Packaging Machinery and Hot Hot Heat!

Depending on when you were born, you may be disappointed with the Hot Hot Heat reference, but we are referring to the product temperature, not the Canadian rock band. Some products require a temperature change to accomplish consistent and reliable fills, or to simply enable the fill. For example, some molten products will be sold as a solid, but must be melted to accomplish the fill in the first place, such as many candle products. How the viscosity change is achieved will depend in part on the types of products running through the machine.

Generally speaking, many hot fills simply allow a change in viscosity so that a product that might be hard to run through a filling machine can be handled easily. Though other reasons exist for performing a hot fill (such as sterilization), we will focus on a couple different ways that products can be filled hot when simply trying to achieve a change in viscosity to enable the filling machine to consistently and reliably fill bottles.

The first and simplest way to complete a hot fill is to heat the tank. A heated tank allows product to reach a temperature at which the product will flow freely through the product pathway and nozzles in to the waiting bottles or other containers. For some products, the heated tank will keep the viscosity low enough to complete the fill. Once filled, a packager may use a power cooling conveyor, with or without the assistance of cooling fans, to allow both product and package to cool before moving to the next packaging phase, which is typically capping and sealing. However, some products will cool or solidify rapidly once leaving the tank, which will require a little more than just a heated tank.

Returning to the candle example above, wax type products have a tendency to cool rapidly when removed from heat. The issue created is that product may solidify and clog the product pathway. That is, once the molten product leaves the tank, it may cool or solidify in a manifold, tubing or even in the nozzles. The solution, then, seems fairly obvious. In addition to the tank, the entire product pathway must be kept heated to achieve the desired fill. This can be done in different ways depending on the filler, the product and other components being used. Product now remains at a constant temperature and viscosity from the tank to the containers, and again a cooling conveyor is likely to be employed to allow the hot liquid to cool or settle.

Hot filling products, just like any other filling project, will require an analysis of many different components to find the best and most efficient solution for getting product from the tank to the containers. NPACK has the experience to assist with such an analysis and help each packager find the ideal solution for their own unique packaging project.

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