New particle-free energy chain from igus for SCARA robots in cleanrooms
21/09/2023
Clean SCARA Cable Solution works almost particle-free to ISO class 2
igus has launched a new energy supply system for SCARA robots in cleanrooms: the Clean SCARA Cable Solution consists of tribologically optimized high-performance plastics and works in almost particle-free conditions specified to ISO class 2 even in high-speed applications. The system is also highly stable and user-friendly compared to classic corrugated hoses.
In the Hollywood blockbuster Deep Impact, a 2.5 kilometre-wide comet strikes Earth, causing worldwide destruction. In highly regulated and controlled cleanroom conditions, tiny particles that are invisible to the naked eye are the comets that can utterly ruin electronic components, semiconductors and displays. So, it is important that machines and systems are as low-friction as possible and do not contaminate the ambient air.
That’s not so easy, especially with SCARA robots, which resemble a human arm and move rapidly over four axes, with cycle times of well under one second. There is an ever-present risk that particles come loose from corrugated hoses and pipes during high-speed applications. “The routing of cables and hoses on SCARA robots in cleanrooms is indeed a science in itself,” says Rob Powell, triflex product manager at igus UK. “Fast movements are pure stress for the material, which incurs abrasion and releases damaging particles.” For this reason, igus has expanded the SCARA Cable Solution energy supply system that was developed in 2020 to include a variant for cleanrooms. “The new Clean SCARA Cable Solution is a cleanroom-compatible energy supply system for high-speed applications – reliable, compact, easy to operate and quick to retrofit,” says Powell.
ISO class 2: virtually zero particles in the ambient air even during the most dynamic movements
At the heart of the new cleanroom energy supply system is the e-skin soft, a modular energy chain that guides cables and hoses in an arc from the vertical arm of the robot to the end effector. Its flexible upper and lower shells can be joined together to form a closed, dustproof, and waterproof tube – ensuring that particles from the pipes and hoses do not enter the ambient air from the inside, even with the wildest movements. “In order to reduce stress on the cables and increase their longevity, we mounted the connections in rotation at the fixed carrier of the energy supply system,” Powell explains. “That’s the real highlight of the system. Simultaneously, the rotary bearings are designed in such a way that they are virtually particle-free even with the most dynamic movements.”
And the e-chain itself is also particularly abrasion-resistant due to tribologically optimized high-performance plastic. This was recently confirmed with ISO certification by the Fraunhofer Institute, an important engineering certification body – the Clean SCARA Cable Solution achieved ISO class 2. This means that the energy supply is so abrasion-resistant that a maximum of just 100 particles up to a size of 0.1 micrometres can be found in one cubic metre of air during operation. For comparison, an average sheet of paper is 80 micrometres thick, 800 times thicker than these particles.
A clean alternative to classic corrugated hoses
With this new energy supply system, igus offers an alternative to classic corrugated hoses, offering two further advantages in addition to cleanroom suitability.
Firstly, thin corrugated hoses that are mainly used in SCARA robots have hardly any inherent rigidity and can therefore bend quickly. The absence of bearings, which absorb torsion, also ensures that the corrugated hoses tear quickly. “Unlike corrugated hoses, the Clean SCARA Cable Solution supports itself and has a unique rotating bearing, making it ideal for short cantilever lengths and highly dynamic applications,” says Powell. “The oval geometry of the chain is particularly beneficial when lateral force is applied, as it provides additional stability.”
The second advantage compared to the corrugated hose is that the Clean SCARA Cable Solution can be opened as easily as a zipper – aka “the zipper principle”. Users can insert cables and hoses very quickly. Additional protection is provided by an optional internal partition, which is also impossible with corrugated hoses. “On request, the customer can receive the new cleanroom energy chain that are ready to connect with chainflex cables as a complete system,” Robert adds. More than 900 highly flexible cables with IPA class 1 are available via igus. More information about the Clean SCARA Cable Solution can be found here.
