… has taken up most of my time since the autumn of 2015; car stuff has taken a back seat – so to speak.
The brief was to replace a 60-year old fabric finishing machine with something that would refine the finishing operation, expand its capability, last for the next 60 years and at the same time bring the control process into the 21st Century by introducing programmable logic control (plc) and touch-screen operation. Oh, and by the way, the finishing room has only small doors so the 2m x 3m machine would have to be assembled on site.
Part of the finishing process involved the delivery of super-heated steam to the fabric and I was lucky to be familiar with the coating process on wallpapers; air knives deliver a metered, high velocity blade of air that blows away surplus ink and leaves an even side-to-side coating on the substrate. Air knives are also used for drying tomatoes and suchlike in food processing plants.
My biggest headache was how to heat the 2m wide rollers that are the last stage of the finishing process. In the original machine, the rollers were heated by steam but over the years the surface temperature had become uneven. Not knowing anything about the internal structure of the cylinders and how they might well have corroded over time, I had to think of another way of heating them. I looked at oil, water and electricity but the downside of all these internal systems was the weight of the finished rollers – around 350kg each! To change a bearing or a seal would require lifting tackle and a gantry incorporated into the structure – the machine would become a different animal. As with all these things, a chance conversation (with Learned Counsel’s brother-in-law, a print technician in Australia) put me on to Infrared. Perfect.
The laser cutting girls and boys swung into action and produced the superstructure and some of the fiddly bits like the brackets for the linear actuators used to wrap the fabric round the heated rollers…
… and with the addition of most of the ancillary rollers, the machine was beginning to take shape.
Next stop: disassembly, powder-coating and reassembly at the client’s premises.
Of course, nothing is as simple as all that – there were plenty of ‘gotcha’s’ on the way and a certain amount of cutting and fitting as this was fundamentally a prototype machine. One of the biggest headaches was (as always) translating the finishing process into a computer programme – something we’re still working on.
Thank you to everyone who, despite my reduced concentration on this blog, has stayed the course and I wish you all a Happy Christmas and all the best for 2017.