Die Mold

Injection Molding Service

Custom molded prototypes and low to high-volume production parts made to your specifications

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IATF 16949:2016 | ISO 9001:2015 | ISO 14001:2015 | CT-PAT | Autogestion (Mexico)

When you need plastic injection molding services, our team at International Assembly, LLC is here to help. Injection molding provides a cost-efficient way to quickly and easily produce plastic parts of simple or complex geometries. We can fabricate anything from small, limited lots to large production runs using equipment ranging from 20 to 400 ton presses. Our capabilities include single and two shot molding as well as in-house mold and fixture repair.


Plastic Injection Molding: An Overview

plastic injection molding processPlastic injection molding produces large volumes of parts for virtually every commercial and industrial application. After the plastic is melted, it gets injected into a closed mold or die where it is cooled rapidly to take the cavity’s shape. Depending on the size, shape, and complexity of the part, the process can take seconds to several minutes.


The Process

The process starts when the worker fills the hopper of a molding machine with plastic resin pellets. The pellets are then heated and mixed until they form a liquid resin. The heated liquid resin is injected into the mold cavity under high pressure, causing it to fill the mold cavity. Once the mold is cooled and the resin has solidified, the machine opens the mold and ejects the part.


Injection Molding Advantages

Injection molding has several advantages, including but not limited to:

  • Highly cost-effective
  • Produces consistent quality
  • Allows for low to high volume production
  • Accommodates a large variety of materials
  • Creates custom finishes


Injection Molding Process Types

Different types of molding processes offer distinct benefits and accommodate various applications.


  • Conventional Injection Molding

Conventional injection molding is ideal for producing large volumes of parts. It is common in mass-production facilities that make the same part millions of times in quick succession, such as bottle caps.


  • In-Mold Assembly (IMA)

This type of injection molding allows a metal insert to be implanted into the part in the same operation, increasing strength and enhancing product structure. The method reduces labor, speeds up the manufacturing process, and eliminates the need for separate molds, presses, and other tools like bowl feeders, conveyors, fixtures, and ultrasonic welders. Examples of products created by IMA include rear truck window assemblies and electrical box covers with molded-in screws.


  • Solid

This method is used to manufacture solid parts without hollow cavities. Solid components may include cross-hatched ribs to increase strength and avoid sink. This method is used frequently to produce automotive plugs.


  • Two-Shot Injection Molding

A two shot molding process, also known as double injection molding, creates complex parts using two different polymers at the same time and in the same machine cycle. During the process, the first polymer is injected into the die, then the machine rotates the mold to allow for the second polymer injection. This method is used to create parts such as automotive firewall shrouds, HVAC doors, and steering column shrouds. Benefits of two-shot injection molding include lower unit costs, improved product quality, reduced handling, and enhanced features.

Quality Plastic Injection Molding Solutions

At International Assembly, LLC, we provide single and two shot molding services, as well as in-house mold and fixture repair. We believe in incorporating lean manufacturing tools and a continuous improvement philosophy in everything we do to ensure that our customers always receive the highest quality products and services. Our presses range from 20 to 400 tons to accommodate virtually any project.



We offer a wide variety of materials for injection molding, including:

  • Acetal
  • ABS
  • Acrylic
  • Copolymer polypropylene
  • Glass-filled materials
  • Nylon
  • PET
  • PEEK
  • PC/Polycarbonate
  • Polypropylene
  • Polyester
  • Polystyrene
  • Thermoplastic
  • Automotive engineering grade plastics, including PVC, polyamide, polyurethane, polyethylene, and POM

Industries Served

We primarily serve the automotive industry, providing plastic injection molded parts such as automotive handles, buttons, and trim components. However, we also serve retail consumer, residential, and other markets.


Additional Services

Our additional service offerings include:



We are proud to maintain the following certifications to ensure optimal quality and compliance to industry standards:

plastic injection molding machine

Get Your Plastic Injection Project Started Today

Plastic injection molding is a cost-effective and efficient way to produce plastic parts. At International Assembly, LLC, we offer a range of plastic injection molding capabilities and services to suit the needs of your project. For more information, or get started on your plastic injection molding solution, contact us or request a quote today.

Plastic Injection Molding - Capabilities


Smaller variety parts (refer to tonnage info below)

Mold Process Types

Conventional Injection Molding
In-Mold Assembly (IMA)


Copolymer Polypropylene
A variety of Glass-filled materials
PC / Polycarbonate
(all Automotive engineering grade plastics)

Clamping Force

55 tons

220 tons

Shot Size

The maximum weight of plastic that can be displaced or injected by a single injection stroke. Generally expressed as ounces of polystyrene.

3 oz

14 oz

Shrinkage Allowance

The dimensional allowance which must be made in molds to compensate for shrinkage of the material on cooling or during the debinding operation.

This is variable, contingent upon the Raw Material being used

Number of Cavities

The number of cavities in the mold used to produce multiple products in one molding cycle.

Contingent upon mold design

Tolerance (+/-)

Our processes produce parts within the acceptable tolerances as specified on Part Drawings by Customers

Additional Services

Product / Process Development
In-House Tool Shop (Repairs / Maintenance / EC’s)
“Decorating” (Painting, Laser Etching, Pad Print)

Production Volume

Prototype / Samples
Low Volume
High Volume
Blanket Orders
Spot Buys
Automotive Service parts

Lead Times

Quoted on job by job basis
Per Customer Releases
Build to order
Emergency services available
Rush Services Available


Lean Manufacturing
Continuous Improvement
Root Cause Problem-Solving
Metric Trend analysis and response


IATF 16949:2016
ISO 9001:2015
ISO 14001:2015
Autogestion Certification (Mexico)

Additional Information

Industry Focus

Retail Consumer/Residential

File Formats

Graphics Interchange Format
Joint Photographic Experts Group
Portable Document Format
Standard for the Exchange of Product Model Data
Tagged Image File Format