DS Smith's Blunham site now future proof

Up to twenty loads of concrete a day, a total of 55,000 work hours, and 12 million pounds Sterling. That’s what has been involved in the rebuilding and re-equipping of the DS Smith (UK and Republic of Ireland Division) site at Blunham as a ‘future proof’ sheetfeeder plant. Yet production ran without stopping throughout this complex six-month revamp.

DS Smith Blunham

“We’ve effectively built a new plant inside the old one without losing a day’s production,” says Adrian Swindells, Sheetfeeding Managing Director for DS Smith, talking about the complete overhaul of the group’s facility at Blunham near Bedford, UK. Over the past six months the plant has seen the replacement of two of its three corrugators with one new Fosber line, along with the installation of completely new condensate, starch, warehousing and materials handling systems. “We’ve also created a new layout which keeps vehicles and people apart,” adds Swindells, “as well as making energy efficiency improvements and refurbishing the building to make it brighter, cleaner, warmer in winter, and a better place to work.” 

From the placing of the order with Fosber to the start-up of the complete 2.8 metre wide corrugator line took just 22 weeks, says Swindells. “It wasn’t a simple installation because we had concrete cross beams under the factory which had to be removed to allow the foundations for the new line to be laid. It meant a lot of excavation and a lot of dust, so we had an awful lot of plastic sheeting protecting those areas that were still running production. We got to a point where we only had one corrugator running, with a large percentage of our production being handled by our two other sheetfeeder plants at Kettering and Louth. From that point in time we really had to crack on and get the project completed as quickly as possible.”

Future-proofing

Gareth Jenkins, Managing Director of DS Smith’s Packaging Division, says that customers were the driver behind the investment at Blunham. “We have to keep moving forward if we are going to stay in this industry and lead it, so we asked our customers what they wanted from us. The response we got was that they liked the wide range of products we produced, but they also wanted us to look at different models for the way we service them as customers.”

Jenkins says that the plant at Blunham had gone as far as it could with its existing corrugator installation, consisting of three lines made up of elements from different vendors, and that the group understood a substantial step forward was necessary to give the plant the capabilities it would need through the next two decades. “We needed improvements in terms of efficiency, in terms of flexibility both now and in the future, and in the product quality that we could deliver,” says Adrian Swindells. “The world has moved on in corrugated sheet supply and today it’s as much about service and the performance of the board as anything. We recognised this and we have invested in the latest technology and installed what we believe is the most advanced automated corrugator in the industry today.”

For David Grantham, Sector Director for Industrial at DS Smith, the choice of machine supplier was the key to ensuring that the installation not only met the plant’s current needs, but also those for many years to come. “When we spoke to Fosber we saw that they understood the sort of relationship we expected to have with the supplier of our new corrugator. We wanted a partner who would continue to develop our machine, long after we installed it, by bringing us their latest innovations. Yes, this machine is the most advanced corrugator in Europe today which is crucial given sheetfeeding supports our own packaging manufacturing plants for contingency in addition to supplying our sheet plant network and wider market. But we have plans in place with Fosber for continuous upgrades so that we maintain that position of leadership.”

Grantham says that, even in the few weeks since the line went live, Fosber have delivered the first such upgrade, this one allowing double-wall to be run faster. “We already have the second and third upgrades lined up, one of which will increase the maximum line speed to 400 metres a minute. What we find really exciting is the unforeseen: those developments yet to come. We’ll be working with Fosber on these.”

Gareth Jenkins agrees that continuous development is a vital issue for the plant and for the DS Smith group. “It’s not about putting machinery in; it’s about satisfying our customers by achieving technology leadership and keeping it. I expect this organisation to really stretch the capabilities of this line, which is key for us in terms of the difference we can make in the market.”

Short lead times

Given that the plant mainly supplies independent sheet plants, Adrian Swindells says that the most important customer service factor for the plant is offering short lead times. “Our customers have to cope with very short lead times from their own customers. Even though I think we already offer the shortest lead times in the UK, being able to keep that up, day-in, day-out, involves having the capacity to cope with the peaks in demand. During our busiest period, from September to Christmas each year, our intake can lift by twenty percent. If you don’t have the extra capacity to cope with that uplift then your service level has to drop.” The 2.8 metre width and fast running speed of the Fosber line is key to the plant’s increase in capacity and shortening of lead times, says Swindells. “The volume it can produce in a twenty-four hour period is thirty to forty percent higher than the combined output of the two machines it replaced. So now we have the volume to match the peaks in demand.”

A further factor in achieving volume uplift and lead-time reduction is the speed of changeover the Fosber line delivers. “Sheetfeeding is different to conventional integrated corrugated manufacture in terms of what the corrugator has to do,” explains Swindells. “So we had the Fosber configured to meet demanding targets in terms of handling very short run lengths, across the widest possible range of paper and board types.”

The wet-end features Fosber's Link-M3 integrated roll stand and splicer, which has a triple-reel positioning system that reduces roll change cycles by an average of 70% compared to conventional roll stand systems. “These roll stands are very advanced and give the fastest changeover going,” says Swindells. “That gives us a bit of an advantage, because the speed of the entire line is determined by the wet end. If you have shorter orders, you can only go as fast as you can change the rolls. Normal roll stands are butterfly arms, but this has three rolls ready, so it’s a real advantage at the wet end.” In conjunction with the automated plastic track full-accumulation roll handling system, the wet-end at Blunham is able to comfortably handle and manage multiple and very frequent paper changes.

The Fosber’s Smart 400 single facers are equipped to run B, C, E, and R flutes, and all the associated double wall combinations, with very fast flute-change capability. The on-board peripheral steam heating system is fitted with automatic differential control, allowing the machine to run automatically from 15 bars down to 4 bars, with true zero wrap.

The dry-end is made up of Fosber’s latest series 400 range of equipment, designed to carry out gapless order changes at 300 metres per minute. The Twin400 slitter-scorer is equipped to run a wide range of scoring profiles on back-to-back orders that include offset (normal and reverse), point-to-point, and point-to-flat, and also features a web cleaner system to remove dust. The Master Cut-Off knife and Terminal 400 downstacker optimise the production of short chop lengths at the highest line speeds, and have very short order cycle-change capabilities. 

Complex materials handling

 A dual side-stack discharge system means partially run orders are managed totally separately to completed orders, which optimises the efficiency of the plant's Dücker materials handling system. “It’s unique in the UK, and I believe there is only one in Europe,” says Adrian Swindells. “It allows us to run wider, in more parts, and the parts build up in that section, which reduces our pallet costs, strapping costs, and transport costs.”

For Swindells, the installation of the materials handling system was almost a bigger job than that of the corrugator. “In a traditional integrated plant the materials handling is relatively straightforward, but for sheetfeeders like us it’s not so. The Dücker system has to interface with all the other systems in the plant and that is a complex task.” Among the functions that materials handing has to interface with are those of the extensive warehouse area. An outside pallet feed system means there is no need for truck movements inside the warehouse and also makes sure that there is a continuous supply of pallets.

In the warehouse, two double palletisers, which can handle jobs of different sizes at the same time, process up to 350 pallets per hour, while two autostrappers print and shroud, and a doubling unit allows two stacks to be put away simultaneously. “It’s a fully automated, fully tracked system,” says Swindells. “It was one of our biggest challenges, because we came from a manual system and we have a lot of complex instructions for wrapping, stack heights... that type of thing.”

A further advantage of the investment for DS Smith’s sheet-plant customers is that the revamp is delivering a more consistent product. “Because it’s fully automated in terms of warp and moisture control, and it has auto diagnostics, the Fosber line gives the customer consistency of product. For each board grade it knows what the perfect settings have been in the past to get minimum warp of the board. Every time that grade comes up, it reapplies those settings.”

Fosber’s Syncro complete corrugator control provides the full automation and synchronisation of the corrugator line, monitoring and managing the various settings and variables of the corrugating process. Its Profile laser bar constantly measures and detects the slightest board warp and, in conjunction with a moisture balance monitoring system, adjusts the process settings to provide closed-loop automatic control. The Syncro system also collects production and process data in real time for every order run off the corrugator, storing it for a year. This data includes the actual steam, power, starch and air consumptions for the order and a photograph of each individual stack as it is discharged. This information not only provides a complete provenance for each individual order produced, but also allows the plant to know exactly what consumption was required to produce it.  

The line additionally features Fosber’s intelligent Target Speed control feature, which ensures that the corrugator is automatically pushed to reach set speeds for each board quality. On reaching the target the system continues to increase line speed in incremental steps until a new maximum speed is reached, which then becomes the new target.

Just like the corrugator, the new condensate and starch systems are fully automated. “All told, it’s taken the ‘black art’ out of corrugating,” says David Grantham. “We’re using the technology to run the machines and the operators are now managing the orders.”

Own it

Ensuring employee buy-in to the project was an important objective for DS Smith. “This has been an enormous people engagement programme,” says Gareth Jenkins. “You can have all sorts of fast kit, but if the people running it don’t appreciate the difference they make to the business, then you won’t get the performance you aspire to. It’s one of the most difficult things to achieve, but the increased level of performance from the new machine, as opposed to that from the two machines it replaced, is significant and that’s all about the people involved.”

Adrian Swindells says that plant management spent a lot of time talking with the workforce about the strategy of the business and the part they play in it. “We also have employee focus groups called “Own it” teams, which look at specific problems and come up with action plans for improvement. It’s a bit of a change from the top-down culture of DS Smith in the past. Now the people on the shop floor come up with the ideas, make a case, and improvements come quickly.”

The new installation at Blunham has been specified with energy and resource efficiency in mind. Along with the natural benefit of one corrugator replacing two, the Fosber line has energy efficient motors and drives fitted. Its totally enclosing noise-reduction system not only cuts overall acoustic emissions to below 85dB(A), and acts as machine guarding, it also allows heat from the line to be re-routed, via a self controlling ventilation system, to warm the plant in winter or to vent out in summer. The Fosber Express double backer is fitted with four independently controlled heating sections, each able to run down to 0.5 bars and each fitted with a closed loop condensate recovery system. The Thermostack pre-heater is fitted with independent steam controls on each drum, each with zero wrap capability, while the Crest double glue unit has an automatic torque controlled rider roll contact system, with specially designed applicator rolls, so that starch and steam consumption is noticeably reduced. Also designed to save resources is the new starch system which recycles waste water and means the plant has done away with the need for an effluent treatment plant. “Across the site we’re saving around 35% in energy,” says Adrian Swindells.

Growing sector

The revamp of Blunham is very much a DS Smith group strategic move, says Adrian Swindells. “We supply board mainly to the independent sheet plant sector. We’re probably unique in the sheetfeeding market because we have three sites - so we can offer a broad range of products from brown box-board and specialities, through to tapes, single face, and fan-fold. The bulk of the brown-box comes from this site and, as well as the efficiency and consistency improvements, the new equipment gives us capabilities we didn’t have in the past. It gives us the ability to run with cut-to-mark register, clay coats, F-flute and light papers. At the moment we produce most of our speciality out of Kettering on a 1.8m corrugator. Now our 2.8m line can compliment that. So it’s an investment for the whole DS Smith group.

Gareth Jenkins says that the drivers behind the group’s investments are the delivering of whatever the market requires. “We’ve seen a lot of growth in certain retail markets, and that has created growth in the sheet plant sector. So there needs to be a supplier who can meet their requirements for range, speed of delivery and quality of board. We expect the machine at Blunham to be the most efficient corrugator in Europe, not just in the DS Smith group, but in Europe as a whole. It’s just weeks into operations and it’s already performing incredibly well, so I have no doubt that we will achieve that.”