[4] 10 mm. ball; 500 kg. load. [5] Shore. [6] 10 kg. load. 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 20.—_Synthetic resins and other plastics: Heat properties_ -----------------------------------+--------------------+--------------- | Thermal | Specific | conductivity | heat +--------------------+--------------- Type | 10⁻⁴ calories | | per second per | | square centimeter | Calories per | per 1°C. | °C. per gram | per centimeter | -----------------------------------+--------------------+--------------- Synthetic resins: | | Tar-acid—Formaldehyde: | | Molded, wood flour filler | 4-12.2 | 0.35-0.36 Molded, mineral filler | 8-20 | 0.25-0.35 Molded, fabric filler | 3-5 | 0.30-0.35 Laminated, paper base | 5-8 | 0.3 -0.4 Laminated, fabric base | 5-8 | 0.3 -0.4 Laminated, asbestos cloth base | | Cast | 3-5 | 0.3- 0.4 Tar-acid—Furfural: | | Wood flour filler | 3.5-5 | 0.3- 0.4 Mineral filler | 10-20 | 0.3- 0.4 Fabric filler | 5-8 | 0.3- 0.4 Urea—Formaldehyde | 7.13 | Vinyl, unfilled | 4 | 0.244 Vinyl, filled | Varies | Varies Acrylate | 4.3-6.8 | 0.45 Styrol | 1.9 | 0.324 Other plastics: | | Shellac compound | | Cold molded: | | Nonrefractory | | Refractory | | Rubber compounds: | | Chlorinated rubber | |