Massive Volume Reduction: Compressing the waste by a ratio of 50:1 to 90:1, which slashes transportation and storage costs.
- Creating a New Raw Material: Turning a costly waste stream into dense, valuable blocks or ingots that can be easily sold and shipped.
- Enabling the Circular Economy: Providing the essential intermediate step that allows manufacturers to affordably acquire and reuse polystyrene to make new, long-lasting products.