was asked by a beginner in mold industry: What is
difference between HotRunner Mold &
Normal Mold for injection molding machines? Is hotrunner mold
benefited to reduce wastage & increase production?
the question is fairly basic, there is quite a range of answers, and those
answers are not simply boiled down to one or two sentences.
indications, guidelines and factors as well as all the different variations for
use of a "cold runner"
versus a "hotrunner"
are going to vary, and would range beyond the scope and ability to answer the
will have to examine your application and choose accordingly, but I will try to
explain briefly some of the advantages to a hotrunner solution.
As I currently work for a hotrunner company
I see many parts that benefit from this application. Here are a few basic
reasons to look into hot runners:
Less waste -which in turn reduces contamination
Controlled melt temperature - reduces warping of part as well as plastic
Great gate vestige - Reduces the need for
Lower injection pressures - allows for more cavities per mold
Shorter cycle times - improves production efficiency
example of this would be a high cavitation part such as a small cap. A hotrunner could
be used for this part creating a good cosmetic gate, no waste, with
a cycle time.
A hotrunner can
be used for all thermoplastic resins, and yes even rigid PVC if done
would suggest that you strongly consider the SPE training program, hold at the
Chicago Hilton/Indian Lakes Resort, Bloomingdale, Ill. Topics include: plastic injection mold design and
building; plastic materials and processing; extrusion of engineered plastics;
reheat stretch blow molding; injection molding
plastic component failure analysis; thermoplastic elastomers, thermoforming
process technology, plastic part purchasing and quoting; screw design;
snap/press fits and plastics welding; blow mold tooling and part design;
rheology, biopolymers and other new technology. Another alternative to consider
is having someone come to your plant to conduct training.