Vacuum impregnation seals porosity without changing the castings’ dimensional or functional characteristics. This means manufacturers can use parts that would otherwise have been scrapped. It is a simple method and is approved by OEMs for a variety of components.
Specialist fuel, oil and air filtration systems company Ultrafine Vacuum Impregnators (UVI) has acquired the assets and client base of specialist castings vacuum impregnation company Casting Material Company (SA) (Pty) Ltd from Ted Attenborough, a long-time industry stalwart who has been involved with the foundry industry since 1961 and a member of the South African Institute of Foundrymen for 48 years.
CMC has an established track record in industry with both the foundries and the casting consumer sector supplying their vacuum impregnation service since 1982.
Components are cleaned and positioned into stainless steel baskets, which are in turn loaded into the system and cycled through an automated process, using a vacuum to pull the low viscosity sealant into the pores by means of a capillary action
“Through our holding company Ultrafine Depth Filtration (UDF) we have been a client of CMC for many years whereby the company has been vacuum impregnating the heads of our fuel filters that are used in extreme conditions such as the automotive, mining and agriculture sectors,” said Johan Henning, one of three partners in the recently established UVI.
“The decision by UVI to invest in this plant stemmed from a very real industry need for someone to continue with a specialised high-technology vacuum impregnation unit that is capable of consistent high-quality vacuum impregnation component processing, which will positively impact customer scrap reduction efforts with an associated total manufacturing cost reduction.”
After centrifuging to remove excess sealant from surfaces the components are transferred to a heated curing tank to polymerise the liquid resin and achieve permanently sealed components
“UDF’s fuel, oil and air filtration units are required to operate with military spec standards because of the environment that they operate in. Therefore, there is no room for porous castings or air leakage paths in a casting. With Ted’s imminent retirement it was necessary for us as UDF to secure their supply of components that have been vacuum impregnated.”
“UDF has been in existence since 1995 and built up a solid reputation with OEMs, companies and individuals.”
“For example, UDF have had a long-standing relationship with Voetspore owner Johan Badenhorst, having fitted fuel systems to his various vehicles that he has utilised on treacherous expeditions over the past 16 years – travelling more than 300 000kms on the African continent and Madagascar, visiting 40 countries.”
“We established UVI in March 2020 with me, Dean Puntis and Shane Chapman as the directors and UDF as one of our valued clients.”
What exactly is impregnation?
“What exactly is impregnation? Very simply impregnation is the process of sealing porous areas and imperfections in various casting alloys which are inherent in the casting process. Although inspections on components are widely carried out in casting and allied industries, minute porosities are difficult to detect. For example in the case of enclosed porosity, the defect will not manifest itself until after the machining process.”
The size of the components that can be vacuum impregnated depends on the size tank. Vacuum impregnated treated components should also be able to withstand operating temperatures ranging from -90 degrees Celsius to +200 degrees Celsius. Of course a major benefit of using a controlled process is that components can be processed as a casting or a fully machined component without risk of damage to machined surfaces. All components should be fully machined before processing
“The vacuum impregnation process is based on an advanced porosity sealing technique. It is used for permanently sealing micro-porosities by filling them with a specialised methacrylate/resin impregnation sealant. The material cures deep inside the pores and leaves practically no residue on part surfaces. The use of impregnation can vastly improve component quality with many international customers processing their components through vacuum impregnation as a matter of routine. However, more importantly, the process has a proven positive impact on total manufacturing cost reduction for the customer by allowing components to be used that would have otherwise been scrapped due to porosity defects.”
“Components are cleaned and positioned into stainless steel baskets, which are in turn loaded into the system and cycled through an automated process, using a vacuum to pull the low viscosity sealant into the pores by means of a capillary action. After centrifuging to remove excess sealant from surfaces the components are transferred to a heated curing tank to polymerise the liquid resin and achieve permanently sealed components.”
“Vacuum impregnation is a preferred OEM process that seals porosity and leak paths in metal castings, sintered metal parts and electrical castings that form during the casting or moulding process.”
“Typical applications sealed successfully include automotive components, hydraulic/pneumatic valves, fittings and pumps. More complex parts such as engine blocks, cylinder heads, vehicle brake components and high-pressure systems have all been reliably sealed by the vacuum impregnation process over many years with no loss of performance.”
Batch or single components can be processed
“What should the primary considerations be for customers when evaluating a vacuum impregnation service provider? Customers should ensure that the components processed by a vacuum impregnation service provider are firstly ready for use once processed and that the processed components are clean and free of any corrosion or oxidation. Secondly, the cured resin in the imperfections on the processed component should be capable of withstanding attack from oils, greases, liquid fuels, coolants, solvents and virtually all acids.”
No post processing needed
“Vacuum impregnated treated components should also be able to withstand operating temperatures ranging from -90 degrees Celsius to +200 degrees Celsius. Of course a major benefit of using a controlled process such as ours is that components can be processed as a casting or a fully machined component without risk of damage to machined surfaces. All components should be fully machined before processing.”
“For quality purposes all components are subjected to a pressure and dark room tests once the vacuum impregnation process is completed.”
“As previously stated, all castings should be vacuum impregnated not only to eliminate defects but also to save on long-term costs. UDF’s filters offer fuel savings, have a longer life with extended service intervals and reduced emissions.”
“The process can be carried out on ferrous, aluminium, bronze or carbon components.”
For further details contact Ultrafine Vacuum Impregnators on TEL: 011 609 9947, Dean Puntis on
083 677 7909 or Johan Henning on 082 903 4224 or visit https://www.facebook.com/UltrafineVacuumImpregnation/