Solid steel bake oven belts have been at the heart of continuously operating bake ovens for nearly 100 years, the first one having been installed in 1925 by Swedish-based company IPCO, then operating as Sandvik Process Systems.
Multiple factors lie behind their enduring use, including excellent heat transfer properties and outstanding durability. An occasionally less recognised benefit is their versatility. A steel belt can be used to bake products as diverse as biscuits, brownies, crackers, pastries, pies, sponges and pizza bases. Indeed some products, such as American-style all-butter cookies, can only be baked on a solid steel belt. Any other type would see the fat from the product drip into the oven, resulting in an increased risk of fire, not to mention a less than perfect end product.
In many ways, the quality of a baked product is a direct reflection of the quality of the steel belt. The flat belt surface is in direct contact with the underside of the product and this gives it an even colour and a flat underside. Belt straightness and thickness have a bearing on the baking operation too. A high quality belt will deliver reliable operation and a consistent product quality.
There’s another area in which the smooth, flat surface of the belt plays a key role in maximising product quality, and that’s ease of cleaning. Regular removal of baked on deposits is probably the most important maintenance task there is for a bake oven belt. Left unchecked, a build-up of dirt leads to less than perfect products and can also have a negative impact on human health. A steel belt has the major advantage in this respect in that it has no gaps, recesses or crevices in which carbon deposits can collect, making it inherently quicker and easier to clean than a mesh belt.
Various cleaning techniques are available, involving the application of chemicals, dry ice, baking release agent or detergents and great deal of manual input. Factors such as belt type, end product, oven type and personal preference determining the method of choice. Belt manufacturer IPCO has been working on a solution to this in the form of laser-based cleaning technology. The laser is installed above the belt and as the belt travels beneath the beam, deposits are burnt off and collected by a vacuum system. Once the strip has been cleaned, the laser head can be moved across to the next section. IPCO’s laser cleaning technology is already in operation in Europe and North America and plans are in place to extend this service to Africa and the rest of the world.
IPCO service support
IPCO’s experience in producing, installing, maintaining and servicing bake oven belts has led to a detailed understanding of how the system works as a whole. This in turn has driven the development of a range of components covering every aspect of a conveying system from tensioning and drive stations to break points, graphite stations and all-important tracking systems.
Marko Leber is global product manager, Food at IPCO. “To our service engineers, the steel belt acts as a window into the performance of the entire bake oven. We understand how a belt interacts with the other components that make up the system as a whole and the condition of a belt gives us an insight into how an entire system is performing.”
For example, wavy edges on a belt could be an indication of side wandering, or of uneven temperature in the oven. It can also indicate uneven pressure from the belt cleaner or scraper, or a belt scraper that is wider than the belt itself. IPCO’s engineers will look for deformations in the belt, which could suggest problems with drums, belt supports or other parts coming into contact with the belt. Remedial actions include cleaning the drums, cleaning or replacing belt supports, and checking scrapers, rollers and belt
tensioning.
