Confectionery is often a fragile product. With the wrong handling tools, it can soon come to a sticky end during the pick and place manufacturing process. Although much of the focus in automation is on the robotic arm, it’s the end-effector that performs the task of handling products. Whether you are picking loose or packaged candy, chocolate or bakery items, get the design and specification right at the outset and you can pre-empt most production issues, maximising product quality and lowering wastage.
There are typically four categories of end-effectors on the market today – vacuum systems, magnets, grippers and clamshell style– and Pacepacker offers in excess of 15 variants to handle virtually any food assembly or packing scenario.
Vacuum gripping is generally the mainstream end-effector. Also known as suction cups, they are especially commonplace in environments where you want to minimise product-contact, such as the picking and placing of individual chocolates into boxes. Compressed air usually generates the vacuum, and valves can be configured to the product being picked, including the type of packaging. Suction cups are ‘bellowed’ in design and soft-lipped, enabling them to mould gently to different contours and sizes of individual chocolates. These can also be manufactured using food grade plastics to meet hygiene standards.
Where more vacuum is required, for instance when handling pots of cream or yogurt, a pump or even a high-airflow pump can be requested, thus ensuring a good seal between valve and product.
Another benefit of vacuum grippers is they can be multi-functional – one large gripper can pick up the different size variants on the same line, for example multi-packs or individual cartons. Where interchangeability is required, compressed air vacuum electronics can be quickly disconnected and re-attached using quick release couplings.
Clamshell-type picking is especially suitable in bakery environments where products are more easily damaged and irregularly shaped. Tasks performed can range from placing pastries and other sweet goods into merchandising containers, dipping baked goods into an icing glaze, or packing muffins and cupcakes. A compressed air system controls the opening and closing, with bodies often tailored to the shape of the item and lined with a cushioning material, such as foam. This clamshell style gripper is especially deft at handling tubes of sweets or narrow boxes.
Grippers, meanwhile, are far less aggressive than they sound, typically cradling product rather than clasping it. Widely used for loading products in flexible packaging into bulk bins and trays, as ever with end-effectors, the key is to strike the right balance between secure and gentle handling. For example, stainless steel needle-grippers and food-grade vacuum cups are becoming more widely used when de-panning baked foods, including delicate cakes topped with glazed fruit, nuts and candies.
Electromagnet grippers or earth magnets are designed for tinplated containers, such as travel-sized sweets, biscuit and chocolate tins and seasonal confectionery gifts.
The technical capabilities available for end-effectors are evolving all the time. Pacepacker is an integrator of Festo Mechatronics who recently introduced a system of ‘adaptive fingers’, with ‘prehensile’ abilities not unlike an elephant’s trunk. This exciting development makes it possible to pick up delicate but irregular-shaped objects, such as fragile glass sweet-jars to delicate foil wrapped products like Easter eggs and artisan confectionery.
While it’s important that robot interfaces are user-friendly, it is just as important to consider how your system and end-effectors will adapt to new products. The confectionery market is driven by retail and consumer trends and is continuously evolving, and there are always new packaging formats, such as chocolate lollies often shaped to reflect the most popular characters in film and on TV. These fads change constantly. Confectionery manufacturers can select interchangeable end-effectors which add to the flexibility. The fact that you can move a robot to a different application as production needs change is very appealing, especially when there are so many seasonal product variations in the confectionery market.”
THE HEIGHT OF CONVENIENCE
Further considerations when designing a bespoke system include the possible use of height compensators. These are sprung loaded features mounted onto suction cups which can pick up items with height irregularity, for example non-rigid outer packaging like selection packs wrapped in cellophane.