ABS Vs Polypropylene: Their Key Difference
When it comes to manufacturing perfectly designed plastic parts, you may get mixed up by the range of raw materials available. It can be particularly challenging to choose between two of the most popular engineering plastics — ABS plastic and propylene (PP). Each of these materials has unique features and qualities that make it suitable for specific applications.
This comprehensive guide aims to simplify the comparison between ABS and propylene so you can know their differences and make an informed decision about the ideal material for your next project. Read on!
What Is ABS(Acrylonitrile Butadiene Styrene) Plastic?
Acrylonitrile butadiene styrene (ABS) is a popular, opaque plastic material. This amorphous polymer consists of three monomers; acrylonitrile, butadiene, and styrene. It is typically created through the emulsification process. ABS plastic is known for its excellent impact resistance and toughness, making it suitable for a wide range of applications.
Combining these individual monomers produces a strong plastic material with exceptional durability. What’s more, manufacturers can adjust the amount of each monomer to achieve desired characteristics. For example, increasing the acrylonitrile content boosts rigidity and heat stability. Similarly, a higher butadiene amount translates to a softer, more pliable material. The versatility of ABS plastics has led to widespread use across different sectors, including automotive parts, consumer electronics, and household appliances. However, it is important to note that ABS plastic can have some disadvantages, such as poor weatherability and potential chemical interactions with certain substances.
What Is PP(Polypropylene) Plastic?
Polypropylene (PP) is a low-density, heat-resistant, thermoplastic material consisting of propylene monomers. It is the second most common plastic in the world after polyethylene (PE).
There are two different types of polypropylene; homopolymers and copolymers. Homopolymers are the most commonly used general-purpose grade polypropylene material. They only contain propylene monomers in a semi-crystalline form. On the other hand, copolymers have additives and fillers such as ethene, glass fiber, and carbon fiber. These additives enhance the mechanical properties of propylene including impact resistance and malleability.
What Is The Difference Between ABS and PP?
Now that we’re familiar with ABS and PP plastic, let’s take a look at how they differ from each other. We’ll explore differences in aspects such as physical characteristics, chemical composition, and mechanical properties.
ABS Vs. PP: Properties and Impact Resistance
Properties
Properties
Properties
Density:
0.9 - 1.53g/cm3
0.90 - 0.94 g/cm3
Specific gravity:
1.04
0.91
Tensile elongation:
32%
__
Tensile strength:
4100 psi
4800 psi
Tensile modulus of elasticity:
294,000 psi
__
Flexural modulus of elasticity:
304,000 psi
225,000 psi
Heat deflection temperature:
200/177 F
210/ __ F
Hardness:
R 102
Shore D 75
Water absorption
0.30%
Slight
Heat resistance
Good
Excellent
Impact strength
High
Moderate
Water resistance
Good
Excellent
ABS Vs. PP: Pros and Cons
ABS plastic and PP are common materials amongst plastic manufacturers thanks to their significant advantages. However, like any other material, ABS and PP both have their fair share of disadvantages. In this section, we’ll highlight the pros and cons of these engineering plastics.
ABS Pros:
Cost-effective plastic: ABS is relatively inexpensive thanks to its low production costs. It’s, therefore, an excellent option for price-sensitive applications.
Lightweight material: ABS plastic has an excellent strength-to-weight ratio. It is a popular choice for applications that require durable yet lightweight materials, such as aerospace components.
Good insulator: ABS plastic parts have good insulative properties. They are, therefore, used for certain electronic components as well as electrical cable insulation.
Thermoplastic properties: When heated, ABS resin will become more pliable and harden upon cooling. This is why it’s a popular injection molding material.
Recyclable material: ABS plastic can be melted down and reshaped multiple times without losing its properties.
Sturdy and ductile: While ABS material is easily machinable it maintains good chemical resistance. This polymer also offers excellent abrasion and impact resistance. It can withstand harsh processes without losing any of its features.
Wide range of finishing options: ABS plastics allow for a variety of surface texture options and can be painted virtually any color.
ABS Cons:
Relatively low melting point: Compared to other plastics, ABS has a low melting point and is not an ideal choice for applications involving high temperatures.
Non-biodegradable: ABS is a non-biodegradable material. If it’s not recycled it can end up in landfills or the ocean causing environmental degradation.
Poor weather resistance: ABS parts are affected by UV light. Prolonged sun exposure causes color fading, brittleness, and loss of mechanical strength.
Flammability: ABS is highly flammable and generates significant fumes when it burns. Flame-retardant additives can be used to enhance fire resistance.
PP Pros:
Chemical resistance: PP has excellent chemical resistance. It’s often used in the manufacture of pipework and containers used to store a variety of acids, bases, and solvents.
Electrical insulation: This material has good insulative properties. You’ll therefore find it in various electrical and electronic components.
Water resistance: PP is highly impermeable, making it suitable for water-proofing and components that are submerged in liquids.
Durable and strong: Polypropylene is known for its good mechanical properties, including high strength and durability. Its capacity to withstand loads and forces makes it an excellent option for structural components.
Lightweight material: Despite being a tough material, PP is a lightweight plastic. This makes it suitable for making lightweight products that are also tough.
Versatility: PP is easily molded and shaped to create diverse products for different industries. This thermoplastic polymer is a popular choice in injection molding applications.
Cons：
Poor fire resistance: Polypropylene has a low melting point and flash point. It is highly susceptible to combustion if exposed to an open flame or high temperatures.
Low UV resistance: PP is unsuitable for outdoor applications since prolonged exposure to UV light causes material degradation.
Poor adhesion: Polypropylene has poor bonding properties making it difficult for adhesives or paint to adhere on its surface. This issue is rectified using special surface treatments and adhesive formulations.
Environmental impact: Polypropylene is non-biodegradable and can contribute to environmental pollution. PP recycling has helped mitigate its impact on the environment.
ABS Vs. PP: Applications in Injection Molding
ABS and PP both offer desirable properties that have led to applications in various industries. Here are some critical applications of each material.
ABS Applications
Automotive parts: In the automotive industry, ABS is a common material used to make various parts including seatbelt components, dashboards, handles, mirror housings, and door panels. This material is preferred due to its strength and impact resistance.
Medical applications: ABS plastic is a commonly used material in the medical sector due to its purity, durability, and chemical resistance. It is used to manufacture instrument housings, nebulizers, syringes, drug delivery systems, and other medical devices.
Household appliances: Appliances made out of ABS are widely used due to their strength and wear resistance. This material can be found in vacuum cleaners, food processors, shavers, fridge liners, and coffee makers.
Sports and recreation equipment: One of the best features of ABS plastic is its impact resistance. As a result, this material is used when making protective headgear, skateboards, and even bicycles.
Plastic toys: Being such a durable thermoplastic, manufacturers often prefer ABS when making kids’ toys such as Lego bricks.
Musical instruments: ABS provides excellent performance in musical instruments such as recorders, plastic clarinets, harmonicas, and clarinets.
Prototype development: ABS has proven beneficial during prototype making. It is compatible with the manufacturing processes commonly used during prototyping — CNC machining and 3D printing. The ideal production technique will typically depend on the manufacturing volume.
PP Applications
Packaging materials: One of polypropylene’s most common uses is as a packaging material. It is low-cost and flexible, making it a great alternative to paper and cellophane. PP is also chemically inert and can be used in storing food. Polypropylene packaging materials include bottles, hot beverage cups, and yogurt containers.
Medical equipment: In the medical industry, propylene is used in the manufacture of various devices and components thanks to its microbiological and chemical resistance. This includes syringes, petri dishes, laboratory equipment, pill containers, and IV components.
Automotive components: PP is commonly used in the production of automotive parts such as battery casings, interior trim, instrumental panels, engine covers, and dashboard components. Its moldability, impact resistance, and lightweight nature make it suitable for these applications.
Electrical and Electronic components: One of the key features of propylene is its insulative properties. It’s, therefore, used in electrical goods and consumer electronics such as computer keyboards, printer parts, electrical enclosures, and more.
Household products and consumer goods: Chances are you interact with propylene products every day. This material is used in the production of everyday products including kids’ toys, bags, storage containers, furniture, rugs, kitchen utensils, and household appliances.
Textile industries: PP is an invaluable asset in the textile space. Due to its durability and lightweight nature it is used in fabrics, ropes, carpets, and more.
Author
Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.