It’s a widely used process, but what is injection molding? It’s a method for manufacturing high-volume parts made of glass, metal, and other materials. Plastic injection molding, in particular, is a popular, cost-effective way to mold various plastics into specific shapes.
Using a specialized hydraulic or electric machine, melted plastic is injected into a metal mold. The cavity holds the plastic, while the core is positioned in the cavity to create the desired shape.
After the mold has been created, it’s simply a matter of repeating the injection process, which is what makes plastic injection molding an efficient, affordable way to mass-produce parts. It’s essentially a six-step process:
. Clamp: The two parts of the mold are pressed together.
. Inject: The liquid plastic is injected into the mold, with special care taken to ensure the temperature of the liquid remains the same throughout the process.
. Dwell: Pressure is applied to make sure the liquid plastic fills every corner and crevice of the mold.
. Cool: The plastic is left to cool and solidify.
. Open: The clamp is released so the molded plastic can be removed.
. Eject: The finished product is slowly pushed out of the mold. Any waste material is removed and often recycled.
Many different types of plastics can be used in this process.
Materials That Can Be Injection Molded
Plastic injection molding is suitable for a wide range of materials, and your choice will depend upon your budget and the desired characteristics of the finished product.
ABS: Ideal for strength and stability, with a smooth finish
Acetal: Common for automotive parts; vulnerable to acids and UV light
Acrylic: Clear and resistant to UV light, water, and shattering
Copolymer Polypropylene: Good stress crack resistance and low-temperature toughness when compared to homopolymer
Homopolymer: Higher impact and creep resistance when compared to copolymer; can be used for lighter, thinner parts
HDPE/LDPE: The most commonly used plastics offering good chemical resistance
Nylon: Resists abrasion and dampens noise; not ideal for marine applications
PEEK: Food-safe with excellent mechanical strength and heat resistance
Polycarbonate: Lightweight with high impact strength; naturally transparent with good optical properties
Polyester: Excellent impact resistance, heat resistance, and stiffness
Polypropylene: Semi-rigid, heat resistant, and recyclable
Polystyrene: Lightweight and inexpensive, resistant to moisture and bacteria
Polyurethane: Available in commercial, medical, and industrial grades; superior temperature and chemical resistance
Thermoplastic: High strength and impact resistance
Typical Parts Made by Tech-Way Industries From Injection Molding
Many industries rely on plastic injection molded parts for various products and equipment. At Tech-Way, we manufacture components like the following:
Gas Pump Nozzles
Meat Slicer Parts
Choosing the Right Material
The most important aspect of choosing an injection molding material is considering the environment your finished product will be exposed to—and what properties it needs to perform its duty in that environment. Considerations include:
Strength and durability
Weather, moisture, and UV light resistance
Stiffness and hardness
Scratch and abrasion resistance
From there, you need to align your performance requirements with your budget. At Tech-Way Industries, we can help you weigh the pros and cons of each material choice within your price range and recommend the best options for your finished product.
How Tech-Way is Different
At Tech-Way, our engineers and technicians have experience and cross-training with almost all plastic molding methods. With this in-depth understanding, we’re able to determine whether plastic injection molding is the best choice for your product, recommend the right materials, and develop and produce the best plastic products available. This is what we have to offer:
ISO 9001:2015 Quality Management System
In-house tool building
Knowledgeable and experienced engineers and technicians
Design for manufacturability
Enhanced customization options
End-to-end servicing, including concept and development, prototyping, production, assembly, and packaging
A large, trusted network of material suppliers
Dedication to customer satisfaction
We’re proud to partner with companies in the medical and pharmaceutical, aerospace and automotive, defense, electronic, alternative energy, industrial, firearms, and other industries to create the high-quality plastic components they need. To learn more about plastic injection molding and what materials can be injection molded, contact us.
Plastic injection molding is a manufacturing process that melts a plastic resin into a liquid state and then uses a high-pressure system to inject it into a mold. There, it cools and solidifies into plastic parts with tight tolerances. This repeatable process allows companies to produce large quantities of identical parts at a low cost per part.
Here we’ll discuss the advantages of plastic injection molding in more detail.
Produces Intricate Details and Complex Geometries
The plastic injection molding process reduces the time and capital required to produce large volumes of uniform, complex parts. You can quickly achieve repeatable tolerances as low as ±0.500 mm or, with some projects, even ±0.125 mm. For even tighter tolerances, molded parts can be machined down to ±0.025 mm.
For easy ejection and higher precision, plastic injection molding companies should consider:
Rib and boss design
The consistency of the molded parts relies on collecting and analyzing data about the techniques used as well as the expertise of trained engineers. Their specialization in injection molding allows them to document and execute the steps necessary for a successful, repeatable molding operation.
With the right team of designers and engineers, plastic injection molding is the most efficient way to produce low-cost, high-volume plastic parts. An optimized design reduces problems during the production cycle, and each cycle is very fast, creating large quantities in a relatively short amount of time.
After the mold design is approved by the customer according to their specifications, the injection molding press is programmed with the proper settings. The molding process itself is very rapid, achieving a high-volume production rate that brings the cost of each part down.
A hot runner injection mold system is especially efficient, producing consistently high-quality parts with rapid cycle times. The process may not be compatible with some heat-sensitive polymers, but it remains a highly efficient method of producing parts from compatible materials.
As plastic injection molding machines and resin materials have advanced, the cost of this manufacturing process has significantly decreased. Plus, with advanced tooling techniques and automation, labor input has also reduced. These developments in the field have made it very cost-effective for companies to opt for plastic injection molding services.
Compared to other molding processes, injection molding has low labor costs and high output rates. Modern molding machinery is equipped with automated, self-gating tools to streamline mass-production with little supervision. These features all contribute to a lower final cost for manufacturers and their customers.
Trusted Plastic Injection Molding Services From Tech-Way Industries
Plastic injection molding can produce high-quality, high-efficiency, cost-effective, and detailed plastic parts for your application. At Tech-Way Industries, our expert team can help you prototype, design, manufacture, assemble, and package your plastic parts. As an ISO 9001:2015, UL, and ITAR certified plastic injection molding company, we offer comprehensive customization options, in-house custom mold and tool building, a large network of resin suppliers, and more.
Plastic injection molding is a versatile, fast, and affordable way to produce high-quality, custom components. Its compatibility with numerous medical-grade polymers and capabilities for producing high volumes of durable, precision parts make injection molding an ideal fit for the healthcare industry and medical manufacturing.
Advantages of Medical Injection Molding
The injection molding process can generate a wide variety of medical parts and devices uniformly and efficiently. The many advantages that this process offers the healthcare sector include:
Durability. Medical-grade plastics are resistant to abrasion, impact, breakage, moisture, chemicals, sterilization, and other environmental conditions. Injection-molded parts can withstand the rigors of medical applications for optimal part longevity.
Tight tolerances. Given the critical nature of medical applications, and the fact that injection-molded components are often part of bigger assemblies, parts with tight tolerances are a necessity in this sector. This precision helps parts fit together as expected.
Versatility. An extensive array of plastics are compatible with plastic injection molding, allowing you to meet virtually any customer requirement for grade, performance, temperature resistance, biocompatibility, appearance, and budget. Also, injection molding gives you the flexibility to generate parts in a variety of sizes and configurations.
Repeatability. Injection molding is also beneficial for its repeatability. The process can generate identical parts despite its high speeds and production volumes.
Mass production and time savings. Injection molding is well-suited to mass production. Once tooling is complete, the process is incredibly fast for greater efficiency and throughput. Also, given the tight tolerances it can achieve, injection molding saves on time you might otherwise have to spend on rework.
Cost-effectiveness. As injection molding can generate extremely high volumes of identical parts without a loss in quality or precision, the process minimizes upfront mold costs with economies of scale and a lower per-part cost. Reduced labor expenditures, material waste, and part reworking offer further savings.
Materials for Medical Injection Molding
A broad spectrum of material options is available for medical injection molding, so selecting the appropriate material will depend on your application and performance requirements. Common plastic varieties that are compatible with injection molding and available in medical-grade formulations include:
Eastman Tritan Copolyester. Strong, durable, and clear, this BPA-free copolymer resists heat, impact, and chemicals.
Polycarbonate (PC). This transparent thermoplastic is a durable, engineering-grade material that manages to be both strong and flexible with good dimensional stability. PC also has several resistance capabilities against such conditions as high heat, flame, UV light, impact, and vibration.
Polyetheretherketone (PEEK). PEEK plastics tolerate chemicals, high heat, radiation, and general fatigue and wear. The heat resistance in particular makes PEEK an ideal option for medical components that will undergo frequent sterilization, with other applications in orthopedic and implanted devices.
Polyetherimide (PEI). Another plastic with dimensional stability and high-temperature resistance, PEI can withstand those high operating temperatures permanently. It resists hydrolysis and high creep, as well.
Polyoxymethylene (POM). Stiff, stable, and strong, POM withstands sterilization by steam. It also tolerates many solvents and cleaning agents, making it an ideal choice for the medical sector.
Polyphenylene Oxide (PPO). This dimensionally stable plastic has advantageous thermal, electrical, and mechanical characteristics, offering minimal thermal expansion, resistance to flame, and superior insulating capabilities. It also absorbs little moisture.
Polyphenylene Sulfide (PPS). A semi-crystalline thermoplastic, this polymer can maintain its mechanical strength at temperatures of 392° F or more. PPS is also resistant to chemicals and creep.
Polypropylene (PP). Resistant to high heat even for an extended timeframe, PP also has good resistance to electricity, radiation, chemicals, and some solvents. This economical material is lightweight yet strong, and suitable for parts that undergo multiple rounds of autoclave sterilization.
Polysulfone (PSU). This material offers good mechanical as well as creep strength, maintaining its rigidity and related properties over a wide temperature spectrum.
Applications of Medical Device Injection Molding
The plastic injection molding process is ideal for creating identical, precision parts and products for such medical applications as:
Biocompatible, implantable devices and components such as flow shield medical assemblies
Surgical instruments and equipment
Pharmaceutical delivery equipment
Prosthetics and orthopedics
Equipment casings and enclosures
Medical Injection Molding From Tech-Way Industries
Since 1964, Tech-Way Industries has custom-manufactured turnkey plastic components for diverse industries. For the medical sector, we produce products such as medical devices, flow shield assemblies, and more utilizing 12 molding machines from 8 to 110 tons for horizontal molding, vertical molding, and insert molding. We’re the only privately held medical incubator facility in the state of Ohio, and we’re equipped with Class 7 and 8 Clean Room capabilities to best serve the industry and meet regulatory requirements.
Our ISO 9001:2015-certified operation offers a full suite of services from design and prototyping to assembly and packaging. Contact us to learn more about our innovative plastic injection molding services for the medical sector, or request a free consultation today.