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iglide® GLW - Material data
Materials table
| General features | Unit | iglide® GLW | Test method |
|---|---|---|---|
| Density | g/cm3 | 1.36 | |
| Color | Black | ||
| Max. humidity absorption at 73° F/50% R. H. | Wt.-% | 1.4 | DIN 53495 |
| Max. water absorption | Wt.-% | 5.5 | |
| Coefficient of surface friction, dynamic, against steel | µ | 0.1-0.24 | |
| p x v value, max. (dry) | psi x fpm | 8650 | |
| Mechanical properties | |||
| Modulus of elasticity | psi | 1,116,500 | DIN 53457 |
| Tensile strength at 68° F | psi | 34,075 | DIN 53452 |
| Compressive strength | psi | 10,730 | |
| Permissible static surface pressure (68° F) | psi | 11,600 | |
| Shore D hardness | 78 | DIN 53505 | |
| Physical and thermal properties | |||
| Max. long-term application temperature | °F | 212 | |
| Max. short-term application temperature | °F | 320 | |
| Min. application temperature | °F | -40 | |
| Thermal conductivity | [W/m x K] | 0.24 | ASTM C 177 |
| Coefficient of thermal expansion (at 73° F) | [K-1 x 10-5] | 17 | DIN 53752 |
| Electrical properties | |||
| Specific volume resistance | Ωcm | > 1011 | DIN IEC 93 |
| Surface resistance | Ω | > 1011 | DIN 53482 |
Permitted p x v values
For iglide® GLW plasic bushings with 1 mm wall thickness in dry operation against a steel shaft, at 68° F, installed in a steel housing.
We can offer our customers bushings made of the material iglide® GLW as an alternative to iglide® G300 for high volume applications. Possessing similar characteristic values as iglide® G300 plastic bushings, the iglide® GLW plastic bushings are especially recommendable for static loads in particular. For these applications, where the dynamic properties of iglide® G300 can be largely dispensed with, they represent an extremely cost-efficient alternative.
Figure 25.2: Deformation under load and temperatures
Compressive Strength
Figure 25.2 shows the elastic deformation of iglide® GLW with radial loads. Under the maximum recommended surface pressure of 10,150 psi and at room temperature, the deformation amounts to less than 3%. Under this load a plastic deformation can be negligible. However this also depends on the period of action.
Permitted surface speeds
iglide® GLW is developed for low to medium surface speeds. In continuous operation, maximum speeds up to 157 fpm (rotating) and 492 fpm (linear) respectively are permitted. Here too, the maximum values stated in the table are attained only with the minimum pressure loads and are seldom achieved in practice, as the temperature rises above the permitted maximum value.
| fpm | Rotating | Oscillating | Linear |
|---|---|---|---|
| Continuous | 157 | 118 | 492 |
| Short-term | 196 | 137 | 590 |
Figure 25.3: Maximum recommended surface pressure dependent on the temperature
Temperatures
The ambient temperatures influence the properties of bushings to a high degree. With a short-term permitted maximum temperature of 320° F, it is possible to subject the iglide® GLW plastic bushings to a paint drying process, so long as they are not stressed otherwise. With increasing temperatures, the compressive strength of iglide® GLW plastic bushings decreases. Fig. 25.3 clarifies this connection.
The bushing wear also rises with increasing temperatures in the bushing system.
Temperature limits
| iglide® GLW | Application temperature |
|---|---|
| Lower | - 22 °F |
| Upper, long-term | + 212 °F |
| Upper, short-term | + 320 °F |
| Additional axial securing | + 176 °F |
Figure 2.4: Coefficients of friction dependent on the surface speed, p = 108 psi (1050 hard chromed)
Friction and wear
The coefficient of friction alters like the wear resistance with increasing load. Interestingly, the friction coefficient µ declines with increasing load. This connection illustrates the excellent suitability of iglide® GLW plastic bushings with high loads.
Friction and wear depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. For iglide® GLW a ground surface with an average roughness range of 8 - 64 rms is recommended for the shaft
Coefficients of friction for iglide® GLW against steel (Shaft finish = 40 rms, 50 HRC)
| iglide® GLW | Dry | Grease | Oil | Water |
|---|---|---|---|---|
| Coefficients of friction µ | 0.10 - 0.24 | 0.09 | 0.04 | 0.04 |
Picture 25.7: Wear with different shaft materials (p = 108 psi , v = 98 fpm
Shaft materials
To a large extent, friction and wear depend on the shaft material. Shafts that are too smooth increase both the coefficient of friction and the wear of the bushing. A ground surface with an average roughness between 4 an 8 rms is the most suitable. The graph shows an extract of the results of tests with different shaft materials using iglide® GLW plastic bushings.
Please contact us in case the shaft material scheduled by you is not included in this list.
Installation tolerances
iglide® GLW plastic bushings are standard bushings for shafts with h-tolerance (recommended minimum h9).
After the installation in a housing bore with H7 tolerance, the inner diameter of the bushing automatically adjusts to the E10 tolerance.
| Diameter d1 [inch] | Shaft h9 [inch] | iglide® GLW E10 [inch] |
|---|---|---|
| Up to 0.019685 | 0 - 0.0009846 | +0.000551 + 0.0021260 |
| > 0.1181 to 0.2362 | 0 - 0.0011811 | +0.000787 + 0.0026772 |
| > 0.2362 to 0.3937 | 0 - 0.0014173 | +0.000984 + 0.0032677 |
| > 0.3937 to 0.7087 | 0 - 0.0016929 | +0.001260 + 0.0040157 |
| > 0.7087 to 1.1811 | 0 - 0.0020472 | +0.001574 + 0.0048819 |
| > 1.1811 to 1.9685 | 0 - 0.0024409 | +0.001969 + 0.0059055 |
| > 1.9685 to 3.1496 | 0 - 0.0029133 | +0.002362 + 0.0070866 |
| > 3.1496 to 4.7244 | 0 - 0.0034251 | +0.002834 + 0.0083464 |
| > 4.7244 | 0 - 0.003937 | +0.003346 + 0.0096456 |
Chemical resistance
iglide® GLW plastic bushings have a good resistance against chemicals. They are resistant to most lubricants. The iglide® is not affected by most weak organic and inorganic acids. The moisture absorption of iglide® GLW plastic bushings amounts to about 1% in standard climatic conditions. The saturation limit in water is 5%. This should be considered according to application conditions.
The moisture absorption of iglide® D plastic bushings amounts to about 0,2% in standard climatic conditions. The saturation limit in water is 1%. This low moisture absorption also allows the use in wet environment.
Radioactive rays
iglide® GLW plastic bushings are radiation resistant up to a radioactive intensity of 3 x 10² Gy.
UV-resistant
iglide® GLW plastic bushings are permanently resistant against UV rays.
Vacuum
In vacuum, iglide® GLW degases. The application in vacuum should be checked earlier.
Delivery program
The iglide® GLW plastic bushings are manufactured according to order specifications. Please contact us for applications with large numbers of plastic bushings made of iglide® GLW as alternative to iglide® G300.
| Medium | Resistance |
|---|---|
| Alcohol | + to 0 |
| Hydrocarbons, chlorinated | + |
| Greases, oils, without additives | + |
| Fuels | + |
| Diluted acids | 0 to - |
| Strong acids | - |
| Diluted alkaline | + |
| Strong alkaline | 0 |
| + resistant 0 conditionally resistant - non-resistant |
Electrical properties
| Specific forward resistance | Surface resistance |
|---|---|
| > 1011 Ωcm | > 1011 Ω |