In the sweet and savory world of snacks, biscuits and breads, TPU belts are often the workhorses – and hidden heroes – of food processing. They’ve earned this well-established position thanks to the versatile properties of the TPU coating such as high resistance to abrasion, which keeps the belt surface smooth and easy to clean for longer. Add to this high flexibility, a wide range of operating temperatures, resistance to oil and grease, good release properties to deal with sticky dough, plus the fact that the coating does not affect the taste of the conveyed goods; it is clear why TPU belts are so valued.
These excellent TPU qualities are important because food processing belts are subject to very demanding environments that can impact not only belt lifetimes but also the operational efficiency of the processing plant. We’ve picked out four key challenges to illustrate this in more detail:
Challenge No. 1: Operating at elevated temperatures
TPU belts used for infeed and outfeed of oven applications are continuously exposed to, and absorb, high temperatures from the oven and from the hot, freshly baked cookies. The majority of baking processes today have a constant operating temperature of the belt that can reach 110 ⁰C (230 ⁰F). Belts that are unsuitable for continuous exposure to such temperatures will need to be replaced more frequently, especially in hygiene-sensitive applications, due to fatigue and cracking of the belt surface.
Another common risk can be joint failure, which in some cases may even result in halting the production line altogether. This can be avoided by using belts suitable for continuous operation at elevated temperatures.
Challenge No. 2: Moist processes and oily environments
To achieve a flavorful biscuit, the baking processes require good control of moisture removal from the dough. How this process takes place will depend on the level of crispiness expected from the final product, and also on the ingredients of the dough itself. Moisture and oils contained in the raw product may be absorbed by the fabric of the belt, especially on the running side. This creates a risk of microbial growth and biofilm formation, posing serious challenges for food safety.
TPU materials are also inherently prone to degradation through reaction with water, which in moist processes may accelerate belt ageing. The ingress of oil may eventually lead to changes in the coefficient of friction, or cause shrinkage or even delamination, affecting the overall output of the line.
Challenge No. 3: Aggressive cleaning procedures
In any food production application, maintaining the highest levels of hygiene is a top priority. Cleaning protocols are extremely demanding for all the equipment used in food processing, including conveyor and processing belts, primarily due to the fact that frequent cleaning is necessary for maintaining the stable shelf life of the final product.
Protocols in which steam- or water-based cleaning agents are used may affect the belt lifetime due to hydrolysis. Additionally, in the case of steam, the belt will also age faster because of the high temperatures applied. Using belts with good hydrolysis resistance that are suitable for higher temperatures ensures more stable cleaning results with less frequent belt replacements. The type of TPU material also matters, as some are better than others at handling the chemical agents used.
Challenge No. 4: Food residues
The raw materials used in the bakery industry are frequently oily and sticky, causing food residue accumulation on the belt surface. This residue is often removed during the production run by food scrapers, which can have an impact on the belt surface as they may damage the top layer of the belt and make it unsafe for food applications. If the belt has a structured surface, it may be more difficult for the scraper to remove the food residue, which in turn can affect product release and cause wastage, as more dough stays on the belt. This can be avoided by using belts with good dough release properties.
High grade TPU belts meet the challenges
It’s clear from these challenges that high grade TPU belts can certainly handle the very demanding requirements of the bakery industry. They can deal with food oils even at elevated temperatures, and are rightfully appreciated in the market for their uniform, pore-free surfaces with good release properties, excellent longitudinal flexibility, and great lateral stability at a wide range of temperatures.
New Habasit Premium TPU food belts
To help our customers deal even better with the challenges, we have just released a new generation of Habasit Premium TPU food belts with improved lifetime. These hydrolysis resistant belts are equipped with enhanced running side impregnation, which protects the belt against wicking. A new combination of spun fabrics and non-fray knitwear limits the risk of tearing long fibers out of the coating layers and makes the belts nosebar suitable, which means they can be used for the tightest transfers. Habasit Premium TPU food belts are available with matt, glossy and waffle surfaces in white and blue.
Are you having problems with your conveyor belts in a bakery or biscuit process? Or would you like my advice on how to optimize your processing line? Please get in touch by leaving a comment under this article, or send an email to: email@example.com.