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.

Sunday, September 17, 2017

Short shot or short molded Defect Product

this type of defect is caused by A molded product that is incomplete because the mold cavity was not filled completely. If a part short shots, the plastic does not fill the cavity. The flow freezes off before the flow paths have completely filled.


commonly the main caused could device in two main problem One of these occurs because, in the middle of the flow of the molten plastic, the front end of the flow gets cooled and solidifies. The second is caused, in the flow process of the molten plastic, because air traps are generated in the flow depending on the conditions of the flow.



sample short shot



Molding equipment

Increase the amount of material feed. If material feed is still insufficient at maximum material feed capacity, change to a larger capacity machine.
Install a screw with a back-flow check valve.
Increase injection pressure
Raise the cylinder temperature setting. Raise the nozzle temperature, too.
Make sure there are no severed lines to the heater.
Make sure the nozzle is not clogged. If the nozzle clogs frequently, raise the mold temperature or shorten the cycle time.
Increase injection speed

Mold

Raise the mold temperature.
Increase the mold gas release.
Increase gate cross section surface area.
Increase the molded product thickness.
Add ribs to the molded product design to improve flowability.
Choose a low-viscosity high flow material type.
Apply surface lubricant. (Add 0.05-0.1% by weight.)