| Stack molds are some of the most amazing | | | | level. |
| production tools to be found anywhere. The | | | | What are the applications for stack molds? |
| engineering and craftsmanship that goes into a | | | | Because they are for high production products, |
| stack mold is truly a marvel. | | | | the common applications are for cosmetics and |
| For the layman, who has never built a plastic | | | | consumables, such as deodorant or toothpaste |
| injection mold, it might look like a big, fancy piece | | | | containers. Automotive and medical products are |
| of machinery that produces plastic widgets. Yet, | | | | also frequently produced using stack molds. |
| from the perspective of an plastics mold maker, | | | | More and more products are being designed to |
| stack molds represent a very high level of | | | | use soft overmolding, such as toothbrushes or |
| expertise. | | | | hairbrushes. These are perfect applications for |
| What is a stack mold? | | | | stack molding.Because the part is injection molded, |
| There are numerous variations on the theme of | | | | ovemolded, cooled and ejected in sequential |
| stack molds, but some common features are: | | | | cycles, production costs can be minimized. |
| - Built for very high production runs | | | | What are the benefits of stack molding? |
| - Have a one cavity and multiple cores | | | | Stack molds are available in numerous |
| - Use indexable cores to injection mold | | | | configurations to meet a variety of molding |
| multi-materials | | | | demands. Stack molding offers an economical and |
| - Have the ability to do multiple operations in the | | | | efficient manufacturing solution for the production |
| molding cycle | | | | of multiple plastic parts. Injection molding |
| Basically, a stack mold has a stationary "A" half, | | | | companies are always looking for more efficient |
| and at least two "B", or moveable halves. They | | | | way of molding, and for the right |
| are similar to the rotary molds that have been in | | | | A few of the benefits of the stack molding |
| use for many years, but are vertical rather than | | | | process include: Increased output efficiency |
| horizontal. | | | | (productivity) |
| This means that the moveable cores rotate about | | | | - Decreases number of machines required |
| a vertical axis, rather than a horizontal. Also, the | | | | - Lower machine size requirement vs.. multi-cavity |
| stack mold is very compact and has a much | | | | single face molds |
| smaller footprint. | | | | - Produce twice as many parts without increasing |
| Are stack molds expensive? | | | | press size or clamp tonnage, which greatly |
| Yes, stack molds are quite expensive. That is | | | | reduces part costs |
| why a high volume is required to justify their | | | | - Set-up time and run-time costs are divided by all |
| expense. However, especially in medical or | | | | the parts produced |
| cosmetic molding, the ROI is quickly realized. | | | | - Producing the front and back parts of a key fob |
| Considering the tremendous amount of | | | | at the same time is a good example of an |
| engineering and mold making involved, the | | | | application for stack molding |
| expense is understandable. Designing and building a | | | | - Mold ejection functions are self-contained, no |
| stack mold is not for beginners, or mold makers | | | | additional labor or steps required |
| who cut corners! Plastic injection molding is not | | | | Stack molds are not for everyone! |
| easy, and stack molding is on an entirely new | | | | |