There are instances in manufacturing where metals cannot meet the weight and deflection demands specified by the application. When this is the case, thermoplastics often provide a solution. Thermoplastics are among a group of materials that melt when heated. They are common in manufacturing because heating makes them viscous, allowing for the formation of specific shapes which the material retains after cooling.

Injection molding is the most common method for thermoplastic processing. There are a broad range of resin materials used in injection molding, including thousands of materials categorized as thermoplastics. At Abtec, Inc., we specialize in injection molding and in the identification of materials

Consequently, making the right choice to fit a specific application can be a daunting task. Abtec helps our clients choose the right thermoplastic materials for their design and application based on our thorough industry knowledge and significant experience with the injection molding process. This page will provide readers with a better understanding of the various thermoplastic types and the process of injection molding as a beginning point.


Polyolefin High Density Polyethylene (HDPE)

What to Know About Thermoplastics

There are thousands of resin compounds included under the definition of thermoplastics, making it difficult to distinguish which ones might best serve various applications. However, classifying these resins into nine categories helps simplify things considerably. The nine categories include:

  • Acrylonitrile butadiene styrenes (ABS). ABS is the most recognizable material by most consumers. Even at low temperatures ABS plastics are rigid and tough. They offer dimensional stability, abrasion resistance, chemical resistance, heat resistance, and provide balanced tensile strength.


  • Acetal Copolymer Polyoxymethylenes. This thermoplastic is easier and faster to process than traditional homopolymer resins due to its lower melting point. These thermoplastics are creep-resistant, remain stable when used in high temperature applications over a long period of time, and have good moisture resistance. Additional qualities include excellent lubricity, high tensile strength, and fatigue resistance.


  • Acetal Homopolymer Polyoxymethylenes. Distinguishing features of these thermoplastics include toughness under repeated, moderate impact along with high tensile strength, stiffness, resilience and the highest fatigue endurance of all unfilled thermoplastics. They also feature low moisture absorption properties, along with high abrasion resistance and creep-resistance.


  • Acrylics. This type of thermoplastic is a common substitute for glass in a variety of applications. These thermoplastics transmit and control light and possess outstanding weatherability and scratch resistance. They are also stable against discoloration and possess low haze and scratch resistance, making them ideal for optical applications.


  • Polycarbonates. These plastics present exceptional toughness over a wide range of temperatures. This category of thermoplastics includes a broad range of grades ranging from general-purpose and extrusion molding to special grades with flame retardant properties or contamination resistance for food processing and medical applications. Dimensional stability, heat resistance, toughness and transparency are distinguishing features of polycarbonates.


  • Polyethylenes. Low water absorption, dimensional stability, hardness and stiffness are some of the main characteristics of this type of plastic. They are available in both amorphous (transparent) and semi-crystalline (opaque) forms. Gas barrier and chemical resistance properties (except for alkalis) make these plastics valuable for a broad range of manufacturing applications.


  • Polypropylenes. These plastics feature a lower density with good thermal, chemical, and electrical use properties. Due to their limited heat resistance, they require heat-stabilization to perform well at high temperatures. They have less toughness than high-density polyethylene and are less brittle than low-density polyethylene, but they have a high resistance to fatigue, making them an ideal solution for plastic hinges.


  • Polystyrenes. These low-cost amorphous thermoplastics have a lower heat resistance than the other types and require a continuous service temperature that is below 200º F to maintain their integrity. However, their characteristics include excellent colorability, processing ease, hardness, and clarity as well as good electrical properties at room temperature and under normal levels of humidity.


  • Nylons. A broad range of grades are common within this classification of thermoplastics and each has its own valued properties. In general, Nylon features good fuel, oil, and chemical resistance properties along with excellent fatigue resistance, good toughness, and a low friction coefficient.


Please note: The above is not a complete list of all the materials which Abtec can utilize for your project. Click here for a complete list of our plastic injection molding materials and thermoplastics!


An understanding of the general properties of each of these types of plastics can help narrow down the selection process for specific applications. Users must keep in mind that various grades highlight different properties within each classification.


Acetal Copolymer Polyoxymethylene (POM), also known as Celcon or Amcel

The Advantages and Disadvantages of Thermoplastics

The various types of thermoplastics used for injection molding include a broad range of advantages and disadvantages for specific applications. However, there are some general advantages and disadvantages common to thermoplastics. The advantages include:

  • Energy efficient processing
  • Broad range of beneficial properties
  • High volume manufacturing with excellent precision at lower cost
  • Various types can replace metals with a considerable weight-saving advantages
  • Higher fatigue resistance than most metals
  • Greater deflection toleration than most metals without deforming

These advantages make thermoplastics ideal for an expansive range of designs and applications. However, the following are disadvantages among thermoplastics, which may impact material selection:

  • Thermoplastics degrade more easily in direct sunlight or under UV exposure
  • Not all thermoplastics resist hydrocarbons, organic solvents, and polar solvents
  • Some types experience creep under long-term loading
  • Can fracture rather than deform under high stress

It should be noted that these disadvantages are not common for all thermoplastics, which makes proper selection of the right material a critical consideration for applications which may experience any of the above conditions.

Applications of the Common Types of Thermoplastics

Thermoplastics are extremely important in manufacturing, covering a wide range of applications throughout almost every possible industry. Consequently, it is easier to list some of the various applications of each type of thermoplastic rather than attempt to identify their use by specific industry. Some of the common uses of each type include:

  • ABS: LEGO bricks, safety hats, whitewater canoes, musical instruments
  • Acrylic: Lucite, Perspex, Plexiglass
  • Polyester: Yarn, rope, conveyor belts, clothing, furniture, blankets, mouse pads
  • Polypropylene: Lab equipment, carpets, textiles, packing, labeling
  • Polystyrene: Foam cups, smoke alarm housings, models, disposable cutlery, CD/DVD cases
  • Cellulose Acetate: Cigarette filters, playing cards, eyeglass frames, adhesives, photography
  • Nylon: Carpet, rope, strings for musical instruments, fishing line, fabric

What is the Difference Between Thermoplastics and Thermoset Plastics?

There are some close similarities between thermoplastics and thermoset plastics which make it necessary to distinguish between them. The main difference between the two relates to how they react to heat. You can melt and reform thermoplastic numerous times, but thermoset plastics cure after heating and can be formed only once.


Polyolefin Polyethylene (PE)

Abtec Provides Custom Injection Molded Thermoplastics

Custom injection molding of thermoplastics is a primary specialty of Abtec. Though the process is simple, significant expertise is required to achieve tight tolerances and high repeatability. Our expertise in injection molding comes from a thorough understanding of engineering concepts surrounding thermoplastics and how each type should or should not be used.

In addition to the injection molding process, we also provide custom mold design and mold making to meet the precise component specifications, timelines, and budget costs of each client. Our value-added services allow one-stop, in-house solutions that include:

  • Sonic welding and heat staking
  • Final assembly and kitting
  • Packaging with blister packs, header cards, or boxing
  • Protection from contaminants in our Class 10 ISO 4 clean work cell

The expertise and special care taken by Abtec on every project provides our clients with the assurance of quality and top-rated service for all their injection molding and thermoplastic needs.

The injection molding process of thermoplastics is critical in a broad range of industrial applications. A thorough knowledge of the injection molding process and of thermoplastic materials allows us to produce durable components with a variety of properties and characteristics. Ultimately, injection molding supports high-volume, precision production at a lower cost.

Abtec, Inc. has the expertise necessary to provide advanced thermoplastic injection molding along with a variety of value-added solutions to meet the needs of our clients.

Contact us to learn more about the solutions we can provide for your organization.


Abtec, Inc. offers injection molding services for custom molds based on your design. We have a broad catalog of materials and thermoplastics, plus years of expertise to help get the job done right!

Read our infographic below for some of the major advantages of custom injection molding, then contact us for more info or to request a quote!


infographic for advantages of custom injection molding plastic   


Abtec’s custom injection molding services work with a wide variety of materials that range from commodity resins to high-tech, engineering-grade polymers. We work with the latest equipment and technology to design high-quality molds that create intricate and durable end products.

One of the materials we’re most excited to use is liquid crystal polymers (LCPs). These aromatic polyester polymers offer a wealth of benefits to plastic molders because they create highly durable, corrosion-resistant, and heat-resistant components. Using LCPs, manufacturers can build essential parts for products ranging from cars to medical devices to electronic appliances.

What Are Liquid Crystal Polymers?

Liquid crystal polymers (LCPs) are materials whose molecules form crystalline alignments that hold their shape as the material solidifies. This high degree of crystallinity typically forms during the melting phase, hence these polymers’ name. Production of some LCPs began in the 1970s, but LCP resins didn’t become popular in commercial applications until 1984. Over time, research into the use of LCPs has enabled these materials to be used in injection molding.

Some of the unique properties that LCPs offer include:

  • Molding to tight tolerances
  • Low flammability
  • Good weatherability
  • Low thermal expansion
  • Low water absorption
  • Low electric conductivity

These properties make LCPs useful for a wide range of applications. LCPs can be easily injected into molds of all shapes and sizes when in their liquid state, but once they harden, they retain their form in the face of a slew of adverse conditions. This means that LCPs work just as well when building circuit boards as they do in microwave-safe containers, industrial bearings, and surgical equipment.

For these reasons, LCPs are an essential material for products in a wide range of industries, such as:

  • Aerospace
  • Automotive
  • Consumer electronics
  • Electric housings and components
  • Military
  • Medical devices
liquid crystal polymers
Liquid crystal polymers (LCPs) – Abtec, Inc.

Are LCPs Good for Injection Molding?

LCPs offer a wealth of advantages to injection molders. They’re especially useful for creating strong packaging and external casings because they offer high-frequency properties that outperform the likes of ceramics, thermosets, and metal. LCPs are also more cost efficient than these materials.

The low-dissipation factors of LCPs and the commercial availability of laminates make them especially suitable for use in microwave-frequency electronics. Several grades of LCPs comply with medical standards, including ISO 10993-1 and USP Class VI. What’s more, standard grades of LCPs come with glass-fiber or mineral reinforcements, while specialty grades can be designed for applications that require:

  • Platability
  • HF shielding
  • Low-specific gravity
  • Thermal conductivity

LCPs are unique in that they can gain a highly ordered structure in the liquid phase. This means that they can be injected as a liquid without sacrificing manufacturers’ confidence that they’ll solidify into a rigid, durable plastic.

Contact Abtec for the Manufacturing of Your LCP Parts

Abtec Inc. has more than 100 years of experience in the design, development, and manufacturing of custom injection molds. We can work with a variety of CAD formats as well as client-submitted drawings, sketches, models, and molds.

We strive to provide the highest-quality products and services at the best possible prices. We are an ITAR-registered, DOD-compliant, and ISO 9001:2015–certified injection molding firm that provides quality products to clients around the world. If you would like to learn more about our services and offerings, contact us today and request a free quote.


The Properties of Polyetherimide (PEI)


What are some of the properties of polyetherimide (PEI)? Watch this informative video on why polyetherimide is a preferred thermoplastic for molding and design. It’s versatility is excellent across a range of industries!

Contact us to request a quote, or for more info on how we can help with your next project!

One of the biggest problems associated with creating or building materials is that sometimes, standard parts don’t fit your specific application. Sometimes, the tools you need to create these parts don’t even exist.

Increasingly, manufacturers are turning to custom injection molding to create specialty parts and products that they can’t find using standard procurement methods. Custom injection molding creates high-quality parts and tools to client specifications in record time, allowing you to quickly order large volumes of materials with the confidence that they’ll be delivered on time, and without deficiencies.

Using custom injection molding results in:

  • Quicker turnarounds
  • High degrees of accuracy
  • Opportunities to work with a wide range of materials
  • Efficient automated processes
  • Cost-effective production cycles

What Can You Make With Injection Molding?

A wide range of industries rely on custom injection molding to quickly produce large volumes of materials to precise specifications. This process benefits industries as varied as:

  • Military & defense: Items and equipment for defense and the military must be as reliable as they are uniform. The accuracy of injection molding for these items and parts ensures high quality in everything from canteens to headsets, vehicle components to backpack fasteners, and flashlights, too!
  • Food and beverage processing: Because custom injection molding works with lightweight, nonpermeable polymers, it’s perfect for creating water bottles, bottle caps, lids, and all manner of food containers.
  • Medical and pharmaceutical manufacturing: Custom injection molding creates sterile housings for medical and pharmaceutical products as varied as pill containers, surgical equipment, X-ray components, test kits, and anything else that requires the use of FDA-approved medical-grade resins.
  • Toymaking: Custom injection molding helps create a full range of unique and innovative toys; highly accurate molds combined with plastic’s nonconductive properties make it easy to incorporate electronics into toy designs as needed.
  • Consumer and commercial packaging: Packagers rely on this process to quickly create containers, cases, and housings to precise specifications.
  • Furniture and other domestic product production: Custom injection molding can build lightweight, affordable consumer goods such as plastic lawn furniture, fencing/fence accessories, window clasps and seals, and kitchen appliances.
  • Automotive accessory production: Automakers use custom injection molding to create many of the internal components of their vehicles, including cup holders, steering wheels, dashboards, door handles, and switches.

Custom injection molding also benefits manufacturers and assembly processes by creating unique tooling that can’t be found elsewhere. Industrial companies have ordered custom injection-molded parts for their facilities that include:

  • Conveyor belt parts
  • Electrical switches
  • Filters
  • Food processing equipment
  • Specialty tools and seals

The Difference Between Injection Molding and Thermoforming

Many businesses choose between injection molding and thermoforming, another popular plastic-working process, when designing parts. While both these processes efficiently create many different plastic products, several distinctions exist between them.

Thermoforming creates materials by heating plastic sheets until they’re soft enough to easily manipulate. Manufacturers then work the warmed plastic sheet into a single-sided mold and allow it to cool. During the thermoforming process, manufacturers also use methods like pressure forming, vacuum forming, and mechanical forming as needed.

Thermoforming typically works best when creating prototypes or mass producing large parts. Generally, products need to exceed 4’ × 4’ in size for thermoforming to be an efficient assembly method.

Custom injection molding more accurately creates smaller and more intricate parts no matter the production volume. This process is also great for designing parts that later assembly process must fit together.

While custom injection molding usually comes with higher initial costs than thermoforming, most of these costs are only associated with creating the mold. After this step, custom injection molding becomes much more cost efficient than thermoforming, which has to repeat several processes for each individual part.

Who Benefits From Abtec’s Custom Injection Molding?

Abtec works closely with clients to develop unique molds tailored to precise specifications. Our products have appeared across the country in applications as varied as industrial process equipment, indoor and lawn furniture, and life-saving medical devices.

If you would like to learn more about how our custom injection molding services will benefit your bottom line, contact us and request a free quote today.