Fillers pressure profile

Fig. 3. Pressure profile inside the flat slit channel in PS Keroplast melt flow (contains 0.3 (vol.) shares of a filler). Volume consumption is 1.3 mm per s. Filler-Kerogene 90 (o), shale ash ( ). light marks-isothermic regime (T = 453 K), dark-non-isothermic (reservoir temperature 453 K) [10]...

Figure 3.11 TSE configuration and pressure profile for filler incorporation [8].

The analogous large-volume series ZSK MEGAvolume with 8.7 Nm/cm3, a diameter ratio of 1.8, and screw speeds of up to 1800 rpm is used for compounds with a high solid matter content, such as those often found in the chemical/food/pharmaceutical industries. The maximum speeds of up to 1800 rpm are used mainly for low-viscosity products, such as pressure-sensitive adhesives and silicon sealants because they provide better elastomer and filler dispersion. Other processes often require large volume only and operate at very moderate speeds of 100 to 600 rpm to protect the product or for direct extrusion into films, sheets, or profiles. 

The pressure required for shaping the product (sheet profile or pellets) depends upon the flow rate, the aperture geometry, and the viscosity of the filled polymer at the exit shear rate. In general, the viscosity of a polymer-filler mixture (pc) increases as the... 

The discovery of chromium (molybdenum) and titanium catalysts for the low pressure synthesis of polyethylene in the mid-1950s was a milestone in the preparation of plastics [1, 2]. Research efforts in the area have been greatly directed toward several commercial goals that comprise low production cost, which is related to an efficient process chain, and an appropriate property profile, which is related to a market requirement and/or an application [3]. The use of a supported catalyst that allows steering of the morphology of the product is an essential part of the production process [3,4]. The property profile of polyolefins can be substantially extended by dispersion of fillers into the material (http //www.matweb.com/). 

Automation by fast, stable and accurate control loops for consistency, flow, pressure and level is elementary for providing the necessary constancy in the approach flow system. Variations in pressure for example will mainly directly influence the MD profile whilst stock consistency deviations will affect both CD and MD basis weight profiles. In addition the retention on the paper machine and the chemical conditions of the water systems must be kept constant. Here a retention control loop is standard in many appHcations keeping the white water consistency constant by adapting the quantity of retention agent added. Controls for filler, color, air content, cationic demand or zeta potential are also available today. Combining the different controls to a total control concept will lead from purely functional controls to control systems which also address quality and production issues. 

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