Hot or cold?
January 22, 2016
by Dan Malovany
When it comes to belting, bakers and food processors need to calculate how hot or cold the process is. Such extreme conditions could affect the type of belt and a lot more.
“The temperature range is important,” noted Ricky Milner, technical service engineer, Wire Belt of America. “We manufacture belting out of T302 stainless. If the temperature exceeds the material range, we would select a higher-temperature material. Also, some applications require the belt to aid in heating the products. If the wrong mesh and material is selected, the application will fail.”
In ovens 300 ft long or more, belting may expand 15, 18 or 20 in. in length when heated, depending on the material and internal temperatures. Likewise, extreme cold also plays a role, especially in product orientation.
“When you get down to -30°F or -40°F, the belt is going to contract,” observed Bryan Hobbs, sales and service manager of North America for Ashworth Bros. “In some spiral freezers, the belt may contract 10 ft. How do you compensate for that? You need the spiral design to allow for this extra belt that is either shrinking in cold or expanding in extremely warm temperatures.”
Frost is another matter to consider. “Some customers think they need a really tight mesh, but a tight mesh in a freezer is probably going to frost up. Air is not going to flow through the belt, which is going to affect processing,” Mr. Hobbs explained. “Through experience, we can tell you what mesh might work better in certain applications to keep the belt more open or prevent it from frosting up.”
Air knives as well as wire or nylon brushes can remove most of the frost and keep the belt functioning correctly to ensure proper processing times, he said.