Category Archives: Magnus Chemistry

Magnus Solvent Cleaning

Immersion Cleaning with Solvents

Magnus Engineered Equipment has been making agitation immersion cleaning equipment since the 1950’s.  With this long experience, we understand how to manufacture parts cleaning equipment which can handle solvent based cleaning solutions.  The low flash point of many industrial solvents poses a fire risk and the equipment must be designed to both minimize the risk of fire and prevent the spread of fire should one occur.

Magnus equipment is inherently safe; only shop compressed air is used.  Electrical components, electrical enclosures and flammable materials are not utilized as these components would compromise the safety of the equipment.  Components on the cleaning tank are permanently electrically bonded to comply with the NFPA and OSHA requirements and metal-to-metal moving surfaces are eliminated to avoid spark generation.  Should a fire occur, a fusible link reacts and causes the tank lid to automatically close.  This suppresses the flame and minimizes the availability of air which can feed the fire.  Solution filtration is accomplished via the use of a grounded air operated pump which is compatible with the solvent being used.  It’s advisable to utilize an aqueous cleaner where possible, however if the cleaning operation requires a solvent based chemistry, then use equipment which has been specifically designed to handle the solvent chemistry and minimizes the risk and spread of fire.

The ML 2918 cleaning system presented herein is affectionately called a “Senior” as it has been utilized in the cleaning industry for more than 65 years.  The system is suitable for modification for use with solvent based cleaning solutions and is manufactured and supported by MEE in Willoughby, Ohio and spare parts are generally available via next-day delivery.

                                                

Operation of the wash tank is conducted via a three-position selector lever on the side of the tank.

    • RAISE : This position will raise the platform.
    • LOWER : This will lower the platform down to “soak” in the lowest position.
    • AGITATION : This will lower the platform and activate the agitation process. Agitation rate is adjustable.

TECHNICAL SPECIFICATIONS

    • 12 gauge, 304 stainless steel, insulated tank construction
    • Stainless Steel tank jackets and cylinder guard
    • Manual, hinged stainless steel lid
    • 35” long x 28.5” wide x 53.75” high overall dimensions
    • 30” long x 22” wide x 20.5” high inside tank dimensions
    • 29” long x 18” wide x 11” high dipping space dimensions
    • 29” x 18” stainless steel grate platform
    • 125 lb. lift capacity (at 100 psi)
    • 40 gallon capacity
    • Pneumatic agitation control
    • 25” drain with Stainless Steel Ball Valve
    • Optional integral filtration system compatible with a solvent cleaner including air operated diaphragm pump and filter housing with air regulator, pressure gauge and drain port.
    • Requires 2 to 4 cfm @ 100 psi compressed air
      • Achieves 140-180 strokes per minute (70-90 cycles per minute)
      • 5” to 2.5” travel per stroke

SAFETY FEATURE ADD-ONS

    • FUSIBLE LINK with Dump Solenoid, adds safety when working with flammable materials. A one-piece hinged cover with a 212oF melting point, automatically closes when the link melts causing the platform to lower and the cover to close.
    • Permanent electrical bonding per NFPA and OSHA compliance
    • Elimination of metal-on-metal moving surfaces
    • No electrical supply or electrical boxes on the system

Magnetostrictive Ultrasonic Cleaning Succeeds Where Less Powerful Piezoelectric Ultrasonics Fail

Case Study: nPB (N-Propyl Bromide) Replacement

N-Propyl Bromide (nPB or 1-Bromopropane) is a toxic solvent often used in cleaning or vapor degreasing applications. As a suspected human carcinogen and proven animal carcinogen, it has been targeted by the U.S. Environmental Protection Agency for risk evaluation and the European Union has banned it’s use without authorization after July 4, 2020. It is clear that nPB use will soon be banned or greatly restricted and existing users are encouraged to look for a replacement.

Companies presently using nPB are searching for safe, economical and effective replacements for nPB and Magnus Engineered Equipment has been successful in assisting customers to replace nPB with less costly, non-hazardous chemistry while accomplishing the same or improved cleaning. The following is an example where Magnus Engineered Equipment helped a customer develop a cleaning process utilizing nPB and then further helped them replace nPB with non-hazardous, environmentally friendly chemistry.

Highly crosslinked polyurethane is one of the toughest and most durable polymers, and producers often mold this material into usable items such as wheels for roller coasters and skateboards, hoses and automotive suspension bushings. The molds can become contaminated and cleaning the molds is a difficult and time-consuming process.

MEE worked with a customer to develop a chemical cleaning process for their polyurethane molds (steel and aluminum). Previously, a media blasting method was utilized to clean the molds and the process required mold dis-assembly and up to 4 hours of blasting. Using MEE Powersonics, the world’s most powerful magnetostrictive ultrasonic cleaning technology, MEE was able to demonstrate mold cleaning in less than 5 minutes with no mold dis-assembly. (This result was not achievable with less powerful piezoelectric ultrasonic cleaning). With this success in hand, attention was directed at finding a safer chemistry. Powersonics coupled with Acrastrip chemistry by US Polychem was able to replicate the performance achieved with nPB. Acrastrip is a water-soluble, non-hazardous environmentally friendly cleaner that was designed to replace acetone, toluene, MEK, Methylene Chloride, Xylene, MIBK, NPB, Ketones, and other petroleum-based products. In addition, Acrastrip is HAPS free, biodegradable, non-flammable, non-toxic, pH neutral and recyclable.

A Polyurethane mold cleaned with powerful 20 kHz magnetostrictive ultrasonic technology and water-based Acrastrip cleaner

The cleaning tandem of MEE magnetostrictive ultrasonics and Polychem Acrastrip is one example of how MEE can assist customers who are looking to replace nPB with a safer, more cost-effective and quality cleaning operation. MEE Powersonics is the world’s most powerful ultrasonic cleaning technology and can often deliver successful cleaning where less powerful piezoelectric ultrasonics fail.

 

Passivation, Dross and Weld Discoloration Removal

Many metals protect themselves from corrosion by forming a passivation layer on their outer surface.  This protective layer is composed of metal oxide or metal nitride and is very thin.  For stainless steels, the layer may be only 1-3 angstroms thick and for metals such as aluminum and titanium, the layer may be up to 50 angstroms thick. (A human hair is 500,000 angstroms thick for comparison).  Passivation can occur naturally with exposure to oxygen or can be assisted by various passivation techniques such as electrolytic anodization, plasma treatment or chemical treatment.  Due to the limited thickness of the passivation layer, the substrate being passivated must be very clean to begin with to prevent discontinuities in the passivation layer which would then compromise the protective nature of the passivation layer.

Machining, cutting, welding, polishing or otherwise “working” a metal substrate generally introduces contaminants which prevent the formation of a uniform passivation layer.  Even particulate in the shop air can contaminate the metal surface and prevent uniform passivation.  Magnus Engineered Equipment can supply the proper equipment to clean and passivate the metal substrates.

Laser or plasma cutting stainless steel or other metals can produce a dross which needs to be removed for part functionality and proper passivation.  The same is true for stainless steel or other metal discoloration that occurs from welding.  Often, aggressive etchants such as hydrofluoric acid and nitric acid are used to remove dross and less aggressive chemistry can be used to remove discoloration.  The use of ultrasonics is useful for removing dross and discoloration and the 20 kHz ultrasonics offered by Magnus Engineered Equipment is the most powerful ultrasonics in the cleaning industry.

Contact Magnus Engineered Equipment to see how we can assist with your metal passivation, dross and discoloration removal needs.