For nearly 20 years, the founders and owners of Paradies Eis, together with 20 or so employees, have been producing almost 1 million liters of ice cream per year. There are over 50 varieties in the company’s range, from classics such as vanilla to exotic flavors such as mango curry.

“Varieties with our acclaimed chocolate sauce or a chocolate coating are especially popular at the moment,” Steen explained. 

Processing with hot chocolate sauce

The chocolate has to be dosed at a temperature of approximately 60 degrees Celcius into the ice cream, where the liquid mass then hardens again. At Paradies Eis, peristaltic pumps are used for this task. Without valves, seals or moving parts in the fluid path, peristaltic pumps are ideal for operation in hygienic environments; the pumped media comes into contact with only a food quality tube. Moreover, media is pumped very gently and with extremely low shear forces, so product quality is never compromised. Peristaltic pumps also offer high precision and reproducibility, which help maximize product consistency, an important consideration in ice cream manufacturing. Further benefits include low maintenance requirements and rapid product changeovers, WMFTG said.

However, even within the peristaltic market, there are significant differences between pumps, the company said.

“We were previously using a peristaltic pump from another manufacturer, which did not deliver the required precision on a consistent basis, and the insertion of the tube was complicated,” Steen reported.

The tube did not locate securely in the track, which meant that the operator often had to make adjustments. After just one year of use, pump reliability and precision declined even further, prompting the company to seek an alternative supplier, WMFTG said.

Excellent processing

The solution was found in the Watson-Marlow 500 series, a compact range of cased peristaltic pumps for flow rates up to 3.5 liters per minute.

“From the beginning, we noticed that the quality of the WMFTG pump is completely different [than] that of our previous pumps,” Steen said. “It runs quietly and evenly, and performs reliably with a high degree of accuracy.”

After this positive impression, it soon became clear that when production expanded, the company would again turn to WMFTG.

“We have just purchased our third ice cream machine and fitted it with a peristaltic pump from WMFTG,” confirmed Steen. “The new 530 model is demonstrating the usual quality and reliability.”

Depending on the recipe, the pump delivers up to 70 liters of chocolate sauce per hour. WMFTG said the 530 series pump is operated via an intuitive keypad with large buttons and a clear color display for easy operation with gloved hands in a production environment.

Compared to other peristaltic pumps, the 530 model scores high, with ±0.5% accuracy and a precise speed control range of 2200:1. What’s more, the 530 pump is self-priming and capable of dry running. And thanks to its robust and simple construction, it can be easily operated by different personnel, including temporary workers. This is especially important in a sector such as ice cream, which can witness large seasonal spikes in demand during periods of warm weather, necessitating the employment of temporary workers, WMFTG said.

Pump and tube from a single source

To ensure high reliability and maximum service life of the pump and tubing, it is important that both are perfected matched. WMFTG manufactures both peristaltic pumps and tubing in a number of materials, Paradies Eis said.

The Bioprene peristaltic pump tubing used at Paradies Eis is USP Class VI and FDA regulation 21CFR 177:2600 compatible for contact with aqueous food, at operating temperatures up to 80 degrees Celcius. The long peristaltic life means stoppages for a tube change are rare events and easily fitted in with general maintenance downtime at the ice cream manufacturing plant, WMFTG said.

“With our old peristaltic pump, we had to change the pump head after just one year, but with our WMFTG pumps we have never had to change a single pump head,” Steen stated. “Tubing merely needs to be changed from time to time, which is quick and easy. As our order books are full, we really do not have time for maintenance-related downtime.”