Procter Machine Safety has made a substantial investment in a state-of-the-art LVD Pullmatic 720 CNC punch press and an LVD Easy-Form press brake to increase production flexibility, reduce lead times and enhance quality.
The two new machines will be used in the manufacture of high-quality machine guards, including custom designed machine guards, enclosures for machining centres, and the range of Nelsa standard machine shop guards for drilling machines, milling machines, lathes and similar workshop machinery.
Managing Director Jeremy Procter explains: “We have a very widespread of customers. At any one time we can be doing work for a quarry, a steelworks, a paper mill and a food manufacturing plant – as well as our work for machine tool manufacturers – so it is very diverse.”
Procter Machine Guarding has earned a reputation for providing an exceptionally high standard of customer service, so scheduling production to suit the different customer requirements is never straightforward. On a daily basis, the company needs to manufacture an extremely wide range of components, in different thicknesses, sizes, materials and volumes, and often with complex multiple angles and shapes. All of the components have to come together accurately as a kit of parts for fabrication, which calls for flexible, responsive and reliably accurate machine tools.
In 2011 Procter Machine Guarding decided it was time to upgrade its old Pullmax CNC punch press, which had given 15 years of reliable service, so there was no hesitation in choosing a new Pullmatic machine – now manufactured and supplied by LVD. As Jeremy Procter says, “We’d had a first-class return on the previous machine, so it was a logical choice to go for a Pullmatic.”
The latest generation Pullmatic 720 is a very versatile machine that can handle sheets up to 3m x 1.5m. It is a single-head machine with 20 tools stored in a revolving carousel. This gives a number of key advantages: any tool can be rotated a full 360 degrees; each carousel position can hold any size tool (up to 90mm), and tool-to-tool times are very fast. Changing tools in and out of the machine is also very quick with a simple cassette-style changeover for punch and die assemblies. The single-head design of the Pullmatic also gives the machine the ability to form parts with flanges up to 75mm high – so the machine can manufacture small components complete from a sheet.
Approximately one-half to two-thirds of the machine guard production involves punching, bending and fabricating sheet metal. Jeremy Procter comments: “The punch press is the heartbeat of the department, so we felt it was a really important investment for the business. The new machine is quicker, can do bigger sheet sizes, has more tools and we have the possibility of doing more forming and bending work.”
He explains that a key factor was the same as when the company bought its previous machine, namely the ability to switch rapidly from one product to another: “Because we use a lot of different thicknesses of material – from 1mm up to 5mm – and work in small batch sizes, we can be changing the tools and dies two or three times a day. The speed of tool change is, therefore, a critical issue for us. Auto-indexing was very important too and, because the Pullmatic is a single-head machine, you get that on every tool. The faster tool changes are contributing to us being able to quote shorter lead times, which helps our customers.
“We do not do a lot of forming on the Pullmatic at the moment, but we are looking at making parts such as small brackets on it and are also looking to use wheel tool technology.”
The new Pullmatic was installed in September 2011 and was quickly followed by a new 3m, 135-tonne LVD Easy-Form press brake. This is equipped with LVD’s patented Easy-Form adaptive forming system that uses automatic in-process measurement and correction to ensure that the bend angle is always right the first time.
Working two shifts per day, processing around 50 or 60 sheets per shift, the Pullmatic punch press creates a lot of parts that need bending. Nevertheless, the Easy-Form press brake ensures that forming is not a bottleneck.
Production Manager Graham Mayo explains: “A kit of parts for a guard will include components in a number of different thicknesses – and we need all the parts to be able to make the fabrication. We, therefore, have to have the flexibility to change quickly from one thickness to another on the press brake too. And because the parts are all nested on the sheet, the orientation with respect to the rolling direction will change too – and that also affects the bending parameters.”
That is where the power of the Easy-Form system to compensate for these variations comes into its own, even on longer parts that are otherwise hard to bend consistently along their entire length.
Graham Mayo says: “We make complicated parts, such as large trays, where you are bending at multiple angles. On parts such as big base trays or cranked sliding doors, we are talking complex mitres and multiple angles that all have to come together correctly when the part is fabricated. It is very critical that we get the angle right.”
According to Graham Mayo, the fabrication department is noticing the difference: “When we did the first job on the new press brake, the fabricator commented straight away on how easy and how much quicker it was to fit the parts together. All the angles were right so it went together perfectly – which is also important for the appearance of the finished guard.”
The LVD press brake has also increased output, accounting for approximately 40 per cent of the company’s bending capacity, with other forming carried out on two further press brakes. Compared with the other press brakes, however, the LVD machine offers the advantage of faster setups – with no need to make trial bends or adjust for different thicknesses.
Jeremy Procter concludes: “The new productivity provided by the LVD machines means that we have been able to not only keep up with increasing customer demand, but we are ahead of our delivery targets and have the capacity for new business too.
For our customers, the investment in state-of-the-art machinery is resulting in an even higher standard of finish, shorter lead times and prices that are remaining extremely competitive for high-quality machine guards, whether the need is for one-offs or series production.”