Mold Vents
“There are generally two types of molds used in the production of rubber articles, such as tires. The first type is the ventless type wherein the mold gasses are vented through cracks in the mold surfaces. The second type of mold is the vented type which comprises a plurality of venting bores in which pins or other devices are inserted to block the flow of rubber while venting the mold. The blocking devices allow the air and mold gasses to vent while preventing the flow of rubber. Without the blocking devices, tiny spues or rubber shoots form on the surface of the article resulting in a hedge hog appearance. Prior art blocking devices may stop the formation of these rubber shoots, but may result in marks on the surface of the tire.”
[Serener-Thielmann, US Patent 7,896,653 (3/1/2011)]
Recent US Patents
3/1/2011
7,896,643
Venting device for mold
Serener-Thielmann of the Goodyear Tire & Rubber Company, Ohio, developed a mold and mold blocking member for a vent bore of a mold for the manufacture of rubber products. The mold blocking member has a tubular hollow body having a first end and a second end, wherein the first end has a cap having an outer dimension greater than the diameter of the tubular body, wherein the cap has at least one undercut forming an opening, wherein the opening is positioned to be adjacent the mold surface. (RDC 9/10/2011)