Ultrasonic Cleaning with Flammable Solvents Resource

How Can I Use Flammable Solvents in an Ultrasonic Cleaner?

Examples of a widely used flammable solvents are IPA (Isopropyl alcohol), Acetone, and IMS (Industrial Methylated Spirits). Any time flammable solvents are used for cleaning purposes there is risk of fire or explosion due to ignition of volatile vapors by a flash source. Ignition can occur from any source due to spills or as flammable solvent vapors spread. This guide will explain how you can safely use flammable solvents in an ultrasonic cleaner.

You may not have to use a flammable solvent as your cleaning solution. Watch the video below for details on selection a cleaning solution for your ultrasonic cleaner.

Cleaning with flammable solvents requires extreme caution in any case but ultrasonic cleaning with flammable solvents requires specially designed equipment and procedures. That’s because of the real danger of a fire or explosion if spilled solvent or vapors are ignited by sparks from internal electronics or external sources.  This post describes equipment to use and precautions to observe for ultrasonic cleaning with low flash point flammable solvents. 

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Get the details on ultrasonic cleaning with flammable solvents.

Examples where Flammable Solvents are used in Ultrasonic Cleaning

The following examples use IPA but can apply to other volatile solvents.

  1. Ultrasonic cleaning with flammable solvents is widely used to remove mold support and other surface contaminants from 3-D printed parts
  2. Surgical Implants. One of the most common applications is cleaning surgical implants.  These are frequently cleaned using IPA. Reasons?  It evaporates quickly, is relatively non-toxic, and residue-free.
  3. Small X-ray tube components are cleaned in a volatile solvent to yield absolutely contamination-free results.  In an example using three steps the first step uses the solvent to remove oils that are deposited on the stainless/Kovar assembly.  Following this cycle, the tank is drained and filled with acetone for the second cycle.  After the acetone is drained the tank is refilled with the solvent for the third ultrasonic cleaning cycle to achieve the extreme cleanliness required. 
  4. Electronic Components. Printed circuit boards, motherboards and other electronic components may accumulate solder flux and other contaminants during manufacture that must be removed prior to shipment.  PCB manufacturers may be requested to use a flammable solvent to accomplish this.  The process is faster, safer and more thorough than using sprays and brushes, the latter of which could damage delicate soldered joints.
  5. Regularly cleaning powder coating nozzles is an important procedure to maintain quality coatings.  A supplier of powdered coated parts to the transportation industry uses an IPA solvent to thoroughly remove powder residues that accumulate on nozzles. 
  6. Epoxy resin adhesives used in manufacturing liquid crystal display (LCD) screens and similar applications are applied to surfaces with automated dispensing machines through precisely machined nozzles.

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Click here for details on cleaning 3-D printed parts, surgical implants, spray paint nozzles, or epoxy dispensing nozzles. Read our case study on how solvent ultrasonic cleaning is used to remove machining oils and particulates from piece parts and brazed assemblies.

How to Select the Right Ultrasonic Cleaner to Use with Flammable Solvents

There are several possible approaches to consider to clean parts with a flammable solvent (i.e., any liquid with a flash point) in an ultrasonic cleaner. Low flash point solvents when used in an ultrasonic cleaner create a hazardous location. This is because fumes or spilled solvents can be ignited by extraneous sources. To minimize potential hazards, we recommend selecting an explosion proof ultrasonic cleaner or that you isolate the solvent from the environment. The ultrasonic cleaner you select will depend on the following:

  • Size – The size of the components being cleaned today and, in the future, must be considered.
  • Cleaning Solvent Flashpoint – Because an ultrasonic cleaner is explosion proof, does not mean it will work with all flammable solvents. If you have questions, the experts at Tovatech can ensure you get the correct unit.
  • Compliance – Make sure the ultrasonic cleaner you purchase meets all regulations and standards. Questions? Chat with our team and will help.

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Ready to select the unit that’s right for your cleaning needs? Click here for details on selecting the right ultrasonic cleaner.

Baskets and Accessories Boost Ultrasonic Cleaning Efficiency

Ultrasonic cleaning baskets can help with the following:

  1. To keep products being cleaned from contact with the bottom of the ultrasonic cleaner tank. Otherwise severe damage and eventual leaking will result due to vibrations.
  2. To ensure cavitation (cleaning) action is maximized by holding products at the optimum level above the tank bottom.  This is why different tank dimensions call for correct basket specifications.

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Wonder which basket or accessory might be best for your application? Click here for details on selecting baskets and accessories.

Product Options from Tovatech for Cleaning with Flammable Solvents

If you’re planning to clean parts with a flammable solvent (i.e., any liquid with a flash point) in an ultrasonic cleaner, there are several possible approaches to consider. The options available from Tovatech are as follows:

  • Clean Small Parts with Solvent in a Beaker
  • Clean Larger Parts in Low Flash Point Solvent (e.g., IPA, acetone)
  • Clean Micro Parts with Volatile Flammable Solvent in Elmasolvex VA
  • Switch to a Non-flammable Cleaning Agent

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Looking for more information on each product option? Click here for details on each ultrasonic cleaning with flammable solvents product option.

Other Safety Precautions when Using Flammable Solvents

As noted earlier operating ultrasonic equipment when cleaning with flammable solvents creates what is called a hazardous area due to cleaning solvent and solvent fumes.   

Fumes must be vented using approved ventilation systems. Electrical equipment, wiring, lighting fixtures, outlets and similar equipment in the area must be rated as intrinsically safe by the National Electric Code, NFPA-70 Articles 500-503. 

In short, all components and equipment must be listed by a nationally recognized testing lab such as Underwriters Laboratories or Factory Mutual.  Contact Tovatech for information on selecting and using an ultrasonic cleaner with flammable solvents.

About Bob Sandor

Bob began working as a chemist in 1987 and remains a science geek to this day. After his PhD he worked on the bench in materials and inorganic chemistry for 10 years. He then took on a love for marketing and sales. He combined his passion for science and business and took entrepreneur general management positions in large corporations like Hoecsht Celanese now Sanofi Aventis, Bel-Art and Smiths Detection. There he learned what it would take to run a business and finally Tovatech was co-founded in 2006. Bob’s hobbies include playing, listening and composing music, skiing, working out, the internet and all things science. Read More