If you package tablets or capsules in bottles, induction sealing may give you an advantage. Induction sealing creates a visible seal that assures consumers of the product’s safety. As a consequence, you’re more likely to earn their repeat business. This article discusses induction sealing components, selection, and installation.
Using an induction sealer requires you to cap bottles with a closure that includes a foil inner-seal, sometimes called a liner. As the capped bottles travel along the conveyor, the induction sealer fuses the inner-seals to the bottle openings using an electromagnetic field. After the bottle exits the electromagnetic field, the foil cools. The hermetic, air-tight inner-seal provides visual tamper evidence, prevents leakage, promotes child resistance, and protects your product from dust, mist, fumes, vapors, and gases. In some cases, the inner-seal also extends shelf life.
The two major components of an induction sealer are the power supply and the sealing coil.
Power supply - The power supply (inverter) transforms input power into the power and frequency necessary to seal bottles. The power supply’s kilowatt rating indicates its suitability for the application. In general, the more bottles to seal (and thus the faster the bottling line) and the larger the bottle opening, the higher the kilowatt rating required. Manual or handheld systems require as little as 0.5 kilowatt, while high-speed lines may require 6 kilowatts, which is the largest unit on the market. The industry workhorse has a 2-kilowatt rating.
Sealing coil - The sealing coil is a metal conductor surrounded by ferrites and enclosed in a non-conductive housing. The ferrites direct and focus the electromagnetic field for sealing efficiency. Virtually any coil configuration is possible, but the two basic designs are flat coils and tunnel (or channel) coils. Flat coils are used for the inner-seals of child-resistant or standard flat caps ranging from 20 to 120 millimeters in diameter. Tunnel coils are used with spouted, dispensing, push-pull, yorker, or fliptop caps, most of which are used to package non-solid dosage forms. You can mount either coil design over an existing conveyor or you can unitize the system by placing the coil and the power supply on a cart for easy movement from line to line.
GETTING YOUR MONEY’S WORTH
When evaluating the purchase of an induction sealer, you should recognize that the return on investment lies mainly in the long-term benefit of adding an inner-seal, which is difficult to quantify. But when comparing induction sealers, look at the service life you can expect from the machine and the quality of service you can expect from the supplier.
First you need to decide whether adding an inner-seal to your bottle will significantly improve your packaging. Next, look at the sealer’s electronics, which typically dictate its life expectancy. Induction sealers are manufactured to last a long time.However, the availability of the electronics used to build the equipment is always a factor. As electronics are upgraded, replacement parts are harder to find. Reputable manufacturers design equipment based on components that they can replace for years to come.
When examining a supplier’s service (after-sale support), ask if the vendor will:
• troubleshoot the system with you over the phone or by sending a service technician, or must you return the system to the factory for service?
• furnish the power supply independent of the sealing coil? If the two components are separate, the failure of one won’t force you to remove the entire system from production line.
Finally, you may want to choose a system that’s large enough to accommodate many shapes and sizes of caps and bottles, as well as one that can handle high line speeds. That way, you won’t need to replace the unit if your application changes or your output increases. Paying a little more now for a larger power supply or more flexible coil design may save you money in the future. If you know that the application will change, look for a system that allows you to interchange sealing coils without tools.
• Aluminum-free foil detection and rejection device.If there is no aluminum foil inside the cap, it will reject it and display the number in the display so that bottles with faulty seals don’t reach the end of the line.
• Plugging automatic stop device.When the time of bottles passing through the heating coil is exceeded the set value,it will cut off the power of the sealing machine automatically to prevent the aluminum foil in the bottle from being overheated and causing a fire.
Induction sealers are easy to install. The sealer requires 3 to 5 feet of straight, unimpeded conveyor for mounting or placing the sealing coil. The coil is always mounted parallel to the conveyor. To prevent accidental heating, keep the sealing zone clear of metal components.