The thermal processes employed to cook and dry pet food and treat products can be a major expense for processors. New technologies and equipment designs for thermal processing systems offer increased consistency, measurability and customization. Manufacturers are also placing an emphasis on reducing processing times. Together, these advancements can have a huge impact on plant efficiency and profitability.

Automation and instrumentation

A lot of the improvements in modern thermal technologies and equipment are related to automation and instrumentation. “When it comes to drying technology, the focus is on reading airflow, reading moisture levels, reading temperatures and maximizing the efficiency of the air running through the system,” says Daniel Tramp, technical sales, companion animal division, Wenger Manufacturing Inc., Sabetha, Kansas.

“Automated process control systems remove operator error and provide consistency and security to the thermal processing of pet food,” says Eric Hanrahan, Allpax.

“Automated process control systems remove operator error and provide consistency and security to the thermal processing of pet food,” explains Eric Hanrahan, vice president and general manager, Allpax, Covington, Louisiana, a manufacturer of retort processing and sterilization equipment. “These systems provide control and monitoring of the sterilization process to ensure the sterility of the product. They also ensure compliance with the regulatory requirements for record keeping and management of critical control points (CCPs). Additionally, these systems offer many line optimization tools to manage and track OEE [overall equipment effectiveness], uptime, preventive/predictive maintenance, and other production metrics to identify process improvements for the manufacturer,” he adds.

Extru-Tech, a key supplier of extrusion solutions for the pet food industry, strives to ensure that product specifications define the process controls. “As the pet food market continues to mature ‘novel’ products onto the mainstream shelves, our process methodologies have had to evolve to make these products commercially viable,” says Rachel Ulreich, marketing specialist, Extru-Tech, Inc., Sabetha, Kansas. “The ability to properly manage our CCPs through scientific validations and tune them to the product (instead of tuning the product to meet our CCPs) has been critical in the development of specialty diets.”

Sam Pallottini, director of cookie, cracker and pet food sales, Reading Bakery Systems, Robesonia, Pennsylvania, emphasizes the importance of automation and instrumentation in thermal processing. “When designing our ovens, we utilize our industry-leading SCORPION Profiling System, which measures the heat flux, temperature, air flow, and humidity through a tunnel oven to guarantee we are providing the most efficient and consistent bake,” he says.

Reducing processing time

Reducing the time needed to bake and dry pet food products is another focus for thermal processing system manufacturers. Heat and Control recently introduced the Rotary Dryer Roaster (RDR) to the pet food market. “The RDR is a continuous dryer/roaster which can dry or roast various pet treats, from jerky treats to nugget-type treats,” says Doug Kozenski, sales manager, processing, Heat and Control, Hayward, California. “The RDR greatly reduces the process time to dry product as compared to traditional rack oven/smokehouse methods. In testing... treats with beginning moistures of approximately 60-70% have been dried to less than 10% in around 2 hours or less. Because the RDR reduces process time needed, the gas consumption required for equivalent production rates is likewise reduced.”

Cozzini, LLC, a subsidiary of the Middleby Corporation, understands the importance of reducing processing time to improve overall productivity rates. ALKAR, also a subsidiary of Middleby, recently introduced a continuous linear oven called the Turbo Chef by ALKAR. It combines convection heating, microwave technology, humidity control, natural smoke and metal belting. “In working with companies within the industry, we have been able to produce extruded pet snacks, and whole muscle pet snacks that normally have process times of 6-10 hours in under 20 minutes,” says Jim Gaydusek, US and Canada sales director, Cozzini LLC, Chicago, Illinois.

Minimizing losses

Minimizing product loss is a key consideration for any processing facility. Managing the moisture content in pet food and treat products is one way for processors to achieve this aim. “We want to keep moisture levels as maximized as possible while still being safe. Technology needs to be accurate with getting to a target moisture percentage, and not allowing us to get into a wasteful situation,” Tramp says.

Ondrej Nikel, director of engineering, Topos Mondial Corporation, Pottstown, Pennsylvania, highlights the importance of keeping fuel costs to a minimum. “If you can buy less fuel per pound of product produced, then you’re going to do better with your costs and you’ll increase your profit. Thanks to their insulation and unique construction, our J4 ovens can help minimize losses. This means that you’re not heating up your production plant, you are just heating up the product zone.” Topos Mondial also offers heat recovery systems on their J4 ovens, which can further reduce fuel costs. “For customers who are a little more north and incur substantial costs with heating up their plants or offices, we can put a system on the stack of the oven or dryer that will recover the heat that would otherwise go into the atmosphere,” Nikel explains.

The way in which expensive utilities are supplied, managed, and reused can minimize losses and positively impact the overall profitability of pet food processing plants. “Systems that reuse water, recapture heat, and recover live steam are becoming key components affecting both the return on investment into capital equipment, and compliance with energy savings and ‘greener’ production facilities,” Hanrahan remarks.

Evaluating solutions

With a wide range of thermal solutions available, it’s important for pet food processors to evaluate their needs. Tramp identifies product integrity as one of the key areas to consider before purchasing thermal processing equipment. “On any thermal production, one of the things you worry about is, do I have a product that can hold up? Will it be able to be conveyed, moved around, put in a bag, put on a shelf, and not crumble apart?” he says. “It’s also vital to look at how the equipment affects product safety and the repeatability of the process,” he adds.

Aside from the attributes of the equipment, processors should assess the reputation of the supplier. “The experience of the OEM, good manufacturing processes (GMPs) for sanitation, and a proven reputation for customer support are important factors to consider,” says Tim Clark, president and CEO, Radio Frequency Company, Inc., Millis, Massachusetts.

Other important factors to consider with any large equipment purchase include return on investment (ROI) and total cost of ownership (TCO). “Understand that the TCO involves energy and water usage as well as uptime, and have the supplier leverage energy recovery systems and predictive/preventive control systems to lower TCO,” Hanrahan says.

Best practices for managing thermal solutions can help processors maximize efficiency and profitability. “As with any thermal system, good maintenance of the combustion system is paramount to maintaining efficiencies,” Kozenski says. “Doing so keeps fuel costs as reasonable as possible and results in efficient processing and consistent product.”

Processors can also benefit from consulting with other experts in their field. “I think it’s always a smart idea to look for industry experts outside of your own staff, whether those experts represent OEMs for temperature or control systems or a broader based consultant,” Clark says.

Finally, processors should take care not to overlook key areas that can impact efficiency and profitability. “A lot of attention is placed on what happens in the oven or dryer, but people forget what happens when the product comes out. All the heat you put into your product will now come into your ambient air. This can be avoided by walling off the area where your product is cooling and exchanging that air with ambient air. As a result, your air conditioning costs will be substantially decreased throughout the whole plant,” Nikel explain.

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