Overview

This article will provide a brief guide on injection molding your next prototype. Including

What is a Rapid injection mold?

How is it different from a regular production mold?

Why choose a rapid injection tool?

What materials can be molded in a rapid injection mold tool?

What is the cost difference?

How many parts can I get from my rapid injection mold tool?

Is there an MOQ for ordering parts from my Rapid Injection Mold?

What mold textures are possible for rapid injection mold tooling?

Why choose Prototype Finder to help with your next rapid injection mold project?

What is a Rapid Injection Mold

A rapid injection mold is an injection mold tool that is made much faster than a production injection mold. The mold steel is cut on a CNC machine and probably an EDM machine then polished and assembled. The tool is not hardened. We often use a shared mold base, which means we only need to manufacture the core, cavity and ejector plate. It is then fitted into the shared mold base. This greatly reduces the workload and therefore cost and leadtime to make the mold.

How is it different from a regular injection mold

A regular production injection mold takes around 3 months to manufacture. The core and cavity are made from a high-grade steel that will be hardened using heat treatment. After heat treatment the mold needs to be finished, fitted and polished, which is a slow and laborious process, not to mention costly. The production mold can be made to produce more than 1 million moldings if required. A production mold is invariably a stand alone mold base, which means it is only used for that particular part. A rapid injection mold tool is designed to be quick and the life of the tool is lower than that of a production tool. Often the tool life is 50,000 parts. The core and cavity are not hardened after machining and polishing.

Why choose a rapid tool?

If you need plastic parts fast, a rapid tool is probably the way to go. There are many reasons why a client will need plastic parts very quickly. It may be that another supplier has let you down, or there has been some miscommunication within an organization, or maybe a last minute design change. The point is if you have an urgent need for injection molded parts, you will be interested in the cost and lead time of rapid tooling. We can manufacture a rapid tool and mold parts in as little as 10 days. The mold cost is likely  to be half that of a production tool or even less.

You may also be producing a part that will only ever need a small quantity. If this is the case rapid injection mold tooling is something that should be considered. The part quality will be good and the amortised unit price will also be very attractive compared to a production tool with a small part quantity.

Another great advantage of rapid tooling is the flexibility. When we are under pressure, manufacturing can be extremely tough, and sometimes mistakes are made, and things are missed. If you get halfway through a project, the tooling has been ordered and then you see a problem, this is the worst nightmare for a engineer/designer. The good news is with rapid tooling, we can make changes very quickly, often just a matter of a couple of days. Good luck achieving that with production tooling!

What materials can be molded in a rapid injection mold?

We can mold any injection material in a rapid tool that can be molded in a production injection mold tool. The machines used for production are the same regardless of the type of tool. We even have machines that are only used for white color parts and clear parts. We can mold parts used for automotive or household use with fire retardant additives, or any other application that you will need for your plastic parts. We can over mold thread inserts if threads are required, or heat stake the inserts in after molding if the quantity of inserts is large.

What is the cost difference?

Mold cost is only one driving factor but none the less an important one. On average the cost of a rapid injection tool will be less than half the price of a production injection mold tool. When considering cost, also factor in the lost time if you need to wait an additional 10 weeks for a production mold tool. How much does 10 weeks lost production add up to within your organisation? All things considered Rapid tooling can reap very big savings for some projects.

How many parts can I get from my rapid injection mold tool?

Molds are generally given a class and according to that class a number of moldings can be expected to be produced from that mold. A rapid injection mold would be considered class 104 and you would expect the mold life to be less than 100,000 parts. A high volume production mold would be class 101 and you would expect to get more than a million parts from this tool over it’s normal life cycle.

Is there an MOQ for ordering injection molded parts?

There is no MOQ for ordering a batch of molded parts. If you only need 100 parts or even less at a time that is fine with us. There is of course some set up costs which must be amortised over the batch, but this is generally a relatively small cost in the grand scheme of things. It does make financial sense to order a batch that will last for perhaps 3 or 6 months of production if possible.

What mold textures are possible for rapid tooling?

When it comes to the surface texture of an injection molded part, often a sand blasted mold texture is a very easy and appealing option. For a production tool that is going to produce upwards of a million parts, it may be desirable to have a more complex and visually pleasing texture. This is achieved using an outsourced service which is referred to as Mold tech. The mold surfaces are textured so that the molded part has a surface finish that can have a pattern. A great example of this is the dashboard of a car, next time you are in the car, take a close up look at the finish. It is achieved using high tech processes such as chemical etching and laser etching. It is costly and time consuming but it does yield a very nice result.

For Rapid tooling, this is often not the most popular choice, it often comes down to price and lead time. A surface finish that is polished or sand blasted is a popular choice that looks good and is resilient. We can advise on a one-to-one basis when discussing your project what surface texture is best for you.

Why Choose Prototype Finder to help with your next rapid injection mold project?

We at Prototype Finder have a wealth of experience working with customers that need plastic parts fast. Experience is something that helps us to identify potential issues early and point them out to the client. Once you decide to work with Prototype Finder we will act as a partner in the project from start to finish and share information and advice at every stage. We will guide you through all aspects of things to consider in terms of material choice, surface texture, color, and part design. We will do a full design for manufacture report before starting to cut the mold. This will show where the parting line will be any potential unsightly areas caused by welding lines for example and also any potential warping. It will also show any potential sink marks and a proposal to remedy the issue. If you are in the market for Rapid injection molded parts, get in touch with us today and get the ball rolling.