Cast phenolic

It is likely that the quinone methide and related structures formed at these temperatures account for the dark colour of phenolic compression mouldings. It is to be noted that cast phenol-formaldehyde resins, which are hardened at much... 

Figure 27 Synthetic plastics imitated successfully exclusive natural materials a Bakelite ash tray with built-in match holder and striker in marble Roanoid, with marbleized, brass-tipped cigarette holder, 1930s. Carvacraft desk set in amber cast phenolic, 1948-51 double inkwell, notepad holder, blotter and paper knife with clear acrylic blade. Smiths Sectric alarm clock with marbleized urea-formaldehyde case, 1932. Ardath Tobacco cigarette box in ivory and black urea-formaldehyde with lid moulded to simulate a classical relief, 1935. Propelling pencil with black and orange mottle typical of vulcanite, 1930s (Photo Stephen Brayne, Collection Sylvia Katz)...

Figure 13.4 Cast phenolic brooch, imitatii amber (magnified).

The decorative form of Bakelite was cast phenolic, which used a syrup for moulding. The manufiictuiing process was slower, but allowed for li t, bri t and even transparent colours. Reinforcing fillers were not added to cast phenolic. 

Bakelite (as cast phenolic) was used to make bristly coloured jewellery, for example bracelets and brooches. It was also used as a simulant for organics such as jet. It was most successful as a simulant for amber, and it can be difficult to distinguish the two... 

Phenolic and Other Tar Acid Resins Casting. Phenolic and other tar acid resins for casting are disclosed from 1934 to 1937, and phenol-formaldehyde for casting is disclosed from 1938 to 1941 and for 1943 (11). 

Cast phenolics. Phenolic casting resins are available as syrupy liquids produced in huge kettles by the condensation of formaldehyde and phenol at high temperature in the presence of a catalyst and the removal of excess moisture by vacuum distillation. These resins, when blended with a chemically active hardener, can be cast and cured solid in molds constructed from various materials and of a variety of mold designs. They will exhibit a broad-based property profile as described in Table 2.14. 

TABLE 2.14 Properties of Cured Cast-Phenolic Resins... 

The final products of cast phenol-formaldehyde polymers have a number or exceptional properties, including high tensile and compressive strengths, good electrical insulating capabilities, and excellent adhesive qualities. Also, they can be polished and machined. Finally, the presence of very small water droplets in the material gives the surface a superb appearance. 

Subclass or Properties Modification Cord Filled Cellulose Filled Unfilled Cast Phenolic, Mechanical and Chemical Grade... 

Acetate Epoxy Resins, Polyesters Urea Formaldehyde Cast Phenolics Polyvinyl Bulyral Plastics... 

VINYL CHLORIDE ACETATES CAST PHENOL FORMALDEHYDE HAVEG 41 (Mod Phenolic x. asbestos) HERESITE (phe no formaldehyde)... 

Steel castings have been declining while non-ferrous castings, mainly aluminum base, are gaining. The automotive industry is the major user of castings. Phenolic resins are the most common type of binder utilized (Table 32). 

Fig. 35. Dissipation factor vs frequency for polar polymers at 25°C. A, Clear cast phenolic B, plasticized PVC C, poly(vinyl chloride-co-vinylidene chloride) (saran) D, unplasticized PVC E, poly(methyl methacrylate) G, poly(hexamethylene adipamide) (nylon) H, poly(2-chlorobutadiene) I, plasticized ethyl cellulose J, cast epoxy K, methyl silicone rubber L, polyurethane foam (d = 33 g/L) and M, 50% polystyrene-50% chlorinated biphenyl.

Cast phenolics, allyls, cellulosics, and many other clear plastics show a natural tendency to absorb in the blue and to be yellowish. Ultraviolet photodecomposition is largely responsible for the development of... 

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