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Injection Molded Plastics

IQS Directory provides a comprehensive list of injection molded plastic manufacturers and suppliers. Use our website to review and source top injection molded plastic manufacturers with roll over ads and detailed product descriptions. Find injection molded plastic companies that can design, engineer, and manufacture injection molded plastics to your companies specifications. Then contact the injection molded plastic companies through our quick and easy request for quote form. Website links, company profile, locations, phone, product videos and product information is provided for each company. Access customer reviews and keep up to date with product new articles. Whether you are looking for manufacturers of injection molds, wheel well molding, medical injection moldings, or customized injection molded plastics of every type, this is the resource for you.

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You won't find better quality injection molded plastics anywhere else in the industry. We have built ourselves up from a small manufacturing company to a large company with decades of experience. We can provide effective, efficient, and affordable solutions that will help you meet your goals and get the job done right. Contact us to learn more today!
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We manufacture a variety of injection molded plastics for industries around the world. We use the latest technology, most innovative systems, and digital manufacturing to ensure that we create products that you can rely on. We make it our goal to build the best plastic products that you can depend on even in today's challenging world. Find out more by contacting us today!
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Our passion is to create quality injection molded plastics to meet the needs of customers big or small. We have 100 years of experience, and we have kept up with all industry changes and technology while still offering customers the benefit of our vast industry knowledge. You can learn more about us when you visit our website or call today!
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With presses from 260 ton to 1000 ton, Penguin has the ability & resources for every step of your injection molded plastic requirements - from a competitive part quote to part & product development support, from start to finish. Penguin has an established infrastructure like no other and can simply mold parts for you or completely assemble & ship your finished products anywhere in the world.
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Xcentric Mold & Engineering makes buying custom plastic injection molded parts more convenient than ever. ISO 9001:2008 certified, we are leaders in rapid prototype & rapid injection molding with low cost production. No matter what kind of part you need, no matter how complicated, we`ll put it in your hands faster. Our molding expertise means no geometry limits for quality parts done right.
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We may have started small, but today, we offer our products and services to companies around the world. We are dedicated to our customers, and our goal is to offer better service and pricing to any customer no matter the size. We use the latest technology in injection molded plastics to meet your needs. It is our goal to find the right solutions at the right price. Contact us for details!
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We believe in evolving to meet the needs of current customers. That is why, even though we have been around since 1953, we offer the latest in technology and manufacturing techniques. We are the best in injection molded plastics, and we provide the tools that our customers need to succeed. Contact us with your questions today!
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Industry Information
View A Video on Injection Molded Plastics - A Quick Introduction

Injection Molded Plastic is resin that has been heated until molten and then forced into a pre-made mold or cavity in the shape of the intended plastic product or object. When the melted plastic has cooled and hardened, the mold is removed to reveal a hard, plastic part in the shape of the mold cavity. Products made from plastic injection molding, or custom injection molding, include a wide range of everyday household items such as mop buckets, plastic containers, screw driver handles and even video game cartridges.

Injection molding can use a wide variety of starting materials, including most polymers. Plastic injection molding gives the injection moulders the freedom to choose exactly what the best material for the final molded plastic part would be and requires a lot of calculation as to composition of the resin as well as temperature and pressure in the mold. All these variables can affect the final quality of the plastic. Injection molding uses thermoplastics, called thermoplastics injection molding, thermoset materials or elastomers, depending upon the intended use of the final product. Thermoplastics and thermosets harden completely after cooling in the plastic injection mould; elastomers however, retain a sense of elasticity and so are used to produce items such as rubber bouncing balls. Other variations of plastic molding, or insert molding, include gas assist injection molding which uses an inert gas, such as nitrogen, to create a hollow portion in the mold, and to force the molten plastic into the mold cavities. Another is reaction injection molding; reaction injection molding machines require one further step which is the addition of a curing agent in the mold. This is required for the specific product material to maintain shape and strength once removed from the mold.


The basic machinery used in the process of injection molding consists of a hopper - where the plastic pellets are placed prior to being heated. The plastic material is then fed into a heating unit where it is heated and mixed until molten, at which point dyes or other chemical agents can be added to change the final appearance and feel of the product. Next, an injector, or screw, forces the molten plastic into the mold cavity under hydraulic or mechanical pressure, to ensure that there are no air pockets. Most molds will allow air bubbles to escape to avoid damaging the final product. Cooling liquids are sometimes used around the mold chamber of the machine to extract heat from the plastic and speed up the cooling process, thus saving time in overall manufacturing.  The two halves of the plastic injection mold are then pulled apart to release the plastic part. Ejecting pins or rods may have to be used to remove the plastic part from the mold. The entire process can take a matter of seconds or as many as a few minutes to get one complete plastic part. Injection molders are not limited by manufacturing capabilities when it comes to material choice, and are able to fabricate a wide range of product shapes and sizes. If a mold can be made for an object, plastic molding can be used to produce a product. Everything from car bumpers to intricate medical equipment can be made using the techniques of melting the appropriate material, forcing it into a pre-made cavity and allowing it to cool.

Compared to other forms of plastic parts production, injection molding is a cost effective manufacturing method. It can be used for high production runs, and in fact the more parts that are made from a mold, the more cost-effective it is. Once a mold has been made for a certain product, it can be used again and again to produce the same object with close tolerances. In injection molding, there is little or no change in the manufacturing process between cycles, and so often the plastic part extricated from the mold will need little finishing. Furthermore, because the molten plastic is forced only into the space of the cavity, there is very little material waste apart from joining lines and negligible other amounts. The production of minimal scrap saves further money and is a responsible manufacturing practice. Furthermore, what plastic is wasted and considered scrap can often be melted and recycled. Labor costs for the injection molding process are minimal as there is little need for human interference in the injection process.
There are important considerations to be made when discussing plastic injection molding however. Firstly, all the plastic material that is forced into the mold needs to be removed at some point, therefore mold design needs to be carefully considered. A complex rigid, square design might result in cracks or stress marks on the final product when trying to extricate it from the cavity. There also needs to be rods or pins in place to help remove the plastic part from the mold. Plastic injection molds are costly and so it is imperative to ensure that the plastic part can be removed from it once cooled. Another consideration concerning removal is the existence of joining lines, or imperfections in the final products that may require finishing services before being used. The finishing required will usually be minimal, but it is dependant on the quality of the starting material and mold. Finally, while injection molding plastic is a cost effective method of producing plastic goods, custom injection molding will be more costly due to the necessary production of a specific plastic injection mold for the custom product. If however, the quantity of product manufacturing is high, the cost of the plastic injection mold will balance out over time. With so much variance in injection molded plastics, it is helpful to consider the industries which make use of it such as automotive, medical, consumer and household goods.


Injection Molded Plastic Types

  • Custom injection molding is an injection molding process in which the mold is not pre-made, but is formed specifically for the consumer's application.
  • Double-shot molding is a two-step process in which either the color or the material is injected first. Upon the hardening of the material, a second color or material is injected into or around the first shape.
  • Gas-assist injection molding is a process in which inert gas, such as nitrogen, is forced into the melt while it is entering the mold, packing the plastic into the cavities. Gas-assisted injection molding reduces cycle time, part weight, warpage and stress to the cooled parts, as well as minimizing other problems.
  • Injection blow molding is the process in which plastic is injected into a mold to form a plastic tube. The tube is then blown into a cavity mold to form a hollow part.
  • Injection molding is a process by which plastics parts and products are formed.
  • Injection moulders are the tools and die machines used to mold molten plastic.
  • Insert molding is an injection molding process in which plastic gets injected into a cavity surrounding an insert piece just prior to molding. Plastic insert molding results in a single piece encapsulated by the plastic.
  • Molded plastic pieces are parts that are formed by pouring heated plastic into molds.
  • Plastic injection molding is a process by which plastic is heated into a malleable form and pressed into molds.
  • Plastic injection mold processes are used to fabricate parts with a range of complexities, from simple shapes to precision parts of geometric complexity
  • Plastic manufacturers fabricate plastic products by injecting molten plastic into molds or dies.
  • Plastic molding is one of the most common methods of part manufacturing.
  • Push-pull molding is a process that involves multiple layers with different orientations, providing more uniform properties to the parts than if they were molded from a single direction
  • Rapid injection molding is primarily used in prototyping and the low-volume production of plastic parts since the production time is drastically shorter than conventional molding process. 
  • Reaction injection molding is an economical option commonly used for larger, more complex polyurethane plastic and rigid foam parts produced in small quantity.
  • Thermoplastics injection molding is the most common method used to process thermoplastics, due to its ability to fabricate parts with a range of design variances, from simple shapes to high precision parts of geometric complexity.

Injection Molded Plastic Terms

Backing Plate - A plate that provides support for the mold cavity block, guide pins, bushings and so forth.
 
Cavity - The space inside a mold into which the material is injected.
 
Charge - The amount of material needed to fill a mold during a single cycle.
 
Cooling Channels - Channel through which a cooling medium flows to control the temperature of the surface of the mold. Cooling channels are located within the body of the mold.
 
High Density Polyethylene (HDPE) - Plastic used to package products with short shelf lives, such as bottles for milk, juice, water and laundry products. Unpigmented HDPE bottles are translucent and have good stiffness.
 
Hydraulic Units - Devices that use the force of fluids to move the mold in the injection molding process.
 
Linear Low Density Polyethylene (LLDPE) - A plastic that is used predominantly in film applications due to its toughness and flexibility. LLDPE is the preferred resin for injection molding because of its superior toughness and is used in items such as grocery bags, garbage bags and landfill liners.
 
Mold - A series of steel plates, which contain cavities into which plastic resin is injected to form a part.
 
Monomer - A relatively simple compound that can react to form a polymer.
 
Melt Index - A test that measures the ability of molten plastic to flow.
 
Melting Point (Tm) - The temperature at which crystalline portions of polymers melt. A material becomes soft and completely amorphous once it reaches the Tm.
 
Melt Viscosity - A term that refers to the measure of resistance to flow. For all materials, the viscosity decreases as the temperature increases.
 
Polymer - A term that means many units. These units are linked together to form chain-like structures that give polymers unique properties.
 
Polypropylene (PP) - A very strong substance that has the lowest density of the plastics used in packaging. PP has a high melting point, making it ideal for hot-fill liquids.
 
Polystyrene (PS) - A very versatile plastic that can be rigid or foamed and has a relatively low melting point. General purpose polystyrene is clear, hard and brittle.
 
Resin - Any of a class of solid or semi-solid organic products of natural or synthetic origin, generally of high molecular weight with no definite melting point. Most resins are polymers.
 
Thermoplastics - Materials that can be melted by heating and then re-solidified by cooling. Blends of thermoplastics can be prepared by melt-mixing.
 
Thermosets - Materials that "cure" to form solids when heated. Unlike thermoplastics, solid thermosets do not melt when heated, so they are very useful for high heat applications.
 
Toggle Unit - Device that uses mechanical links to move the mold during the formation of injection molded plastics.




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