抽真空成型的抽气孔设计是模具设计的关键
抽真空成型的抽气孔设计是模具设计的关键,抽气孔应位于片材最后贴模的地方,如凹模成型时在凹模底部四周及有凹陷的地方,凸模成型时在凸模的底部四周等,具体情况视成型塑件的形状和大小而定。
The design of air vent in vacuum molding is the key of mold design. The
air hole should be located at the last place where the sheet is attached
to the mold, such as around the bottom of the die and the concave place
when forming the concave die, and around the bottom of the punch when
forming the punch. The specific situation depends on the shape and size
of the molded plastic part.
对于轮廓复杂的塑件,抽气孔应集中,对于大的平面塑件,抽气孔需要均布。孔间距可视塑件大小而定,对于小型塑件,孔间距可在20~30mm之是选取,大型塑件应适当增加距离。
For the plastic parts with complex contour, the air holes should be
concentrated, and for the large plane plastic parts, the air holes
should be evenly distributed. The hole spacing can be determined by the
size of the plastic part. For small plastic parts, the hole spacing can
be selected between 20 and 30 mm, and the distance should be
appropriately increased for large plastic parts.
通常成型塑料流动性好,成型温度高,则抽气孔小些;坏料板材厚度大,则抽气孔大些;坯料板材厚度小,由抽气孔小些。总之,对抽气孔大小的要求是既能在短时间内坯材与模具成型面之间的空气抽出,又不在塑件上留下抽气孔的痕迹。一般抽气孔的直径是0.5~1mm,以最大抽气孔直径尺寸不超过片材厚度的50%为宜,但对于小于0.2mm的板材,过分小的抽气孔就无法加工。
If the thickness of the sheet is smaller, the thickness of the sheet is
smaller, and the thickness of the sheet is smaller. In a word, the
requirement of the size of the blowhole is that the air between the
blank and the molding surface of the mold can be drawn out in a short
time, and no trace of the air hole is left on the plastic part.
Generally, the diameter of the air hole is 0.5-1 mm, and the maximum
diameter of the air hole should not exceed 50% of the thickness of the
sheet. However, for the plate less than 0.2 mm, too small air hole can
not be processed