Plastic Injection Molding

50 to 100,000+ Parts

Molds and Moldings

Start With A Free Project Review

Plastic Injection Molding Service

At Star Rapid we specialize in producing high-quality plastic injection molded parts and mold tools. We offer all machining and finishing services to make tools from a variety of materials, and can produce 50 to 100k+ finished parts in all major resins. What truly sets us apart is our advanced material verification, inspection and testing to ensure your parts meet and exceed your highest expectations. Contact our international injection molding experts for a free quote today

What Is Plastic Injection Molding?

Plastic injection molding is by far the most common way to produce large volumes of finished plastic parts for every kind of commercial and industrial use. Molten resin is injected under high pressure into the cavity of a metal die and then rapidly cooled, forming a solid shape. A single cycle to make a finished part may take anywhere from a few seconds to minutes depending on part complexity and size.

Advantages Of Plastic Injection Molding

Among the many advantages of plastic injection molding are the following:

  • Thousands of plastic resins to choose from for any application
  • Most cost-effective way to make large volumes of parts fast
  • A single tool can last for up to millions of cycles
  • Excellent surface quality and dimensional characteristics can be achieved
  • Different plastics can be overmolded for even more design options
  • The process is stable and reliable for predictable results
Plastic Injection Molded Watch

Plastic Injection Molded Watch

Plastic Injection Molded Camera

Plastic Injection Molded Camera

plastic injection

Plastic Material

Plastic Injection Molding Blog Posts

Check out our most recent blog posts relating to plastic injection molding. Topics range from how to choose the best plastic for your next project to understanding what are the best surface finishes for your desired look.

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Plastic Injection Molding Process

Once your plastic injection mold tools are ready, the molding process consists of the following basic steps:

Step 1. The plastic resin comes in raw pellets. These are dried to the right moisture content, and then if necessary they can be blended with pigments or master batch colorants.

Step 2. The dried pellets are poured into the hopper of the molding machine. A reciprocating screw inside the barrel of the machine will transport these pellets towards the mold.

Step 3. Within the barrel, the pellets are mixed and heated until fully molten, forming the liquid resin.

Step 4. The heated mold closes automatically and resin, under great pressure, is injected through a gate and into the mold cavity.

Step 5. The mold is cooled to solidify the part inside.

Step 6. The mold opens and the part is ejected to begin a new cycle.

Plastic Injection Molding Tolerances

All plastic material will expand and contract under the influence of heat and moisture. Our tolerance guide will give more general information on the characteristics of most common resin types for typical part features.

We will work closely with you to optimize your designs for manufacturing. We will indicate any areas where poor design may produce thermal stress, shrinkage, warping, etc. Consult our design guide for more information on common defects and how to avoid them.

Unless otherwise specified, we comply with the DIN 16742 standard tolerances for plastic injection moldings. Read about the visual quality standards that we apply to injection molded parts.

Plastic Injection Molding Materials

Mold Tools

We make injection molding tools and dies from Aluminum 7075, P20 and NAK80 semi-hardened steels and H13 fully-hardened steel. Additionally, we offer standard SPI finishes, EDM texturing and a range of etched textures.

Each of these material types will have distinct advantages for certain applications. Considerations include:

  • Cost of the raw material
  • Durability and resistance to corrosion or abrasion
  • Machinability
  • Ability to take a high surface polish
  • Time required for heat treatment
  • Expected tool life

Contact our technical specialists to learn more about which one is right for you.

Plastic Injected Parts

There are thousands of thermoforming and thermosetting plastics to choose from for your project. In addition, mechanical and chemical characteristics can also be enhanced with additives like glass fibers, UV stabilizers and lubricants. Our materials sheet will give you more detailed information about the standard types and the tolerances to expect with each.

Your choice of resins may depend upon one or more of the following considerations:

  • UV, chemical, abrasion and impact resistance
  • Cost of raw material
  • Mechanical strength
  • Weight and density
  • Flexibility
  • Transparency
  • Recyclability

Contact one of our technical specialists to learn more about material properties.

Plastic Injection Molding Machines At Our Star Rapid Facilities

Plastic Injection Molding Machines

Injection Molded Pens

Production Of Injection Molded Parts

Injection Molding Production Parts

Injection Molding Production Parts

Tooling for Injection Molding

Tool For Injection Molding

Golden Samples For Plastic Pellets

One Man One Mold Service

In a hurry for quick-turnaround plastic injection mold tools? Our OMOM® service was created to provide injection tooling in half the time of conventional tools. We do this by streamlining the entire tooling project, from conception to completion, using a single master machinist who takes ownership of the project from start to finish. 

Design For Manufacturing

It is important to design for manufacturing when developing a new product to avoid costs and delays down the line. Learn more about design for manufacturing.

Color Consistency

Challenges can arise when trying to achieve color consistency in your parts. Read our color consistency white paper to learn more.

Cause And Avoidance Of Sink Marks

Read our white paper on what causes sink marks in plastic injection molding, and how to avoid them on your next project.

Get Your Plastic Injection Project Started Today

Once you send us a 3D CAD file, our engineers will review draft angles, wall thickness, corner angles, material type and more to ensure it is optimized for manufacturing. We will also make sure correct materials are combined with the correct design considerations so your project meets and exceeds your expectations. Contact us today for your free quote.

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Plastic Injection Molding Service