The Temperature Within The Pellet Machine

Heat and pressure are two of key parameters that need to be achieved when making pellets. Without enough heat and pressure the pellet cannot form properly, moisture is also key in this relationship. Pressure is dictated by the moisture content of the raw material, the die template and obviously the temperature present. So what temperature does the pellet machine need to get up to before its making quality pellets? Reading around articles on the internet you may come across comments like 'you need to wait for the pellet machine to warm up first'. This is a very general comment, and does not really provide much valuable information. The temperature you require does depend on the material in question, and more specifically how dense are its fibres. Low density fibre materials like field grass only require a temperature around 50 Degrees Celsius before the lignin will start to melt and bind the pellet effectively. However if you are processing wood, the fibres are much tighter and require closer to 100 degrees to achieve the same results. You cannot really measure the temperature at the point of compression, as that is happening in the centre of the die holes. However with even a basic IR (Infrared) temperature gun you can see what temperature the die template is at to within a few degrees. So the question now comes, how do you get the die to the right temperature? Well you find some people will say clamp the rollers and die down tight and leave the pellet machine running for about 20 minutes. This will build up heat, but not enough heat and it will also damage the roller bearings and the bearings on the main pellet die shaft. Really the rollers and die should never touch. The only way to built the die up to the required temperature is processing the material. However you need to start slowly, and gradually increase the feed rate until the pellet machine is up to operating temperature. However with many of the small cheap Chinese pellet machines many people never get this far, as pretty soon the die gets blocked and they have to clean out the holes.