Stack Molding For Plastic Injection Molding


Stack molds are one of the most amazing production tools found anywhere. The engineering and craftsmanship which goes into a stack mold is a marvel.

To the layman, who has never built a plastic injection mold, it may appear to be a major, fancy part of machinery which causes plastic widgets. Yet, from the outlook during an plastics mold maker, stack molds represent a really higher level of knowledge.


Just what is a stack mold?


There are several variations on the party's theme of stack molds, however some common features are:


 Built for very high production runs

 Have a one cavity and multiple cores

 Use indexable cores to injection mold multi-materials

 Have to be able to do multiple operations inside the molding cycle


Basically, a stack mold carries a stationary "A" half, and a minimum of two "B", or moveable halves. They may be similar to the rotary molds that were available for quite some time, but you are vertical rather than horizontal.


This means that the moveable cores rotate in regards to a vertical axis, rather than horizontal. Also, the stack mold is extremely compact and contains a significantly smaller footprint.


Are stack molds expensive?


Yes, stack molds can be expensive. This is why a high volume is needed to justify their expense. However, particularly in medical or cosmetic molding, the ROI is easily realized.


Considering the boat load of engineering and mold making involved, the expenses is understandable. Designing and creating a stack mold is not for novices, or mold makers who take shortcuts! Plastic injection molding is difficult, and stack molding is on an entirely new level.


Which are the applications for stack molds?


Because they are for prime production products, the normal applications are suitable for cosmetics and consumables, such as deodorant or toothpaste containers. Automotive and medical items are also frequently produced using stack molds.


A growing number of items are being desinged to use soft overmolding, for example toothbrushes or hairbrushes. These are generally perfect applications for stack molding.Because the part is injection molded, ovemolded, cooled and ejected in sequential cycles, production costs could be minimized.


What are the advantages of stack molding?


Stack molds can be found in numerous configurations to meet a variety of molding demands. Stack molding gives an economical and efficient manufacturing solution to the production of multiple plastic parts. Injection molding organizations are always searching for more efficient strategy for molding, and also for the right


Many of the making use of your stack molding process include: Increased output efficiency (productivity)


 Decreases amount of machines required


 Lower machine size requirement vs.. multi-cavity single face molds


 Produce double as many parts without increasing press size or clamp tonnage, which greatly reduces part costs


 Set-up serious amounts of run-time cost is divided by all the parts produced


 Producing the back and front parts of a key fob as well is a good example of the application for stack molding


 Mold ejection functions are self-contained, no additional labor or steps required


Coto Mold is a plastic injection mold making company located in Shenzhen of China that very close to Hong Kong. Today we have 10+ years experience in plastic mold making industry and we have strong technical background including our sales staff. More than 90% molds we made are for overseas customers, the mold including 2K mold, over mold, insert mold, hot runner mold etc., the products are for different fields like Automotive , Home appliance, Electrical, Medical, Packaging and so on.