Mixer Blades

Much of a heater–cooler mixer’s performance comes down to its blades. However powerful the motor, it is the blade that transfers that energy into the material. Erk PVC Makine supplies mixing blades and spare parts for heater and cooler mixers.

What the blades do in a heater mixer

In a high-speed heater mixer the blade set usually has several tiers. The bottom blade scrapes the floor of the vessel, keeping material from settling and overheating there, and throws the charge upwards. The upper tiers turn the material into a fluidised vortex. That movement provides both the even distribution and the frictional heat needed to melt the additives. Blade angle and tier arrangement are among the factors that set how fast the blend heats up and how long each batch takes.

Blades in the cooler mixer

In the cooler the aim is not to generate heat but to keep bringing hot material into contact with the cooled walls. Cooler blades therefore run at lower speed and focus on renewing the material along the wall. Scraping matters here too, because a layer of material stuck to the wall weakens heat transfer.

Wear and balance

PVC blends, especially highly filled ones, gradually wear the blade edges. A worn blade moves the material less effectively, heating takes longer and the number of batches per hour may fall. Weight differences between blades cause vibration at high speed and put extra load on the bearings and shaft. That is why replacing blades as a set, with balance checked, is recommended.

What to check during maintenance

During planned stops, inspect the blade edge profile, the fixing bolts and the clearance between the bottom blade and the vessel floor. As wear opens up that clearance, more material is left behind on the floor, and later batches can show scorching or discolouration. Regular checks are the simplest way to avoid unplanned downtime. Blade-related symptoms and other frequent issues are covered in our guide to PVC turbo mixer maintenance and common faults.

Ordering replacement blades

To identify the right part, send us the make and model of the mixer, the vessel volume, the dimensions of the current blades and, if possible, photographs. If you are thinking of renewing the whole mixer, take a look at the EPM-H horizontal mixer and EPM-V vertical mixer series.