MASTER injecting the material into the mold

MASTER reaction injection moulding unit is responsible for both heating and injecting the material into the mold. The first part of this unit is the hopper, a large container into which the raw plastic is poured. The hopper has an open bottom, which allows the material to feed into the barrel. The barrel contains the mechanism for heating and injecting the material into the mold. This mechanism is usually a ram injector or a reciprocating screw. A ram injector forces the material forward through a heated section with a ram or plunger that is usually hydraulically powered. Today, the more common technique is the use of a reciprocating screw. A reciprocating screw moves the material forward by both rotating and sliding axially, being powered by either a hydraulic or electric motor. The material enters the grooves of the screw from the hopper and is advanced towards the MASTER china plastic mold as the screw rotates. While it is advanced, the material is melted by pressure, friction, and additional heaters that surround the reciprocating screw. The molten plastic is then injected very quickly into the mold through the nozzle at the end of the barrel by the buildup of pressure and the forward action of the screw. This increasing pressure allows the material to be packed and forcibly held in the mold. Once the material has solidified inside the mold, the screw can retract and fill with more material for the next shot.

MASTER plastic mould parts supply

Holes are easy to produce in MASTER plastic mould parts. Core pins that protrude into the mold cavity make the holes when the part is molded. Through holes in the molded parts are easier to produce than blind holes, which do not go all the way through a part. Blind holes are made by core pins supported on one end only. The pins can be deflected and pushed off center by the pressures of the molten plastic material during MASTER injection molding supplies process. A good rule of thumb: the depth of the blind hole should be about twice the diameter of core pins up to 3/16", and up to four times the diameter of core pins over 3/16". The guidelines for blind and through holes are seen below.

The use of ribs is a practical way for mold

If there was only one rule for the MASTER injection mould process it would have to be to maintain uniform wall thickness. Many times the stiffness of a part must increase because of the load applied to the MASTER injection mould design. One of the easiest ways to cure this problem is change the part geometry by adding ribs. The use of ribs is a practical way and economical means of increasing the structural strength of a part. But there are guidelines that govern adding ribs without causing sink marks or surface blemishes to your parts.

MASTER Plastic parts maker

MASTER plastic injection mold makers parts are always designed with a taper or draft in the direction of mold movement to allow part ejection or removal from the mold. Since plastics shrink when cooled, it is common for parts to shrink (or grip tightly) to cores. A good definition for draft would be: the degree of taper of a side wall or rib needed to allow the molded plastic part to be removed from the metal mold. Without proper draft, plastic parts may be difficult to remove from the mold. A draft angle of 1/2 degrees is regarded as minimum for most applications. Draft angles of 1 1/2 to 2 degrees per side are considered normal for MASTER china plastic injection molding.

MASTER injection mould design for you

MASTER injection mould design our machines instructing the end mills where to travel on the X, Y and Z planes, so the machine can rapidly mill both sides of the mold out of an aluminum block. Any pick outs, cams or additional mold features that need to be fitted are also created at this time. Your MASTER injection mould is now in a Protomold surface finish stage of F0, or as-milled. The mold moves into our build department where a mold operator is assigned to polish your mold at your desired level of finish.

You can specify mold at MASTER

Once a 3D CAD model is uploaded to MASTER mould maker, you can specify material, quantity, finish,overall expectation of the part in a notes section, and essentially, communicate as much information about that part as possible at the time of upload. The MASTER mould information part will be analyzed based on MASTER’s quick-turn manufacturing process to generate an automated quote; the quote you receive is your initial engagement with MASTER. From there, you can call a Customer Service Engineer with questions about our process and how it relates to your part geometry and make any modifications that are needed.

Start your project at MASTER.

MASTER china plastic injection molding uses the industry standard production process for parts, so it’s an excellent predictor of manufacturability when you move to large-scale production. At MASTER, we support an ever-increasing maximum part size and degree of complexity, and continue to introduce new materials that help designers and engineers make better products.Start your project off right with the experience and capabilities here at MASTER. Simplifying the injection mold maker Process allows us to provide you with the lowest possible pricing to bring your products to market faster than you ever thought possible.