摘要:
A phenol resin composition for forming pulleys used in motor vehicles is disclosed. The composition comprises 35 to 45 wt % of resol, 35 to 45 wt % of glass fiber, 5 to 15 wt % of one or more inorganic powders selected from the group consisting of calcium carbonate, clay, and wallastonite, and 1 to 3 wt % of polyvinyl butyral. The phenol resin pulley for motor vehicles is almost free from swelling or shell cracking on the surface at a high temperature of 250° C. or more and exhibits high mechanical strength and superior thermal shock resistance.
摘要:
A phenol resin composition for forming pulleys used in motor vehicles is disclosed. The composition comprises 35 to 45 wt % of resol, 35 to 45 wt % of glass fiber, 5 to 15 wt % of one or more inorganic powders selected from the group consisting of calcium carbonate, clay, and wallastonite, and 1 to 3 wt % of polyvinyl butyral. The phenol resin pulley for motor vehicles is almost free from swelling or shell cracking on the surface at a high temperature of 250° C. or more and exhibits high mechanical strength and superior thermal shock resistance.
摘要:
The invention provides a process for producing a phenolic resin-made pulley having a metal insert embedded therein. The process includes a step of sealing a gate of a mold with a gate-sealing pin, and simultaneously therewith or thereafter moving forward the part or the whole of a movable side die of the mold, which was moved backward, to a predetermined position to mold the pulley, whereby the packing density of the molding material in the cavity is increased.
摘要:
The present invention provides a process for producing a phenolic resin-made pulley having a metal insert embedded therein, which process comprises: setting a metal insert in the form of a cylinder or a circular solid shaft in a cavity of a mold having a movable side die, a fixed side die and the cavity, closing the mold in a state in which a part or the whole of the movable side die has been moved backward by a given distance from its predetermined position to be taken when a pulley to be produced has a final shape, injecting a phenolic resin molding material into the cavity to fill the cavity with the molding material, preferably sealing a gate of the mold with a gate-sealing pin, and substantially simultaneously with or after the gate sealing moving forward the part or the whole of the movable side die moved backward, to said predetermined position to mold a phenolic resin-made pulley. This process is particularly effective to mold a phenolic resin-made pulley having holes formed in its disc portion. Said pulley can be produced according to the above process, for example, by closing the mold in a state in which pins used for forming said holes have been moved backward from their predetermined positions to be taken later, injecting a phenolic resin molding material into the cavity to fill the cavity with the molding material, preferably sealing a gate of the mold with a gate-sealing pin, and substantially simultaneously with or after the gate sealing moving forward the pins to said predetermined positions to mold said pulley. The present invention also provides a phenolic resin composition suitably used in the above process for pulley production.