We live in a world dominated by plastic. From the moment we wake up, we interact with various plastic items, such as toothbrushes, food containers, and even the cars we drive. Undoubtedly, plastic has become an integral part of our lives due to its affordability, versatility, and durability. However, selecting the right plastic material for prototyping purposes requires careful consideration.
With countless plastic types available, finding the perfect material for your product can be a daunting task. While it is tempting to spend extensive time searching for the ideal formula, it is worth exploring common plastics during the prototyping stages. These materials are readily accessible and benefit from advanced manufacturing technologies. In this article, we will introduce you to some popular prototyping materials that offer a wide range of options without the need for expensive or hard-to-find resources.
PolyMethyl Methacrylate (PMMA)
You may not be familiar with the technical name PMMA, but you have undoubtedly encountered acrylic glass in various forms, such as car lights, windows, displays, and lamps.
Advantages: PMMA boasts transparency and shatter resistance, surpassing traditional glass. These properties, along with its corrosion resistance, have made PMMA an integral part of our daily lives. Additionally, this material is highly processable, allowing for cutting, casting, and forming. It is rigid, dimensionally stable, and can withstand temperatures up to 160 degrees Celsius.
Disadvantages: Despite its toughness compared to glass, PMMA remains brittle in comparison to other plastics. It is also susceptible to water and certain hydrocarbons, which cause swelling and dissolution, respectively.
PMMA serves as a reliable alternative to glass in situations where shattering is a significant concern, such as traffic lights and automobile lamps. Moreover, it finds applications in fields like medicine, where transparency and durability are essential. Additionally, PMMA is commonly used in experimental setups and demonstrations. For those seeking exceptional transparency that can be polished to mimic glass or enclose objects in a transparent casing, PMMA is an excellent choice.
Nylon
While PMMA offers rigidity, Nylon is known for its flexibility and strength. It is interesting to note that Nylon’s exceptional properties also make it suitable for producing fibers, which means you may even be wearing plastic clothing.
Advantages: Nylon exhibits remarkable flexibility, strength, and wear resistance. It is not prone to shattering. Furthermore, Nylon is lightweight and boasts a higher temperature resistance than PMMA, withstanding up to 195 degrees Celsius.
Disadvantages: Nylon is less resistant to chemicals and corrosion compared to some other plastics. It can dissolve when exposed to certain acids, alkaline substances, and strong liquids. Additionally, it fares poorly under sunlight, as prolonged exposure to UV light weakens its microstructure. Like PMMA, it swells when in contact with water. Moreover, Nylon exhibits a high shrinkage rate, which poses challenges during injection molding.
Nylon finds extensive use in the production of fibers for clothing, making it a common component in dresses, backpacks, and even car tires. Its strength and wear resistance make it suitable for parts that experience friction. If you require bearings or gear mechanisms, Nylon is an excellent choice.
Acrylonitrile Butadiene Styrene (ABS)
ABS has gained popularity, particularly in the realm of additive manufacturing. Its low shrinkage, excellent forming properties, and cost-effectiveness have positioned ABS as a leading plastic for rapid prototyping.
Advantages: ABS exhibits resistance to many agents that weaken other plastics, including acids and alkalines. It offers a glossy finish, making it an appealing option for products requiring shine. ABS is also shock-resistant.
Disadvantages: Compared to other plastics, ABS lacks strength. Additionally, it has a relatively low working temperature, with a threshold of under 90 degrees Celsius. ABS carries a slight toxicity, making it unsuitable for use in toys or children’s products. Furthermore, it exhibits significant shrinkage during the cooling process.
ABS’s affordability and ease of forming make it an ideal choice for 3D printing, with many custom or self-printed parts made from this material. Its glossy appearance also makes it suitable for creating enclosures for appliances and phones. If you are on a tight budget or uncertain about your design, consider 3D printing or machining your prototype from ABS to minimize costs.
Polyoxymethylene (POM)
POM possesses a microstructure that closely resembles that of crystalline materials, enabling it to mimic certain properties of metals while maintaining its lightweight nature.
Advantages: POM exhibits high strength, fatigue resistance, and excellent high-temperature stability (up to 166 degrees Celsius). It is rigid, corrosion-resistant, and possesses favorable friction properties. POM also stands out among plastics due to its high resistance to moisture.
Disadvantages: POM presents challenges due to its uneven shrinkage, making it difficult to predict and creating complications during casting or forming processes. Additionally, the presence of strengthening particles renders this plastic quite hard, leading to increased tool wear during cutting operations.
POM’s high tensile properties make it a common choice for engineering parts and machinery, including plastic pumps that require excellent friction properties. It is also employed for moisture-absorbent components to prevent swelling.
Polycarbonate (PC)
Polycarbonate is a formidable competitor to glass and PMMA in the realm of transparent materials. Whether you seek transparent or tinted products, PC offers a versatile solution. Opaque variations are also available.
Advantages: PC surpasses PMMA and glass in terms of shock resistance. It exhibits high heat resistance and can withstand temperatures above 150 degrees Celsius.
Disadvantages: PC is slightly less resistant to UV light than other materials, resulting in a gradual loss of transparency over time. It is prone to scratches, necessitating the application of special films to maintain clarity. Furthermore, PC should not be used with food or organic substances, as it may emit harmful vapors.
PC finds applications in anything requiring transparency, much like PMMA. Automotive lights and reinforced glass are common examples. PC is widely used in rapid prototyping, often more so than PMMA, making PC prototyping a cost-effective choice. If you need a highly durable transparent or tinted prototype, PC should be on your radar.
In conclusion, the plastics discussed above represent a wide array of options for your prototyping needs. When selecting a material, consider the desired rigidity or flexibility, the working conditions, and the temperature requirements. Conduct a thorough tensile analysis to determine the most suitable choice. Lastly, decide whether transparency is a critical factor in your prototype. With these considerations in mind, you can confidently navigate the world of plastics and choose the optimal material for your prototyping endeavors.
