Not all pellets are uniform and you cannot buy pellet of ideal quality on every corner. This is not a wonder as it is an innovation even among the state-of-the-art heating technologies.
Fortunately there are a few tests that can be performed by everyone which help identifying the quality of the product we bought.
The pleasure of pellet
Consumer, protect yourself!
Only those can call themselves pellet manufacturers who can ensure the following:
- raw material of adequate cleanness: sawdust, woodchips – free from foreign materials and preferably from barks;
- adequate raw material, with approx. 10 % moisture content;
- raw material with proper grain size;
- proper pressure and temperature during pressing (800-900 bar, 90-100 °C);
- appropriate pellet length (2-3 cm);
- cooling after pressing;
- separation of chips before packing.
Demand that you get these features when you buy pellet! If the manufacturer observes the above steps than meeting pellet is a real sensual joy.
The surface of pellet is smooth and glossy – as if it was lacquered – and free from longitudinal cracks. Pellet with such a surface most probably has appropriate compactness and solidity, and its wear resistance and abrasion is also appropriate.
- Drop a few pieces of pellet into water! They should sink as their required density is higher than 1 kg/dm3.
- Select 5 – 10 pcs of pellets from the pile and break them in two! If it is difficult to break them and the line of fracture is sharp and shows a conchoidal surface than this is the sign of appropriate compactness.
- Try to crumble the pellet by hand. If you can do it than the pellet is definitely of inferior quality. If the pellets bend in your hand and crack instead of breaking the density is not appropriate either.
- Turn over the packaging and check – if the packaging is transparent – the amount of crumbs at the bottom. If there are many, it is a sign that the pressure and temperature was not appropriate or possibly too dry material was fed into the press.
- The smell of fresh, warm pellet is intensive and pleasant but it quickly melts into the air so it cannot be used for classification at the time of purchase.
- The pure “white” pellet probably does not contain barks but it is also possible that it was made of hardwood or the pressure in the press was too high and the surface got a little bit burnt.
- If you observe greyish stains on the pellet surface this refers to the inappropriate storage of the raw material and the resulting harmful biological processes (fungoid growth) which leads to the deterioration of quality.
Always insist on proper quality when buying pellet!