Acetal vs Delrin: A Comprehensive Comparison for Manufacturing and Mechanical Design

Polyoxymethylene, also named Acetal copolymer, is a thermoplastic which has semi-crystalline nature. Acetal copolymer has excellent dimensional stability, durability, and high friction. Acetal homopolymer known as Delrin has exceptional stiffness, strength, and flexibility. In this article, you will understand the difference between Acetal and Delrin. Acetal copolymer is used in applications where long-term chemical exposure is required because acetal copolymer shows excellent chemical resistance. Delrin, an acetal homopolymer is used in applications where high toughness is required.

What is Acetal?

Engineering material Acetal copolymer is organic and has a chemical structure in which central carbon is attached with two oxygens. The reaction of ketone or aldehyde with alcohols by removal of water results in the formation of acetal copolymer. During the acetal copolymer reaction, an intermediate is formed called hemiacetal which is not stable. Acetal copolymer is an engineering material that exists in mixed form with different R groups or symmetrical form with the same R groups. Acetal homopolymers are used in applications like door locks, power windows, vehicle tanks, containers, guitar picks, acetal resin, and electrical components.

What is Delrin?

A high-performance acetal homopolymer resin having excellent mechanical and physical properties known as Delrin. The acetal homopolymer known as Delrin is a semi-crystalline engineering material with excellent dimensional stability, flexibility, stiffness, impact resistance, and durability. Delrin can operate at a wide temperature range from -40°C to 120°C. Delrin has excellent wear resistance and low friction that’s why used in making mechanical parts like gear, rolling, actuators, rollers, valves, and safety restraints. precise Delrin machining can be done by CNC with excellent dimension stability.

Delrin chemical structure.

Types of Delrin

The types of Delrin depend upon the amount and type of filler added to improve the desired properties like chemical resistance, wear resistance, strength, and stiffness. High-performance applications require filled grades of Delrin.

Filled grades:

Delrin 570: This grade contains 20% glass fiber. It improves the mechanical properties of the Delrin.

Delrin 525GR: This type has high stiffness, strength, and creep resistance and contains 25 % glass reinforcement.

Delrin AF DE588: It is a certified grade used by the US Navy.it is fully tested and contains 20% of PTEE.

Delrin AF 500: This grade is used in applications where low friction and wear are required it contains 20% Teflon PTEE fiber.

Delrin AF 100: This grade is best known for excellent lubricity; wear resistance and coefficient of friction and contains 13% PTEE fiber.

YouTube video explaining the difference between Acetal and Delrin.

https://www.youtube.com/watch?v=135MfI69_tE&pp=ygUPYWNldGFsIHZzZGVscmlu

Acetal Copolymer vs. Acetal Homopolymer

Acetal exists in two forms, copolymer and homopolymer. The copolymer form of acetal is flexible and has excellent corrosion resistance while homopolymer form also known as Delrin is best known for high mechanical properties. Further comparison between both types is discussed below.

Definition and Comparison

Acetal:The cooperation of monomeric multiple subunits in the polymer chain is known as polyoxymethylene plastic or Acetal copolymer. Acetal copolymers show excellent heat resistance and chemical resistance for acids and solvents up to a PH range of 4 to 13. Acetal copolymers show lower outgassing and up to 100 degrees Celsius hydrolysis resistance. Less centerline porosity which provides excellent structural integrity and consistent color. Acetal copolymer has less chance of bacterial growth.

Acetal round rods.

Delrin:An Acetal homopolymer with a uniform crystalline structure and distinct mechanical properties is known as Delrin. It has a chemical structure with a CH2O repeating unit. Compared to Acetal shows less chemical resistance up to 4-9 PH. Delrin shows hydrolysis resistance up to 60 degrees Celsius. Delrin shows higher outgassing and has a higher potential for bacterial growth. The centerline porosity is very high, which is why structural integrity is compromised and shows inconsistent color.

Delrin plastic mechanical parts.

What are Delrin and Acetal used for?

The applications where acetal and Delrin are used are listed below:

• Gears
• Bushings
• Fuel system components.
• Insulators
• Switches
• Connectors
• Zippers
• Buckles
• Handles
• Conveyor belts
• Bearings
• Rollers
• Guitar picks

YouTube video explaining the type of acetal copolymer and homopolymer.

https://www.youtube.com/watch?v=3nzbXXwWcTQ&pp=ygUPYWNldGFsIHZzZGVscmlu

Use in Food Processing

Acetal centerline porosity is less and hence has more structural integrity, excellent chemical resistance, and less chances of bacterial growth making it ideal to use in food processing equipment and containers. Compared to Acetal, Delrin is less chemically resistive and has high centerline porosity, making it less suitable for food processing applications.

Advantages and Disadvantages

The table below shows the contrast between advantages and disadvantages of acetal and Delrin.

Key Differences Between Acetal and Delrin

The contact between properties of acetal vs Delrin is numerically compared below in table.

Material Science Insights

The material science includes chemical structure, mechanical properties, thermal properties, and respective applications of acetal and Delrin. Chemical structure of acetal and Delrin and different types of plastics used in engineering is given below.

Crystal Structure and Material Composition

Acetal:It is a polyoxymethylene semi-crystalline structure. It has monomeric multiple subunits in the polymer chain.

Delrin: Has repeated CH2O units in its chemical structure. It has a uniform crystalline structure.

Types of Plastic Used in Engineering

Types of plastic used in engineering are listed below:

• Polyamides (nylons)
• Acrylonitrile butadiene styrene (ABS)
• Polyether ether ketone (PEEK)
• Liquid crystal polymers (LCPs)
• Polycarbonates (PC)
• Polyesters
• Ultra-high-molecular-weight polyethylene (UHMWPE)
• Polytetrafluoroethylene (PTFE)

Manufacturing and Machining Perspectives

The manufacturing of an engineering material is a very crucial step because small changes in the parameter and concentration of raw material will result in compromised properties. Similarly machining of an engineered material to desired shape is also crucial for dimension stability and surface finish. Both manufacturing and machining of acetal and Delrin are discussed below.

Machinability of Acetal vs. Delrin

Acetal and Delrin both are engineering materials that can be machined through CNC machining. Delrin is harder compared to acetal so has more wear and abrasion resistance during machining. Compared to Acetal Delrin has excellent dimensional stability so can be machined to a high tolerance. Delrin has high centerline porosity due to which has inconsistent color. Pores and bubbles in Delrin cause the trapping of gases and liquids making them not suitable for medical and food applications.

YouTube video explaining Delrin machining by CNC.

https://www.youtube.com/watch?v=rz8CNaPPTuc

Tools and Techniques

Acetal and Delrin machining can be done through CNC easily. For CNC machining of Delrin and Acetal, we should consider the following things.

• Sharp high-speed steel cutting tool with a high relief angle and high rake would improve the final product finish.
• Mitigation of acetal parts tool marks by bead blasting
• More frequent tool changes are required for Delrin due to higher hardness[8].

Dimensional Stability in Product Design

Compared to Acetal Delrin has excellent dimension stability. Overall, both have good dimensional stability, which is why are used in a wide range of industrial applications. Tight tolerance and high precision are attained by both materials even in making parts of assembly.

Cost and Practical Considerations in Choosing Materials

Acetal vs Delrin cost and availability consideration is compared also maintenance and long-term durability consideration is discussed below in table.

Expanding Topics, you Don’t Know About

Acetal and Delrin are compared with other plastics below. Discussing acetal and Delrin with other plastics will help you know the key differences between them and choose the best for you.

Acetal vs nylon

Acetal copolymer and nylon thermoplastics are versatile engineering materials. Acetal has excellent dimension stability, higher stiffness, and low friction. Acetal copolymer is used in applications where high mechanical strength and chemical resistance are required. Nylon on the other hand has flexibility, abrasion resistance, and higher toughness. Nylon is used in applications where high flexibility, fatigue resistance, and impact resistance are required.

Ultem vs Delrin

Ultem and Delrin are different thermoplastic materials, both have different properties and applications. Ultem has a polyetherimide structure, high flame retardation, exceptional strength, and high heat resistance. An acetal homopolymer, Delrin has high wear resistance, stiffness, excellent dimensional stability, and high strength. Ultem is used in applications where high strength, high-temperature resistance, and flame retardation are required. while Delrin is used in applications where flexibility, low friction, and stiffness are required. Delrin machining is easy compared to Ultem.

Ultem component.

HDPE vs Delrin

HDPE is known as high-density polyethylene known for high chemical resistance, flexibility, and impact strength which is why it is used in applications like packaging, bottles, and pipes. HDPH has high chemical resistance and flexibility compared to Delrin, but Delrin excels in mechanical properties.

HDPH bottles.

Delrin 150 vs Acetal

Acetal resin types Delrin 150 and Acetal are used for different purposes. Delrin 150 is used for extrusion applications due to its high viscosity. Delrin 150 has low die deposits and high thermal stability. Acetal is used in versatile applications where chemical resistance and high mechanical properties are required.

Delrin 150 components.

Black Acetal vs Delrin

Both black acetal and Delrin are Acetal resins with different characteristics. Black acetal is used for aesthetic purposes and has excellent dimensional stability, low friction, and stiffness.

Black acetal sheet.

Delrin vs Acetal Homopolymer vs Copolymer

The comparison between the properties of Delrin, Acetal copolymer and homopolymer are given below in table.

YouTube video explaining the difference between Delrin vs acetal homopolymer vs copolymer.

https://www.youtube.com/watch?v=Fzk6aIekIwk&pp=ygUPYWNldGFsIHZzZGVscmlu

Conclusion

It is concluded that both acetal and Delrin are thermoplastic polymers. Acetal has two types copolymers and homopolymers. The homopolymer form of acetal is known as Delrin. Acetal is formed by the reaction of ketone and aldehyde by alcohol. During the reaction, water is removed. Acetal has two oxygen atoms bounded by a central carbon atom in its chemical structure. Acetal and Delrin both can be machined through CNC machining. Compared to Acetal Delrin is more expensive. Major manufacturers of Delrin are DuPont. Acetal is mainly known for its chemical resistance, low friction, and higher impact resistance. Delrin is harder than acetal and is mainly known for its mechanical strength, stiffness, and excellent dimension stability.

FAQ

Is acetal the same as Delrin?

NO! They are not the same, but both are thermoplastics. Delrin is also a type of acetal but is a homopolymer but acetal itself is a copolymer. Acetal is used in applications where chemical resistance is required and is good for food and medicine packaging due to low bacterial growth. Delrin has high centerline porosity so has more probability of growing bacteria that’s why is not considered good for food and medicine packaging.

What is stronger than Delrin?

Ultem is stronger than Delrin and is a high-performance thermoplastic with high strength and stiffness compared to Delrin.

Is acetal a hard or soft plastic?

Acetal is thermoplastic which is hard known for its high strength, excellent dimension stability, and stiffness.