Pressing Advantage

Tandem press brake with 12m bed transforms large bending operations

Wordsworth Holdings does not do anything in small measures. With eight divisions spread across 57 acres in Grantham, Lincolnshire, this progressive OEM employs more than 650 people, who man vast manufacturing halls where yellow goods such as site dumpers and tipping trailers take shape - and where the longest production line is a quarter of a mile long! The name of the holding company may not be a familiar one, but divisions such as Barford Construction Equipment and Fruehauf Ltd are well known to all who operate in the yellow-goods sectors.

With the construction industry booming the world over, the order situation has never been so buoyant. In fact, in July last year, the company announced the opening of a second Barford production line within its central manufacturing facility. This line enables the company to complete 4,000 site dumpers per annum - a 60% increase. With the company also managing to set a new sales record for Fruehauf tipping trailers in 2007 (some 700 units), growth rates are greater than at any time in its history.

The longest Fruehauf trailer bodies measure 11.9m, and it has always been an ambition of group production director Terry Wyman to produce them in a single piece, rather than having to join two separate sheets. "This was the primary driver behind sourcing a 12m press brake," he confirms. "Initially we approached our existing supplier of fabrication machinery, but the quote we received was far higher than we were expecting. By chance, we saw a competitor of ours at an exhibition, and they were clearly managing to produce long trailer bodies in a single piece. We did some investigation and discovered that they were using a press brake supplied by Axe & Status."

Tandem operation

Having phoned the company to organise an initial consultation, Mr Wyman was impressed by the professionalism of Axe & Status Machinery Ltd, Milton Keynes (Tel: 01908 647707), as well as by the potential advantages offered by the Durma AD-E 60400 three-axis CNC synchro-hydraulic press brake.

This machine has a bending length of 6,050mm, and two can be used side-by-side (in tandem) to operate as individual press brakes or as one single press brake, thus providing Wordsworth Holdings with the 12m 800-tonne bending facility it required. Other benefits offered by the AD-E 60400 include the ability to program very slow pressing and return speeds when handling large sheets. This greatly improves the handling of the sheet, as it is pushed into the lower die to create the bend; and by slowing the pressing speed down to a "creep", it is possible to virtually eliminate conventional sheet "whip up", which can make it very difficult for the operator to manipulate the part in a controlled manner. The ram can also be programmed to go up very slowly for a short distance and then pause while the operator takes the sheet back under control, instead of the ram simply releasing the sheet at the bottom of its stroke and immediately returning to the top, which makes it difficult to handle large sheets comfortably. This pause in the ram movement not only improves material handling; it can also improve part quality by virtually eliminating "dishing" or "bowling" around the bend area. Moreover, a delay or pause can be programmed at the bottom of the stroke, which is useful when setting a bend in stainless steel or exotic materials.

A substantial company

Durmazlar (Durma) was established in 1956 and now produces more than 4,500 machines a year. It is one of the largest companies of its type in the world (employing more than 1,000 people), and it has been represented in the UK by Axe & Status since 2000.

Mr Wyman says: "The Durma machine seemed ideal for our application. Not only did it have everything we need; it was also 40% of the price quoted by our existing supplier for a comparable model."

Two Durma AD-E 60400 press brakes were installed by Axe & Status during January this year. These 400-tonne machines stand side by side, allowing them to be operated as a single 12m 800-tonne press brake when required. Despite weighing over 36,000kg each, the innovative design of the frame allows the machines to simply be bolted directly to the factory floor, without extensive excavation or foundation works. The machines were supplied with the Cybelec DNC 880S control, CNC motorised crowning, a 1,000mm back-gauge, a 750mm throat depth, Sick light guards and full-length tooling.

The training process was another factor that impressed the management team at Wordsworth Holdings, as Mr Wyman points out: "We've known some machinery suppliers to suggest a two-week training course, so when Axe & Status said it would only take two days, I was sceptical. However, their training representative is a former press brake operator, and he imparted his knowledge very effectively and efficiently."

Currently, 80% of the machine's capacity is being taken up by Barford site dumper products, which feature mild steel sheet from 2 to 12mm thick, as well as aluminium components. However, in the coming months, up to 30% of the press brake's capacity will be dedicated to trailer bodies up to 12m long. These parts are typically between 3 and 5mm thick, and they tend to be manufactured from Hardox - a proprietary high-carbon steel that exhibits the high levels of hardness, strength and toughness required to handle loads of rocks and construction-site rubble.

Typical batch sizes range from two to 200, and the site at Grantham never stops; it works round the clock, seven days a week. The new press brakes operate in unison with a newly acquired Esab high-definition plasma cutter, which also has a 12m capacity.

While most parts require fairly simple bending procedures, some are intricate; and although tolerances are not exactly microns, they are tighter than would be expected of such large fabrications - largely because some parts proceed to robotic welding operations, where there is little margin for misalignment.

Pioneering manufacturer

Innovation in the company's manufacturing department is matched by its design prowess. Barford, for instance, is recognised for pioneering new ideas and standards within its industry. Examples of this include its introduction of the first 8- and 9-tonne rotary tippers, plus the first 10-tonne forwardtipping dumper. Even today, Barford remains the only manufacturer to offer an 8-tonne rotary-skip dumper.

From a Fruehauf perspective, the subsidiary has responded to customer demand with the introduction of rigid bodies, designed and built to the same quality standards as its tipping semi-trailers. These new rigid bodies offer the bulk tipping industry the same well-known Fruehauf virtues of low weight, durability, reliability and good residual values.

There are also several other business streams at Wordsworth Holdings that make the company one of the most diverse large manufacturers in the UK. These include: Huffey Engineering Security, a manufacturer of security product solutions such as doors, grilles and gates for prisons and police stations; Stanhay Webb Ltd, a manufacturer of seed drill machinery for agricultural applications; and Landforce, a producer of wood-chipping and shredding machines. Everything is manufactured on-site at Grantham.

In conclusion, Mr Wyman says: "There aren't many big manufacturers left in the UK, but we are pleased to be bucking the trend. Our policy of retaining production in-house continues to serve us well. Prior to the installation of the Durma press brakes, many of our large fabrications that required forming operations had to be out-sourced at considerable expense, and for this reason we anticipate a fairly rapid return on our investment. The markets in which we operate are extremely competitive, so any advantage that we can gain can only help preserve our status at the forefront of our industry."

Article reproduced with kind permission from Machinery Market - 3rd April 2008