Injection molding plastic materials range from common polymers to polymer blends and specialty plastics. There are hundreds of plastic resins, each with different processing requirements and end-use properties. They also come in various grades with fillers such as carbon or glass fibers.
As you seek reliable injection molding services from providers like Mina Products, ensure you pick the right materials for your venture. Whether you are into creating components for your automotive industry or are involved in the medical field, professionals help you quickly go from design to final production.
6 Robust Plastic Injection Molding Materials
Here are the commonly used plastic materials for injection molding and their properties.
1. Thermoplastic Polyurethane (TPU)
Thanks to its superior features, TPU has emerged as a significant material in production. The flexible material results from the reaction between polyols and diisocyanates. It stands out due to its high durability and elasticity. TPU can be easily molded into various sizes and shapes, serving a variety of applications in different industries.
The material is favored for its exemplary features, including:
· Flexibility: Polyurethane is easily adjustable to fit different applications, from rigid to soft.
· Mechanical strength: TPU is designed to withstand significant forces, which is a property that leads to durable products.
· Abrasion resistance: TPU is also resistant to wear, making it suitable for high-durability applications.
Properties of TPU
Thermoplastic polyurethane possesses the following properties:
· Elasticity: The material displays excellent elasticity, allowing it to return to its original shape after being stretched or bent.
· Durability: TPU exhibits unmatched impact and abrasion resistance, leading to durable products.
· Oil and Chemical resistance: The materials can withstand greases, solvents, oils, and various chemicals, allowing them to be used in harsh environments.
2. Acrylic
Acrylic is also referred to as Plexiglas or PMMA. The translucent material is reasonably priced and widely accessible, making it an excellent choice for manufacturers with unique products at a lower cost. It’s occasionally layered with a PC to add scratch-resistant properties for better strength.
Acrylic injection molding applications include creating aquarium screens, automotive windows, and mobile phone displays. In reality, it’s frequently used as an inexpensive and lightweight alternative to glass.
Properties of Acrylic
· Thermal properties: Acrylic has a maximum operating temperature of 93ºC and a melting point of 130 – 140 ºC. It’s, therefore, ideal for working at high temperatures, although it can easily be heat-firmed. The low conductivity allows it to be an excellent thermal insulator.
· Mechanical properties: Acrylic has a tensile strength of about 8000 psi. It can withstand high pressure, demonstrating that it is a strong material.
3. Polycarbonate
Polycarbonate is as popular as acrylic when it comes to injection molding materials. It’s a tougher thermoplastic with high impact resistance, often used where durability and safety are crucial. Polycarbonate has remarkable flame retardant and heat resistance properties.
Polycarbonate is known to be more impact-resistant than acrylic and glass, making it suitable for high-demand applications. It’s also more flexible than acrylic, allowing it to be shaped at room temperature. The materials are non-flammable, making them ideal for heat exposure applications.
Properties of Polycarbonate
· Strength and durability: Polycarbonate can withstand impact better than acrylic and glass, making it unbreakable in various applications. Thus, it becomes an excellent choice where durability and safety are supreme, such as protective face shields and bulletproof windows.
· Versatile applications: Polycarbonate’s high heat and impact resistance make it ideal for many applications. Its flexibility allows it to be shaped into complex shapes.
4. Polystyrene
Polystyrene is a moderately strong, rigid, transparent plastic material made through polymerization. It’s used in various forms, including film, rigid plastic, and foam, for electronics and food packaging applications.
Polystyrene is an excellent electrical insulator that is resistant to chemicals. Although it’s a brittle material, it can be recycled and reused in different forms and shapes. It can be used in its foam, film, and solid form. Cups and plates made from polystyrene are durable with good heat resistance.
Properties of Polystyrene
Polystyrene is an odorless and non-toxic material possessing the following properties:
· Transparency: Polystyrene is a transparent material suitable for clear plastic components like food packaging and utensils.
· Thermal properties: Polystyrene has a melting point of about 210-250ºC, lower than most engineering plastics. As a result, it makes the molding process easy, requiring less energy for manufacturing.
· Chemical properties: Polystyrene is resistant to bases and acids, making it excellent for medical applications and food packaging. However, it may not withstand chemicals such as s nitric or sulfuric acids.
5. Nylon
Nylon is the most common injection molding plastic material. It exhibits excellent crystallinity, crucial in improving its thermal performance and mechanical strength. Nylon is available in various forms, but PA 12, Nylon 66, and Nylon 6 are the most common in the manufacturing industry.
Properties or Nylon
Nylon is favored in injection molding due to its mechanical and physical properties and flexibility. It has the following properties:
· Fatigue resistance: This characteristic makes nylon suitable for components like gears that undergo cyclic loading.
· High-temperature resistance: Nylon is praised for its maximum operating temperature properties compared to most engineering plastics. Plastic parts can be created with temperatures of up to 145ºC.
· Low melt viscosity: The low melt viscosity of nylon improves the moldability for components with thin side walls. The melted nylon easily flows through squeezed spaces during the injection molding process.
6. Polyethylene
PE is a commercial polymer with a wide application in the injection molding processes. By melting PE, you can convert them into different applications, such as seals and lids. Low-density PE and high-density PE both provide good chemical resistance. However, they differ in terms of their optical transparency and flexibility.
PE injection molding is often used in food containers, automotive parts, and housewares.
Properties of Polyethylene
· Chemical and moisture resistance: LDPE, PET, and HDPE all resist chemicals and moisture.
· Flexibility: PE can be hard and rigid or flexible and soft.
· Temperature resistance: Polyethylene maintains structural integrity in various temperatures.
Wrapping Up
Plastic materials discussed in this post are common in injection molding processes. With so many options on the market, this expert advice can help you choose the plastic resins for your project.
