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 Product Design. Show all posts
Showing posts with label Product Design. Show all posts

Friday, September 14, 2007

Wall Thickness Design - Maksimum

Dependent on the part design and size, typically, for injection molded parts, the wall thickness will be in the range 0.5 mm to 4 mm (0.02 - 0.16 inch).
For parts made from most thermoplastics, nominal wall thickness should not exceed 4.0 mm. Walls thicker than 4.0 mm it is will increase time required for cooling and will result in increased cycle times

Changing the wall thickness of a component has a significant effect on the following key properties:

1.component weight
2.achievable of cycle time because more time 3.for cooling and injection
4.tolerances of product
5.achievable flow lengths in the mould
6.production cycle time of the component
7.rigidity of the moulded part
8.quality of the component in terms of surface finish, warpage and voids.
9. will affect to determines mechanical properties

What the Disadvantage when Thickness not Uniform

In the design of plastics components, it is important to aim for uniform wall thickness. Different wall thicknesses in the same component cause differential shrinkage which, depending on component rigidity, can lead to serious warpage and dimensional accuracy problems

what we should do when design a mold that have different thickness, look at the following picture, we should make as possible uniform or make the transition of product is gradual



Generally, the maximum wall thickness used should not exceed 4 mm. Thicker walls increase material consumption, more need time for cycle time considerably, and cause high internal stresses, sink marks and voids, look at picture below