|General features||Unit||iglide® L280||Test method|
|Max. humidity absorption at 73° F/50% R. H.||Wt.-%||1.3||DIN 53495|
|Max. water absorption||Wt.-%||6.5|
|Coefficient of surface friction, dynamic, against steel||µ||0.08 - 0.23|
|p x v value, max. (dry)||psi x fpm||6,600|
|Modulus of elasticity||psi||507,600||DIN 53457|
|Tensile strength at 68° F||psi||18,130||DIN 53452|
|Permissible static surface pressure (68° F)||psi||8,702|
|Shore D hardness||77||DIN 53505|
Physical and thermal properties
|Max. long-term application temperature||°F||194|
|Max. short-term application temperature||°F||356|
|Min. application temperature||°F||-40|
|Thermal conductivity||[W/m x K]||0.24||ASTM C 177|
|Coefficient of thermal expansion||[K-1 x 10-5 ]||9||DIN 53752|
|Specific volume resistance||Ωcm||> 1013||DIN IEC 93|
|Surface resistance||Ω||> 1012||DIN 53482|
For iglide® L280 plastic bushings with 0.03937 (1 mm) wall thickness in dry operation against a steel shaft, at 68° F, installed in a steel housing.
High wear resistance, particularly in environments with abrasive media or in connection with coarse shafts, distinguishes the iglide® L280 material. Among all iglide® materials, this is the most insensitive to such external influences.
iglide® L280 shows a very high compressive strength despite high elasticity. Figure 5.2 shows the elastic deformation of iglide® L280 with radial loads. Under the maximum recommended surface pressure of 8700 psi, the deformation at room temperature amounts to less than 3%.
A plastic deformation at room temperature is practically negligent within the maximum recommended surface pressure of 8700 psi.
Even at higher surface speeds, the coefficients of friction of iglide® L280 plastic bushings do not increase. Therefore compared to other materials it can attain slightly higher surface speeds, for instance up to 295 fpm rotating and up to 984 fpm linear.
Due to the extraordinary wear resistance, the bushing wear remains low also in long-term application with high speeds.
Extremely high speeds can be attained with iglide® L280 plastic bushings on hardened, not too smooth shafts.
|iglide® L280||Application temperature|
|Lower||- 40 °F|
|Upper, long-term||+ 194 °F|
|Mechanically secured||+ 266 °F|
|Upper, short-term||+ 356 °F|
|Additional axial securing||+ 140 °F|
iglide® L280 plastic bushings are extremely insensitive to alternating external influences. This applies also to temperatures. iglide® L280 plastic bushings retain their extraordinary abrasion resistance even up to the maximum permitted application temperatures and do not tend to become brittle at low temperatures.
In contrast the mechanical properties limit the usability of iglide® L280 at high temperatures. A relaxation of the bushings can occur at temperatures of 176° F. In the process the bushing's press-fit force can reduce so strongly that with re-cooling and the entailing shrinking, the bushing can creep out.
In order to prevent this, in applications from 140° F the iglide® L280 plastic bushings should be certainly mechanically secured in addition.
|Coefficients of friction µ||0.08 - 0.23||0.09||0.04||0.04|
The coefficients of surface friction of the iglide® L280 decreases with increasing load. In dry operation paired with steel (Cold Rolled Steel), they reduce by about 25% just in the load range of p = 72.5 to 507.5 psi.
In contrast to other iglide® materials, the coefficient of friction of the iglide® L280 remains constantly low even at higher peripheral speeds.
Friction and wear also depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. Smooth shafts entail the danger of stick-slip. The squeaking noise as an effect of stick-slip is often the result of extremely smooth shafts. Please note that a smoothing of the shaft surface can also occur due to the operation.
For minimum coefficients of friction with iglide® L280 plastic bushings, the shaft surface should not be too smooth. Shaft surface finish of 16 to 20 rms are the ideal (see Fig. 5.6) For the iglide® L280, the wear resistance is still excellent with this surface finish as the friction adopt the minimum value.
The diagrams display a summary of the results of tests with different shaft materials conducted with bushings made of iglide® L280.
In rotating applications the wear shows variations indeed according to the shaft at low loads, but the iglide® L280 displays excellent to acceptable coefficients of wear with all tested shafts. iglide® L280 like hard shafts. The iglide® L280 is the most suitable iglide® material at low radial loads and with hard-chromed shafts and hard shafts made of corrosion-resistant steel (X90). The soft shaft materials ST37 and machining steel are not as suitable for the iglide® L280 bushings.
At high loads, hardened shafts should be chosen. Diagram 5.8 clearly shows the differences with rising loads. A similar picture emerges in pivoting applications. With initial low loads, the wear for the pivoting motion lies actually lower than that for a rotation at the same load. This picture changes with higher loads.
Please contact us in case the shaft material scheduled by you is not included in this list of tested glide partners.
|Up to 0.0197||0 - 0.000984||+0.0005512 + 0.0021260|
|> 0.1181 to 0.2362||0 - 0.001181||+0.0007874 + 0.0026772|
|> 0.2362 to 0.3937||0 - 0.001417||+0.0009842 + 0.0032677|
|> 0.3937 to 0.7087||0 - 0.001693||+0.0012598 + 0.0040157|
|> 0.7087 to 1.1811||0 - 0.002047||+0.0015748 + 0.0048819|
|> 1.1811 to 1.9685||0 - 0.002441||+0.0019685 + 0.0059055|
|> 1.9685 to 3.1496||0 - 0.002913||+0.0023622 + 0.0070866|
|> 3.1496 to 4.7244||0 - 0.003425||+0.0028346 + 0.0083464|
|> 4.7244||0 - 0.003937||+0.0033464 + 0.0096456|
|Alcohol||+ to 0|
|FGreases, oils, without additives||+|
|Diluted acids||0 to -|
|Specific volume resistance||> 1013 Ωcm|
|Surface resistance||> 1012 Ω|
iglide® L280 plastic bushings have a good resistance against chemicals. They are resistant to most lubricants. iglide® L280 is not affected by most weak organic and inorganic acids.
The humidity absorption of iglide® L280 plastic bushings amounts to about 1.3 Wt.-% in standard climatic conditions. The saturation limit in water is 6.5%. This should be considered according to environmental influences.
iglide® L280 plastic bushings are radiation resistant up to a radioactive intensity of 3 x 10² Gy.
iglide® L280 plastic bushings are permanently resistant against UV rays. A minor variation in the color (dark) through UV radiation and other atmospheric exposures influences the mechanical, electrical or thermal properties only insignificantly.
The potentially absorbed humidity of the iglide® L280 plastic bushing degasses in vacuum. The application in vacuum is therefore possible only restrictedly.
Plastic bushings made of iglide® L280 are electrically insulating.