Abstract: A method of making a high load tool having a hard body of plastic material with compression plates on opposites sides to compress and strengthen the body. The method includes the steps of inserting passage forming pipes into a container and retaining the passage forming pipes in predetermined locations. Epoxy resin is poured into the container to cover the passage forming pipes and then the epoxy resin is cured. Elongated rods are inserted into the passage forming pipes and a pair of load spreader plates are placed at opposite ends of the elongated rods. Threaded bolts are advanced on at least one end of the elongated rods to move the spreader means towards one another and to compressively load the body.

Abstract: Epoxy tooling which inherently expands and contracts with temperature changes for making parts of metal or plastic has elongated rods extending through guide tubes within the tooling and compression washers or plates on opposite sides thereof. These compression devices for strengthening the tool can be selectively adjusted toward and away from one another using nuts threaded on the rods for varying the compression load on the tooling in accordance with varying tool operating loads, working temperatures and amounts of expansion or contraction. Epoxy tools for molding plastics are heated and expanded to a working temperature and then compressively loaded in selected areas prior to molding operations to prevent tool stress cracking or epoxy tools for metal stamping are compressively loaded and supported in selected areas of high tensile stress and operated at room temperatures for high load metal stamping without fracture.

Abstract: This mold tooling has a hot drop assembly operatively mounted in a bore formed therein which opens to a mold face. Heated plastic material is fed to a feed tube of the hot drop assembly and this material is heated at a temperature higher than the working temperature of the mold during its transit the face of the tool by electrically energized heater bands encircling the feed tube. The space between the heater bands and bore wall accommodates tubing through which a flow of chilled cooling air is injected. The temperature and amount of the cooling air may be regulated to match the heat energy discharged by the heating bands into the bore and to the body of the tooling. The flow of cooling air transmits heat energy out of the bore so that heat sensitive plastic materials being molded is not degraded by hot drop assembly heat energy that otherwise would be conducted by the tool body to the tool face.

Abstract: A reinforced plastic retainer ring for use in a sheet metal stretch forming process. The ring is reinforced with a plurality of metal brackets embedded in the rim portion generally radially aligned toward the center of the ring.

Abstract: Very large tools can be cast-to-size by making a pattern of the article to be formed by the tool, laying the pattern up in a pattern box, applying a release coat and coating the pattern and box with a tough, curable tool surface layer. A small amount of epoxy filled with a thermally conductive particulate filler is cast into the pattern box before the surface layer fully cures. Relatively large chunks of thermally conductive material are added to the box which are covered with additional cast epoxy. The cure of the epoxy is controlled to effect complete cure at room temperature within a few days but never to exceed a peak cure temperature above about 70.degree. C.

Abstract: Truly amorphous silicon having a low level of undesired impurities, and therefore suitable for semiconductor applications, may be prepared by the present process. Impure silicon, for example, metallurgical grade silicon, is prepared at an elevated temperature, e.g., above 1400.degree. C. The impure silicon and at least one binary silicon fluoride compound, e.g., silicon tetrafluoride, are chemically combined at the elevated temperature to form silicon difluoride gas. The silicon difluoride gas is polymerized. The silicon difluoride polymer is then thermally decomposed to produce the purified, amorphous silicon and binary silicon fluoride by-products. The binary silicon fluorides are recycled in the process to be chemically combined with the impure silicon. That step and the succeeding steps serve to reduce the level of unwanted impurities in the silicon produced by at least several orders of magnitude.