What Is Flash Drying In Plastic Recycling - And Why Smarter Alternatives Are Taking Over In Australia
If you search “flash drying” in plastics, you’ll find it described as a process where hot air is blasted over washed material to quickly remove moisture. It sounds simple enough, but in practice it’s energy-hungry and doesn’t always get you the results you need. That’s why many recyclers in Australia are moving away from this traditional approach and adopting smarter drying systems that cut costs and deliver cleaner, drier material.
What Flash Drying Means in Plastics
Flash drying was borrowed from industries like food and paper, where fine particles are dried in seconds with a stream of hot air. In plastics recycling, the principle is the same: washed flakes are exposed to high-temperature air in a vertical column or duct. The rapid airflow removes surface water before the flakes are collected.
The problem is that plastics don’t behave like powders. Residual water often clings stubbornly, especially inside folds of LDPE film or around pelletised edges. Industry benchmarks show that even after flash drying, flakes may still hold around 15% residual moisture, depending on the input material and line configuration. For applications like extrusion or food-grade recycling, that’s far too high.
Why Traditional Flash Drying Falls Short
For Australian recyclers, the shortcomings are clear:
- Energy demand – Heating large volumes of air is costly, especially with electricity prices continuing to climb.
- Inconsistent results – Moisture can remain trapped, leaving loads unsuitable for downstream processing.
- Maintenance and wear – Air ducts and filters can clog with fines, adding downtime.
In short, flash drying works on paper, but in practice it can leave recyclers with higher operating costs and material that still needs further drying.
Smarter Alternatives Already in Use in Australia
This is where modern equipment makes the difference. Two proven technologies – the Telford Smith Mechanical Dryer and the RUNI Screw Compactor – are helping Australian recyclers achieve moisture levels that flash drying rarely reaches, while using less energy per ton of output.
Mechanical Dryers – Reliable Moisture Reduction
Mechanical dryers use centrifugal force and friction to remove water from flakes. Unlike air-only systems, they physically drive moisture out, making them more efficient for plastics.
- In industry trials, centrifugal and mechanical dryers typically bring moisture down to ~1–2%, compared with 15% in air-based flash systems.
- For film above 50µm where there’s no cling, mechanical dryers are often the most efficient solution.
- That final dryness level is often what’s required for PET or HDPE flakes going into extrusion.
For Australian operators, this means fewer rejects, smoother processing, and lower reliance on costly thermal drying.
RUNI Screw Compactors – Dewatering and Compaction in One Step
The RUNI SK370, available through Telford Smith, squeezes both water and air out of materials. Instead of blasting with heat, it uses pressure.
- According to manufacturer data, RUNI screw compactors can reduce moisture content to as low as ~5% in clingy, thin-gauge LDPE film — a material that’s notoriously difficult to dry with air-only systems.
- They are also widely used in plastics recycling for RDF preparation and for removing residual water from fines in water treatment plants.
- Energy use is relatively low – around 20 kW per ton of LDPE film processed.
For waste streams like food packaging, RDF feedstock, or liquid-filled containers, the RUNI offers both dewatering and volume reduction, lowering transport and disposal costs at the same time.
What This Means for Australian Recyclers
The shift away from flash drying isn’t just theory – it’s already happening across recycling plants in Australia. By swapping hot-air systems for mechanical dryers or screw compactors, recyclers are:
- Cutting energy costs per ton of material.
- Achieving moisture levels that meet downstream processing requirements.
- Reducing maintenance headaches tied to heat-based systems.
- Increasing the value and quality of recycled outputs.
And in many high-output film processing lines, the most economical solution is a combination of a Mechanical Dryer and a Screw Compactor, each doing the job it’s best suited for.
Finally...
Flash drying might look like a quick fix, but for plastic recycling in Australia it’s rarely the smartest option. Mechanical drying and screw compaction are proving more efficient, more consistent, and better suited to the demands of modern recycling plants.
Telford Smith supplies both technologies and works with facilities across Australia to match the right drying solution to the material stream.
Want to see how this could improve your line? Get in touch with the Telford Smith team today to discuss a system configuration that reduces costs and boosts throughput.
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