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.

Съдържание


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.

СобственостTypical ValueWhy It Matters
Сила на опън60–70 MPaHandles static loads
Модул на огъване2.8 GPaHigh stiffness
Удължение при скъсване20–40 %Добра здравина
Плътност1.41 g/cm³Lighter than metals
Operating Temp.-40 °C to +105 °CWide service range
Water Absorption (24 h)<0.3 %Stable dimensions
Коефициент на триене0.2 (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

ФункцииDelrinНайлон 6ABSUHMW-PE
Абсорбиране на влагаНисъкВисокаНисъкVery low
Friction CoefficientVery lowНисъкУмеренUltra low
ОбработваемостОтличенДобърFairТрудно
Heat Distortion °C100809070
Relative CostСреденLow-mediumНисъкВисока

5. Main Grades of Delrin

СтепенFiller or AdditiveMain Benefit
Делрин 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

Инжекционно формоване

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

CNC обработка

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

ИндустрияPart ExampleReason for Delrin Choice
Автомобилна индустрияWindow gearLow noise, high wear life
електроникаConnector housingTight tolerance, dielectric
МедицинскиInsulin pump gearChemical resistance, precision
ConsumerKnife handleGrip strength, machinability
ИндустриаленConveyor 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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