Patent ID: 6884301

Claim:
A method for cleaning and/or treating substrate surfaces comprising the steps of: providing a biological cleaning tank containing a bath comprising a surfactant for cleaning and emulsifying oils and/or greases on a substrate surface and microbes for digesting the emulsified oils and/or greases; providing a pre-treatment tank for pre-treating the substrate to be cleaned, the pre-treatment tank containing a bath comprising a composition which is biologically compatible with the cleaning bath; immersing the substrate to be cleaned in the pre-treatment bath for a sufficient time to pre-treat the substrate; removing the pre-treated substrate from the pre-treatment bath and immersing the pre-treated substrate in the biological cleaning bath for a sufficient time to clean the substrate; removing the biologically clean substrate from the biological cleaning bath; removing a portion of the pre-treatment bath and adding the removed portion to the biological cleaning bath where the components of the bath are digested by the microbes; replenishing the pre-treatment bath; and continuing the above steps until the desired number of substrates are cleaned.