Steel belt management for efficiency

Steel belt expert IPCO shares its close analysis of the conveying system that it performs to ensure the efficiency and the integrity of the belt over time. Two of the most important maintenance tasks, aside from regular checks, are lubrication and effective cleaning, Marko Leber, Global Product Manager, Food, IPCO, highlights. On solid steel belts, cleaning is usually carried out using rotating brushes, with the application of scrapers as necessary. The brushes should be adjusted to gently clean the belt surface and the belt should be rubbed manually with clean cloths at the same time. Ineffective cleaning will result in a build-up of carbon deposits on the baking side of the belt, leading to sub-
standard products and, potentially, a risk to human health due to the presence of hazardous acrylamide. “A range of factors – belt type, end product, oven type, personal preferences – will determine the most effective approach to cleaning and will usually involve the application of chemicals, dry ice or detergents and a great deal of manual input,” Leber explains.

The application of an appropriate belt lubricant is also extremely important, he stresses: “The easiest way to achieve this is by installing graphite skid bars, which deliver a gradual deposit of graphite to the inside of the belt.” This reduces friction and helps to eliminate the risk of rust caused by condensation, reduces wear, prevents belt distortion, and ultimately extends the belt’s life. It also helps to maintain a regular belt color for a more even bake. IPCO graphite skid bars are available for all standard belt widths.

“If this type of skid bar cannot be used, then graphite should generally be applied to the inside of the belt once a month for the first three months after installation, then every three to six months. If graphite is not permitted for any reason, specially selected oils can be used instead,” IPCO’s specialist recommends.

While it is virtually unheard of for a steel bake oven belt to reach ‘end of life’ due to fatigue stress, a lifespan of 20 years is not uncommon and good maintenance extends it up to 50. During the baking process, the belt is placed under considerable thermal stress as it heats up and cools down every time it completes a revolution. “A combination of steel belt grade and special manufacturing phases is used to achieve the necessary thermal properties of the material. These properties give steel belts the durability to operate for decades under what are severely challenging processing conditions,” Leber says.

In terms of maintenance, qualities such as good tension, tracking characteristics and resistance to stretching combine to result in significantly less downtime than other belt materials, important considerations when even an hour’s lost production can be costly. IPCO can help with conveying system maintenance with sales/service offices and trained service teams in over 30 countries. “And, of course, prevention is better than cure,” concludes Leber, adding that IPCO also offers comprehensive Preventative Maintenance Agreements (PMAs), designed to identify risks of failure before they have a chance to disrupt production. Preventative maintenance checks will cover all major system components:
+ Terminal drums, rollers and skid bars must be aligned horizontally and at right angles to the centerline of the longitudinal axis of the oven line
+ Terminal drums and rollers should rotate freely
+ Tension devices
+ Tracking devices

Once the cause of the problem has been identified and rectified, the belt itself is inspected to repair any damage that may have occurred to ensure that it continues to deliver reliable operation for years to come.