Abstract: A rigid fiberboard suitable as a replacement for the natural woods presently used for the manufacture of pencils is provided. The fiberboard essentially comprises a fiber network, together with a filler and binder. A lubricant is added to improve the sharpening characteristics of the fiberboard, and dimensional stability is preserved by incorporating a waterproofing agent to minimize the absorption of water by the fiber network.

Abstract: A low fiber, high filler content matrix board is provided. The matrix board is characterized by a total mold shrinkage of not more than 0.002 "/", wherein the shrinkage is substantially non-directional. In addition to the fibers and fillers, the board further comprises a resin binder. A matrix mold made from the board is provided together with a method for forming a flexographic printing plate from such a matrix mold and a printing plate made according to this method.

Abstract: A multi-component heat shield is provided. The shield includes at least one heat insulating component and at least one heat reflecting component having different coefficients of thermal expansion. The insulating and reflecting components are arranged with at least a portion of one of the insulating component's surfaces in registration with at least a portion of one of the reflecting component's surfaces. Movement of the components relative to one another is restricted at selected positions while the movement of the components is unrestrained between these positions. As heat is applied to the shield, the component with the greater coefficient of thermal expansion tends to expand at a greater rate than the component having the lower coefficient of thermal expansion. The stress which develops in the shield due to the restriction of the components at the selected positions is accompanied by changes in the spacing between the components.

Abstract: A matrix coating system and method of manufacture thereof is presented wherein the matrix coating contains chemical blowing agents which permit low pressure molding and also the formation of printing plates having deep relief. The method of manufacture is such that a foamed coating is produced which at molding temperatures is highly compressible at low pressures and which also expands into the relief or nonprinting regions of the pattern plate. The unusually low molding pressures necessary result in less distortion of rubber pattern plates or made from photo polymers. In addition, the combination of high compressibility in appropriate areas, and of volume expansion in relief areas allows the board coating to conform before and during cure to pattern plates of deep relief, so that in the cured state there results a rigid, durable high fidelity mold useful for molding numerous flexographic printing plates.

Abstract: A matrix board and the method of manufacture thereof are presented wherein the board has a relatively thin carrier sheet, a relatively thick layer of syntactic foam on the carrier sheet and a relatively thin layer of phenolic resin and filler over the relatively thick syntactic foam layer. The matrix board is capable of being molded at low pressures on the order of fifty psi, thus making it particularly suitable for use with rubber and photopolymer pattern or master plates and also making it particularly suitable for formation of deep relief matrix boards.