Guide for Manufacturer
CLASSIFICATION OF INJECTION MOLDS UP TO 400 TONS (CONT.)
.............................................................................................................................................................................................
CLASS I UNIT INSERT
-
Detailed mold design
required.
-
Insert retainer to
be uniform hardness of at least 280 BHN.
-
All molding and/or
functional details are to be made of tool steel hardened
to at least 48 R/C.
-
Slides must have
wear plates.
-
Temperature control
provisions to be in cavities, cores and slides wherever
possible.
-
Over the life of
a mold, corrosion in the cooling channels decreases
cooling efficiency thus degrading part quality and
increasing cycle time. It is therefore recommended
that plates or inserts containing cooling channels
be of a corrosive resistant material or treated to
prevent corrosion.
-
Molding details should
be plated for protection unless stainless steel is
used.
-
Parting line locks
are required to be on all molds.
-
Insert retainers
must have leader pins and bushings or some similar
guidance system.
-
It is recommended
that the entire insert retainer be electroless nickel
plated, parkerized or in some similar way protected
from rust or corrosion.
CLASS II UNIT
INSERT
-
Detailed mold design
recommended.
-
Insert retainer to
be uniform hardness of at lest 165 BHN.
-
Cavities and cores
must be 280 BHN or higher.
-
Water channels to
be included.
-
All other extras
are optional.
CLASS III UNIT
INSERT
Can be constructed from
aluminum, cast metal, cast epoxy or any material with sufficient
strength to produce at least 500 injection molded pieces.
(Important: Refer to
the general specifications to complete the details of this
section, except for prototype molds.)
NOTE: the trade customs
outlined herein represent the historic and customary practices
prevailing in the plastics moldmaking industry. Contract
forms of individual moldmakers may vary in some details.
