Tags: Plastic Blow Mold  Plastic Auxiliary Machine Plastic Pipe Extrusion Line
Stack molds are some of the most amazing production tools to be found anywhere. The engineering and craftsmanship that goes into a stack mold is truly a marvel.
For the layman, who has never built a plastic injection mold, it might look like a big, fancy piece of machinery that produces plastic widgets. Yet, from the perspective of an plastics mold maker, stack molds represent a very high level of expertise.
What is a stack mold?
There are numerous variations on the theme of stack molds, but 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 the ability to do multiple operations in the molding cycle
Basically, a stack mold has a stationary "A" half, and at least two "B", or moveable halves. They are similar to the rotary molds that have been in use for many years, but are vertical rather than horizontal.
This means that the moveable cores rotate about a vertical axis, rather than a horizontal. Also, the stack mold is very compact and has a much smaller footprint.
Are stack molds expensive?

Tags:Plastic PET Preform Mold   Plastic Cap Mold  Plastic Auxiliary Machine
Hot runner systems require a new level of expertise on the part of the mold maker. However, this does not mean that it is overly complicated or highly specialized. A well designed system is relatively free from maintenance, once it is properly installed.
It can, and does happen, that mold makers become frustrated with hot runner systems and swear that they are too much trouble. This is usually due to the fact that the system is not properly installed or incorrectly operated in the molding process.
The leading hot runner system manufacturers have a well-trained team of specialists on hand to assist in the proper installation and operation of the systems. The time spent listening to these specialists is time well spent!
Are there different types of hot runner systems?
There are almost as many types of hot runner systems as there are suppliers! Most share some common features, however. There are sprue gated systems, valve gates, tip gates (the most common), and edge gates. Any of the major suppliers can describe in great detail why their system is the best for your application. Hot runner systems are some of the most important mold components
Long term benefits
Even though there is an initial investment with hot runner systems, it is easy to justify the long-term benefits. Without increasing the complexity of the design of the mold, a hot runner equipped mold can significantly reduce costs. Because the hot runner is designed and manufactured independently, yet concurrently, the lead times are not affected.
Mold makers should always suggest methods for his customer to reduce molding costs and increase the output of the mold. Being knowledgeable with hot runner systems is a good way to demonstrate an active role in helping the molders bottom line. This in turn makes the likelihood of increased business even greater for the mold maker.

Automation boosts injection moulding quality (1)

The prime aim of the automation of injection moulding systems is not to save high labour costs but to ensure high process and product quality, says Engel.
Nowadays, handling devices and robots are "run-of-the-mill" equipment in the manufacturing industry.
In an injection moulding shop, for example, the manual placing and removal of inserts is the exception rather than the rule, and the same goes for the feeding of moulded parts to downstream finishing stations.
The prime aim of automation is not, however, to save "high labour costs" but, rather, to ensure high process and product quality, this being an absolute prerequisite in a modern production facility.
Handling devices and robots operate in an exactly reproducible rhythm, and at extremely high speeds and round the clock.
 Besides injection moulding machines, Engel also offers matching automation systems - from the simple handling device to the complex production cell incorporating product-specific downstream finishing stations.
Since all system units are produced by Engel, the responsibility for everything, including CE conformity, rests entirely with Engel.
Engel automation, whether standard or special, partial or complete, permits reproducibility to the highest standard.
Continuous growth from the very beginning Engel has been involved in automation technology since the 70s (at that time it was still the parent company Engel Maschinenbau), beginning with simple pneumatic devices for assisting the demoulding operation.

Tags: Plastic Cap Mold  Plastic Automotive Mold  Plastic Injection Molding Machine
Machining of materials for medical applications has moved to a new level of precision. In parallel with this, molding technology has improved through the increased use of sensors in moulds, enhanced design simulation and processes such as micromolding. High cavitation moulds have been used for many years to mold plastic medical components in high volumes. Close-looping the injection process achieves improvements in cavity-to-cavity repeatability in the order of 40%. This is combined with a significant improvement in the accuracy of the molded part. For example, in a 32-cavity mould, the thickness accuracy near the end-of-fill for a part, which is 40 mm long and 1.5 mm thick, could be improved from 100 µm to 30 µm, across all 32 cavities.
Recent developments allow information from temperature sensors placed near the end-of-fill in multicavity moulds to be used to adjust the temperature of the valve gates, which directly control injection into the mould cavity. The difference between this and a conventional overmolding process is the level of precision that is involved. Mould design and accuracy for this type of process is critical for efficient operation. Medical components such as overmolded needles have been produced and minute amounts of polymer as small as fractions of a gram can be reliably injected.
Gates for micromolds can be less than 60 µm in diameter. This is important to minimize the gate vestige left on microparts and to allow automatic degating in the process via three-plate mould designs. Examples of micro-parts moulded using auto-degating include bioresorbable staples and X-ray opaque probes with tip diameter of 0.15 mm.