One common question in the plastic manufacturing industry is, “what are the best plastic injection molding material?” However, there is no specific answer for that because there are several available materials, each with its unique properties. So before you choose any plastic for your project, you need to consider the part’s application and the physical environment to which the part will be exposed. Environmental challenges like moisture, temperature fluctuations, UV light, chemical exposure, etc.
The material's strength, longevity, flexibility, color, and price are factors to consider. To help you focus your search, we'll review the characteristics of the ten most popular plastic injection molding resins that Ars Prototyping uses for most of the parts we produce.
Because injection molding works with so many different types of plastic, it is widely used in several industries. However, covering all of them in a single write-up is impossible. So, we will discuss the most common ones:
It is also known as polymethyl methacrylate. It is a thermoplastic substance with a fair amount of mechanical strength, is lightweight, and appears clear and transparent. However, despite not being ductile, it has good shatter resistance. One of its greatest advantages is how easily it can be machined. Acrylic parts that have undergone injection molding are simple to modify and finish.
However, it has some drawbacks. Its tendency to scratch easily also detracts from its clarity. In addition to affecting its surface characteristics and transparency, it also becomes dirty from oils and greases. Extreme temperatures also impair its performance. Acrylic is frequently used for windows, solar panel protective casings, and decorative showcases.
Abutrene Butadiene Acrylate (ABS)
One of the popular injection molding materials is ABS. It is strong and resilient, resilient to impacts, and chemically resistant to acids, bases, and oils. It can be injection molded in various colors and is entirely opaque. It is also relatively inexpensive compared to the other materials for plastic injection molding on this list.
HHowever, it does not do well in humid environments or exposed to strong sunlight. It's best to stay away from such applications. Automotive components and high-impact sporting goods are two industrial-grade applications for which ABS is ideally suited. Due to its affordability and practicality, it is also very suitable suitablefor rapid prototyping.
Nitrile Polyamide (PA)
Heat resistance, toughness, and surface friction properties make nylon an excellent material. It is a naturally occurring substance that can also be synthesized. Its synthetic form is the most suitable for injection molding. It is also perfect for creating noise dampeners because of its vibration-damping properties. The common grades of nylon are:
● Nylon 11
It is a bio-based polymer with good dimensional stability, UV, and impact resistance. It also absorbs remarkably little water.
● Nylon 12
This material resembles Nylon 11 but has a higher abrasion, UV resistance, and slightly lower impact strength.
● Nylon 46
It is excellent for applications requiring high impact strength, wear resistance, chemical and electrical resistance at high temperatures.
● Nylon 66
It is a good substitute for metallic components. It has excellent stiffness, strength, abrasion, wear, and fatigue resistance characteristics.
Nylon's high levels of shrinkage make injection molding difficult at times. When designing a mold, it's essential to consider appropriate allowances and drafts. Nylon grades also react with acids and bases. Gear parts, bearings, guitar strings, water- and wear-resistant fabrics, and ropes are examples of nylon products.
Outstanding strength, impact resistance, and shatter resistance are all characteristics of polycarbonate (PC) PC characteristics. It appears to be transparent. It also has the advantageous property of retaining its mechanical characteristics and appearance over a broad temperature range. As a result, it performs well in hot environments.
Indeed, it frequently has better optical clarity than glass. This makes it a very well-liked injection molding substance for producing goggles, machine shields, and helmet visors. But PC has been shown to harm human health, particularly the reproductive system. As a result, sectors like the food and beverage industries do not use it.
It is best known for its suitability for products that need to be highly precise. Because of its stiffness and rigidity, it has excellent dimensional stability. It also has a low coefficient of friction and good lubricity, making it perfect for applications involving a lot of contacts. Additionally, even at very low temperatures, its properties are stable.
It is preferable when plastic injection molds tough automotive parts like handles and switches. Additionally, it is used in furniture, ball bearings, gears, and kitchen knives.
Polypropylene is a material that is all around us, particularly in the food containers that are kept in our kitchen cabinets. It is one of the most popular FDA-approved materials for plastic injection molding. It is tough, and highly resistant to heat, chemicals, and recycling. It is user-friendly because of these features.
One of its drawbacks is Its high thermal expansion coefficient, and high temperature can hinder it. Additionally, it develops flammability after injection molding and undergoes UV light degradation. Food containers, rugs, toys, and household appliances are just a few of its uses.
Polystyrene (PS)
One of the few brittle injection molding materials is PS. Due to its uniform thermal shrinkage inside the mold, it is exceptionally lightweight, resists moisture and chemical reactions, and is well suited for injection molding.
It used in making products like toys, appliances, and containers. Gamma radiation, the primary technique used to sterilize medical equipment, does not damage it. It is also one of the primary materials used in manufacturing medical equipment. So, PS is used in the injection molding process to create equipment like Petri dishes and culture kits.
Polyethylene (PE)
High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), and Polyethylene Terephthalate are the three main categories of PE that vary in density. PE grades typically have good impact strength, creep resistance, and flexibility. They can withstand chemical reactions as well.
HDPE is more rigid and stronger. As a result, it is useful for molding items like jugs, tubs, and pipes. LDPE, on the other hand, is more adaptable. It is a superior packaging material with market-leading goods like shopping bags, foils, and films worth billions of dollars.
TPE is distinctive among injection molding materials in that it is a mixture of plastic and rubber. It combines the benefits of both materials. It is vital, recyclable, and flexible enough to be stretched out to long lengths. Additionally, it has the advantage of being more affordable than most rubber substitutes.
However, it is not recommended for use because it loses some of its material characteristics at high temperatures. TPE shouldn't be stretched too far or for too long because it is prone to creep
It has numerous, diverse applications. It can be used to create bumpers, flexible tubes, anti-vibration mounts, footwear components, and seals, among other things.
Polyurethane Thermoplastic (TPU)
TPU is yet another rubber-plastic hybrid that benefits greatly from its polyurethane base. It is very hard and has excellent compression strength, abrasion, and chemical resistance. Furthermore, even at very high temperatures, these characteristics hardly alter.
But it's one of the trickiest materials for injection molding. You need a specialist to work with this injection molding material because of its hardness and crystallinity, which frequently cause issues during molding. It can be used for various things, such as footwear, inflatable rafts, power tools, caster wheels, and protective enclosures and casings.
Even for experienced product developers, the range of material options available for injection molding can occasionally be overwhelming. As a result, we offer a concise and detailed guide to choosing an injection molding material. It can help you narrow your material options to a manageable number, but finding the injection molding material you require is not a foolproof method.
In most situations, hardness is an important quality that cannot be compromised. In applications involving hardness, nylon grades work well. Thermoplastic Polyurethane (TPU) is a good option for extremely high-performance applications. The material itself and its injection molding are pricey, so consider that.
Many of the materials used in injection molding are flexible. Thermoplastic elastomer and polypropylene are particularly well suited for applications requiring high levels of flexibility. TPE typically outperforms PP in high temperature and fatigue resistance, but PP is safer and recyclable to use.
PP and PS may be the best choices in terms of material costs. Both are affordable and easily accessible.
At high temperatures, Nylon and ABS do a great job of holding their shape and material properties. POM is remarkably stable at temperatures below zero.
In the end, everything comes down to the intended application. The material you choose ought to be a good fit for the applications used by end users.
Ares Prototyping is the leading provider of high-caliber injection molding servicesYou can confidently choose your injection molding materials thanks to our sizable material catalog. We offer a wide variety of plastic materials, cutting-edge manufacturing tools, a knowledgeable staff of experts, and a sizable selection of materials for our customers.
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. Get in touch with us about your rapid prototyping projects!