Custom Injection Molding

The Experts for All of Your Custom Plastic Injection Molding Needs

For more than five decades, EnviroTech Custom Plastic Injection Molders has been delivering the best custom plastic injection molding in the industry for our customers. We take a highly personalized and interactive approach to plastic molding manufacturing, working closely with you to develop the solutions you need.

We have the ability to take your project from concept to production in-house. This means that every step of the process, from design and engineering to tooling, protype, and full production, is done under the watchful eye of our experienced team. We have the capacity to produce custom molded products of all types, including pump parts, filtration system components, industrial valves, pipe fittings, and more.

 Custom Injected Molded Products

We are specialists in conceiving and executing custom plastic molding manufacturing solutions for our customers.

Injection-molded product fabrication is a complex and potentially costly process, especially when no off-the-shelf solution will work for your needs. We have worked hard to streamline our processes to ensure that even custom solutions can be delivered quickly and cost-effectively.

When you trust EnviroTech for your custom plastic molding manufacturing needs, you will see what we are the industry-leading expert. Our unique approach ensures that you get what you need when you need it. Our customization abilities far exceed those of our competitors, allowing us to go as far as engineering resins and formulating thermoplastic materials just for you.

With the ability to injection mold shot sizes up to 580 lb. and wall thicknesses in excess of 5 inches, EnviroTech Custom Injection Molders is anything but typical. With more than 50 years of experience we have become the world leader in large, thick wall plastic parts. Time and time again our customers have turned to us for their Custom Injection Molding needs because other suppliers claimed their products were impossible to manufacture. From polycarbonate fighter jet canopies with perfect optics to void-free 200 lb. pipe fittings, the possibilities are almost endless.

Advantages of Custom Injection Molding

When you need a specific part for your manufacturing business that is uncommon or not readily available, you may turn to plastic molding manufacturing. Whether you have your engineers design the piece or you use our staff, you can rely on our custom plastic molding company to produce the part you need.

You may think that a short run of a custom injection molding piece would be prohibitively expensive, but our injection molding company specializes in producing custom orders for clients for a reasonable price. Using plastic injection molding provides a variety of benefits besides cost savings, and these include flexibility, consistency, speed, strength and efficiency.

Working with EnviroTech provides additional benefits over working with other custom plastic injection molding manufacturers. Our decades of experience instill confidence in our customers that our processes work — and not just our custom plastic molding processes, but also other functions of a dependable supplier, such as timeliness, pricing and customer service.

Additionally, we provide services you can’t get at every injection molding supplier. These include:

  • Near net shape molding 
  • Slab stock molding 
  • Filter plate molding 
  • Industrial molding 
  • Large part injection molding 
  • Thick-walled injection molding 
  • Heavy injection molding 
  • Filter plate manufacturing 


Bauer Cyclone Head, a copy

Injection molding is a common method of plastic molding manufacturing. Parts manufactured using injection molding vary in size, shape and complexity. Injection molded plastic parts are used in a variety of situations from engine parts to medical equipment. The functionality and use of an injection molded part determines the type of raw plastic material or resin that should be used in the injection process. Plastic is melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part. The steps in the molding process can be complex based on the plastic resin used and part complexity. The process cycle for injection molding varies based on the part size and thickness, times may vary from a few seconds to 30 minutes. Since EnviroTech’s proprietary bulk injection molding processes allows us to mold larger parts, the cycle-time tends to be longer. The main injection molding process steps include clamping the mold shut, injecting the resin into the mold, cooling the molten resin, and ejecting the part.




The two halves of the mold are securely clamped by means of a hydraulic press or motor. Both halves of the mold must be carefully designed so that the part will be able to leave the mold without being damaged or getting stuck.


Resin material, generally in the form of plastic pellets, is fed into the machine. The resin is then heated and melted as it travels down the barrel of the machine. When fully molten, the plastic is injected quickly into the mold, typically by a reciprocating screw or plunger.


After filling the mold, the plastic is allowed to cool fully. The time required to cool may vary depending on the part size and wall thickness.


The mold is opened and air quickly fills the vacuum of the cavity half of the mold, sometimes causing part shrinkage. Ejector pins are then used to remove the part from the core half of the mold. Molds must be designed carefully, incorporating a proper draft angle and making sure all part surfaces are reachable in a straight line perpendicular to the parting line. This will allow parts to be removed from the mold without any damage.

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  • Shot size from 2 oz. to 580 lb.
  • Void free wall sections in excess of 5 inches
  • Economical production runs – 50 to 50,000 pieces per year
  • Complex configurations
  • Lightweight parts – 80% lighter than most metals
  • Corrosion resistance – Plastics can operate in severe chemical environments
  • Abrasion resistance – Plastics offer superior abrasion resistance

Frequently Asked Questions (FAQ’s)

Can I choose the type of plastics used in my injection molding products?

Yes, we use almost a dozen different types of polymers to create our injection molding products. Each engineering resin has its own strengths and other benefits, so choosing the best one — or ones — is important. Our engineers make recommendations to you about which plastic to use for your plastic molding manufacturing so that your product has optimal strength and durability. 

What is the difference between plastic injection molding and die casting?

Plastic injection molding uses plastic resins, while die casting produces steel products. Sometimes the project you’re working on determines whether you must use plastic or steel parts, but other times either can work. One of the obvious benefits of plastic is that it is lighter weight than steel. It’s also cheaper and it can be produced faster. You get all these benefits along with the assurance that your plastic injection molding products will be accurate and conform explicitly to the design. Plastic injection molding processes also allow for the addition of other, non-plastic products that increase its strength. 

Do you do thick-walled injection molding?

Yes, EnviroTech is a leading thick-walled injection molder, successfully producing large runs quickly. We are also known for our large part injection molding and heavy injection molding capabilities. While a benefit of plastic injection molding is the light weight of the product, sometimes a design calls for that product to be heavier, and we can easily meet this need.