Oral · Pages 150–155
Abstract
Research summary supplied by the authors
The tanning process is a very complex and specialized system that requires experienced and high-level manpower in specifi c skills. Although craftsmanship is fundamental, there are some phases in which labor is superfl uous because the operator simply performs a purely manual function, feeding the process lines with the leather, taking it from the pallets, trolleys or air hangers. Where the skill is essential is at the end of the line where is performed the quality inspection as well as the handling and manipulation of the leather. We have invented and patented various robotic and automatic systems where the unskilled manpower is superfl uous and non- essential, achieving the result of reducing fi xed costs and mobilizing the role of operators in tanneries, avoiding diffi cult and unsatisfactory work. From an idea that seemed impossible and visionary, a new BRS (Barnini - Robot System Automation) brand was born, created for the most skeptical, created for those who say that it is impossible, created for those who cannot see the future and are satisfi ed with knowledge of the present. Three different solutions have been created, all patented and operating in two relevant tanneries in Tuscany and in our internal research & development laboratory. Here, today, we are the architects of the tanning industrial revolution. The year 2022 represents the turning point of the beliefs and traditions of the sector. 1. State of the art, process and specs Currently the tanning industry is full of systems and automatic machines to perform various processes. Barnini, which has always been a leader and specialized in automatic process lines for single or multi-stage spray fi nishing ofl eather with associated thermal treatments. Typically, the lines are developed on wire belts (different materials for different processes). The width of the inlet belt can be of variable size according to the type ofl eather and/ or the process methods used. The same goes for the speed of advancement of the product on the belts. The part is moved on the conveyor and sprayed by a rotary, alternating or parallel system. The lines can be made on sets of widths suitable for the products to be treated, starting from useful widths of 1500 mm up to 3800 mm, and calibrated for product feed speeds which can vary from 5 to 25 meters/ min. Currently there are and are marketed systems for collecting the hides coming out of the machines, based on conveyor belts. On the outfeed belt, using centrifugal rotary systems that allow the passage from the wire belt to the belt, the leathers are transported and with simple kinematics "stacked" and palletized. The same technology is also used to feed airways lines on hangers. 151 Currently, no anthropomorphic robot or "full automation" technology, therefore based on the concept of "NOT SURVEILLED", is instead applied to the loading of the product at the beginning of the phase. The main issues are: • Variability of shapes and sizes of the product to be handled (eg half calves, calves, sheep and goats) • Variability of thickness and type ofleather (eg. From 0.5 to 2mm, including breathable product) • Variability of the support materials to be taken from (eg pallets, by air, "horses", drying racks). • Process speed. A speed of 15 mt / ruin presupposes a feeding with a cycle time that varies between 6 and 10 seconds depending on the size of the product. • Loading methods. In many cases the products to be handled do not arrive in a precise order, but for process reasons they can be stored with the finished faces in contact or in opposition (flesh/ flesh - finished/ finished). This assumes that the loading system also has the ability to overturn the pieces (meat-> finished and vice versa) Focusing on the intention to automate for the Automotive tannery project, we have summarized the specifications and input data as follows: 1. Belt to be interlocked with maximum useful width of3800 mm 2. The leather must be picked up from trolley 3. The part to be loaded will be for the maximum size of 3200x3000mm, up to 28 kg weight Focusing on the intention to automate the air chain for the shoe upper and leather goods tannery project, we have summarized the specifications and input data as follows: 1. The leather can be picked up by air transport conveyors with variable geometry and size according to the layout of the leather goods 2. The part to be loaded will be for the maximum size of 2500x2000mm, up to 18 kg weight or an half cow For both solutions: 3. Maximum production speed requested 15 mt/min 4. Total integration with spray line including the status and logic operation synchronization In all the tanneries there are people dedicated to load and manipulate leather into the spraying lines. The number of operators depends from the product. For small part, goat or half cow could be enough just one, from bigger or faster line, 2 are the minimum. All of this works in a very non-ergonomic condition, picking from the ground in case of pallet stack with a continuous 180° rotation for the bust and up and down grab. Similar for the air conveyor, where the operator must drop down from the hangers. The impossibility to stop the line for the process needs a continuous job, making it very stressful. In many countries this operator must be rotated during the shift. In big production operation 3 shifts are used. The impact of unqualified manpower to make the job is 3 to 6 per day. 2. Technology implemented Real tests on pallets unloading have shown the need to "help" the deposition on the main process belt with devices that help to remove wrinkles and "stretch" the leather to make it flat. This can be performed using a movement in opposite directions (eg robot in a positive direction, belt in a negative direction). Based on these experimental tests, the project idea is conceived as follows (Fig. 1, 2):