An insulation jacket manufacturer with an appetite for digitalisation has ramped up its use of automation technologies for manual production processes thanks to help from the Advanced Manufacturing Research Centre.
Powertherm Contract Services Ltd makes thermal insulation jackets for the power generation and petrochemical industries; relying largely on a hand-crafted process due to the bespoke nature of the designs and the varied application of its products.
The Sheffield-based company purchased an Eastman CNC ply-cutting machine to automate some of its time-consuming processes, such as the manual cutting and marking of high temperature resistance glass fibre fabrics; but needed help optimising use of the machine as it was only in operation two or three times a month due to not being fully incorporated into the company’s manufacturing process.
The ply-cutter is now used daily following support by the University of Sheffield AMRC which looked at ways Powertherm could better integrate the kit into shop floor production.
Digital designs
Research engineers from the University of Sheffield AMRC’s Composite Centre visited Powertherm’s Handsworth (West Midlands) factory to evaluate its current process for making glass fibre insulated jackets.
They found that while this involves skilled operatives cutting fabric by hand, they largely work to paper drawings which means the company doesn’t have the digital drawings of designs required by the machine.
A number of recommendations were made by the AMRC team to help Powertherm better integrate the ply-cutter into day-to-day operations, including trialling the use of computer assisted design (CAD) tools to create a 3D model able to generate digital product designs to be interpreted by the ply-cutter.
“In order to digitise the current design process to complement the use of the CNC ply cutter on the shop floor, we suggested CAD methods could be used for flattening of 3D geometry to 2D patterns to streamline some of the simpler product designs,” explains Calum Dickinson, research engineer at the AMRC Composite Centre.
“Once set up, that model would generate digital 2D line wire frame drawings which can be sent to the CNC ply cutter for it to then automatically cut out the required glass fabric shapes needed to construct the insulation jackets. We think this would be possible for about 30-40% of what they currently manufacture and would definitely mean a reduction in production time.”
Made to measure
During the visit, Calum and the team found that the ‘made-to-measure’ nature of the jacket manufacture process posed a number of challenges when considering digitalising operations.
“The majority of the products designed and manufactured are one-off bespoke items, made-to-measure for a specific pipework installation,” says Calum. “This means, at the moment, the glass fabrics are cut out by hand with operatives working to a job card and paper drawing of what they are supposed to be cutting out.
“The process works but it also means they can’t just jump straight onto the Eastman CNC ply-cutter and use it because they don’t have the digital drawings of these jacket designs which the machine requires.”
Previously, the design and production process flowed from the Powertherm’s one experienced designer, Mike Taylor, who would follow a set of rules and relationships from the measurements taken on site to develop a jacket design and produce technical drawings by hand.
These would then by sent to the shop-floor with a job card for skilled operatives to manufacture.
“The process is very labour intensive and because of the bespoke nature of the products, the design stage of the process is quite a large proportion as it’s done for every single product made,” Calum notes. “This factor, coupled with limited CAD experience within the company, means that potentially the time invested in making a CAD drawing of each part isn’t necessarily beneficial.”
Cost savings
To find a way forward, AMRC engineers and technicians visited Powerterm’s factory on two separate occasions to carry out process timing trials.
A trial was set up to measure, mark and cut a 2m piece of fabric by hand, it took about 30 minutes. On the ply-cutter it was five minutes. However, the AMRC team found this wasn’t the same for all the different sizes of materials because for some pieces the operatives use templates which takes out the measuring step.
Calum said: “For some parts, they will save time using the ply-cutter, particularly the bigger parts where it takes longer to measure if they haven’t got a template. They will definitely save time using the machine but it is hard to say precisely how much time because each of the products they make are different sizes.
“Another useful suggestion we made to them when using the ply-cutter was automatically nesting all designs onto fabric to make good use of the material. Nesting means rotating and positioning pieces to minimise scrap, typically resulting in 70 – 80% material utilisation.”
“We have clearly seen areas where they can make changes and save on time, material and, ultimately, on cost,” Calum concludes.
