Sliding element, in particular for a stretching installation and/or conveyor chain, and associated stretching installation or conveyor chain

1. A sliding element, for a stretching installation and/or conveyor chain, comprising graphite or electrographite, wherein

the sliding element has pores, the open pore size being ≥7.5% by volume, and

the particle size of the graphite particles used as a starting material for the sliding elements is between 3 μm and 15 μm,

wherein the sliding element is impregnated with inorganic salts and/or inorganic salts are embedded in the sliding element.

2. A sliding element according to claim 1 , wherein the open pore size is at least ≥8% by volume.

3. A sliding element according to claim 1 , wherein the open pore size of the sliding element is ≤20% by volume.

4. A sliding element according to claim 1 , wherein the particle size of the graphite particles used as a starting material for the sliding elements is greater than or equal to 4 μm.

5. A sliding element according to claim 1 , wherein the graphite particles used as a starting material for manufacturing the sliding elements are in a particle size distribution in which the median value d( 50 ) for the particle size is between 14 μm and 18 μm, and the value for d( 10 ) is between 2 μm and 4 μm and for d( 90 ) is between 42 μm and 50 μm.

6. A sliding element according to claim 1 , wherein at least 60% of the pores provided in the sliding element are soaked with oil.

7. A sliding element according to claim 1 , wherein the inorganic salts are embedded at least in a surface layer of the sliding element and/or the sliding element is impregnated with inorganic salts in this region.

8. A sliding element according to claim 1 , wherein the sliding element is impregnated with inorganic salts or comprises embedded inorganic salts, which consist of or comprise phosphates or tertiary orthophosphates.

9. A sliding element according to claim 4 , wherein the inorganic salts make up 1% by weight to 10% by weight.

10. A sliding element according to claim 1 , wherein the sliding element is formed as an isostatically pressed sliding element.

11. A sliding element according to claim 1 , wherein the sliding surface of the sliding element has a maximum roughness at which height deviations are below 5 μm.

12. A sliding element according to claim 11 , wherein the sliding surface of the sliding element is polished.

13. A stretching installation or conveyor chain for a stretching installation, comprising sliding elements, wherein

the sliding elements comprising graphite or electrographite, and

the sliding elements have pores, the open pore size being ≥7.5% by volume,

the particle size of the graphite particles used as a starting material for the sliding elements is between 3 μm and 15 μm, and

wherein the sliding elements are impregnated with inorganic salts and/or inorganic salts are embedded in the sliding elements.

14. A stretching installation or conveyor chain for a stretching installation according to claim 13 , wherein, as a counter partner for the conveyor chain, a carrier construction in the form of a guide rail and/or carrier rail and/or control rail is provided, the thermal expansion coefficient of which corresponds to the thermal expansion coefficient of the sliding elements or deviates therefrom by less than 25%.

15. A stretching installation or conveyor chain for a stretching installation according to claim 14 , wherein the guide rail and/or carrier rail and/or control rail consists of a material having a degree of hardness which corresponds to the degree of hardness of the sliding elements or deviates therefrom by less than 25%.

16. A stretching installation or conveyor chain for a stretching installation according to claim 14 , wherein the guide and/or carrier and/or control rail is heated above a temperature limit value to reduce the coefficient of friction.

17. A sliding element according to claim 1 , wherein the open pore size is at least ≥15% by volume.

18. A sliding element according to claim 1 , wherein the open pore size of the sliding element is ≤11% by volume.

19. A sliding element according to claim 1 , wherein the particle size of the graphite particles used as a starting material for the sliding elements is greater than or equal to 10 μm.

20. A sliding element according to claim 1 , wherein the particle size of the graphite particles used as a starting material for the sliding elements is less than 14 μm.

21. A sliding element according to claim 1 , wherein the particle size of the graphite particles used as a starting material for the sliding elements is less than 5 μm.

22. A sliding element according to claim 1 , wherein over 95% of the pores provided in the sliding element are soaked with oil.

23. A sliding element according to claim 1 , wherein at least 99% of the pores provided in the sliding element are soaked with oil.

24. A sliding element according to claim 1 , wherein the sliding element is impregnated with aluminium phosphate.

25. A sliding element according to claim 4 , wherein the inorganic salts make up 4% by weight to 6% by weight.

26. A sliding element according to claim 1 , wherein the sliding surface of the sliding element has a maximum roughness at which height deviations are below 1 μm.

27. A stretching installation or conveyor chain for a stretching installation according to claim 13 , wherein, as a counter partner for the conveyor chain, a carrier construction in the form of a guide rail and/or carrier rail and/or control rail is provided, the thermal expansion coefficient of which corresponds to the thermal expansion coefficient of the sliding elements or deviates therefrom by less than 5%.

28. A stretching installation or conveyor chain for a stretching installation according to claim 14 , wherein the guide rail and/or carrier rail and/or control rail consists of a material having a degree of hardness which corresponds to the degree of hardness of the sliding elements or deviates therefrom by less than 5%.