Sessions Label Solutions has specified PSD80 linear actuators, GV3 guides and MCS aluminium framing, all from HepcoMotion, for a special-purpose labelling machine.
Sessions Label Solutions often undertakes labelling projects that its competitors have declined. Recently the company was selected by an international confectionery company to build a special-purpose labelling machine.
A single machine was required to apply security labels to all four sides of a box of sweets and also to accommodate a range of pack sizes. And that meant designing a system whose labelling heads and parallel conveyors could be moved in unison to predetermined positions to suit box dimensions. Having used HepcoMotion linear motion products for many years, Sessions once again put its trust in this brand.
The basis of the resulting system is two pairs of parallel conveyors mounted on linear slides that are coupled together to form an 'L' shape. These parallel conveyors on each leg of the handling system provide the means to adjust the width to suit the different box sizes. For the maximum box width of 400mm the conveyors are at their widest apart and, for the smallest, 100mm, they are brought together and almost touching.
This has to be precisely accomplished, as the customer requires L-clip labels to be applied. To achieve this, the box has to overhang the 30mm wide conveyors on two opposing sides, so the label can be affixed to the side and bottom faces of the box. The linear speed of the conveyors is 30m/minute with a maximum product throughput of 60 boxes per minute.
To move the conveyors in and out, Sessions chose the HepcoMotion double-acting PSD80 screw-driven linear actuator. This well suited to this duty, with drive from a stainless steel lead screw operating with a bearing polymer nut. It employs HepcoMotion's Herculane ultra-high-performance wheels mounted in an adjustable carriage body for zero-play linear motion. The double-acting version of this unit proved suitable, as it permits the adjustment of both conveyors from the operator side.
Gary Hall, Sessions' Sales Director, comments: "The ability of the PSD80 to run dry was an important factor in our choice. So too was its neat design, especially the enclosed screw on the linear adjustment." Indeed, one of the most popular features of this product is its stainless steel cover that effectively seals the unit from debris. It is therefore a natural choice for many food handling applications that require a space-saving and hygienic drive.
Linear motion system
The labelling heads of this special-purpose machine are fixed to the carriage plates of HepcoMotion's flagship GV3 linear motion system that easily provides the required positioning accuracy of +/-1mm. The entire machine is mounted on the HepcoMotion MCS aluminium machine construction system. Hall adds: "We like this product because it looks smart, it is easy to build and versatile to accommodate changes. Quick delivery and good price are important factors too."
In operation, the conveyors and label heads on both sections of the machine are manually adjusted to suit the dimensions of the next batch. On leaving the packaging line, the boxes then travel down the first pair of conveyors to the label heads where the L-clip labels are applied to the first two opposing sides of the box and secured underneath. They are then turned through 90 degrees by the crossover unit and steered along the second pair of conveyors for the application of L-clips to the two remaining faces.
Hall concludes: "The system and the HepcoMotion products are working very well. We have successfully fitted HepcoMotion to many of our systems over the years and have always found them to be good value and good quality products." Both are very important factors in an industry where cost and production efficiency are vital.