Today is Sunday, Dongguan Plastic mold factory of the majority of colleagues, you are to work or work it Edit the mold factory where most mold people have been holiday break, only a handful of few people in overtime. Today for everyone to introduce plastic mold compression mold convex, concave mold with the form.
(1) overflow compression mode
Overflow type compression mold convex, concave mold without matching section, punch and die in the sub-surface contact, the contact surface should be smooth and smooth. To reduce the thickness of the flash, the contact surface should not be too large, generally designed to width of 3 ~ 5 mm ring surface, the excess plastic can overflow through the ring surface. As the annular surface area is small, by virtue of the pressure of the press will lead to the ring surface premature deformation and wear, so that plastic parts stripping difficult. To this end, in addition to the annular surface and then increase the pressure surface or in the cavity around the edge of 3 to 5 mm at the edge of a spill groove, groove outside the pressure surface, the tank is within the flash surface.
(2) does not overflow compression mode
The structure of this mold is characterized by the size of the feed cavity section, the same shape and cavity, no extrusion between the two. Mold mold, the upper mold punch and die die was part of the fit, with the gap should not be too small, otherwise the molding cavity gas can not be smooth discharge, and the mold is used at high temperatures, the gap is too small, convex , The mold is very easy to scratch, bite; the other hand, too large gap will cause a serious flash, not only affect the quality of plastic parts, and difficult to remove the flash. Feeding cavity and punch generally press H8 / f8 with, usually take a single gap 0.025 ~ 0.075 mm is appropriate. In order to reduce the friction area, easy to open mode, with the height should not be too large, often take about 10 mm, feeding chamber entrance should be R1.5 mm chamfer, and set 15 '~ 20' slope as a guide. Putter and the template with the length of h to take 4 to 5 mm.
(3) semi-overflow compression mode
The structure of the semi-overflow compression mold is characterized by the use of a horizontal extrusion surface. In order to make the residual pressure of the press machine be completely supported by the extrusion surface, a pressure bearing block or a pressure bearing surface is provided on the upper and lower mold clamping surfaces of the semi-overflow compression mold M. The width of the bearing surface should not be too small, otherwise it will easily lead to the edge of the die inward tilt and the formation of inverted cone, hinder the smooth release of plastic parts.
Note: The above information is chaired by Jiezheng on the Internet, welcome reproduced, indicate the source!