Mold Manufacturing

Plastic injection mold is the mother of plastic injection molded parts, every plastic molding parts requires a mold tool for production. With a injection mold tooling, we can produce a plastic parts at high efficiency, large volume, and consistent quality.

A plastic injection mold normally made of steel(some of prototype mold could be made of aluminum),  consists of cavity(A plate), core(B plate), injection system, guiding system, ejection system, and cooling system.

A complex part requires more complex mold structure, which calls sliders or lifters that used to specially obtain some windows, shaft, screw, snap-on, etc. As sliders and lifters move parallel while mold cavity and core opens and closes.  

While plastic injection molding process, the molten plastic material on the injection molding machine is forced into mold cavity through injection channel, where the material would solidifies and cools to obtain the desire shape or products. This is how a plastic part produced.

Mold Life-time: 500,000-1,500,000 shots

Injection Molded Parts Precision: 0.01~0.05 mm

Mold Manufacturing Standard: DME,EMP, HASCO(Europe), MEUSBURGER,JIS, ANSI, DIN(German), BS, LKM(China)

Mold Steel: FINKL(America), ASSAB(Sweden), Thyssen(Germany),  DAIDO(Japan), AUBERT & DUVAL(France), LKM (China)

Mold Base: EMP, HASCO, FUTABA, DME, LKM.

Hot Runner: MOULD MASTER, HASCO, DME, YUDO, INCOME, SYNVENTIVE, etc

Texture: VDI 3400, Mold-tech, Yick Sang, Tanazawa etc

Step 1>. Part DFM & Refine

When we take a project from our client, the first thing we do is to perform a DFM, which helps client to check out part thickness, strength, fitting, and injection molding ability. Meanwhile, we will provide improvement solution or revise part design directly, and send stp file to clients for confirmation.

Step 2>. Mold Design

Once the part refine process is finalized, our professional mold designers would start with mold design job, at this time, a mold design DFM report will be sent to clients for review prior to 3D mold design, which includes mold steel, mold layout, injection gate position & type, parting line, sliders & lifter deployment, ejection pins, and cooling channel. In this way, our client can clearly understand how the mold design will go forward.

If our client confirmed our mold design DFM, then we will begin 3D mold design immediately.  

Step 3>. Mold Base, Mold Steel, & Standard Parts Sourcing

As soon as our mold design drawing is confirmed by client, we will out-source mold base, mold steel, injection pins, sleeves, or hot runner if have.

Step 4>. CNC Machining

CNC machining is the first mold manufacturing process, which is used to make some mold cavity, mold core, sliders, or lifter. If any EDM process needed, we will keep a 0.2mm remaining material based on design drawing.

Step 5>. Wire Cutting

Wire cutting is a quick way to manufacture some sliders, lifters, or insert components. Meanwhile wire cutting can be used to obtain holes, slots, and other shapes of mold features.

Step 6>. EDM

EDM is known as electric discharge machining process that used to make mold features with accurate dimension. During the process, a discharge copper is mounted on EDM machine, it gives spark discharge or sink discharge to remove material from work piece.(mold steel).

Step 7>. Polish

In order to obtain a certain finish of part. We need to polish the mold cavity or mold core. For different level of finish, we can categorize them as mirror polish, high polish, or normal polish. On the other hand, a polish can help part to be ejected from mold tool easier without scratch while injection molding production.

Step 8>. Mold Fitting and Assembly

Prior to mold assembly, we will get all of mold components inspected by CMM machine, and ensure each mold parts are accurately manufactured based on our mold design drawing. After that, our mold makers will get them assembled and fitted.

Step 9>. Mold Trial

Mold trial is a useful process to check out if our mold tool is correctly designed or manufactured. Our mold QC will check out the first molded sample. If everything is OK, we will send 10 pcs of sample to clients for review. If not, we will take quick troubleshooting action, so that the first molded sample can be produced and shipped to clients for review.

Step 10>. Mold Refine

40% of our mold has a perfect performance when first mold trial, however, 60% of new mold exists some imperfection or defects. So we need to improve our mold tool immediately after first mold trial. And try to fix all of problem as sooner as possible.

Step 11>. Texture

If mold tool is completely refined, the last step we do is to add some texture on mold tool. So that our molded parts will have a good touch feeling or appearance. We perform VDI 3400, Mold-tech, Yick Sang…as our standard texture sample. If any special texture needed, our client will have to send us physical samples for reference.

Injection mold cost could be a large spending for many projects. But few of us really know why and how it’s so expensive.

Molding USA makes high quality injection mold with globally competitive price. Most of mold tooling cost ranges from $1,500~$4,500, some complex mold cost would be a little bit higher.

Here below we would like to share some of our experience on what factors that could affect a injection mold cost, hope it’s helpful for any reader to better understand it and make a right decision when you out-source a plastic injection mold tool.

Number of Cavity:

Relative to say, the more cavities we have, the more cost we will spend for mold making. For example, a single cavity is much less cheaper than a 4-cavity or 8-cavity mold.

Harden Mold or Soft Mold:

For different mold life(different manufacturing volume), the injection mold can be divided into hard mold and soft mold. The harden mold requires to use higher quality mold steel, and much different manufacturing process as well as different manufacturing facility. since the mold steel is too hard to manufacture. Certainly the cost would be about 30% more expensive compared to a normal mold as it needs more labor, longer mold manufacturing time, higher precision equipment.  

Sliders/lifters needed or not:

A single part without any sliders or lifters would be much cheaper than a complex mold that requires to us sliders or lifters. Because we need more mold parts and more manufacturing time. So when we design a plastic parts, just try to make the parts as simple as possible(avoid sliders or lifters), in this way, the injection mold cost and molding cost would be cheaper.

Smaller part size or large part size:

It’s easy to understand that a coin size parts and a plastic chair will definitely have different injection mold cost. As they need much different mold material and manufacturing time.

Simple part or complex part:

The cost of simple part is much cheaper than a complex part mold. For example, a phone case mold(simple) cost is about $2,000, however a automotive bumper mold could reach $300,000.

Multi-color molding or single color molding:

Multi-color molds means two color or three color mold, it can be used to produce different color of material with one mold. Certainly it needs complex mold structure and mold manufacturing process. This is why the mold cost would be much expensive(3~5 times) than a single color mold.

Hot Runner Mold:

Hot runner is used to save injection molding material and improve manufacturing efficiency. It’s widely application of high volume injection mold tooling. A single nozzle of hot runner costs about $2,500(Mould Master), a two nozzle of hot runner cost at least $4,000(Mould Master).

So you can see, if a mold without hot runner could be cheaper than a hot runner mold.

A high quality injection mold can produce high quality plastic parts and last for longer mold-life. So it’s very important to control the plastic injection mold making quality.  

Molding USA take strictly quality control from early evaluation, mold design, to final mold completion. We source high quality mold steel, mold base, and other standard mold components from top level of suppliers. Ensuring all of mold parts are accurate, durable, and interchangeable.

During our mold making process, all of copper tool, mold spare parts, mold cores would be seriously inspected by our professional mold QC. If any deviation found, we will rework or replace them before putting them in use.

After mold trial, a detail injection molded part qualification report will be released and followed up by our mold engineer. We will make mold improvement tracking list for any imperfection we found, and hit each checkpoint completely before project sign-off.