| | brittle | -----------------------+---------------+--------------+----------- [1] Specified refractive degree. NOTE.—The values for the properties in this table are based upon maximum and minimum figures submitted to Modern Plastics by a number of manufacturers of each type of material. Differences in test procedures and sizes of test specimens may lead to erroneous conclusions in some cases if direct comparisons are attempted. Special grades of materials are often available which excel in one particular property. Source: Modern Plastics, vol. 15, no. 2, opp. p. 120. October 1937. TABLE 18.—_Synthetic resins and other plastics: Molding properties_ ------------------------------+--------------+-------------+------------- | General | Compression | Compression Type. | molding | molding | molding | qualities | temperature | pressure ------------------------------+--------------+-------------+------------- | | _°F._ |_Pounds per | | | square inch_ Synthetic resins: | | | Tar-acid—Formaldehyde: | | | Molded, wood flour filler | Excellent | 280-360 | 1,600-4,500 Molded, mineral filler | Excellent | 270-350 | 1,600-6,000 | to fair | | Molded, fabric filler | Good to fair | 270-330 | 3,000-8,000 Laminated, paper base | | 250-365 | 1,000-3,000 Laminated, fabric base | | 250-365 | 1,000-3,000 Laminated, asbestos cloth | | 250-325 | 1,000-3,000 base | | | Cast | | | Tar-acid—Furfural: | | | Wood flour filler | Excellent | 330-400 | 1,000-3,000 Mineral filler | do | 330-360 | 1,000-3,000 Fabric filler | Good to fair | 300-360 | 1,000-3,000 Urea—Formaldehyde (alpha | Excellent | 290-325 | 1,500-6,000 cellulose filler) | | | Vinyl, unfilled | Good | 240-275 | 1,500-2,000 Vinyl, filled | Excellent | 250-300 | 2,000-2,500 Acrylate | do | 285-315 | 1,500-5,000 Polystyrene | Good | 280-325 | 300-2,000 Other plastics: | | | Shellac compound | do | 240 | 1,000-1,200 Cold molded: | | |