Injection Mould Construction

A molding according to the function of each of its parts can be divided into four sections 1. Introductory part of the plastic nozzle into the cavity cavity 2. penunjuang system (support system) 3. demolding system 4. heat transfer system

Mold Base Standard Part

In the manufacture of injection mold, mold base is an integral part, mold maker can make your own mold base or buy a standard mold base, the system of the mold base can be adjusted with the construction standards required, both for the two plate and three plate, stripper plate ejectors, hot runner and mold base for a screw, when the entire standard mold base is not there to meet the new final step is to make a special mold base.

Injection Mould Classification

classification or types of mold injection very depend on what we need to make the plastic parts, because every parts have specific and unique design. when design molds we must see what the influencing factor like geometry, number of cavities, ejection principle, plastic material and shape of part.

Injection Mold Cooling

This section is the most important part of the overall mold cylcle time, because in one cycle time, the process of heat exchange to spend about 70-80% of the total cycle time, thus setting the optimal heat transfer system will greatly affect the quality and cycle time of a product.

Undercut System : Cam, Angular, Lift Cavity, Loose core

cavity and core, and its derivatives when there are undercut on product, design and construction of a good core cavity and in accordance with the requirement could increase the life of tooling itself, reduce material consumption, reduce dependence on maintenance inserts, and can reduce the cost of making the mold so the mold cost per products also declined.

Showing posts with label mold calculator. Show all posts
Showing posts with label mold calculator. Show all posts

Saturday, October 25, 2008

shringkage of mold calculation, mold calculator

as the request, lot of people need engineering and calculation of injection mold and mold design, so i try to make little software, the name is mold calculator, it's freeware so download it and you can publish it, now it still under development, in this beta version this software only provided various shrinkage formula.

what is shrinkage ?

Shrinkage is inherent in the injection molding process. Shrinkage occurs because the density of polymer varies from the processing temperature to the ambient temperature
There are linear and volumetric shrinkage. Both methods are difficult to measure accurately.
see more information about shrinkage and what the main thing that affecting shrinkage in http://plastics-engineering.blogspot.com/search/label/shrinkage

Relation Between Injection parameter setting and shrinkage
picture below shown relation between shrinkage and injection machine parameter.


Mold Calculator software beta 1
calculating shrinkage is basic when designing mold, so
i try to make little software, more than 4 year never learn or make some program again, then now i still learn .net frame work, as the practice i try make this software, becouse I'm not professional software designer please don't hesitate to contact me, give some advice both in programming and mold calculation.

this software is still under development, on this version you can calculate, shrinkage value, dimension after and before shrinkage, and exact shrinkage scale to input in 3D modeling software.

to download those mold calculator, i have 2 version, In Indonesian language version and English language version, download at

English version

Indonesian version

you also need download .net framework 3.5 from Microsoft

Basic Formula of Shrinkage

D' = D x(1+shr)
with
D' is dimension after shrinkage
D is dimension before shrinkage
shr is shrinkage (in persen %)

so to calculate shrinkage we can use formula

shr = (D'/D)-1

from this basic formula we can develop by substitute with other formula