|Genera l features||Unit||iglidur® A181||test method|
|Max. humidity absorption at 23°C/50% R. H.||% weight||0,2||DIN 53495|
|Max. water absorption||% weight||1,3|
|Coefficient of surface friction, dynamic, against steel||µ||0,10 - 0,21|
|pv values (dry)||MPa x m/s||0,31|
|Bending E-module||MPa||1.913||DIN 53457|
|Tensile strength at +20 °C||MPa||48||DIN 53452|
|Maximum recommended surface pressure (20° C)||MPa||31|
|Shore D-hardness||76||DIN 53505|
Physical and thermal properties
|Max. long term application temperature||°C||+90|
|Max. short term application temperature||°C||+110|
|Minimum application temperature||°C||-50|
|thermal / heat conductivity||[W/m x K]||0,25||ASTM C 177|
|Coefficient of thermal expansion (at 23° C)||[K-1 x 10-5]||11||DIN 53752|
|Specific forward resistance||Ωcm||< 1012||DIN IEC 93|
|surface resistance||Ω||< 1012||DIN 53482|
Due to their technical characteristics and compliance with applicable regulations, iglidur® A181 plain bearings are predestined for use in food technology applications. Directly comparable to iglidur® A180 with respect to temperature and media resistance, iglidur® A181 represents yet another improvement with respect to wear resistance in most applications.
With increasing temperatures, the compressive strength of iglidur® A181 plain bearings decreases. Fig. 02 clarifies this connection. Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it.
Figure 03 shows the elastic deformation of iglidur® A181 with radial loads.
iglidur® A181 is developed for low surface speeds. Maximum speeds up to 0.8 m/s (rotating) and 3.5 m/s (linear) respectively are permitted for continuous application in dry operation. The values specified in Table 02 state the limits to which the long-term permitted temperature rises due to friction heat. In practice these limit values are not always reached due to interactions.
|iglidur® A181||Application temperature|
|Lower||- 50 °C|
|Upper, long-term||+ 90 °C|
|Upper, short-term||+ 110 °C|
|Secure axially in addition||+ 60 °C|
The upper long-term application temperature of +90°C allows for a variety of applications in the food industry. As Fig. 02 shows, the compressive strength decreases with increasing temperatures. The additional friction heat in the bearing system should be considered in the temperature observations. An additional securing is recommended at temperatures higher than +60°C.
Coefficient of friction and wear resistance alter with the application parameters(Fig. 04 and 05). In the iglidur® A181 plain bearings, the alteration of the friction coefficient µ dependent on surface speed and the shaft's surface finish is only negligently pronounced.
|Coefficients of friction µ||0,10 - 0,21||0,08||0,03||0,04|
Figure 06 displays a summary of the results of tests with different shaft materials, which were conducted with iglidur® A181 plain bearings. Special emphasis is given to the corrosion-resistant shaft types in thefood industry. Fig. 06 shows that low wear rates can be achieved especially in combination with these shafts. As in many iglidur® materials, the wear rate increases in rotation with otherwise identical parameters (Fig. 07).
|Greases, oils without additives||+|
|Diluted acids||0 to -|
|Strong bases||+ to 0|
|Specific forward resistance||< 1012 Ωcm|
|Surface resistance||< 1012 Ω|
iglidur® A181 bearings can be used under various environmental conditions and in contact with numerous chemicals. Table 05 gives an overview of the chemical resistance of iglidur® A181 bearings at room temperature.
iglidur® A181 bearings are radiation resistant up to a radioactive intensity of 2 · 10² Gy.
iglidur® A181 bearings are permanently resistant against UV rays.
In application in vacuum, the potentially existent moisture content is degassed. For this reason only dry bearings are suitable for vacuum.
|Maximum moisture absorption|
|by +23 °C/50 % r. F.||0,2 weight-%|
|Max. water absorption||1,3 weight-%|
The iglidur® A181 bearings absorb up to 0.2% water through atmospheric humidity (+23°C, 50% relative atmospheric humidity), when saturated with water they absorb 1.3%.
|Up to 3||0 - 0,025||+0,014 +0,054||0 +0,010|
|> 3 to 6||0 - 0,030||+0,020 +0,068||0 +0,012|
|> 6 to 10||0 - 0,036||+0,025 +0,083||0 +0,015|
|> 10 to 18||0 - 0,043||+0,032 +0,102||0 +0,018|
|> 18 to 30||0 - 0,052||+0,040 +0,124||0 +0,021|
|> 30 to 50||0 - 0,062||+0,050 +0,150||0 +0,025|
|> 50 to 80||0 - 0,074||+0,060 +0,180||0 +0,030|
|> 80 to 120||0 - 0,087||+0,072 +0,212||0 +0,035|
|> 120 to 180||0 - 0,100||+0,085 +0,245||0 +0,040|
Iglidur® A181- bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed for press-fit in a housing with h7 tolerance. After the installation in a housing with nominal diameter, the inner diameter of the bearing automatically adjusts to the E10 tolerance.