Injection molding is quite popular for its versatile and diverse applications. This widespread success is large because of the enormous choice of compatible injection molding materials.
This guide will discuss the top 10 injection molding materials, their properties, advantages, and disadvantages, and we’ll also give detailed guidelines on how to inject molding material for your project best.
Several materials can be used for plastic injection molding, and its products are in every industry and house. It is impossible to mention all the materials in this article, so we’ll just mention the most common ones.
This is one of the most popular injection molding materials. It has perfect toughness, impact resistance, good strength, and chemical resistance to oils, bases, and acids. ABS is one of the cheapest injection molding materials that have high quality. Additionally, It is opaque and can be molded in several colors.
ABS is ideally suited for automotive components and high-sporting equipment. Due to its affordability and practicality, it is also extremely popular for quick prototyping. However, it does not thrive well under moist environments or direct sunlight. So it is better to prevent such applications.
Poly (methyl methacrylate) is also known as Acrylic. It is a form of thermoplastic with reasonable mechanical strength, see-through, and a clear appearance. Despite not being ductile, it has good shatter resistance. However, one of its main advantages is its ease of machinability. After using them for injection molding, the acrylic parts can easily be altered.
Acrylic has a few disadvantages. It doesn't fare well in high temperatures. It also gets stained from greases/ oil, which affects its surface clarity. Acrylic is also prone to scratches, and this can also affect its clarity. Some of the applications of acrylic are windows, protective casing for solar panels, decorating showcases, and so on.
Nylon is a good material that heats resistance, surface friction properties, and toughness. It is a natural material, but it can also be manufactured synthetically, and its synthetic form is beneficial for injection molding applications. Nylon is an ideal material for producing noise dampers because of its vibration-damping characteristics. The popular grades of nylon include:
● Nylon 11
It is a bio-based polymer with dimensional stability, UB resistance, and excellent impact strength. It also possesses low water absorption characteristics.
● Nylon 12
This is similar to nylon 11 but has a higher UV resistance, abrasion, and lower impact strength.
● Nylon 46
It is suitable for high temperature, wear resistance, impact strength, and electrical and chemical resistance applications.
● Nylon 66
Polycarbonate has amazing impact resistance, shatter resistance, toughness, and transparent appearance. It also has the suitable quality of preserving its appearance and mechanical properties for a large temperature range. This implies that it is suitable for high-temperature injection molding applications.
PCs have wonderful optical clarity, which is sometimes better than glass. As a result, it’s a common injection molding material for manufacturing goggles, protective machine e shields, and helmet visors. However, scientists have discovered that PC harms the human body, especially the reproductive system, and this is why it’s not used in the beverages and food industries.
Polypropylene can be found everywhere, especially in food containers in your kitchen cabinets. This is one of the common plastic injection materials approved by the FDA, and it can be recycled severally, hard, chemical resistant, and heat resistant. All of these characteristics make it user-friendly.
However, PP has a higher thermal expansion coefficient, which hinders high-temperature applications, making it hard to manage when molding. After molding, it decomposes under UV light and becomes flammable. Applications of PP are toys, rugs, home appliances, and food containers.
Polyoxymethylene is popular for its compatibility with products that need high precision. Because of its stiffness and rigidity, it has excellent dimensional stability. However, it has good lubricity and low friction coefficients, making it the perfect contact-intensive application. POM regains its properties even at low temperatures.
It is preferred to plastics when molding complex automotive parts like switches and handles. Applications of POM are ball bearings, furniture, gears, and kitchen knives.
One of the few fragile injection molding materials is polystyrene, which is lightweight and resists chemical and moisture reactions. Due to its homogeneous thermal shrinkage in the mold, it is perfect for injection molding.
It makes items like toys, appliances, containers, etc. PS does not decay with gamma radiation, so It has a unique position in medical equipment. Examples of equipment molded with PS are culture kits, Petri dishes, etc.
TPE is a unique material because it mixes rubber and plastic. This material is preferred by many because it combines the functions of both plastic and rubber. TPE is recyclable, strong, and can be stretched to linger lengths. Its main benefit is that it’s cheap compared to other rubber alternatives.
This is a perfect alternative to the metallic material. It has high strength, stiffness, wear properties, fatigue resistance, and abrasion. PE comes in three main categories that differ in density: Polyethylene Terephthalate (PET), Low-Density Polyethylene (LDPE), and High-Density Polyethylene (HDPE). PE can withstand mechanical loads for a long time without deforming, have good impact strength, resist chemical reactions, and are ductile.
The strongest form of PE is HDPE, which is essential for molding pipes, tubs, and jugs. LDOE is the most flexible. It produces suitable packaging materials, and its products are worth billions of dollars in the packaging industry.
TPU is a rubber-plastic mixture composed of polyurethane. It has different qualities like hardness, chemical resistance, abrasion resistance, and excellent impact strength, which remain unchanged even at extreme temperatures.
However, it’s one of the most challenging injection molding materials. Its crystallinity and hardness can be difficult to handle when molding. TPU has to be handled by a machine expert. Some of the applications of TPU are footwear, caster wheels, power tools, protective casing and enclosures, and inflatable rafts.
However, it shouldn’t be used at high temperatures because it can lose some properties. It should also not be overstretched because it’s prone to creep. Splice tons of TPE are bumpers, foot ware parts, flexible tubes, seals, and anti-vibration mounts.
Injection molding is so vast that the range of materials available can be overwhelming, even for experienced product developers. However, some factors can guide you in selecting the most suitable one. The factors include:
Application of the intended part is essential. The material you choose must be suitable for the part.
In most situations, hardness is an essential quality that cannot be overlooked. Nylon works best for applications involving hardness, and thermoplastic Polyurethane (TPU) is a good option for extremely high-performance applications. However, the material and its injection molding are expensive, so consider that.
The best materials in terms of cost are PS and PS, and they are both readily available and cheap.
A variety of materials for injection molding are flexible. Polypropylene and thermoplastic elastomer are well-suited for applications requiring high levels of flexibility. TPE usually outshines PP in terms of high temperature and fatigue resistance, while PP is safer and recyclable.
ABS and Nylon are very good at maintaining their material properties and shape at high temperatures. On the other hand, POM isn’t stable at extreme temperatures.
You can figure out which material is suitable for plastic injection molding with the help of these guidelines. These are some parts and their materials:
Power tools are used often and are susceptible to vibrations and high forces, and they may get hot from being used too much. It's challenging because there are numerous additional factors, the primary one being the precise application. However, good material options for power tools include nylon, PET, ABS, and TPU.
This requirement is a minimum amount of hardness since they’ll be used a lot. The material has to be resistant to heat because cars in the heat and engines generate heat. ABS would be an excellent place to start because it is affordable and offers these qualities.
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At Ares Prototyping, we place a high priority on quality, cost reduction, and client satisfaction. Because of this, we promise quick quotes, DFM analysis reports, and a remarkable molding tolerance of +/- 0.005 mm, all with the convenience of round-the-clock engineering support.
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