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Polyurethane vs Polypropylene Wheels: The Right Choice For Industrial Caster Wheels

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Polymers have a wide variety of features and properties. This is why they are used for numerous applications and industrial equipment manufacturing processes. Two of the most common polymer types are Polypropylene and Polyurethane.

Polypropylene and Polyurethanes both are different kinds of plastic that are synthetic (man made) in nature. Both these polymers are quite similar at the first glance. However, even though they look and feel similar, both these polymers have different characteristics, uses, physical properties and chemical properties.

In this blog we will take a look at the differences between both these polymers, the advantages and disadvantages that each has to offer and discuss which one is best for manufacturing industrial caster wheels.

What is Polypropylene?

Polypropylene, commonly referred to as PP, is created by polymerizing propylene gas. It is a kind of thermoplastic which means that it can be liquified under high temperatures. Thermoplastics are easy to mould into any shape due to their liquefaction which is why they are majorly used materials in the manufacturing of small caster wheels in India.

PP offers a wide range of other physical properties that make it one of the most sought out materials in the industry of industrial caster wheels production. It features a high resistance to shocks and impacts which is why it is one of the top choices for small caster wheels manufacturers. PP castor wheels can easily handle heavy loads while resisting shocks, they perform well even in environments with a high temperature as well as offer a long lasting nature.

Physical Properties of Polypropylene (PP)

High Resistance To Heat:

Polypropylene is a kind of plastic which is the most heat resistant out of the rest. This high resistance towards heat makes it the ideal material for making industrial equipment such as industrial caster wheels, food processing equipment, automobile equipment, etc since these industries require apparatus that can work in high temperatures. PP has an extremely high melting point of 173°C or 343°F which makes it perfect for such industries.

Resistant To Impact:

Polypropylene is a strong, tough and durable material which is why it is the ideal material for industries such as the small caster wheels industry, automobile industry, etc. The tensile strength of PP is 48 MPa which is similar to that of steel. The material is long lasting since it is resistant to fatigue, abrasion and impact.

Tensile And Flexible:

Polypropylene is flexible in nature which makes it the perfect material for the manufacture of versatile industrial equipment. It has high tensile strength which makes it agile and suitable to be moulded into a wide range of shapes. It can be moulded into complex shapes as well since it is not brittle and will not break easily.

Lightweight:

Polypropylene is one of the lightest polymers of plastic available on the market. It has a low density of approx. 0.9 g/cm3 which makes it suitable for being used in the manufacturing of industrial equipment that needs to be lightweight as well as sturdy.

What is Polyurethane?

Polyurethane, also commonly known as PU, is created by chemically reacting di-iso-cyanate with a polyol. It is a thermoset which means that it has a unique and complex structure. The way PU is created, it allows manufacturers to use it in a way that meets their specific design requirements. This is because it can be either created in a way that the resultant is a soft, flexible and elastic material or it can be created in a way that the resultant is a rigid and strong material. This adaptability offered by PU allows manufacturers to to design their products using a variety of processes such as the RIM (Reaction Injection Moulded) process or through a casting process.

Physical Properties of Polyurethane (PU)

  • Hardness:As discussed above, the hardness of Polyurethane depends on the method used for its creation. It can be very soft, spongy, elastic and flexible or it can be as rigid and strong as a metal.
  • Density:
    PU or Polyurethane has an exceptionally low density which is slightly higher than that of H2O or water. This makes it a lightweight material which is easy to manoeuvre.
  • Appearance:
    Polyurethane has a unique property where it can be created to appear a certain way. This means that it can be created to be transparent, translucent or opaque as per your requirements. Depending on the formulation it can also be formed in a way that the resultant is pigmented or coloured.
  • Tensile strength:
    With a high tensile strength of 2.4-4.8 MPa, Polyurethane is a strong and durable material. This makes it the perfect choice for industries that require a material that can withstand heavy loads and weights.

Polyurethane vs Polypropylene Wheels Difference

Although they may look, sound and even feel similar, Polypropylene and Polyurethane are both unique in their own way.

Here are some of the key differences between the two:

Polypropylene

  • Does not easily bond with other chemicals or compounds
  • High resistance to shocks and impacts
  • Low resistance to high temperatures
  • Shaped by using thermoform techniques or can be injection moulded
  • With the use of carbon black, PP can be made conductive

Polyurethane

  • Can bond easily with a number of other components
  • Can be easily moulded into desired shapes and designs
  • High resistance to heat. Can withstand temperatures ranging from -62°C up to 148°C
  • Moulded by using casting methods or by RIM process
  • With the use of carbon black, PU can be made conductive

Advantages of Polyurethane (PU) Caster Wheels

Polyurethane caster wheels offer a wide range of benefits, including:

  • Highly Durable
    Polyurethane or PU caster wheels have a much longer life than rubber wheels. They are much more durable as well as offer protection and resistance against oils, chemicals, grease, etc.
  • Can Handle High Loads
    As compared to rubber caster, PU casters can easily handle heavier loads.
  • Shock And Impact Resistance
    PU casters help cushion any impact and absorb the shock. This makes them the ideal solution for uneven and bumpy terrains.
  • Noise Reduction
    PU wheels make less noise and are much quieter than wheels made out of metals and are perfect for carpeted floors as well.
  • Long Life And Resilience
    PU wheels are resistant to wear and tear which is why they have a long life and do not require frequent new purchases.
  • Smoother Movements
    PU casters offer a smooth and agile manoeuvring which eases human efforts.
  • Floor Protection
    Polyurethane can easily handle heavy weights which is why it does not leave any scratch mark on the floor. Polyurethane wheels work well on slippery floors as well as they offer skid resistant properties.

Advantages of Polypropylene (PP) Caster Wheels

Polypropylene caster wheels offer a wide range of benefits, including:

  • Highly Durable:
    Polypropylene or PP is one of the most preferred materials used by heavy-duty equipment manufacturers. This is because PP caster wheels are resistant to daily usage wear and tear and offer a hightened level of durability.
  • Cost Effective:
    PP caster wheels are incredibly cost effective as they do not absorb any chemical substances. They can be cleaned easily with chemical cleaning methods which makes them low maintenance as well.
  • Resistant To Corrosion:
    Polypropylene, being a kind of plastic, does not rust or corrode which is why it is a long lasting solution.
  • Resistance To High Temperatures:
    Polypropylene caster wheels can withstand high temperatures as they are incredibly heat resistant. They can efficiently work in temperatures ranging from -42°C to 82°C.
  • Do Not Leave Marks:
    PP wheels offer low friction which is why they do not leave any marks or scratches on floors.
  • Low Friction:
    Since Polypropylene is a plastic material that has a minimal friction resistance, it offers a low rolling resistance. This helps reduce the amount of human effort required.
  • Impact Resistance:
    Polypropylene wheels are impact and shock resistant.

Key Takeaways

Now that we have a better understanding of PP we can answer the most commonly asked question: “polyurethane vs polypropylene wheels which is stronger?”

While both Polypropylene as well as Polyurethane offer a wide range of benefits, your choice depends on the individual and unique needs of your business.

Both of these polymers feature their own unique characteristics and offer a wide range of benefits. There may be some common benefits offered by both these polymers however, each material has its own unique structure and properties. You need to establish which properties are best suited for your individual needs.