Since the commercialization of petfood, improved techniques for processing petfoods and treats have resulted in the expansion of the petfood supply by prolonging keeping times, preventing spoilage and increasing the variety of food products available. The latest extrusion, drying and cooling developments from company's like Clextral, Wenger and Aeroglide continue to focus on these very advancements, hoping to continue to improve overall petfood quality for both the consumer and their pets. The question is: Which technology is right for your manufacturing line?

1. Evolum LT 145  (Clextral)

Clextral's Evolum LT 145 extruder offers optimum torque and higher screw speeds for maximum throughput, to help petfood processors achieve exceptional results from their extrusion processing lines, according to company literature. In addition, the Evolum incorporates Clextral's advanced temperature control for managing complex recipes in the processing of premium dry and semi-moist petfoods. The Evolum LT 145 operates at throughputs from 5-10 tons/hr.

The wraparound frame is newly designed to provide maximum accessibility, says Clextral. The machine includes ergonomically designed anti-slip steel footmounts as well as handrail and footrail to allow easy machine access.

The design ensures quick access to operating parts for sanitation and maintenance. Take for example, a simple clamp system that unlocks the barrel from the lantern to allow immediate barrel access for reconfiguration or dismantling. Clextral attests that the oversized lantern opening allows quick access to the bearing block and shaft coupling. The design also allows the dismounting of the mechanical torque limitor without removing the main motor or gearbox.

2. Single/multi-pass conveyor dryers/coolers  (Buhler-Aeroglide)

Maximum drying results with a small footprint, for products that can tolerate repositioning, is one of the many things Aeroglide's single and multi-pass dryers offer.

With Aeroglide's multi-pass dryers, conveyor beds are stacked one above the other in a single insulated enclosure. The ultimate for maximizing capacity in the least amount of floor space, Aeroglide multi-pass conveyor systems provide multiple product turnovers for uniform thermal processing. The systems can be configured to run at the same temperature throughout, or with sequential heat zones allowing precise control of temperature, process air humidity and airflow throughout the process.

Utilizing engineered airflow control throughout the recirculation loop used on the production line, Aeroglide's goal is to set the standard for single and multi-pass conveyor dryers, according to the company. This unique design provides uniform airflow temperature and velocity distribution across the product bed. An additional benefit is in fines management and collection, resulting in safer operation and increased uptime, says Aeroglide.

According to Aeroglide, it was the first company to offer a sequentially zoned dryer to the petfood industry. Providing the ultimate in zone temperature control, this system maximizes production per square foot of floor space, while still protecting the product from excessive temperatures. Sequentially zoned dryers are ideal for temperature sensitive ingredients. New technologies to help petfood manufacturers optimize their process include the AeroFlex adjustable feeder and advanced controls, as well. AeroFlex product spreader may be adjusted on the fly and the fines management system includes floor fines drags and plenum screws.

3. Swivel Valve Cooler MkII  (Geelen Counterflow)

The new Swivel Valve Cooler MkII from Geelen Counterflow has been designed for customers with very high food safety requirements where frequent cleaning and inspection are necessary, even if the risk of cross contamination is small to begin with. The main advantage of the improved cooler design is that it enables fast and effective cleaning, inside and outside, with a minimum of cleaning residue, according to Geelen.

The hood of the cooler has been redesigned to avoid horizontal surfaces inside and outside. There are no ledges where cleaning water can stay behind. All external stiffening bars are in stainless steel. The air exhaust has no horizontal surfaces so no risk of product accumulation. The bin walls contain giant doors which allow the side of the cooler to be completely opened for fast cleaning and inspection. The redesigned swivel valve discharger minimizes the risk of cross contamination between different products.

4. Rotante Dryer  (Clextral)

Clextral's Rotante dryer, with new technology achieves uniform drying for a wide range of high value and hard-to-dry products, while achieving exceptional energy efficiency. Additional advantages of this innovative design include: product changeover in less than three minutes, real-time recycling of fines generated in the drying process, simplified cleaning and reduced maintenance.

The Rotante has a unique design that conveys product through a continuous rotation to ensure uniform airflow on all product surfaces, thus eliminating product over-heating or unequal moisture distribution that can lead to rejected product and lost profits.

Why is the Rotante so energy efficient? According to Clextral, several factors contribute to the high energy efficiency of this dryer: product is distributed in thin layers that require lower air velocity; process air temperatures and humidities are independently controlled in multiple zones to achieve optimal drying for each product; and the dryer has reduced interior volume to minimizes process air quantities. Improved product quality is achieved by the continuous, homogeneous drying process and uniform residence times that ensure a final product moisture variation of +-0.1%, says the company.

5. C2TX Conical Co-Rotating Twinscrew Extruder  (Wenger)

Wenger's new C2TX generates compression continuously and the interesting co-rotating conical screws have a special profile that kneads the ingredients as it is forced through the extruder. Conical intermeshing co-rotating screws provide natural compression from the low density of a preconditioned recipe at the extruder inlet to the dense dough mass at the screw discharge, explains Wenger.

With less material in the C2TX extruder barrel than in the barrel of a conventional single or twin screw extruder, the C2TX cooking extruder is extremely responsive to screw speed change, recipe moisture, recipe temperature and cooking in the preconditioner, claims Wenger. Changes in final product density, color, cell structure, and surface texture are present only seconds after making a change in a process variable. Changing processing conditions will result in immediate changes in product density without changing the extruder die.

The cost of wear parts is reduced when compared to wear costs in a conventional twin screw extruder, another advantage the C2TX.

Extru-Tech Inc. recently announced the introduction of the new Maxxim Series Extrusion Systems. The new line of enhanced single screw extruders are capable of 20 to 30% production rate increases over previous models with the same barrel diameter, according to the company. Extru-Tech's inline drive system has been re-engineered to handle up to 600 hp compared to 350 on previous models. In addition, many ongoing improvements have been made to the barrel design, including changes to the screw profiles and the ribbing design in the sleeves.

Other improvements include a screw support assembly that eliminates metal to metal wear. This assembly also allows for thermal expansion, which occurs as the screws are heated up to operating temperature.