What Is Delrin? A Complete Guide to the Acetal Homopolymer

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.

Spis treści


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.

NieruchomośćTypical ValueWhy It Matters
Wytrzymałość na rozciąganie60–70 MPaHandles static loads
Moduł sprężystości2.8 GPaHigh stiffness
Wydłużenie przy zerwaniu20–40 %Dobra wytrzymałość
Gęstość1.41 g/cm³Lighter than metals
Operating Temp.-40 °C to +105 °CWide service range
Water Absorption (24 h)<0.3 %Stable dimensions
Współczynnik tarcia0.2 (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

CechaDelrinNylon 6ABSUHMW-PE
Absorpcja wilgociNiskiWysokiNiskiVery low
Friction CoefficientVery lowNiskiUmiarkowanyUltra low
ObrabialnośćDoskonałyDobryUczciwyTrudne
Heat Distortion °C100809070
Relative CostŚredniLow-mediumNiskiWysoki

5. Main Grades of Delrin

StopieńFiller or AdditiveMain Benefit
Delrin 100AFPTFE LubricantUltra-low friction
Delrin Glass-Filled25 % Glass FiberHigh stiffness
Delrin UV-StabilizedUV InhibitorsBetter outdoor life
Delrin FDAFood-gradeSafe for food contact
Delrin Low VOCLow outgassingAutomotive interiors

6. Processing Methods

Formowanie wtryskowe

Most Delrin parts are molded. Melt temperature is 190–215 °C. Mold temperature is 80–100 °C for best surface.

Obróbka CNC

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

PrzemysłPart ExampleReason for Delrin Choice
MotoryzacjaWindow gearLow noise, high wear life
ElektronikaConnector housingTight tolerance, dielectric
MedycznyInsulin pump gearChemical resistance, precision
ConsumerKnife handleGrip strength, machinability
PrzemysłowyConveyor rollerLow 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.

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Lee
Lee

I love to learn and share knowledge about CNC machining and various processing materials. I am very happy to pass on knowledge with everyone!

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