Materials can make or break a product. While blow molding and other plastic molding processes use a wide variety of resins, that doesn’t mean every resin is right for your product. Once you isolate the expected applications for your product, select a resin with the properties that best fit those applications.
Here are a few questions you should ask yourself during product development to ensure you select the appropriate resin:
- Does the product need to be finished and colored?
- How impact-resistant does it need to be?
- Should the final item be rigid, flexible, or somewhere in between?
- Is this a product meant for children?
- What regulatory requirements apply to it?
- Should it be food safe?
- Is it close to a heat source?
There are five commonly available types of plastic used for resins. Each of them possesses distinct characteristics, and some plastics have subtypes with even more unique properties. One of these types of plastics will be suitable for nearly any project.
Acetal plastics are ideal for prototypes. The material provides high impact resistance and a low degree of friction. However, acetal doesn’t pair well with 3D printing manufacturing methods. Acetal is also known by the brand name Delrin®.
Acrylonitrile Butadiene Styrene (ABS)
Strengths of ABS include:
- Ease of machining, finishing, and painting for prototype runs
- Ideal for injection molding and 3D printing due to a low melting point
- Impact resistance
- Resistance to corrosive chemicals
Due to its low melting point, ABS won’t pair well with high-temperature applications and fabrication processes. Also, thought non-toxic, ABS can’t be used for medical implants.
Polyethylene has three distinct subtypes:
- High-density polyethylene (HDPE) is stiff, strong, and relatively resistant to chemical damage. Common applications include detergent bottles and cutting boards.
- Ultra-high molecular weight (UHMW) polyethylene is very dense and manufacturers can spin the material into threads. Common applications include composites such as those used in bulletproof vests, because the material has a higher tensile strength than steel.
- Low-density polyethylene (LDPE) has a lower tensile strength, and the material is very flexible. Disposable plastic bags are one of the most most common applications for LDPE.
Polyethylene is a preferred plastic for a wide variety of product types and industries because of its versatility. It can come in many different forms, and each subtype can be processed into unique materials. Polyethylene is non-toxic and food-safe in its solid state.
Polypropylene has distinct strengths and weaknesses. Common applications include internal parts such as gears and living hinges. Its strengths include:
- Chemical resistance in most circumstances
- Electrical insulation properties
- Fatigue resistance
- Low density
- Low friction
Many manufacturers and product designers prefer polypropylene for applications that require a low degree of friction because its surface is slippery.
Polypropylene does have some disadvantages that will make it unsuitable for certain projects. Some of these include:
- Difficulty bonding
- Oxidation risks
- Poor chemical resistance (for aromatics and chlorinated solvents)
- UV degradation
Santoprene™ is a commonly used example of a thermoplastic olefin. These materials have many of the same characteristics of rubber, but they have lower weights and are easier to process.
Plastics are used across almost every industry to create products and parts. Identifying similar products that use plastic can help you choose the right resin and fabrication processes for your industry and application.
Examples of common applications by plastic type include:
Typical uses for ABS include:
Due to polypropylene’s slippery feel and capabilities in low-friction applications, manufacturers use this material to create items such as:
- Contact points for furniture and heavy products
- Electronic components
- Liquid containers for products such as cleaners and first aid kits
- Living hinges
- Promotional tote bags and other products that require plastic fabrics
Since polyethylene doesn’t bleed into the products it comes in contact with, it’s commonly used for food and chemical packing, such as:
- Food containers
- Milk and juice bottles
- Plastic bottles for soaps/detergents/shampoos
- Motor oil containers
- Food package caps
Acetal possesses some of the same slippery characteristics as polypropylene. Typical uses for acetal include:
- Contact points
- Guitar picks
- Pinch valves
- Plastic buckles
Common uses for thermoplastic olefins include:
- Hose connectors
- Knife handles
- Seals for doors, ovens, and windows
- Tool grips
- Wiring and cabling
Thermoplastics and OMICO Plastics
OMICO Plastics is a leading manufacturer of plastic products. Our team can produce prototypes and full production runs with ABS, acetal, polyethylene, polypropylene, and thermoplastic olefins. Our facility is equipped with the tools to blend plastics together to create unique materials targeted to specific applications.
We have extensive experience in blow molding high-quality plastic parts, including:
- Air ducts
- Automotive boots and protective covers
- Bin doors
- Dishwasher parts
- Foodservice panels
- Insulated plates
- Refrigerator drain tubes
- Serving trays
- Vacuum cleaner parts
- Water reservoirs
Contact our team to learn more about our blow molding capabilities.