delrin vs acetal

Welcome to our comprehensive guide on delrin vs acetal – two high-performance plastics that are widely used in various industries. In this article, we will compare the properties, applications, and differences between delrin and acetal, helping you make an informed decision for your specific needs. Whether you are looking for excellent chemical resistance, moisture resistance, or superior mechanical properties, understanding the characteristics of these materials is crucial.

Delrin® and copolymer acetal are both polyoxymethylene (POM) polymers, but they have some key distinctions. Delrin® is a homopolymer, while acetal is a copolymer. Both materials offer outstanding properties, but their applications vary. While acetal is better suited for continuous high-temperature exposure, Delrin® is an excellent choice for applications subjected to continuous cyclic loading.

In the following sections, we will delve deeper into the properties and uses of each material, highlighting the specific areas where they excel. From thermal and chemical resistance to low porosity and high fatigue strength, these high-performance plastics have a wide range of applications across industries. Let’s explore their characteristics and discover which one is the right fit for your needs.

Now that we have a visual representation of delrin and acetal, we can proceed to examine their individual characteristics and applications in detail. Stay tuned for the upcoming sections where we will explore the unique properties of acetal and delrin, as well as their uses in various industries.

What is Acetal?

Acetal is a semi-crystalline engineering thermoplastic that is also known as polyoxymethylene (POM). POM comes in two forms: homopolymer and copolymer. The terms “POM” and “acetal” can often be used interchangeably, with “acetal” generally referring to the copolymer version.

Acetal copolymer is a chain of CH2O molecules with additional comonomers added in after every 70 to 100 units of CH2O. These comonomers disrupt the regular ordering of the molecular chains, making the material less crystalline.


Acetal is a versatile material with a wide range of applications. Its unique properties make it suitable for various industries, including automotive, electronics, healthcare, and more.

Let’s explore the characteristics and uses of acetal in more detail.

Characteristics of Acetal

Acetal polymers offer a range of impressive characteristics that make them highly versatile and suitable for various applications. Let’s explore the key features of acetal:

Thermal Resistance

Acetal polymers exhibit excellent thermal resistance, allowing them to withstand high temperatures without significant degradation in their mechanical properties. This resilience makes them ideal for applications requiring prolonged exposure to elevated temperatures.

Chemical Resistance

Acetal copolymers demonstrate remarkable chemical resistance, providing protection against both organic and inorganic solvents, as well as corrosive acids. This characteristic ensures the longevity and performance of acetal components in challenging environments.

Low Coefficient of Friction

One notable advantage of acetal is its low coefficient of friction. This property reduces the resistance between mating surfaces, resulting in smooth and efficient movement. Acetal’s low coefficient of friction is particularly valuable in applications where friction should be minimized to avoid wear and tear.

Reinforcing Capability

Acetal polymers readily accept reinforcing materials like glass fiber, enhancing their strength and stiffness. The addition of reinforcing agents strengthens the material, making it suitable for applications requiring increased durability and structural integrity.

Low Porosity

Acetal possesses low porosity characteristics, which contribute to its resistance against degradation caused by prolonged exposure to hot water. Its low porosity makes it a reliable choice for applications that require resistance to moisture and water-related damage.

Resistance to Hot Water

Another notable characteristic of acetal is its resistance to hot water. It can withstand prolonged exposure to hot water without experiencing significant degradation in its properties, making it suitable for applications in plumbing, HVAC systems, and hot water handling equipment.

High Continuous Service Temperature

Acetal polymers exhibit high continuous service temperature, allowing them to function reliably under demanding thermal conditions. Their ability to retain their mechanical properties at elevated temperatures makes acetal invaluable in applications exposed to extreme heat.

thermal resistance

Now that we have explored the characteristics of acetal, let’s delve into its various applications in Section 4.

Uses of Acetal

Acetal polymers have a wide range of applications across various industries, making them highly versatile and sought after. Here are some common uses of acetal:

  • Insulin Pens: Acetal is used in the manufacturing of insulin pens, ensuring precise and controlled delivery of medication.
  • Dry Powder Inhalers: Acetal components are crucial in dry powder inhalers, allowing for efficient and accurate medication delivery to patients with respiratory conditions.
  • Electric Toothbrushes: The superior durability and moisture resistance of acetal make it an ideal material for electric toothbrushes, ensuring long-lasting performance.
  • Electrical Connectors: Acetal is widely used in the production of electrical connectors due to its excellent electrical insulation properties.
  • Kitchenware: Acetal’s resistance to heat and chemical exposure makes it a preferred material for manufacturing kitchenware such as utensils, handles, and cutting boards.
  • Gears: Acetal gears are commonly used in mechanical systems due to their exceptional wear resistance and low friction properties.
  • Valves and Pumps: Acetal’s chemical resistance and dimensional stability make it suitable for use in valves, pumps, and other fluid control devices.
  • Fuel Sender Units: Acetal’s resistance to chemicals and automotive fluids makes it an ideal material for fuel sender units in vehicles.
  • Door Locks: Acetal components are utilized in the manufacturing of door locks, providing superior strength and durability.
  • Vehicle Fuel Tanks: Acetal’s excellent resistance to solvents and chemicals makes it a reliable material for constructing fuel tanks in vehicles.

With its combination of desirable properties and ease of manufacture, acetal continues to find new and diverse applications in numerous industries.

What is Delrin®?

Delrin® is a semicrystalline homopolymer POM developed by DuPont. As one of the strongest and stiffest unreinforced polymers, Delrin® offers exceptional performance and reliability. Its unique composition makes it a top choice in various industries.

Delrin® is made up of a uniform backbone consisting of repeating units of CH2O. This composition allows for the formation of larger crystalline blocks compared to other polyoxymethylene (POM) materials. The larger crystalline structure contributes to the material’s strength and rigidity.

There are different types of Delrin®, some of which are filled with additives like glass fiber and PTFE. These fillers further enhance the properties of Delrin®, making it suitable for even more demanding applications.


Properties Delrin®
Strength One of the strongest unreinforced polymers
Stiffness High stiffness
Additives Some types filled with glass fiber and PTFE

Characteristics of Delrin®

Delrin® acetal resin is a versatile material that offers several notable characteristics. These characteristics make it a popular choice for various applications in different industries.

Easy to Mold

Delrin® is easy to mold due to its excellent flowability in liquid form. It fills injection molds better than similar materials, allowing for the production of intricate and detailed parts with high precision.

Crystalline Structure

Delrin® exhibits a high degree of crystallinity, which contributes to its exceptional mechanical properties. The crystalline structure gives Delrin® strength, stiffness, and springback, making it a reliable choice for demanding applications.

High Yield Strain

Delrin® has a high yield strain, meaning it can deform significantly under stress before reaching its elastic limit. This characteristic allows Delrin® to flex with minimal permanent deformation, making it an ideal material for snap-fit connectors and other applications that require flexibility.

High Toughness

Delrin® is known for its high toughness, enabling it to withstand impact and mechanical stress without breaking or cracking easily. This toughness makes it suitable for applications where durability is crucial.

Temperature Resistance

Delrin® has good temperature resistance and can endure high temperatures for short periods without significant degradation. This attribute makes it suitable for applications that experience thermal variations or intermittent exposure to elevated temperatures.

Fatigue Strength

Delrin® exhibits excellent fatigue strength, allowing it to withstand repeated cyclic loading without experiencing fatigue failure. This characteristic makes it a reliable choice for applications subjected to continuous cyclic loading, such as gears or spring-like components.

temperature resistance

The image above showcases the temperature resistance of Delrin®, highlighting its ability to withstand high temperatures while maintaining optimal performance.

Difference Between Acetal and Delrin®

When comparing acetal and Delrin®, several key factors set them apart, including their molecular makeup, strength, composition, hardness, chemical resistance, temperature tolerance, flexural yield strength, tensile strength, porosity, application, and cost.

Molecular Makeup

Delrin® has a more ordered crystalline structure due to its uniform backbone, while acetal has a less ordered structure.


Delrin® exhibits higher stiffness and strength compared to acetal, making it a more robust and durable material.


Acetal is commonly available as copolymers, whereas Delrin® is a homopolymer. The difference in composition affects their performance in various applications.


Acetal has a hardness of 85 Shore D, while Delrin® has a slightly higher hardness of 86 Shore D.

Chemical Resistance

Acetal copolymers have better resistance to acids and bases compared to Delrin®, which may be affected by the presence of acids, bases, or oxidizing agents.

Temperature Tolerance

Delrin® offers a higher temperature tolerance compared to acetal, allowing it to withstand more extreme temperature conditions.

Flexural Yield Strength and Tensile Strength

Delrin® exhibits higher flexural yield strength and tensile strength, making it more suitable for applications that require superior mechanical performance.


Delrin® has increased centerline porosity, which can affect its overall performance in certain applications. Acetal, on the other hand, is less prone to centerline porosity.


Both acetal and Delrin® have a wide range of applications across various industries, including automotive, electronics, and consumer goods. Their specific properties make them suitable for different types of products.


Acetal tends to be more cost-effective compared to Delrin® due to branding and better mechanical properties. The cost difference may influence material selection in certain applications.

Properties Acetal Delrin®
Strength Lower Higher
Hardness (Shore D) 85 86
Chemical Resistance Better Not as good with acids, bases, or oxidizing agents
Temperature Tolerance Lower Higher
Flexural Yield Strength Lower Higher
Tensile Strength Lower Higher
Porosity Less prone Increased centerline porosity
Cost Cheaper Relatively expensive


In conclusion, when comparing Delrin® and acetal, it is clear that both materials offer excellent properties and have their own unique applications. Acetal is the preferred choice for applications that require continuous high-temperature exposure, while Delrin® is better suited for applications involving continuous cyclic loading.

The decision-making process for choosing between Delrin® and acetal should consider the specific requirements of the application. Factors such as chemical resistance, temperature tolerance, and mechanical properties should be carefully evaluated to determine the most suitable material.

Consulting with an expert in plastic materials is highly recommended to ensure the best choice for each specific application. They can provide valuable insights and guidance to make an informed decision that meets the project’s needs.


What is the difference between Delrin and Acetal?

Delrin is a homopolymer POM developed by DuPont, while acetal refers to a more generic copolymer version. Delrin has a more ordered crystalline structure and offers higher stiffness, flex fatigue resistance, and creep resistance compared to acetal.

What are the characteristics of Acetal?

Acetal is a semi-crystalline engineering thermoplastic with good thermal resistance, chemical resistance, low coefficient of friction, and low porosity. It can withstand prolonged exposure to hot water and has a high continuous service temperature.

What are the uses of Acetal?

Acetal is used in various industries, including the manufacture of insulin pens, dry powder inhalers, electric toothbrushes, electrical connectors, kitchenware, gears, valves, pumps, fuel sender units, door locks, and vehicle fuel tanks.

What is Delrin?

Delrin is a trade name for a semicrystalline homopolymer POM developed by DuPont. It is known for its strength, stiffness, and easy moldability.

What are the characteristics of Delrin?

Delrin has a high degree of crystallinity, giving it excellent mechanical properties such as high yield strain, toughness, and temperature resistance. It is also highly resistant to fatigue.

How do Acetal and Delrin differ?

Acetal and Delrin differ in terms of their molecular makeup, with Delrin having a more ordered crystalline structure. Delrin offers higher stiffness, flexural yield strength, and tensile strength compared to acetal. Acetal copolymers have better chemical resistance to acids and bases compared to Delrin.

What are the applications of Acetal and Delrin?

Acetal and Delrin have a wide range of applications. Acetal is commonly used in insulin pens, dry powder inhalers, electric toothbrushes, electrical connectors, and kitchenware, while Delrin is ideal for snap-fit connectors, gears, valves, pumps, door locks, and vehicle fuel tanks.

Which is cheaper, Acetal or Delrin?

Acetal is generally cheaper than Delrin due to branding and better mechanical properties of Delrin.

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