Confectionery depositors are basically controlled “positive displacement” pumping systems. A centrifugal pump moves fluid by spinning an impeller similar to a fan blade. A positive displacement pump can move fluid (product) by forcing it in one direction with a screw mechanism, or draw it into a chamber then push it back out in another direction in the case of a piston or rotary lobe pump.
Regardless, pump performance and efficiency depend greatly on the attributes of the product as well as how the product is introduced into the pump. The same is true for confectionery depositors. Most commonly, temperature and viscosity go hand in hand. Assuming consistent formulation and process (usually cooking), depositors are usually closely temperature controlled so that temperature of the mass remains constant and thus the viscosity and pump efficiency are constant. This is probably the biggest variable affecting piece weight control.
Introduction of the product to the pump has to do with how difficult (or easy) it is to get product into the inlet side of the pump. If the inlet is constricted, the product will have to be drawn into the pump by some vacuum effect. If the inlet is flooded without restriction, then it is much easier for the product to flow in and likewise be pushed out of the pump. The more nuanced engineering term for this is “head pressure”. Simply, the higher the product level above the inlet side of the pump, the easier it is for the pump to push product out the outlet side. The more consistent the level of product above the inlet, the more consistent the weight of product out of the outlet.
Confectionery Depositors Benefit
Confectionery depositors offer a continuous and repeatable method to dose or meter out pieces of consistent confectionery masses.
The key words here are “continuous” and “consistent”. In a perfect world, if the temperature and viscosity of the product are consistent, and if the feed rate into the depositor is equal to the output rate, then the depositor hopper level will not fluctuate. Those conditions will provide the best piece weight control.
For various reasons it may not be practical to process continuously, and product will need to be made in batches. In this case, be sure to discuss the properties of your product, batch size, and piece weight tolerances needed with your equipment vendor to insure the depositor design is best for you.
Learn more about our Pneumatic Depositors and Servo Depositors