Haith Robot succeeds with GRS Bagging
7th April 2003
Kawasaki robots have been fulfilling many different production applications in the automotive industry since 1969, with over 32,000 units sold to date around the world. They were the first robot manufacturer in Japan and their robots perform an important role in the production of many new vehicles including the latest S type and X-type Jaguars.
Robots are seen today as an integral part of manufacture performing repetitive tasks on a 24 hour 7 day basis providing accurate and reliable actions in a wide variety of arduous operating conditions.
The car industry was perhaps the first of many industries to make use of robots extensively. Whereas in the early days of car manufacture, thousands of manual workers were used to place and fit all the various components, with the event of robots more efficient manufacture could be achieved with a smaller work force.
Many manufacturing processes are by nature performed in hostile working condition which are uncomfortable, unpleasant, and sometimes present potential risks for workers. Placing a robot in these working conditions provides a solution to this problem. Being a controlled machine, the robot also has the advantage of performing repetitive tasks without mental boredom effecting the accuracy and speed of performance. Robots are also capable of handling much larger loads than possible by manual labour, with the latest models capable of handling up to 300kg.
Robots are becoming extremely important in palletizing and handling applications because of their ability to consistently handle and stack pallets, bags, crates and boxes in an accurate and repeatable way.
Producers using manual labour are finding that goods that are stacked in an erratic way are unceremoniously rejected by their customers because of the major inefficiency problems that this causes with truck loading and warehouse storage.
Haith Industrial are the preferred systems integrator for Kawasaki in the quarry products market, they use their expertise in resolving the problem and supplying all design, drawings and installation. They also manufacture all conveying roller systems, and magazine installation supplying a complete turnkey packing system.
Haith were approached by GRS Bagging Ltd to build a new system to increase production and reduce manning levels. GRS Bagging was formed in 2000 and is a subsidiary of GRS Roadstone which was formed in 1997 after a management buyout of the former Galliford Roadstone which had traded for the past thirty years. In 1998 Lafarge acquired a shareholding in the company; GRS Bagging operate five plants with an additional two plants opening this year. They have a loyal customer base and supply a bagged range of sands, gravels and specialist products.
Originally Haith had designed and built two plants at Hatfield and Willington for inserting aggregate into 25kg and 40kg plastic bags at a rate of 12 bags per minute.
This system was supplied by loading shovel providing material into a ground hopper which then feeds onto an inclined conveyor at a controlled rate of up to 40/50 tonnes per hour which then delivers material into a twin chute supplying feed to a manual operation. The operator places the bag which is auto-filled onto a weighing machine it then travels by roller conveyor to a hot air automatic bag sealer, it is then ejected off the conveyor by a bag kicker onto a bag flattener conveyor where it travels under a bag press which compresses it to a uniform thickness, from there it travels to a pick-up table where the robot reaches down through the table and picks up the bag with a fingered grab hand, the bag is then transferred to one of two stacking stations (this provides the robot with an option, so that it does not need to stop)The robot builds a pallet of product approx 1200kgs, this is dependant on client requirements, stack patterns are different according to bag size; 40 kg bags @ 5 per layer and 25kg bags @ 7 per layer, the forklift then removes the pallet to either a stockholding position or direct onto transport.
The first systems both utilized a UD100 robot capable of lifting 100kgs at a limited speed and capacity (12-14 bags per min) , this has now been superceded.
In the new plants built at Alrewas and Iver Heath a ZD130S robot was used, this provided the new plants with a robot with a greater capacity to stack faster (20 bags per min depending on product type and flow). This is achieved by telling the robot what it is picking up; it will then perform accordingly in acceleration and deceleration planes.
In addition Haith also interfaced with an Austrian company Statec who have considerable worldwide experience in selling and installing bagging equipment which enabled them to provide a fully automatic plant. This new system was loaded in the same manner as before, the conveyor then delivering the product into two separate weighing units which work totally independent of each other (dependant on product flow) both feeding down a common shute into a single filling head, where the bags are then placed by a bag placing machine and hung under the filling head, the bag is then automatically removed and passed through a continuous heat sealer and onto the bag flattener conveyor to the bag press which in turn passes the bag by conveyor to the pickup table. In addition there is a pallet magazine which auto feeds the pallets by roller table into the robot stacking cell. When the pallets are full they roll onto a roller table out of the system. The length of this table is six pallets, as there is an automatic sensor system the system will shut down if they are not moved by forklift. On removal of the pallets the system will restart.
Haith supplied all their expertise and knowledge to interface the two systems to provide GRS Bagging with two plants that have increased production with greater efficiency. The system was delivered, installed, commissioned and working within 14 days.