Because beauty should never come at the price of your health.
Drobne et al. used the terrestrial arthropod Porcellio scaber as a test organism for determining the cytotoxic effect of TiO2 NPs (anatase). The animals were exposed to TiO2 NPs of two different sizes (25 nm and 75 nm) in the concentration range 10–1000 μg TiO2/g dry food for 3 to 14 days. No adverse effects, such as mortality, body weight changes or reduced feeding, were observed. In fact, quite the opposite, an enhanced feeding rate, food absorption efficiency and increase in catalase activity were observed. The intensity of these responses appeared to be time- but not dose-dependent. It should also be noted that the concentrations tested in this study were much higher than the predicted concentration (4.8 μg/g soil) at high emission scenario of nano-sized TiO2. Using the same test organism another group showed that exposure to TiO2 NPs induced destabilization of cell membrane in the epithelium of digestive glands isolated from exposed animals. They also showed that this effect can be observed after just 30 minutes of exposure.
Rutile titanium dioxide is known for its exceptional whiteness, high refractive index, and excellent durability under UV light. It is produced using various methods, but MBR9668 stands out due to its superior microstructure and unique surface treatment, which provide enhanced dispersion and stability in coatings. This makes it ideal for use in applications where long-lasting brightness and resistance to chalking and fading are crucial.
Figure 14.4. Effect of aeration on oil aging.5 Chart shows percent retained elongation after aging for 28 days at 150°C in Mobil 276.
Oil seals are widely used as sealing devices for machines.
JTEKT's oil seals are described in our catalog, Oil Seals & O-Rings.
However, the catalog uses a large number of technical terms and is very long, so many people seem to have trouble handling it.
Therefore, this series of columns will summarize the following in order:
• The structure, functions, and types of oil seals
• How to select the right oil seal
• Handling of seals, and causes and countermeasures for oil seal failure
The simplest way is to know either the preferred manufacturers part number, the overall sizes of shaft diameter, housing diameter and bore depth, or use our brochure to establish the M Barnwell Services ordering reference. Many of the old traditional names of seal manufacturers have either changed or disappeared in this age of “acquisitions”. If no longer available, we will advise you and offer a suitable alternative seal, from stock whenever possible. If your concern is getting the right seals for the job, you will need to know something about the application as well as the overall sizes. If you have any doubts – contact us, we will help in your seal selection.
Although it does have a higher tensile strength and longer wear times than other materials, it is recommended to be used in dry-running applications sparingly or intermittently.
PTFE, which is used in the well-known brand Teflon®, is less commonly used, but it is the preferred material for specific rotating seals in the chemical, food and pharmaceutical industries. This material is notable for having a very low frictional resistance and the best chemical resistance. It can also withstand a very wide range of temperatures in these types of seals; -80 ˚C to 200 ˚C. The shafts on which oil seals with PTFE lips are used require a harder and finer finish. Something like an axle sleeve can also be used to meet this requirement.