Delrin is a brand name for acetal homopolymer resin. It is an engineering plastic known for strength, stiffness, and low friction. Industries use Delrin for gears, bearings, housings, and many moving parts. This guide explains Delrin’s basic facts, key properties, processing options, and common applications in simple language.
Table of Contents
- 1. Definition of Delrin
- 2. Why Choose Delrin?
- 3. Key Properties of Delrin
- 4. Delrin vs Other Plastics
- 5. Main Grades of Delrin
- 6. Processing Methods
- 7. Design Tips for Delrin Parts
- 8. Industrial Applications
- 9. Care and Maintenance
- 10. How to Source Delrin
- 11. FAQs
- 12. Conclusion
1. Definition of Delrin
Delrin is the trade name for acetal homopolymer made by DuPont (now DuPont-Celanese). Chemically, it is polyoxymethylene (POM). It appears as white or black granules and is molded into strong, precise parts.
2. Why Choose Delrin?
- High stiffness and strength.
- Very low friction and wear.
- Dimensional stability over a wide temperature range.
- Resists many fuels, oils, and chemicals.
- Good fatigue and impact performance.
3. Key Properties of Delrin
The table below lists typical property ranges for unfilled Delrin.
| Property | Typical Value | Why It Matters |
|---|---|---|
| Tensile Strength | 60–70 MPa | Handles static loads |
| Flexural Modulus | 2.8 GPa | High stiffness |
| Elongation at Break | 20–40 % | Good toughness |
| Density | 1.41 g/cm³ | Lighter than metals |
| Operating Temp. | -40 °C to +105 °C | Wide service range |
| Water Absorption (24 h) | <0.3 % | Stable dimensions |
| Coefficient of Friction | 0.2 (dry vs steel) | Low wear in sliding |
Mini Bar Chart: Relative Stiffness Index
Delrin ██████████ (100 %) Nylon ████████ (80 %) ABS █████ (60 %) HDPE ███ (30 %) Rubber █ (10 %)
The bar chart uses simple text blocks to show how Delrin’s stiffness compares to other common plastics.
4. Delrin vs Other Plastics
| Feature | Delrin | Nylon 6 | ABS | UHMW-PE |
|---|---|---|---|---|
| Moisture Absorption | Low | High | Low | Very low |
| Friction Coefficient | Very low | Low | Moderate | Ultra low |
| Machinability | Excellent | Good | Fair | Difficult |
| Heat Distortion °C | 100 | 80 | 90 | 70 |
| Relative Cost | Medium | Low-medium | Low | High |
5. Main Grades of Delrin
| Grade | Filler or Additive | Main Benefit |
|---|---|---|
| Delrin 100AF | PTFE Lubricant | Ultra-low friction |
| Delrin Glass-Filled | 25 % Glass Fiber | High stiffness |
| Delrin UV-Stabilized | UV Inhibitors | Better outdoor life |
| Delrin FDA | Food-grade | Safe for food contact |
| Delrin Low VOC | Low outgassing | Automotive interiors |
6. Processing Methods
Injection Molding
Most Delrin parts are molded. Melt temperature is 190–215 °C. Mold temperature is 80–100 °C for best surface.
CNC Machining
Delrin machines like soft metal. Sometime engineer use sharp HSS or carbide tools. Chips break cleanly, reducing dust. In TUOFA China Machining shop, years of machining Delrin parts, would be a better choice to choose from for a project.
Extrusion and Rod Forming
Sheets, rods, and profiles are extruded for later machining or welding.
Welding and Bonding
Hot-gas welding works. Solvent bonding is hard because Delrin resists many chemicals. Mechanical fasteners are common.
7. Design Tips for Delrin Parts
- Add 1–2 % shrinkage allowance for molding.
- Use generous radii (0.5 mm+) to avoid stress cracks.
- For gears, target 0.2–0.3 mm backlash to handle thermal growth.
- Vent molds well to avoid gas traps and burn marks.
8. Industrial Applications
| Industry | Part Example | Reason for Delrin Choice |
|---|---|---|
| Automotive | Window gear | Low noise, high wear life |
| Electronics | Connector housing | Tight tolerance, dielectric |
| Medical | Insulin pump gear | Chemical resistance, precision |
| Consumer | Knife handle | Grip strength, machinability |
| Industrial | Conveyor roller | Low friction, moisture proof |
9. Care and Maintenance
Delrin resists many chemicals but avoid prolonged contact with strong acids. Clean with mild soap and water. For moving parts, periodic silicone or PTFE lubrication can extend life. Avoid continuous use above 100 °C to prevent creep.
10. How to Source Delrin
- Buy certified resin or sheet from major distributors.
- Check lot certifications for food-grade or medical grades.
- Order sample pieces for prototype tests before large volume runs.
11. FAQs
Is Delrin stronger than nylon?
Delrin is stiffer but nylon is tougher. Choose based on need.
Can Delrin be 3D printed?
Special POM filaments exist, but printing requires a heated chamber.
Is Delrin food safe?
FDA grades are food safe. Confirm certification.
12. Conclusion
Delrin delivers a rare mix of strength, low friction, and chemical resistance in one material. With proper grade selection and design, it serves as a reliable choice for gears, bearings, housings, and many precise parts across industries. When you need stable dimensions, clean machining, and long wear life, Delrin is a smart solution.
