Drives & Controls March 2023

40 n BELTS, BEARINGS AND CHAINS March 2023 www.drivesncontrols.com Pizza-maker stretches chain lives from three months to more than 18 R oller chains that are used to drive food packaging machines need to ensure stable motion. And the conveyors driven by these chains have to maintain the quality of the produce, as well as delivering high throughputs. For many years, a pizza manufacturer in France has been using roller chain to drive a conveyor that moves packaged products to a chilled storage area, ready for distribution. With most of its products being shipped to supermarkets, profit margins are tight. This means that, as well as ensuring quality, the pizza manufacturer has to maximise productivity and make sure that it hits its production targets. The conveyor’s chain is vital to ensuring that products are moved quickly and efficiently to the despatch area, without damaging either the packaging or the pizzas. Previously, the maintenance team had to check the chain for elongation every three days, stopping production each time. The consequences of the chain stretching could include uneven conveyor motion, as well as an increased risk of breakdown. Vibration and slippage of the conveyor could damage the pizzas, as well as causing uneven alignment and disruption to the subsequent packaging process. If the chain failed, the resulting machine breakdown could result in lengthy downtime. Despite regular maintenance, adjustment and lubrication, the company was having to replace the conveyor chain every three months. This had been going on for 15 years, and company eventually decided that investing in a high-quality roller chain would offset the cost of maintenance and downtime needed to replace the inferior chain frequently. It ran a trial on a high-spec chain which resulted in increased productivity and a lower cost of ownership. As a result, the company decided to upgrade its chain to Tsubaki’s GT4 Winner product which incorporates a patented ring coining design that reduces elongation. Applying a cold deformation process around the pin hole of the connecting link plates strengthens them and reinforces the chain around the pin. Reinforcing this stress area allows the chain to be specified to its full kW rating and decreases the effects of elongation. The new chain also had specially designed grooves that retain lubrication between the pin and the bush – the point of highest contact and friction – instead of dispersing the lubricant. This helped to reduce chain wear and elongation, as well as the need for maintenance, extending the chain life. This, in turn, helped to raise productivity. The new chain did not need to be adjusted until after it had been running for 18 months – far exceeding the three-month lifetime of the previous chain. But the longer life resulted in a new challenge that the site’s maintenance engineers hadn’t encountered with the previous chain – humidity. The original chains did not last long enough to be susceptible to corrosion, so Tsubaki suggested changing to its Neptune chain to further prolong the chain life in the plant’s humid conditions. This chain has a special coating and resin tested to remain corrosion-free even after 700 hours of exposure to saline spray. Its carbon-steel base means that it has the same tensile strength and resistance to elongation as the GT4 Winner. The anti-corrosion treatment doesn’t affect the chain’s strength or durability, unlike some rust-inhibiting coatings. Following the new chain’s first adjustment at 18 months, it is expected to provide many months of additional service. The pizza believes that the initial investment in the higher-spec roller chain has provided an economic payback, as well as reducing its need for maintenance and its total budget. n A French pizza-maker was having to check its conveyor chain for elongation every three days, and replace it after three months. After doing this for 15 years, it decided to upgrade to a higher-spec chain that would not just cut its maintenance costs, but also boost productivity. Then it encountered a new problem – corrosion. Tsubaki’s Neptune anti-corrosion chain incorporates a special coating as well as a resin applied to the carbon- steel base chain.