Gathering information such as product characteristics and line capacity forests the stage for a quick, uneventful start up.
When evaluating different depositors, examine all factors, including batter porosity, viscosity and specific gravity in the decision-making process. “The technology varies widely for the depositing of heavy, viscose materials versus thin, easy-flowing materials,” observed Neil Anderson, director of business development, Axis Automation. “Then consider aerated creams and mousse fillings, and you have a whole different ball game.”
Unifiller provides — and often custom designs — depositors and nozzles to handle a diverse range of batter viscosities and specific gravity at high speeds accurately, according to Mr. Macpherson.
Standard depositing nozzles include positive cut-off to avoid tailing. Diving nozzles deposit batter inside paper liners while spreading systems apply a swath of butter on croissant dough. Suck-back nozzles are often installed when spreading heads are used to apply batter and eliminate excess dripping.
Overall, Mr. McIsaac said, pure liquid batters remain the easiest to portion. “Gravity is all you need,” he pointed out. “To run the stiffer batters, you need to adjust the machine to draw them into the portioning mechanism. On our Vemag, it’s a simple change of settings for adjustments.”
Handtmann employs its vane cell technology to handle batters with various viscosities without changing specific gravities after the depositing. Its depositors use an adjustable vacuum level to properly feed the batters and place them into sheet pans or baking trays. “For low-viscosity batter, Handtmann depositors can gradually increase the vacuum level to make the batter flow consistently for proper depositing,” Mr. Zelaya said.
Before the batter hits the pans, mixing and aeration provide the initial controls to ensure its consistency and eventual accuracy, explained Bob Peck, vice-president of engineering, E.T. Oakes. “With a manual system, you need to check densities and the weight of the batter more often than with continuous mixers with automatic density control,” he said. “That’s because we know the incoming density of the product via mass flowmeter prior to aeration. With the Oakes mixer controller, the aeration is achieved through feedback from the mass flow meter and the mass gas meter. We know the mass flow coming in. We have a set point value of the final density, and all of this information is fed to our PLC, which outputs how much air is to be injected into the product.”
Certain products have specific characteristics that require special treatment. “If there is a need to deposit very light, delicate and aerated products such as angel food cake, the machine configuration should have large diameter ports at the intake and the depositing outlet side of the machine,” Mr. Macpherson advised.
Because they’re made with all egg whites, angel food cakes and meringues with a lower specific gravity require greater amounts of air and higher back pressure in the mixing head to make the bubbles in the batter and create a homogenous foam. Mr. Peck stressed that the mass gas and flow meters must work together in the system to achieve the desired final specific gravity for these desserts.
Moreover, Mr. Gregg noted that certain types of piston depositors can handle complex batters since they travel through the depositor with little compression. “Their large product flow paths allow the depositors to handle stiffer, more viscous batters with particulates,” he said. The same depositor often can handle both light to heavy specific-gravity batters.”
Still, it sometimes takes different depositors to handle a delicate sponge cake batter vs. a dense brownie batter to meet exacting product specifications. “The only sure way to enjoy consistency in quality and appearance of end-products is to invest in dedicated depositors for each,” Mr. Anderson said.