It can be easy to overlook the fact that even hazardous chemicals and flammable products must be prepared for the end user by getting those liquids into the proper containers. Of course, packaging flammable liquids presents some unique challenges to packaging machinery manufacturers. While each packaging project will be handled based on the unique characteristics of the package, product and process itself, there are generally two common ways to package flammable liquids using an semi-automatic or automatic filling machines.
Sparks and arcs from the electronic controls of a packaging machine have the potential to ignite flammable liquids when those liquids are being run through a packaging machine. One way to protect against sparks and arcs is to remove the electronic components from the machinery. Therefore, many liquid fillers for flammable products will be manufactured as fully pneumatic equipment, that is, equipment that runs using compressed air rather than electricity. Where a PLC and control panel would normally control settings such as fill time, head dive, pump speed and more, with flammable liquids a pneumatic foot or finger switch may start the cycle, allowing the head dive where necessary, while simple timers would control the duration of the fill, also if necessary. Tabletop pneumatic filling machines are a popular choice of companies that have low to medium production requirements and can meet those requirements with a semi-automatic filling machine.
ELECTRONIC CONTROLS WITH INTRINSICALLY SAFE CONSTRUCTION
In other cases, where pneuamatically controlled machinery simply may not meet the needs of the packager, electronic controls will still be used, but special steps will be taken in the construction of the equipment to protect against the likelihood of a spark or arc from those controls. The machine itself will be constructed as an intrinsically safe liquid filler. In basic terms, PLC's, sensors or any other circuit on this type of machine will be enclosed to ensure that sparks, arcs or other effects are incapable of igniting the flammable liquids being packaged. Explosion-proof filling machines may also use a purge or pressurization for certain enclosures where fumes or vapors may also ignite.
While different filling principles, various options and different levels of automation are all available when filling flammable liquids, pneumatic or intrinsically safe construction is always a must. The construction of such equipment protects not only the machinery itself but also those working in and around the machinery. In addition, the added protection seldom takes away from the performance, reliability or efficiency of the machinery, making it a positive solution for the packager, machine operators and consumers alike.
To learn more about packaging flammable or hazardous products, or for more information on any of our packaging machines, contact a Packaging Specialist at NPACK today.