Fluitec Georg AG Seuzachstrasse CH-8413 NeftenbachTel: +41 5230500 40 Fax:+41 52305 00 44info@fluitec.ch www.fluitec.ch Technical Documentation No. 11.124 Rev. 2

Static mixers for extrusion

CSE-X(G) Melt Mixer

Extrudates of high quality imply melts of a very homogeneous temperature profile. Aproduct ofhigh quality is also characterised by a homogeneous distribution of additives such as flame proofing agents, UV stabilizers and colorants. This goal can be met best by applying CSE-X industrial mixers with the well-known high mixing performance. As a result, significant economies are possible for example due to the lower amounts of colorants or other additives.

In order to meet the increasing quality require- ments of plastics, the homogeneity of the melts must be strictly controlled already in the produc- tion process. Problems such as dimension devia- tion, distortion, inhomogeneous colour or structu- re of the surface often have their origin in an inhomogeneous polymer melt leaving the extruder. Therefore, appropriate measures must be taken to eliminate these inhomogeneities. Fig. 1 CSE-X Melt mixers (welded) Problems caused by inhomogeneities Distribution of colorants Screw pumps rapidly reach their limits by mixing colorants into polymer melts. Schlieren and stains are typical after effects, which often only can be eli- minated by increasing amounts colorants. This, however, is changing the physical properties and often increasing the production costs significantly. The CSE-X mixer is capable to cope with this pro- blem. The unrivalled mixing performance oftentimes allows a reduced dosage of colorants of more than 20% at the same quality. Fig. 2 Brazed, gap-free CSE-X/8 75 element Static mixer are used in many engineering pro- cesses where heat and mass transfer operations are involved. Inhomogeneous temperature profile Extruding machines first have to pump and to melt the solid resins. Homogenizing of the polymer melt and building-up the pressure are the steps follo- wed. These numerous and multifunctional demands often stay in contrast to the required high mixing performance. In addition, the wide range of flow rates makes the mixing process even more difficult. The inhomogeneous temperature profile, as a function of the screw-type and the extrusion performance, leads to significant fluctuations in quality, which often only can be eliminated by using CSE-X mixing elements.