Knowde Enhanced TDS
Identification & Functionality
- Polymer Name
- Technologies
- Product Families
Features & Benefits
- Materials Features
- Product Overview
- Low moisture absorption
- High strength, stiffness
- Easy to machine
- No centerline porosity in Acetron® GP
- Many formulation options: Copolymer, Homopolymer, PTFE filled, and Internally lubricated/enhanced wear grade
Acetal provides high strength and stiffness coupled with enhanced dimensional stability and ease of machining. As a semi-crystalline material, acetal is also characterized by a low coefficient of friction and good wear properties -- especially in wet environments.
Because acetal absorbs minimal amounts of moisture, its physical properties remain constant in a variety of environments. Low moisture absorption results in excellent dimensional stability for close-tolerance machined parts. In high moisture or submerged applications, acetal bearings outperform nylon 4 to 1. Acetal is ideally suited for close tolerance mechanical parts and electrical insulators which require strength and stiffness. It also offers resistance to a wide range of chemicals including many solvents.
Mitsubishi Chemical Advanced Materials offers both homopolymer and copolymer grades of acetal including enhanced bearing grade materials. Acetron® GP acetal is porosity-free and offered as our standard general purpose grade. For slightly higher mechanical properties, we offer a broad size range of the homopolymer acetal (Delrin®) products. For improved frictional properties PTFE-enhanced Delrin AF products are available.
- Product Highlights
Acetron POM-H Delrin is a homopolymer acetal, manufactured and stocked in rod and plate. It offers slightly higher mechanical properties than Acetron® GP Acetal, but may contain a low-density center, especially in larger cross-sections. Copolymer acetal also offers better chemical resistance than homopolymer acetal. Delrin is ideal for small diameter, thin-walled bushings that benefit from the additional strength and rigidity of homopolymer acetal.
Applications & Uses
- Applications
- Plastics & Elastomers End Uses
Properties
- Mechanical Properties
- Thermal Properties
- Electrical Properties
- Miscellaneous Properties
- Note
- The figures given for these properties are for the most part derived from raw material supplier data and other publications.
- Values for this property are only given here for amorphous materials and for materials that do not show a melting temperature (PBI, PAI & PI). DMA settings, oscillation amplitude of 0.20 mm; a frequency of 1 Hz ; heating rate of 2°C/min
- Temperature resistance over a period of min. 20,000 hours. After this period of time, there is a decrease in tensile strength – measured at 23 °C (73°F)– of about 50 % as compared with the original value. The temperature value given here is thus based on the thermal-oxidative degradation which takes place and causes a reduction in properties. Note, however, that the maximum allowable service temperature depends in many cases essentially on the duration and the magnitude of the mechanical stresses to which the material is subjected.
- Impact strength decreasing with decreasing temperature, the minimum allowable service temperature is practically mainly determined by the extent to which the material is subjected to impact. The value given here is based on unfavorable impact conditions and may consequently not be considered as being the absolute practical limit.
- These estimated ratings, derived from raw material supplier data and other publications, are not intended to reflect hazards presented by the material under actual fire conditions. There is no ‘UL File Number’ available for these stock shapes.
- Most of the figures given for the mechanical properties are average values of tests run on dry test specimens machined out of rods 40-50 mm (1.5 - 2") when available, else out of plate 10-20mm (0.4 - 0.8"). All tests are done at room temperature (23° / 73°F)
- Test speed: either 5 mm/min or 50 mm/min [chosen acc. to ISO 10350-1 as a function of the ductile behavior of the material (tough or brittle)] using type 1B tensile bars
- Test speed: either 0.2"/min or 2"/min or [chosen as a function of the ductile behavior of the material (brittle or tough)] using Type 1 tensile bars
- Test speed: 1 mm/min, using type 1B tensile bars
- Test specimens: cylinders Ø 8 mm x 16 mm, test speed 1 mm/min
- Test specimens: cylinders Ø 8 mm x 16 mm, test speed 1 mm/min
- Test specimens: bars 4 mm (thickness) x 10 mm x 80 mm ; test speed: 2 mm/min ; span: 64 mm
- Test specimens: bars 0.25" (thickness) x 0.5" x 5" ; test speed: 0.11"/min ; span: 4"
- Measured on 10 mm, 0.4" thick test specimens.
- Electrode configuration: Ø 25 / Ø 75 mm coaxial cylinders ; in transformer oil according to IEC 60296 ; 1 mm thick test specimens.
- Measured on disks Ø 50 mm x 3 mm.
- Measured on 1/8" thick x 2" diameter or square
- Test procedure similar to Test Method A: “Pin-on-disk” as described in ISO7148-2, Load 3MPa, sliding velocity= 0,33 m/s, mating plate steel Ra= 0.7-0.9 μm, tested at 23°C, 50%RH.
- Test using journal bearing system, 200 hrs, 118 ft/min, 42 PSI, steel shaft roughness 16±2 RMS micro inches with Hardness Brinell of 180-200
- Test using Plastic Thrust Washer rotating against steel, 20 ft/min and 250 PSI, Stationary steel washer roughness 16±2 RMS micro inches with Rockwell C 20-24
- Test using Plastic Thrust Washer rotating against steel, Step by step increase pressure, Test ends when plastic begins to deform or if temperature increases to 300°F.
- The table, mainly to be used for comparison purposes, is a valuable help in the choice of a material. The data listed here fall within the normal range of product properties of dry material. However, they are not guaranteed and they should not be used to establish material specification limits nor used alone as the basis of design.
| Value | Units | Test Method / Conditions | |
| Tensile Strength | 78 | MPa | ISO 527-1/-2 ⁷ |
| Tensile Strain at Break (Elongation) | 25 | % | ISO 527-1/-2 ⁷ |
| Tensile Modulus of Elasticity | 3700 | MPa | ISO 527-1/-2 ⁹ |
| Shear Strength | 62 | MPa | ASTM D732 |
| Compressive Stress (at 1% nominal strain) | 29 | MPa | ISO 604 ¹⁰ |
| Compressive Stress (at 2% nominal strain) | 49 | MPa | ISO 604 ¹⁰ |
| Compressive Stress (at 5% nominal strain) | 85 | MPa | ISO 604 ¹⁰ |
| Charpy Impact Strength (Notched) | 10 | kJ/m² | ISO 179-1/1eA |
| Flexural Strength | 106 | MPa | ISO 178 ¹² |
| Flexural Modulus of Elasticity | 3450 | MPa | ISO 178 ¹² |
| Hardness ¹⁴ | 88 | — | ISO 2039-2, Rockwell M |
| Hardness ¹⁴ | 81 | Shore D | ISO 868 |
| Value | Units | Test Method / Conditions | |
| Melting Temperature (DSC, 10°C / min) | 180 | °C | ISO 11357-1/-3 |
| Coefficient of Linear Thermal Expansion (23 to 100°C) | 95 | μm/(m.K) | — |
| Coefficient of Linear Thermal Expansion (23 to 60°C) | 110 | μm/(m.K) | — |
| Heat Deflection Temperature | 110 | °C | ISO 75-1/-2 (Method A: 1.8 MPa (264 PSI)) |
| Continuous Allowable Service Temperature in Air (20.0 hrs) ³ | 90 | °C | — |
| Minimum Service Temperature ⁴ | -50 | °C | — |
| Flammability (Oxygen Index) | 15 | % | ISO 4589-1/-2 |
| Value | Units | Test Method / Conditions | |
| Electric Strength | 20 | kV/mm | IEC 60243-1 ¹⁵ |
| Volume Resistivity | 10E13 | Ohm.cm | IEC 62631-3-1 |
| Surface Resistivity | 10E12 | Ohm/sq. | ANSI/ESD STM 11.11 |
| Value | Units | Test Method / Conditions | |
| Water Absorption (After 24h immersion in water of 23°C) | 0.21 | % | ISO 62 ¹⁶ |
| Dynamic Coefficient of Friction | 0.3 - 0.45 | — | ISO 7148-2 ¹⁸ |