What is the Mold Material Right for your Mold?

Post by Ace Lu 2015.11.12


There are many types and grades of mold materials to choose from when specifying your mold. So how do you know which is best? Generally, your mold manufacturer can help you make that determination when you sit down to discuss those criteria that will impact what mold material is suitable for your requirements.

Some of the considerations that are critical to the choice of mold material are:

* Program life - Do you expect the program for the particular components to last one year? Five years? or longer? If you anticipate a long program life, then you need a mold that will be extremely durable to provide the most trouble-free molding operation.

* Plastic material - What type of material will be used to mold the parts? This also weighs heavily on the type of mold material you will choose. For example, if the resin is abrasive, i.e. is a glass-filled material, metal-filled, etc., a softer mold material will mean greater wear on the cores and cavities, more maintenance and shorter life of the mold. Unfilled commodity-grade materials such as polypropylene, low-density polyethylene, and even unfilled engineering-grade materials such as polycarbonate or ABS, generally are okay for a softer grade of mold material.

* Number of parts required - How many parts will you require per month? per year? If that number is low - 100,000 parts or less annually - then you can probably get away with a softer mold material. However, if you require five million parts annually, you might want to look at hardened tool steels to meet these requirements.

There are a number of different types of mold materials.

A) Aluminum - This is becoming an increasingly popular material for injection molds, primarily because many of the grades of aluminum can provide a cost-effective alternative to mold soft mold steels. In today's manufacturing world, many programs are seeing shorter lifespans as products evolve to meet changing consumer needs, so that a program that might have lasted five years a decade ago only last a year now. That means fewer parts that need to be molded and an aluminum mold will work just fine. Aluminum is easy to machine, so lead times can be reduced and overall cost-savings realized.

B) P-20/1.2311 - This is a pre-hardened chrome-moly tool steel made specifically for machined cavities. Usually no heat treating is required. Many times, P-20 will be chosen as a step above aluminum for longer life.

C) H-13/1.2344 - This is a chromium-based mold steel designed for increased production and longer mold life. It is thermal shock and fatigue resistant, and offers superior machinability and polishability.

D) S-7/1.2767 - This is a versatile grade recommended for applications demanding high degrees of toughness and moderate wear resistance.

E) Stainless Steel (420/1.2083)- This steel is used for extremely high part volumes and provides high polishability for molding aesthetically sensitive parts, particularly medical-grade components, and products for the cosmetics industmolds-classificationsry.

Pls click here for Molds Classifications from 105 to 101 too.

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