Acetal and Delrin, both types of acetal plastic, are two high-performance POM polymers that find extensive use in various industrial and engineering applications. While these materials may seem similar in certain aspects, they also possess unique characteristics that set them apart from each other.
Despite their exceptional shared properties, Delrin and Acetal have distinct characteristics that further differentiate them and create this complex understanding of which is more suitable for specific applications.
For example, Acetal plastic is ideal for extended exposure to high temperatures, while Delrin is preferred in applications that involve continuous cyclic loading.
This comprehensive article examined the differences between Acetal and Delrin, including their properties, benefits, and limitations to provide you with a better understanding of how to make the right decision.
We promise you will gain the necessary insights to make informed decisions when selecting suitable material, such as POM plastic, for your project.
I. What is Acetal?
Acetal plastic, also known as polyoxymethylene (POM), is a type of semi-crystalline engineering thermoplastic that possesses remarkable mechanical strength and fatigue resistance.
Its semi-crystalline form makes it highly rigid and stiffer. It’s well-known for its ability to boost remarkable resistance to chemicals, abrasion, and moisture in parts to use efficiently in harsh environments.
What sets Acetal plastic apart from any other industrial and engineering POM plastic is its ability to maintain its strength and stiffness even when exposed to high temperatures for extended periods.
Furthermore, its easy machinability makes it an ideal choice for parts that require tight tolerances and precision machining.
With a low coefficient of friction and excellent wear resistance, Acetal is a perfect fit for moving mechanical components such as gears, bearings, and rollers.
Characteristics of Acetal
Several characteristics make Acetal a useful POM plastic for various industrial and engineering applications, including:
- It has exceptional mechanical strength, stiffness, and fatigue resistance.
- It’s excellent resistance to chemicals, acids, bases, and solvents.
- It has good moisture resistance and can withstand prolonged exposure to high temperatures.
- It has good dimensional stability and does not shrink or expand.
- It’s relatively easy to machine and can be machined to tight tolerances.
- It exhibits effective electrical insulation properties and shows outstanding resistance to UV radiation.
- It’s FDA-compliant POM plastic suitable for food-contact applications.
Overall, Acetal plastic is a high-performance material with mechanical, chemical, thermal, and electrical properties that make it suitable for various applications.
Advantages of Acetal
The advantages of Acetal are directly linked to its specifications. Its exceptional mechanical strength, stiffness, and dimensional stability are some of its many benefits. Its crystallized and rigid form is a credit behind its rich properties. Acetal plastic can handle extreme temperatures from 180°C to 210°C (356°F to 410°F).
Moreover, Acetal’s smooth operation in mechanical applications that demand supreme durability for optimal performance is facilitated by its low friction coefficient (typically ranging from 0.12 to 0.20).
Its ability to reduce energy consumption and minimize wear and tear makes it an excellent POM plastic for industrial and engineering applications.
It has excellent dimensional stability and can maintain its shape in extreme conditions. With its low coefficient of thermal expansion (ranges from 1.3-1.5 x 10^-5/°C), it does not expand or contract significantly with temperature changes, and that makes it ideal for precision parts that require tight tolerances.
Applications of Acetal
Acetal serves a large library of industrial and engineering applications, including:
- Automotive industry (fuel system components, airbag components, and seat belt components)
- Electrical industry (electrical insulators, switchgear components, and cable ties)
- Consumer goods industry (zippers, toys, and handles for kitchen tools and utensils)
- Medical industry (medical instruments, surgical instruments, and orthopedic implants)
- Sports equipment industry (ski bindings, golf balls, finishing reels)
The excellent electrical insulation properties, high durability, wear & tear resistance, and biocompatibility of Acetal plastic enable it to serve nearly every industrial and engineering application.
II. What is Delrin?
Delrin, also referred to as Acetal resin or semi-crystalline POM plastic, is a trademark name for this particular polymer. DuPont developed it in the 1950s to replace metal parts in various industrial and engineering applications.
In today’s industry, Delrin cemented its feet in the high-tech sectors like automotive, aerospace, and healthcare.
Delrin is offered in different grades and formulations, such as unfilled, glass-filled, and PTFE-filled, each with distinct Delrin material properties tailored for specific applications. It gives a supreme performance compared to Acetal plastic due to its superior mechanical properties.
Furthermore, its high crystallinity, uniform molecular makeup, and supreme Delrin temperature range set it apart from other POM plastics.
Characteristics of Delrin
Delrin is a supreme thermoplastic polymer renowned for its unparalleled toughness, temperature range, material properties, and versatility.
The many characteristics that make Delrin a popular choice for a wide range of applications are genuinely remarkable, including the following:
- It has excellent strength and rigidity
- Low friction and impeccable dimensional stability ensure it can withstand extreme conditions.
- It exhibits excellent impact resistance down to -40°C and retains impressive strength at elevated temperatures as high as 94°C
- It has the ability to withstand brief temperature peaks of ~120°C (with upper service temperature limits of 82°C in the open air and 65°C in water).
- It’s highly resistant to various chemicals, including solvents, oils, and fuels.
- It boasts impressive creep resistance and electrical insulation properties.
- It can be machined to incredibly tight tolerances.
Delrin is the unequivocal material of choice for industrial and engineering applications when seeking durable and high-performance POM plastic. It is renowned for its robustness and exceptional performance, making it the preferred option across various industries.
Advantages of Delrin
Delrin’s unique properties result from its chemical structure, which consists of repeating units of CH2O and is responsible for its excellent advantages. It has a low coefficient of friction (~0.20 – 0.40), making it a perfect POM plastic for applications that require reduced energy consumption and minimal wear & tear.
Its tensile strength (ranges from 64-80 MPa) and its modulus of elasticity (2.3-3.1 GPa) make it one of the strongest and stiffest polymers.
Its excellent dimensional stability means it can retain its shape and size in extreme temperatures due to its low thermal expansion coefficient and moisture absorption rate of less than 0.25%, which helps prevent warping or deformation.
Delrin material properties along with its remarkable creep resistance, enhance the part’s strength to withstand sustained loads without experiencing permanent deformation. It’s no surprise that Delrin is a material of choice in many industrial and engineering applications.
Applications of Delrin
Delrin’s vast library of applications is credited to its excellent combination of mechanical, thermal, and chemical properties.
- Aerospace industry (gears, bearings, and control cable pulleys)
- Electrical and electronics components (connectors, switches, and housings)
- Automotive industry (fuel systems, airbag components, and interior trim)
- Consumer goods (zippers and kitchen appliances)
- Medical devices (surgical instruments, orthopedic implants, and dental applications)
What makes Delrin an excellent choice for industrial and engineering applications where high performance, durability, and reliability are required is its perfect temperature range and material properties.
III. What Are the Differences Between Acetal Copolymer and Delrin?
When comparing Acetal vs Delrin, it may seem similar to an inexperienced eye, but their molecular structure and unique properties set them apart.
The following are some key differences between Acetal and Delrin:
- Composition: Delrin has an ordered crystalline structure and, therefore, more inter-region bonds. Acetal plastic has a more random molecular arrangement, making it more flexible and resistant to stress cracking, but low strength compared to Delrin.
- Hardness: The hardness of Delrin is typically measured at ~85-87 on the Rockwell scale, while Acetal’s hardness is around ~80-85. This difference results in different durability and wear resistance levels between these two materials, making Delrin a better choice for specific high-stress applications.
- Chemical Resistance: Delrin is highly resistant to most chemicals, and Acetal may not offer the same level of resistance and may be prone to chemical attacks in specific environments.
- Temperature Tolerance: Both materials exhibit good thermal stability. However, Delrin has a slightly higher heat deflection temperature (~95-120°C) than Acetal (~80-110°C). Delrin temperature range and a lower thermal expansion coefficient make it less susceptible to dimensional changes at elevated temperatures.
- Flexural Yield Strength and Tensile Strength: Delrin stands out from Acetal in terms of flexural yield strength and tensile strength, as it offers superior performance in handling higher loads and stresses.
Its higher tensile strength makes it highly resistant to breaking under tension or stretching. Acetal plastic still has good flexural yield and tensile strength and can effectively handle lower loads and stresses without degrading performance.
- Porosity: The porosity of Acetal and Delrin differ due to their molecular structure. Acetal has a more amorphous molecular structure, which means it has a higher porosity than Delrin, which has a more ordered crystalline structure. The higher porosity means the material has reduced strength and stiffness and an increased tendency to absorb moisture.
- Application: Acetal is a better option for applications that require a balance of strength, stiffness, and toughness, such as gears, bearings, and electrical components. Delrin is the material of choice for applications demanding exceptional strength, rigidity, dimensional stability, wear resistance, and creep resistance, making it ideal for automotive components, conveyor systems, and precision machinery parts.
Both materials are used in various industrial and engineering applications due to their durability and ease of processing.
- Cost: Acetal is cheaper and a cost-effective choice than Delrin. Delrin has a more complex manufacturing process involving higher-quality raw materials and tighter production tolerances.
IV. Acetal vs Delrin: When to Choose between Them?
Acetal and Delrin are excellent engineering thermoplastics, but there are specific scenarios where one may be preferred over the other.
Other than application requirements, manufacturing process, and cost, the following are some scenarios where the difference between Acetal vs Delrin is justified:
- Heavy Loads: The material that has the superior crystalline structure and increased inter-region bonds can handle heavy loads more efficiently and in the case of Delrin vs Acetal, Delrin is a more efficient material.
- Friction: Acetal plastic has a lower coefficient of friction compared to Delrin, and that makes it a better choice when low friction is required. And what enables Delrin to maintain its shape and form under extreme stress is its supreme dimensional stability, making it an optimal choice for industrial and engineering applications that involve high loads and pressure.
- Dimensional Stability and Lightweight: Both are excellent materials for applications where dimensional stability and lightweight are essential, but Acetal is lighter than Delrin. However, Delrin material properties give it slightly better dimensional stability due to its ordered crystalline structure.
- Chemical Resistance: Delrin boasts slightly superior chemical resistance, making it a preferred option for applications where exposure to chemicals is a concern. However, both materials should be evaluated for compatibility with specific chemicals and conditions.
- Temperature and Flammability: Delrin’s temperature range is also between ~30°C – ~70°C more than Acetal and can maintain performance even in negative temperatures of -40°C. In terms of material flammability, Delrin is less flammable than Acetal, has a better UL rating, and is less likely to ignite.
It’s important to carefully evaluate the properties of each material and consider these factors to determine the most suitable option for a given application.
V. Acetal vs Delrin: Which is Cheaper?
When comparing Acetal vs Delrin, the cost can be a significant factor in prioritizing one over the other. While the price can vary depending on the supplier and quantity purchased, Acetal plastic is generally less expensive than Delrin. The cost of raw materials is just one aspect; machining, tooling, and processing Delrin is also expensive compared to Acetal.
However, the ultimate cost-effectiveness of a material will depend on the specific applications and the required properties. Acetal may be cheaper, but Delrin may offer superior performance in specific applications making it the more cost-effective investment in the long run.
When material cost, material quantity & quality, cost per unit, machining, and finishing costs add up can significantly affect the overall cost of the material.
We suggest you conduct a cost-benefit analysis to maximize your chances of a successful production of your parts within budget. You must carefully evaluate all these factors and consult with experts to make an informed decision.
Kemal: Manufacturing Plastic Parts for You
With years of experience and a reputation for excellence, Kemal is a trusted partner in the industry. As a leading parts manufacturer from China, we facilitate our customers worldwide with our state-of-the-art facility, ensuring top-quality results at every step.
Whether it’s Acetal, Delrin, or any other POM plastic, Kemal’s skilled team can help you choose the suitable material for your application.
From design and prototyping to production and delivery, you can trust our end-to-end services to ensure the highest standards of quality and efficiency. With a commitment to customer satisfaction, competitive pricing, and a customer-centric approach, Kemal goes above and beyond to exceed your expectations.
A team of experienced professionals, cutting-edge technology, and rigorous quality control processes supports Kemal’s dedication to providing outstanding manufacturing services.
Our comprehensive manufacturing capabilities include CNC machining, injection molding, 3D printing, and more, providing a wide range of options for different part requirements.
Choose us for reliable, efficient, and high-quality plastic parts manufacturing services you can trust. Contact Kemal today to learn more about our services.
Before You Go
Kemal, as a trusted manufacturing partner, brings a unique blend of experience, expertise, and innovation to deliver exceptional value for your business. With a focus on reducing costs, accelerating time-to-market, and providing a competitive edge,
Kemal’s advanced manufacturing techniques, high-tech software, and automation ensure efficient and effective production of your Acetal, Delrin, or other POM plastic parts.
Our specialized automation solutions, flexibility, responsiveness, and commitment to outstanding quality enable rapid scaling while meeting stringent quality and reliability requirements.
Trust Kemal’s experience, insight, and dedication to customer satisfaction to deliver exceptional results for your manufacturing needs.