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【名称】：Injection Molding
【作者】：不详
【格式】：DOC
【页数】：2
【语言】：英文
【出版社】：
【出版日期】：
【摘要或目录】：
Materials for mold construction
Materials commonly used for tools,
suitable in molding Elastollan®
TPU's, are steel or steel alloys.
Molds made from non-ferrous metals,
such as aluminum, also work
successfully.
Sprue
The maximum sprue diameter, when
possible, should not exceed the
maximum wall thickness of the
molded part.
Sprue cones should be as short as
possible and with a minimum angle
of 6° per side. The use of a sprue
puller is advised for easier demolding.
The entrée orifice diameter of the
sprue cone should be adjusted to the
nozzle and exceed the nozzle
diameter by 0.5 mm.
Hot sprue bushings can be used.
The hot sprue should be of the “direct
flow” type (no restriction). This type
of hot sprue minimizes shear that
can degrade the material.
Venting
Air must be able to escape easily
from the mold cavities during the
injection of the melt. This will prevent
trapping air, and causing burn mark.
Vent channels of 0.02 to 0.05 mm in
depth are best located at the parting
line, inserts and ejector pins.
