Mixing Machinery Batch and Continuous

The quality of compounds depends upon not only their composition but on how (or how well) they are mixed. There are many different types of commercial mixing machines whose manufacturers often compete with each other to supply their machines to compounders. In turn, compounders realize that the character if not the quahty of their compounds vary with the type of mixing machine used. 

Mixing machines may be classified as batch or continuous , depending upon whether mixing takes place on individual lots of material or whether ingredients continuously enter the machine and a product stream continuously leaves. This leads to a wide range of different machine types. 

The development of batch mixing machines in the rubber industry has only received limited reviews [1 to 4]. Reviews of continuous mixers are usually by machinery manufacturers and are unbalanced in favor of their particular technologies. Critical reviews with minimal prejudice have been given on the development of continuous mixers by Herrmaim [1, 5] 

In this chapter we describe both the development of mixing technologies and fundamental studies of these machines. 

---

Continuous mixing machinery is utilized 100% of the time during a production run, and plants are in operation which run through meal breaks and shift changes, so operator involvement is not required all the time. With batch mixing the continual presence of labour is necessary in by far the greatest number of cases. 

What about the machinery The proliferation of different rotors made available for batch mixers over the last few years leads one to believe that this part of the industry is in its infancy, rather than approaching old age. It is likely that further designs will appear, but some specialisation may creep in where particular rotor designs are matched to particular parts of the industry. In continuous mixing machinery, the corotating twin-screw machine appears, at last, to be achieving inroads into the rubber industry, and this is likely to continue. Other continuous compounding machines which have had a measure of success in the past are likely to be reintroduced in modified form, particularly those, like the MVX, which were shown capable of outputs in terms of tonnes per hour. 

---