Many different types of plastics can be used when developing new products. The right choice depends on the application-specific criteria.
Based on our experience, developers should consider whether plastic materials are food safe, impact-resistant, flexible, engineering-grade, flame retardant or biocompatible. Below are our recommendations for the most common plastics required for each product.
The use of plastic parts in medical devices and equipment has increased significantly over the past few years. To protect patients and regulate the industry, the ISO-10993 standard helps organize the various medical uses of plastic materials.
Resin can be used to make blood stents, artificial joints and bone substitutes, catheters, prosthesis, infusions, cardiac monitors, valves, tubes, pill dispensers, etc.
It is important to use the correct resin in each application. ISO guidelines determine "biological risk" assessments based on interactions with the human body: permanent implantation, temporary contact with the skin, or for use in medical devices.
Based on these categories, we can make the following recommendations:
Medical tools and equipment：PEEK,POM,PMMA,PC,PVC,HDPE
Long-term exposure or medical drugs: PPSU, HDPE, PMMA, epoxy (for dental implants)
Short-term and skin contact: PE, PS, nylon, PVC, Teflon, PEEK, PP, PPSU
This category of plastic sits repeatedly and reverts to its original shape without denting or cracking.
ABS (acrylonitril butyl diethylene) and HIPS (highanti-flush polystyrene) are used in the manufacture of power tool housings, toolboxes, luggage, sporting goods and other products that, although often abused, remain robust. Adding fiberglass or carbon fiber can make these resin compounds more tough.
There is still a large market for transparent plastic substitute glass. The PC (polycarbonate) is ideal for motorcycle windshields, plastic eyeglasses and lightweight housings.
Engineering plastics are crystalline polymers with mechanical properties similar to metals. They are as durable as similar metal products, while still being lightweight, and, like LC Rapid, are less expensive to produce in mass production.
This category includes plastic materials such as ABS, nylon (polyamide), PEEK (polyetherketone) and POM (polyformaldehyde). They are rigid, temperature-resistant and low-friction. Also, PEEK, ABS and nylon can all be printed through fast 3D printing service to provide more design options.
Some products made of engineered plastics include ball bearings, gears and shafts, shanks, plastic gun bodies, switches and other weight-loss parts for automotive and aerospace applications.
All plastics have a degree of flexibility. Many products do not require high strength, but must be flexible without being completely deformed.
PP (polypropylene) is the king of plastic that makes the hinges of the activity, as seen on the lid of a shampoo bottle or pill dispenser. The plastic can bend thousands of times before breaking, which happens to be during the life of the product.
HDPE is more robust, so it can be found in heavy-duty trash cans that are heavily used.
TPU (thermoplastic polyurethane) is an elastomer. It is elastic and rubbery and can therefore be used in casters, seals and washers, cable housings and sporting goods. Softness and elasticity are controlled by changing the chemical composition.
Plastics for food production, cooking and storage need to meet some standards. They must be sterile and cannot give food any flavor. In most cases, they must be non-biodegradable, non-absorbable and not penetrate into cooking oil and acids.
In all of these categories, PET (polyphenyl glycol) is almost ideal, which is one of the most common plastics in food packaging. It can be found everywhere in water and soda bottles and other food containers. It is both robust and fall-resistant, lightweight and easy to recycle. The form of pet in fiber form is called polyester and is the most common type of artificial fabric used in clothing and insulation materials.
LDPE (Low Density Polyethylene) is used to manufacture food bags and cling films, while HDPE (high density polyethylene) is used for plastic cutting plates. PP (polypropylene) was also found in food containers such as yogurt containers.
It should also be noted that many engineering-grade plastics are also considered safe for food, but are only used for food processing equipment or other durable products due to their high cost.
In the presence of flames or other high heat sources, any plastic will melt and some will catch fire. When using plastic in confined spaces, such as in a car or in an aircraft cabin, attention to fire resistance is particularly important.
However, plastics react differently to fire. When the heat source is removed, some will automatically go out. Others may spread flames vertically or produce dangerous fumes.
The most natural refractory plastic is PVC (PVC). The presence of chlorine helps to burn the oxygen needed for combustion, but chlorine is certainly another serious problem.
The secret to fire resistance is to apply fire-resistant chemicals to plastic materials or add impurities to compounds, which will help disrupt the combustion cycle. Some of these additives include boron, vanadium, chlorine, bromine, aluminum and phosphorus.
Due to the wide variety of variables and formulations, it is best to contact the manufacturer to confirm which UL fire safety ratings the material has. The highest rating is UL94-VO, which means that the material does not burn, will automatically go out and will not drop hot melt to the floor.
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At LC Rapid, we offer a range of in-house prototyping and production services, including plastic injection molding or CNC machining.