Robots in the manufacture of clay drainage products


We're all familiar seeing robots working away in car factories creating masses of sparks as they weld together the various body parts of the latest cars. But robots are now being used in many differing applications across a whole new range of industries. 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 conditions 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 250 Kg.

Robots have been introduced into the manufacture of clay building products. Hepworth Building Products at their Donnington Works in Derbyshire produce a wide range of clay pipes and fittings for use in drainage and flue linings. Their production line, which by nature operates in a arduous environment of building materials such as clay, sand and chemicals, runs 7 days a week, 24 hours a day throughout the year. They decided to commission two of their factory lines with automated production methods. Initially in 1985 six manufacturing cells were fitted with electro-hydraulic robots for handling products from machines to trimmers and setting stations. These performed well and after several years their performance was analysed. From these results it was decided to replace them with the latest technology robotic systems. Hepworth engineers inquired from three major robot manufacturers as to the purchase price, performance, reliability and maintenance costs, together with the backup support, training of maintenance personnel, technical assistance and design of auxiliary equipment. Other criteria needed to be satisfied including the payload and long reach capacity, together with the ability to fit within the existing robot footprint.

After much consultation, the contract to supply five new robots was placed with Kawasaki Robotics UK who displayed that they could meet all Hepworth's requirements within the financial budget of £230,000. Installation and commissioning was a joint undertaking between Hepworth's maintenance staff and the Kawasaki application engineering department. The replacement schedule installed the five new electric robots over a 12 month period, including a specialised station which used a 'seventh axis' for internal trimming of the pressed pipe junction product, making the existing bespoke trimming equipment obsolete at a saving in replacement costs of £56,000.

The Kawasaki robots have now been in operation for almost three years and have totalled around 35,000 operating hour without a single breakdown. They have performed in the tough environmental conditions in the handling, trimming, placement and pallet stacking of the clay products to the total satisfaction of Hepworth engineers and management. For the future, engineers at Hepworth are looking at other sections of the manufacture of their products using manual labour, with a view to introducing more Kawasaki robots to give a more reliable and efficient production line.