35 72 10 oil seal

Wiper seals serve a dual purpose they keep the system clean and enhance operational efficiency. In hydraulic cylinders, for instance, these seals prevent dirt, dust, and other contaminants from entering the cylinder, which can cause wear and tear or even complete failure. By acting as a barrier, wiper seals ensure that the working fluid remains uncontaminated, which is crucial for maintaining pressure and facilitating smooth operation.

1. Leak Prevention The most significant function of oil seals is to prevent the leakage of lubrication fluids from within a mechanical system. Oil leaks can lead to reduced lubrication, resulting in increased friction, overheating, and ultimately premature wear or failure of components.

When it comes to excavator maintenance, the quality of cylinder seal kits cannot be overstated. High-quality seal kits are essential for ensuring a reliable seal that withstands not only the pressures of operation but also the extreme temperatures that hydraulic fluids can reach. Investing in quality kits leads to longer replacement intervals, improved machine performance, and reduced risk of hydraulic failure.

4.3 g/Cm3

Different dermal cell types have been reported to differ in their sensitivity to nano-sized TiO₂ . Kiss et al. exposed human keratinocytes (HaCaT), human dermal fibroblast cells, sebaceous gland cells (SZ95) and primary human melanocytes to 9 nm-sized TiO₂ particles at concentrations from 0.15 to 15 μg/cm² for up to 4 days. The particles were detected in the cytoplasm and perinuclear region in fibroblasts and melanocytes, but not in kerati-nocytes or sebaceous cells. The uptake was associated with an increase in the intracellular Ca²⁺ concentration. A dose- and time-dependent decrease in cell proliferation was evident in all cell types, whereas in fibroblasts an increase in cell death via apoptosis has also been observed. Anatase TiO₂ in 20–100 nm-sized form has been shown to be cytotoxic in mouse L929 fibroblasts. The decrease in cell viability was associated with an increase in the production of ROS and the depletion of glutathione. The particles were internalized and detected within lysosomes. In human keratinocytes exposed for 24 h to non-illuminated, 7 nm-sized anatase TiO_2, a cluster analysis of the gene expression revealed that genes involved in the “inflammatory response” and “cell adhesion”, but not those involved in “oxidative stress” and “apoptosis”, were up-regulated. The results suggest that non-illuminated TiO₂ particles have no significant impact on ROS-associated oxidative damage, but affect the cell-matrix adhesion in keratinocytes in extracellular matrix remodelling. In human keratinocytes, Kocbek et al. investigated the adverse effects of 25 nm-sized anatase TiO₂ (5 and 10 μg/ml) after 3 months of exposure and found no changes in the cell growth and morphology, mitochondrial function and cell cycle distribution. The only change was a larger number of nanotubular intracellular connections in TiO₂-exposed cells compared to non-exposed cells. Although the authors proposed that this change may indicate a cellular transformation, the significance of this finding is not clear. On the other hand, Dunford et al. studied the genotoxicity of UV-irradiated TiO₂ extracted from sunscreen lotions, and reported severe damage to plasmid and nuclear DNA in human fibroblasts. Manitol (antioxidant) prevented DNA damage, implying that the genotoxicity was mediated by ROS.

Safety

Risk managers at the European Commission and in EU Member States have been informed of EFSA’s conclusions and will consider appropriate action to take to ensure consumers’ protection.