Cooling stamping

Injection molding is employed to stamp out copies of the master discs from polycarbonate. The molded polycarbonate discs are cooled and hardened quickly, within about 4—6 sec, and evenly. The dye layer is then applied. The applied dyes are often proprietary and continually modified in an attempt to get a better dye. The dye must be compatible with the system and adhere to the polycarbonate base. It is applied by spin coating i.e., the disc is spun and the dye is sprayed onto the surface. The dye is then dried and cured. 

Oxides of Copper—red oxide of copper—Cu, 0—is prepared by heating one hundred parts of blue vitriol with fifty-seven parts of carbonate of soda until the water of crystallization Is expelled. The rosiduum is afterwards mixed with twenty-five parts of copper filings, and the mixture finely stamped into a crucible. It iB then exposed to a white boat for about twenty minutes, and after cooling and pulverization, the mass is well washed with water. ThiB process yields about fifty parts of fine colored red oxide of copper. 

One other method for manufacture is to use a fast cooling device, such as the Frozen Cone system (Aasted 1992) in which the shape of the sweet is stamped out by a cold die prior to filling and cooling. 

Mrs. Bertha Flowers was the aristocrat of Black Stamps. She had the grace of control to appear warm in the coldest weather, and on the Arkansas summer days it seemed she had a private breeze which swirled around, cooling her. She was thin without the taut look of wiry people, and her printed voile dresses and flowered hats were as right for her as denim overalls for a farmer. She was our side s answer to the richest white woman in town. 

If portions of tissue are greater than 1 cm in maximum thickness, slice them to this thickness to allow more rapid cooling. Tissue length/width simply needs to allow immersion in whatever volume of isopentane present in freezing beaker. Think of a 5- to 8-mm thick postage stamp as an optimal size of tissue to freeze. 

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