Polyoxymethylene (POM): The Engineering Plastic Revolutionizing Precision Manufacturing

Polyoxymethylene (POM), also known as polyacetal or acetal, is an engineering thermoplastic that has gained a prominent place in the manufacture of precision parts.
With properties such as high stiffness, low friction, and excellent mechanical strength, POM has become an indispensable material in a wide range of industrial applications.
This article explores in detail the characteristics of POM and its impact on various industries, from automotive to electronics, highlighting why it is a material you should consider in your engineering projects.

What is Polyoxymethylene (POM)?

Polyoxymethylene (POM) is a thermoplastic polymer obtained by the polymerization of formaldehyde, resulting in a highly crystalline material.
This crystalline structure gives POM high stiffness and mechanical strength, making it ideal for applications requiring dimensional accuracy and durability.
In addition, POM is known for its low friction and wear resistance, making it a preferred material for components that experience repetitive motion or constant contact with rough surfaces.

What are the main properties of POM?

POM exhibits a unique combination of properties that make it exceptionally versatile.
Some of the most outstanding properties include:

High Mechanical Strength: POM is able to withstand high forces without deformation, which is crucial in applications requiring stiffness and strength.
Low Moisture Absorption: Unlike other plastics, POM maintains its mechanical properties even in humid environments, which is essential for outdoor applications or in variable conditions.
Dimensional Stability: POM maintains its shape and size over a wide temperature range, ensuring accuracy in applications requiring tight tolerances.

How is POM Processed in Manufacturing?

POM is highly processable, meaning it can be molded and manufactured into various shapes and sizes with ease.
Common processing techniques include:

Injection Molding: This method is ideal for mass production of complex and precise parts, where maintaining the mechanical properties of the material is required.
Extrusion: Used to create continuous profiles, such as tubes and bars, POM extrusion allows the production of parts with customized lengths.
Machining: POM is easy to machine, allowing for precise fits and high quality surface finishes.

What Industrial Applications Use POM?

POM is used in a wide range of industries due to its versatility and excellent properties.
Some of the typical applications include:

Automotive Industry: POM is commonly used in the manufacture of gears, bearings, and valves, where its wear resistance and low friction are crucial.
Electronics: In this industry, POM is used in the manufacture of housings, connectors, and other electrical components, taking advantage of its dielectric properties and resistance to moisture.
Medical Equipment: POM is valued for its biocompatibility and resistance to sterilization, making it ideal for surgical instruments and implantable devices.

What are the advantages of POM compared to other plastics?

POM is distinguished from other plastics due to its combination of mechanical and chemical properties.
Some of the key advantages include:

Low Friction and Wear Resistance: This makes POM ideal for applications where parts are in constant motion or contact.
Chemical Resistance: POM resists a wide range of chemicals, including solvents, oils and fuels, making it suitable for demanding industrial applications.
Thermal Stability: POM maintains its properties over a wide temperature range, which is crucial in applications that experience thermal fluctuations.

What Challenges Does the Use of POM Present?

Despite its many advantages, POM also presents some challenges that must be considered in its industrial use:

Susceptibility to Degradation by Strong Acids: POM can degrade when exposed to strong acids, which limits its use in certain chemical environments.
Controlled Thermal Expansion: Although POM has low thermal expansion, in extremely temperature sensitive applications, this may require careful design to avoid deformation.

What are the differences between homopolymer and copolymer POM?

POM is available in two main forms: homopolymer and copolymer.
Each has its own specific characteristics and applications:

Acetal Homopolymer: Offers higher stiffness and mechanical strength, but is more susceptible to degradation in the presence of acids.
POM Copolymer: Has better thermal stability and chemical resistance, making it suitable for applications where higher resistance to aggressive chemicals is required.

How does POM compare with other engineering materials?

POM compares favorably with other engineering materials due to its combination of properties.
Compared to other thermoplastics such as nylon or polyethylene, POM offers:

Increased Stiffness and Mechanical Strength: Making it ideal for structural applications.
Better Dimensional Stability: Compared to nylon, POM is less susceptible to moisture absorption, maintaining its accuracy in critical applications.
Superior Wear Resistance: Compared to polyethylene, POM offers better wear resistance in high stress applications.

What are the Emerging Applications of the POM?

With the advancement of technology, POM is finding new applications in emerging areas such as:

3D Printing: POM is being explored as a material for additive manufacturing due to its stiffness and dimensional stability.
Industrial Automation: In automated systems, POM is used for the manufacture of parts that require high precision and durability.
Consumer Electronics: POM is being used in portable electronic devices due to its strength and light weight.

Conclusion: Why Choose POM for Your Next Project?

Polyoxymethylene (POM) is an exceptionally versatile engineering plastic that offers a unique combination of strength, stiffness, and dimensional stability.
These properties make it ideal for a wide range of industrial applications, from automotive to electronics.
If you are looking for a material that can improve the efficiency of your manufacturing processes and offer superior performance, POM is an option you should definitely consider.

Summary of Key Points:

• POM is a highly crystalline polymer with excellent stiffness and mechanical strength.
• It offers low friction and high wear resistance, ideal for high speed applications.
• It maintains its dimensional stability over a wide temperature range, which is crucial for precise tolerances.
• It is resistant to chemicals, making it suitable for automotive, electronics and medical equipment applications.
• Easy to process by injection or extrusion, facilitating the manufacture of complex and high quality parts.

Q: What is Polyoxymethylene (POM) and why is it considered an engineering plastic?

A: Polyoxymethylene (POM), also known as acetal, is an engineering thermoplastic characterized by high toughness, stiffness and hardness, as well as excellent dimensional stability.
It is widely used in precision manufacturing due to its low coefficient of friction and good abrasion resistance.

Q: What are the differences between POM-C and POM-H?

A: POM-C (acetal copolymer) and POM-H (acetal homopolymer) are two types of acetal resins.
POM-C has better resistance to oxidation and hydrolysis, while POM-H offers higher stiffness and hardness, as well as higher crystallinity, giving it excellent dimensional stability.

Q: What are the typical applications of POM in industry?

A: Typical applications for POM include the manufacture of sprockets, screws, springs, and sliding components.
Its high hardness and good fatigue strength make it ideal for parts requiring high precision and wear resistance.

Q: How does POM perform against abrasion and oxidation?

A: POM shows excellent abrasion resistance and good dimensional stability, making it ideal for applications where wear is a critical factor.
However, POM-C offers improved oxidation resistance compared to POM-H.

Q: Is POM suitable for precision machining?

A: Yes, POM is well suited for precision machining due to its high stiffness and hardness, as well as its dimensional stability.
These properties allow machined parts to maintain their dimensions and tolerances consistently.

Q: What advantages does POM offer in terms of slip and impact resistance?

A: POM has a low coefficient of friction, which gives it excellent sliding properties.
In addition, it offers good impact resistance, making it suitable for applications where resistance to shock and vibration is required.

Q: What kind of products can be manufactured with POM?

A: POM can be used to manufacture a wide variety of products such as sprockets, screws, machine components, and automotive parts.
Its high hardness and good fatigue strength allow its use in high performance and precision applications.

Q: How does POM perform in terms of fatigue and creep resistance?

A: POM exhibits excellent fatigue resistance and good creep resistance, making it ideal for applications requiring long-term durability under cyclic loading and constant stress.

Q: What is the melting point of POM and how does it affect its processing?

A: The melting point of POM is approximately 175°C for POM-C and 180°C for POM-H.
This relatively high melting point allows the material to maintain its physical properties at elevated temperatures, facilitating processing and stabilizing the manufactured parts.

Q: What are the outstanding properties of POM as a plastic material?

A: POM is known for its high hardness, stiffness and toughness, excellent dimensional stability, low coefficient of friction and good abrasion resistance.
These properties make it ideal for high precision and performance applications, especially in the manufacture of mechanical and sliding components.