Processing, thermoplastics profile

Fig. 12.50 Contours of the ratio V/F0bj corresponding to some steps of the optimization procedure employed by Nobrega et al. (86,87) [Reprinted by permission from J. M. Nobrega, O. S. Cameiro, R J. Oliveira, F. T. Pinho, Flow Balancing in Extrusion Dies for Thermoplastic Profiles, Part III Experimental Extrusion, Intern. Polym. Process., 19, 225 (2004).]...

D.C. Cobb and J.W. Mercer, Jr., Process for making thermoplastic profiles having reduced melt fracture, US Patent 6100 320, assigned to Eastman Chemical Company (Kingsport, TN), August 8,2000. 

Example of a Thermoplastic Processing Heat-Time Profile Cycle... 

Typical additive packages for engineering thermoplastics have been described by Titzschkau [9], such as processing aids for PA, PP, or PET/PBT, three-component additive packages for polyamides and polyesters (nucleating agent, lubricant and process heat stabiliser) and coated copper stabilisers for polyamides. Additive packages or combinations of up to five or more additives are quite common. A typical white window PVC profile formulation comprises an acrylic impact modifier, TiC>2, CaCC>3, calcium stearate, a... 

Polystyrene (PS), a highly rigid and surface-hardened thermoplastic, is glass clear and almost colorless. Its typical slight yellow tinge is easy to compensate for by adding transparent blue colorants to adjust the color. Polystyrene softens between 80 and 100°C. It is processed between about 170 and 280°C, up to a maximum of 300°C, without color change, by any of the methods which are recommended for thermoplastics. The list of products includes extrusion made sheets, profiles, and films, which are often foamed. 

CPE impact modifiers contain around 35% of chlorine and are thermoplastic in nature. With a similar melting point to PVC, they initially form a network structure which changes to a particulate structure on processing (134). They also have good processability and excellent weathering performance consequently they are also used for window profiles (287). The effect of residual... 

Whereas all conventional thermoplastic fabrication techniques have been successfully employed to convert pellets of HIPS into useful articles, extrusion (film, sheet, profile and multi-layer) and injection molding (solid, structural foam and gas-assist) are the predominant processing technologies. Innovative hardware technologies, in both extrusion and injection molding, have provided means to combine less expensive materials, such as polystyrene, with polymers or structures offering key performance characteristics. 

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