When should you buy an overflow filler:
Over flow filling has been used has been used to fill low viscosity liquids for many decades, if it’s used for the right product and a correct set up it will give you a very accurate fill
The overflow filler will give you the fill level by the depth off the return tube inside the container, once the product reaches these tube It will go through the tube instead of continuing to fill your container. If you reach the overflow tube in four seconds and leave it filling for more time the fill level in theory will be the same, keeping this in mind when you set-up an overflow machine will help you understand that you only need to fill for enough time so all the nozzles have overflown. All fill nozzles will not fill at the exact same rate and it won’t matter, if you leave the machine filling for enough time eventually all containers will fill and you will get an even cosmetic fill.
We talk about a cosmetic fill because the machine will not know what volume it is filling it will only do it by height so if the bottles you purchase have an internal volume that it’s different the machine will always feel the same height but the larger bottle will have more product than the smaller bottle by volume.
There are many settings but you can have an overflow filler some machines Have the capability of filling at different speeds at different times, this is very useful specially on larger containers because you will be able to fill at very high speeds at the beginning and slow down at the end to avoid splashing, if you don’t have this option you will have to fill all the container at the highest speed on which the machine will not splash.
Most nozzle designs on overflow liquid filler will drip, not because they are defective but because the get wet and when they come out there is product on the outer tube, so when the nozzles come up and they drip while the containers are moving you will get product on the outside of your bottles. An easy solution for this is a drip-tray that most companies offer.
By far, the biggest limitation of an overflow liquid filler is not being able to fill thick products, or high viscosity products. Different companies offer different solutions and some companies like to take on projects of higher viscosity than other. If you plan to fill a product thicker than water, make sure you get written guarantees.
The main problem with filling high viscosity products is that the product will have to overflow, so if it’s to thick instead of overflowing it creates an internal pressure inside the container that is stronger than the top seal and instead of overflowing the product comes up and spills from the top of the containers, trust me, not fun!!!
There are different nozzle designs that can help for thicker products, larger overflow, assisted overflow with vacuum, suck-back, etc.. Make sure the nozzle will work for your product and container.
After all’s been said, overflow fillers are a great solution for thin low viscosity products and can be pushed to work some thicker products