China
Africa
Explore chapters and articles related to this topic
Cleaning
Published in Christoph Gerhard, Optics Manufacturing, 2018
Precision cleaning of glass surfaces can also be performed by dry-ice blasting (a.k.a. carbon dioxide snow cleaning). Here, either solid carbon dioxide snow pellets or liquid carbon dioxide is used. In the first case, removal of contaminants is a purely mechanical process, whereas the latter procedure can be described as follows: liquid carbon dioxide is mixed with compressed air and sprayed onto the work piece surface. Due to an abrupt relaxation during mixing, the liquid carbon dioxide becomes solid, resulting in the formation of small dry-ice crystals. These crystals then sublime at the work piece surface; cleaning is thus due to both thermal and mechanical effects, where the process temperature is given by the dry-ice temperature of approximately −79°C. The mechanical impact can be adjusted by the choice of the geometry of the used spray nozzles. Since dry ice features a comparatively low hardness of approximately 2 Mohs,2 this method is also suitable for cleaning sensitive surfaces.
Minimum Quantity Lubrication
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
The machine enclosure should be sealed to contain mists and dust and should be kept at a negative pressure with respect to the ambient air to prevent emissions from escaping during part loading and tool changes [6, 8]. Its interior walls should be cleaned at regular intervals to remove adhering oil and dust not collected by the extraction system. Suitable cleaning methods include manual cleaning, low pressure air or water cleaning, and dry ice blasting [6].
A review on sustainable alternatives for conventional cutting fluid applications for improved machinability
Published in Machining Science and Technology, 2023
D. J. Hiran Gabriel, M. Parthiban, I. Kantharaj, N. Beemkumar
The solid form of carbon di oxide (CO2) is called “dry ice” and it is primarily used as a cooling agent in various fields. Like other gases such as hydrogen, nitrogen, and helium, CO2 is also used in aerospace sectors. Under high pressure and low temperature, concentrated CO2 is converted to pellets (blocks), nuggets (pin shape pressed dry ice) varying in diameter between 1–3 mm, and length of 4–10 mm generated by pelletizer machine. As the dry ice sublimates directly to a gas without leaving any residue, therefore, it is widely used to cool the biological samples, vaccines, beverages, and catering. Among several dry ice mechanical uses; blasting is one of them to clean the surfaces. Dry ice blasting is a mechanical device that crushes CO2 pellets (1000–1500 kg/m3) into small dry ice grains and accelerate these grains through compressed air to strike the target.