Action needed on metalworking safety

In 2008–09 there was a total of 4,107 injuries in the metal products manufacturing industry. Of these, 1,343 were major claims (more than five days off work) and 2,764 were minor (less than five days off), according to WorkCover NSW.

Australian Manufacturing Technology Institute (AMTIL) chief executive officer, Shane Infantiof, believes the manufacturing sector desper ately needs continued education about machine tool safeguarding. “This applies equally to the sup pliers of technology as well as end-users,” Infanti told Manufacturers Monthly.

“The difference between what is ‘law’ and what is ‘standard’ continues to be a subject of uncertainty in our sector. AMTIL, with the assistance of our partner organisations, runs an ongoing series of workshops and seminars around safety law and legislation in the hope that all suppliers and users of manu facturing equipment will under stand the importance of machine safety, the law, and the consequences of non-compliance.”

Dimac Tooling managing director, Paul Fowler, says the company is focussed on finding more effective, safe and productive ways to hold and machine work-pieces. He points out that machine tools, in particular CNC, have rapidly evolved from a safety design standpoint.

“From an operators’ point-of- view, this is evidenced by developments such as door interlocks that prevent the door being opened in cycle, and ensuring reduced capabilities when in manual operator mode, such as much slower rapid traverse rates and spindle speeds when a door is open,” he said.

“However, these features, while very desirable from a safety point-of-view, can cause other issues. For example, when setting up the machine the operator can be hindered from seeing what is happening inside the work area, and this could lead to collisions if a program is not correct. Devices such as a rotary wiper (also known as a spin win dow) can alleviate this problem by providing a clear view through the safety window into the work area, even while copi ous amounts of coolant is splash ing around.

“Another area where operators can be exposed to harm is the risk of dermatitis from handling coolant in the machine, especially when elevated levels of bacteria are present. An effective way to deal with this issue is to fit an oil skimmer to the CNC machine tool. These devices skim the waste slideway oil from the surface of the coolant allowing the coolant to oxygenate, there by stifling the development of harmful bacteria.”

Fowler says that potentially- harmful fine coolant mist can also easily escape a machine enclosure when the door is opened to load or unload work- pieces or access tooling, and operators can inhale the mist.

High-tech systems

Pilz Safe Automation offers holistic machine and automation safety services including detailed risk assessments, safety concepts, safety designs, safety system implementation and vali dation of the solutions. Managing director, Frank Schrever, says that one of the lat est developments is a safe camera system which allows virtual safety zones to be set-up around a machine and by imaging technology alone, slow the machine down if someone approaches, then stop it if they get too close.

“This enables plants to be set up without any physical guarding, thus facilitating very flexible, friendly work environments, with fast changes and set-ups. The next iteration of this technology will allow the human to work alongside the robot, enabling the robot to compute new paths to avoid collision. Also, shape recognition is not far away,” Schrever said.

“Research has proven that risk reduction systems relying on human behaviour will fail, thus the need to minimise risk by design first. It is important to recognise though that more automation means more opportu nity for machines to start unexpectedly and therefore the safety design must be carefully integrated in the controls, which can be very sophisticated.

“The main issue is that the design must be commensurate with the level of risk, and the design is dictated by standards – particularly AS4024.1-2006 ‘Safety of Machinery’, which defines four control designs that increase in fault tolerance and detection as the risk increases.

“Unfortunately there is no tertiary course in Australia which teaches this yet, although most of the engineering graduates carry legal obligations to remove risk by design. There is a big mismatch between education and legal requirement.”