Injection Molding

Injection Molding On-Demand

If you're looking for a significant number of plastic, resin, or metal parts, 3Diligent has you covered with our injection molding service. Offering a range of material options, including polypropylene, nylon, polyetherimide, stainless steel, and a range of additional materials, we have the solution to meet the needs of your application. Moreover, our equipment is housed both domestically and abroad, allowing us to provide you the choice of a faster turnaround or (typically) a lower price.

Introduction to Injection Molding

Injection Molding is one of the world's go-to fabrication methods for mass production. In brief, pellets of material are heated and then injected into a mold cavity, where the part hardens in the shape of the cavity. That part is then ejected to make space for more material to be injected.

Unlike urethane or metal casting, which require significant ongoing labor inputs, the cost for injection molding is largely front-loaded. Tooling for injection molds typically runs in the five figures, with certain highly complex tools costing upward of $100k, but this higher upfront cost comes with a significant per-unit discount. The variable cost of injection molding can sometimes go below $10 per part for certain geometries and materials. As a result, it is an outstanding technology for larger-scale manufacturing. Part runs in the hundreds of thousands or millions are possible.

3Diligent offers both domestic and overseas molding operations. If you have a particular need for domestic fabrication, please specify as much in the Additional Assurances section of a Request For Quote (RFQ) via the platform.

3Diligent has supported hundreds of companies in providing digital-manufacturing solutions for their most challenging project needs.

If you're interested in experiencing the power of our digital-manufacturing solutions firsthand, submit an RFQ through our secure portal or send an email detailing a few of the specifics of your project and we'll be in touch.

3Diligent Material Options

3Diligent offers a range of injection molding options. Among the many materials offered include ABS, silicone, polycarbonate (PC), polyurethane (PU), polyester (HDPE, and LDPE), nylon, polypropylene (PP), and many others. If you have a specific material in mind, please specify it in the Material Notes field of the Request For Quote (RFQ) form.

Beyond Injection Molding

In addition to injection molding, 3Diligent offers fabrication via other technologies such as 3D printing, CNC machining, urethane casting, and metal casting.

Plastic Injection Molding

As detailed above, traditional molding involves the use of pelletized polymers which are heated in a barrel and injected into a mold cavity.

Traditional injection molding can be completed through the use of aluminum or steel tools. Aluminum tools are typically more affordable, but only capable of smaller quantity runs. While made of metal, aluminum tools are sometimes referred to as soft tooling, along with silicone molds. Steel tools are pricier, but with that added cost comes improved longevity. For that reason, they are commonly referred to as hard tools or hard tooling. 3Diligent offers both material options to suit a range of quantities.


Reaction Injection Molding

With reaction injection molding, instead of injecting molten thermoplastic material, thermoset polymer resins are used. Mixing in the tool, a reaction actually takes place that drives the polymerization of the input materials, resulting in a solidified part in the mold.

The lower viscosity of resin relative to thermoplastic allows for larger parts to be fabricated using the process, which often suffers from imperfections when attempted at larger sizes.

For all the benefits of reaction molding, it does have a few drawbacks. The range of materials available to the process is smaller than thermoplastics, and resins generally cannot deliver the same kinds of material performance that are achievable with thermoplastics. Additionally, the relative wait time for parts to set means the process is slower on a per-part basis than traditional injection molding. As a result, it is typically most useful for quantities in the 1000 – 5000 piece range.


Metal Injection Molding

Metal injection molding starts with fine, powdered metal. These particles are filtered into a barrel cavity, along with a binder agent, that rotates and mixes the two agents into an injectable consistency. The rotating rod quickly jams forward, inserting the mixture into the negative space of the workpiece. Air escapes the workpiece's negative space through microscopic holes, allowing the metal filament to fill the cavity without exiting the workpiece as the air did.

After the parts are compressed and ejected from the cavity, they must go through post-processing, often a de-binding step to remove the binder agent and a sintering step to solidify the metal part for end-use.


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