iglide® plastic bushings - temperature

Figure 1.10: Comparison of the long-term and short-term upper application temperatures

Temperatures

Plastic bushings are often underestimated, especially at higher temperatures. It's difficult to believe that they can be used in temperatures over 572°F. Continuous-use temperature is the highest temperature the plastic bushing can withstand for a prolonged period of time without a reduction in the tensile strength of the material.

Please note, these standardized test results have limited application, since bearings are almost always subjected to a load. The wear limits of the material at certain application temperatures is more instructive.

Picture 1.10: iglide® T500 plastic bushings operating in high temperatures in a foundry

Table 1.5: Lower application temperatures

Material	Lower application temperatures [°F]
iglide® G300	- 40
iglide® J	- 72.4
iglide® M250	- 40
iglide® L280	- 40
iglide® T500	-234
iglide® A180	- 58
iglide® A200	- 40
iglide® A290	- 40
iglide® A500	- 148
iglidur® F	- 40
iglide® H	- 40
iglide® H4	- 40
iglide® H370	- 40
iglide® L250	- 40
iglide® P	- 40
iglide® Q	- 40
iglide® R	- 58
iglide® UW	- 58
iglide® V400	- 58
iglide® Z	- 148
iglide® B	- 40
iglide® C	- 40
iglide® D	- 58
iglide® GLW	- 40
iglide® H2	- 40
iglide® J200	- 58
iglide® T220	- 40
iglide® UW500	- 148

Application temperatures

The minimum application temperature is the temperature below which the material becomes so rigid and hard that it is too brittle for standard applications. The maximum continuous application temperature is the temperature which the material can endure without its properties changing considerably.

The maximum short-term application temperature is the temperature above which the material becomes so soft, that it can only withstand low external loads. 'Short-term' is defined as a time period of a few minutes. If the plastic bushings are moved axially or axial forces occur, there is more opportunity for the bushing to lose its pressfit. In these cases, axial securing of the bushing is required in addition.

Table 1.6 shows the maximum ambient temperatures to which the plastic bushings can be exposed in the a short-term. If these temperatures are reached, the bushings may not be additionally loaded. In fact, a relaxation of the bushings can occur at these temperatures, even without an additional load. For this reason, it's necessary to ensure that the bushing can not slide out of the bore. This is achieved by changing the bore construction or by additionally securing the bushing.

Table 1.7 shows the maximum ambient temperature the plastic bushings can tolerate for a short period of time. If these temperatures are acting on the bushings, they should not be additionally stressed. At these temperatures, relaxation of the bushings inside the housing can occur, even without any additional load. Attention should be given to ensuring the plastic bushings are prevented from slipping out of the bore either by changing the bore construction or by additionally securing the bushing.

Table 1.6: Temperature at which additional fastening of the iglide® plastic plain bearing is required

Material	Fastening is to be provided from [° F]
iglide® G300	212
iglide® J	140
iglide"® M250	140
iglide® L280	140
iglide® T500	275
iglide® A180	140
iglide® A200	122
iglide® A290	230
iglide® A500	266
iglide® F	221
iglide® H	248
iglide® H4	230
iglide® H370	212
iglide® L250	131
iglide® P	194
iglide® Q	122
iglide® R	122
iglide® UW	176
iglide® V400	212
iglide® Z	293
iglide® B	122
iglide® C	104
iglide® D	122
iglide® GLW	176
iglide® H2	122
iglide® J200	140
iglide® T220	122
iglide® UW500	302

Table 1.7: Maximum ambient temperature, short-term, without load

Material	Upper short-term ambient temperature [° F]
iglide® G300	428
iglide® J	284
iglide® M250	392
iglide® L280	392
iglide® T500	599
iglide® A180	230
iglide® A200	392
iglide® A290	446
iglide® A500	599
iglide® F	446
iglide® H	500
iglide® H4	500
iglide® H370	500
iglide® L250	392
iglide® P	392
iglide® Q	392
iglide® R	284
iglide® UW	284
iglide® V400	482
iglide® Z	590
iglide® B	266
iglide® C	302
iglide® D	284
iglide® GLW	392
iglide® H2	500
iglide® J200	284
iglide® T220	338
iglide® UW500	599

Picture 1.11: Material tests are possible up to 482° F.

Temperature and load

The compressive strength of plastic bushings decreases with increasing temperature. At the same time, the materials act very differently from one another, for instance iglide® T500 permits loads of 10,150 psi even at 392°F temperatures.

Coefficient of thermal expansion

The thermal expansion of plastics is approximately 10 to 20 times higher in comparison to metals. In contrast to metals, it also does not act linearly on plastics. The iglide® bushing's coefficient of thermal expansion is a significant reason for the required play in the bearing. Seizing of the bearing to the shaft does not occur at high temperatures. The coefficients of thermal expansion of iglide® plastic bushings were tested for significant temperature ranges and the results are given in the individual materials tables in each relevant product section.