September 2019

Another advantage with Hepco’s DLS4s is that they can be specified to a bespoke length to the nearest mm, up to 8m as standard. This offers customers greater flexibility as they can specify the stroke length to suit the production line, rather than having to design around a standard stroke length. This was an advantage for David Wood Foods as they could easily have variable stroke lengths to suit the different processes the DLS4s are used for. Hepco’s DLS modules can also be supplied as joined sets to fulfil longer stroke requirements. After the loaves have baked in the oven, they are transported to the cooler where they spend 2 hours rotating on a cooling rack. Cooling is a key part of the bread manufacturing process to prevent the bottom crust becoming moist and soggy. David Wood Foods have approximately 9kg of loaves in the cooler at one time. Working in parallel with a single motor and attached to a pusher arm, one set of DLS4s push 22 loaves onto the rack, while the other set of actuators push the loaves from the rack onto the conveyor to get transported to slicing and packaging. Breadcrumbs are a recipe for disaster! As with all food industry applications, the resulting breadcrumbs and dust at David Wood Foods creates a hostile, challenging environment. If particles of dirt and debris find their way beyond the seals of any linear motion component, or if they become damaged, the system will become jammed and motion will be impeded. This can result in catastrophic failure – meaning excessive downtime, and a complete system change. DLS4, however, is ideally suited to this harsh environment thanks to its V guide system that functions on the basis of tight geometrical control over matching slide and bearing V’s. In turn this provides a wiping action that expels debris, keeping machines running and reliable. This self-cleaning action eliminates contamination of the slide – a key benefit for David Wood Foods working with extensive breadcrumbs. As small, but central parts of an enormous production system, low maintenance is a core requirement of these actuators. If one part of the system goes down, the entire production line is affected. With a high throughput of 420k loaves a week, any unplanned maintenance is going to have a big impact. The challenge: low maintenance A big advantage of Hepco’s V guide systems is that they have long re-lubrication intervals. Saving valuable downtime and cost, Hepco’s cap seals need re-lubricating every 1000km, compared to every 100-150km with ball rails. These long re-lubrication intervals work well for David Wood Foods, dovetailing with their monthly planned maintenance schedule. In the last 12 months, re-lubrication is the only maintenance that David Wood Foods have had to carry out on the DLS4. Low maintenance cap seals are used to constantly lubricate the system and to provide effective sealing and protection. David Wood Foods require minimal downtime and servicing to achieve continuous operation. When a DLS4 shows sign of wear, the process is simple and does not impinge too much on production time. The eccentric adjustment facility of the V bearings can be used to quickly and simply remove any play that has occurred. Moreover, when the V bearings reach the end of their calculated life, they can be replaced individually, and not as an entire set, saving both time and money. The DLS4s have been in operation for nearly 10 years and the bearings have never been changed. With winter approaching and the onset of chilly nights not too far away, the move towards comforting soups and heart-warming stews will see an increase in demand for scrumptious bread. Hepco’s DLS4s will continue to provide a reliable, ‘fit and forget’ solution ideally suited to this hostile and high duty application. HepcoMotion offers design engineers a range of low maintenance linear and rotary systems which are used across a wide variety of industries.