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Tham khảo tài liệu 'plastic product material and process selection handbook part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Table 8.1 Examples of f gid plas c fcarr prcpe ties Property ASTM Test Phenolic Polyvinyl Chloride Rigid Closed Cell Phenylene Oxide Foam able Resin Polyethylene Medium- Polycarbonate Density Foam Polystyrene Polyurethane Rigid Closed Cell Foamed in Place Syntactic Castable Molded Extruded Density Ib. ft. 2-5 50- 2-4 50 50 5.5-7.0 2.0 2-5 4-8 kg m j 32-80 800-960 32-64 800 800 88-112 32 32-80 64-130 Tensile strength psi D 1623 20-54 1000 1 000 3 300 5 500 110-210 42-68 180-200 90-290 MPa Cttinpres.siiBi strength D 162 22-85 6.89 8 000- 6.89 22.7 5 500 37.9 7 500 0.76-1.45 2-18 0.29-0.47 25-40 1.24-1.38 100-180 0.62-2.00 70-275 at 10 dcllcvlii ti. psi MPaJ Maximum service temperature dry F o 0.15-0.59 Continuous at 300 225 13 000 55.1-89.6.1 275 37.9 200 51.7 270 0.014-0.12 180-200 0.17-0.28 165-175 at 5fi 0.69-1.24 165-175 0.48-1.90 200-250 Thermal conductivity D 2326 149 0.20-0.22 135 1.0 2.0 93.3 132 82-93 0.32-0.34 74-79 0.23 74-79 0.17-0.21 93-121 0.15-0.21 BTU in. hr.-ft - F W mK Coefficient of linear D696 0.29-0.032 5 0.14 100 0.29 40-60 38 25 0.046-0.049 0.033 30-40 0.024-0.030 30-40 0.022-0.030 40 expansion. l F 334 Plastic Product Material and Process Selection Handbook 8 Foaming 335 their uses and applications continue to advance at a rapid pace. The major plastics used as foams are the polyurethanes and polystyrenes Chapter 2 . In addition to the basic plastics in liquid and bead forms with foaming agents fillers additives that include cell controllers and fire-retardants catalysts surfactants styrene monomer systems that vary viscosity from liquid to paste form and other additives are used. The gas can be put directly in to the plastic before the plastic solidifies. Reactant chemicals can be put in the plastic formulation that during polymerization will release a gas and produce the foam. Very popular are extruding expanded polyethylene polypropylene polyvinyl chloride and polystyrene Chapter 5 . Specially designed extruders can handle a mixture of .
