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 Locating Ring. Show all posts
Showing posts with label Locating Ring. Show all posts

Wednesday, July 16, 2008

Locating Ring Design and Construction in Injection Mold

Locating ring is simple part but, very important when mold base attach to injection machine, ok here the construction of locating ring after assembled in mold base.



















then after attach in injection mold, the position of locating ring is like below


Basic Rule Design
1. when design locating ring, first rule is look at your injection machine catalog or hand book, and find the dimension of locating ring. like picture below

from picture above we know that locating ring diameter is 200 mm and diameter of nozzle is 52 mm, so your locating ring outer diameter must same with those injection machine locating ring hole.

2. don't worry about the tolerance, at the injection machine tolerance always about minus 0.01-0.1 mm, then the locating ring tolerance if we buy in standard mold part company is about minus 0.01-0.05.

3D Modeling various Locating Ring
below is some picture of locating ring that was i sketch using Google sketchUp, now i provide two type of locating ring. to choose right locating ring in mould is depend on injection machine nozzle, locating hole diameter, nozzle length in other factor.


Second type





















Third type
this type have large chamfer from top to bottom in inner hole, those chamfer provide shape so nozzle can touch the sprue more precise and easier.


and below is sample picture of locating ring base on Mold Part Industries



Thursday, November 22, 2007

Top Plate, Stripper Plate,Sprue Bush and Runner Lock Pin Design

at the picture below you will see a set of Top plate until stripper plate design related with runner flow, at this picture support pin exclude. the mold type in this picture is 3 plate type.

the runner system accommodates the molten plastic material that coming from barrel, and guide it into mold cavity, the dimension, configuration, shape, and system connection with mold cavity will affect filling process.



as see from that picture, red plate indicate isolated plate, it's doesn't matter you use isolated plate or not, but you must see more in injection machine, if it needed isolated plate give it. number 1 and 2 in black plate it's indicated top plate for number 1 and stripper plate for number 2, those picture shown 3 open mold type.
after injection, in ejection process stripper plate will open because puller bolt pull it( not include at those picture).

runner ejector set will needed to push runner, after ejection, but if you use arm robot or manual take the runner by hand operator it doesn't needed. runner ejector set always contains spring, those spring will push pin in ejector set and will push the runner.

runner lock pin function is to pull runner when ejection begin still in top plate, if runner adhere in stripper plate, the robots or operator will difficult to take the runner, because no ejection system for runner in stripper plate.

when design the runner system and ejection system for runner in 3 plate type of mold you should use those mold accessories.

Monday, September 10, 2007

SPRUE BUSH and LOCATING RING

when you choose sprue bush, make sure you was know the diameter ball nozzle of plastics injection (SR) is less than diameter ball (SR - at picture below indicate by R)

if diameter R of Sprue bush to little than nozzle SR diameter, that will not good match or touching, if injection machine working plastic flash will out between nozzle and sprue

LOCATING RING

some mold designer usually use Locating ring to prevent unmatching nozzle of injection machine, before choose inside diameter of locating ring, we must know the outer diameter of nozzle that will touch with locating ring, at the picture below written in purple

Red color indicating flow of plastic material, from this picture we can take a conclusion that the picture is 2plate type of mold, look at picture there is no runner plate, and the gate type is side gate




Z pin Ejector

is used to make the runner ( RED COLOR) still adhere in core side when mold open and take the product, then Z pin will push the runner together with other ejectors