Filling Machine Challenges: Product Temperature and Viscosity

Filling Machine Challenges:  Product Temperature and Viscosity

Manufacturing filling machines for products ranging from bottled water and window cleaner to jams, pastes and caulks brings with it a host of unique challenges.  Some of these challenges can be as simple as how to best fill a tiny bottle or quickly fill gallons or more.  Corrosive materials sometimes require special construction materials or custom filling solutions.  Even space limitations can lead to challenges in designing packaging equipment.  One recurring challenge, however, is dealing with a product that changes viscosity as it experiences changes in temperature and any liquid filler for such a product will have some unique characteristics.
Some products react to even slight temperature changes, becoming more or less viscous as temperature drops or rises.  These changes in viscosity make it difficult to accurately fill bottles or other containers by changing the way the product flows through the machine.  For these type of products, a constant temperature along the entire product pathway is necessary to allow for a consistent and reliable fill.  Starting with the product tank, through the hoses and right down to the nozzles, the entire pathway will be heated in one manner or another.  Keeping a constant heat protects against the viscosity changes and keeps product flowing at the same rate.  In addition, positive shut off nozzles or anti-drip nozzles may be a necessity on such a machine to avoid build up of product upon exposure to the atmosphere and clogging of the nozzles or pathway. 
Other products may not need to be kept at a constant, static temperature, but must stay above a minimum or within a range to be properly run on a filling machine.  For example, wax products such as candles simply need to reach their melting points and take on a liquid form to be filled.  But taking the temperature too high can also result in evaporation or damage to the product or even the container.  For manufacturing purposes, the difference is not all that prominent, as the entire product pathway will normally still be heated to ensure consistent and reliable performance.  However, the method used to heat to a minimum temperature versus keeping a constant temperature may differ slightly.
In addition to specific and unique characteristics on the filling equipment, most hot fill applications will include some type of cooling conveyor between the filling and capping phases of packaging.  The cooling conveyor allows product to set prior to capping or sealing, avoiding the effect of trapped hot air inside a container.  For more on filling hot products, feel free to contact our offices and speak with a Packaging Specialist today.