Ferlin HotDry

Ferlin HotDry — Hot Air Plastic Dryer

The Ferlin HotDry series are economical machine-side dryers that dry plastic granulate with heated air. They are ideal for NON-hygroscopic materials (those that do not absorb moisture).

For which materials is hot air drying suitable?

Non-hygroscopic plastics hold moisture only on the surface; this surface moisture is removed quickly by the circulation of heated air:

• Suitable (non-hygroscopic): Polyethylene (PE / HDPE / LDPE), polypropylene (PP), polystyrene (PS)
• NOT suitable (hygroscopic): Nylon (PA), polycarbonate (PC), ABS, PET, PMMA — the dry air (desiccant) Ferlin EasyDry series is required for these

Why HotDry?

On non-hygroscopic materials it is a practical solution with a low investment and running cost. It is offered in a hopper volume range of 150–1500 L, with a stainless steel body, a heater + circulation fan, ATR144 process and safety thermoregulators and a wheeled carrier frame.

HotDry is only for non-hygroscopic raw materials; if you will process nylon, PC or PET, you have to move to a dry air model. You can compare the difference between the types on the plastic material drying systems page.

What a hot air dryer can and cannot do

HotDry removes the surface moisture of the granulate with heated ambient air. This is enough for materials that hold moisture only on the surface: PE (HDPE/LDPE), PP and PS. With these materials, buying a dry air desiccant dryer is paying for a capacity that will not be used.

With hygroscopic materials such as PA, PC, ABS, PET and PBT, on the other hand, a hot air dryer falls short. These materials take moisture into the granulate; the moisture the ambient air carries itself is not enough to draw it out.

How the decision is made

The question is simple: is the material hygroscopic or not? The answer is in the material manufacturer's data sheet, and the drying temperature and the recommended moisture level are stated there as well. The values for all raw materials are listed in the material processing data table.

The economical side

A hot air dryer has a simpler structure: it contains no desiccant circuit, no regeneration heater and no dew point control. This lowers both the purchase price and the energy consumption. In a plant processing non-hygroscopic material this is the right choice.

If you move to a hygroscopic material

If your raw material portfolio shifts towards nylon or PC, you have to move to the dry air EasyDry models.