The filling of cartridges for electronic cigarettes based on e-liquids is booming. According to Watson-Marlow Pumps Group, this has resulted in a rapid rise in orders for refilling solutions such as the company’s Flexicon peristaltic liquid dosing technology. Indeed, one manufacturer in Europe says it has sold more than 20 filling lines for e-liquids in the past year alone. Its customers are contract packers working for distributors, as well as people who have started their own business. Almost daily, more and more companies are switching away from the manual refilling of cartridges.
2500+ e-liquid types
Cartridges for e-cigarettes are dosed commonly with 10ml volume, but sometimes with 20ml or 30ml. Along with up to 19.9 mg/ml of nicotine, the refills contain various flavours as well as propylene glycol and vegetable glycerine. In total, there are thought to be well over 2500 e-liquid types available on the market.
With this in mind, the main requirement is to change batches quickly with minimum product loss, ambitions made possible through the adoption of a Flexicon peristaltic filler in the filling process. Here, the product only comes into contact with the tube of the pump, so the machine does not need to be cleaned - only the tube only has to be replaced or discarded whenever a batch is changed. No cross-contamination is possible using Flexicon pumps. In contrast, using piston or syringe type pumps would be entirely unsuitable due to the number of cleaning operations required. Flexicon peristaltic fillers easily can also prevent dripping between each fill and also reduce foaming.
Flexicon pumps can be supplied to suit a range of applications, including semi-automated or fully automated variants in line with throughput requirements. Watson-Marlow says that many companies filling e-liquid cartridges are now upgrading to fully automatic solutions.
For instance, one customer which bought its first semi-automatic filling solution for producing between 500 and 600 x 10ml cartridges per hour using four operators, has since found that volume requirements have increased and it now needs to go five times faster. As a result, an automated line has since been built in accordance with pharmaceutical standards that is capable of filling up to 5000 cartridges per hour. Furthermore, only one operator oversees the line.
As things stand, no specific standards exist in this sector. It is up to manufacturers to convince customers of the need for machines that guarantee hygienic filling, facilitate good traceability and are capable of working on a wide variety of different batches. Only this is likely to keep the regulators at bay in the long term.