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Huge precision

Heckert large machining centres in moulding

Sometimes businesses have to take extremely brave decisions to be successful, and the story of Otto Hofstetter AG is a great example. It is partly thanks to its brave decisions that the medium-sized Swiss company has risen to second place in the world in production of tools for PET bottle premouldings. The decision to bring plate production in house and acquire three Heckert HEC 1250 type large machining centres was a key factor in the company's current success.

Otto Hofstetter Senior founded the company back in 1955 as a contract manufacturer for companies in the surrounding area, but within two years had started producing injection moulding tools. He recognised the potential of the emerging plastic materials and the injection moulding method and quickly established an excellent reputation as a high precision tool manufacturer. The company specialises in tools for extremely hard to inject thin-walled products, especially food packaging. In addition, moulds for products such as flower pots continue to play an important role in the company's product range.

The Uznach-based company got a crucial break in 1977, when Coca-Cola was looking for a new type of packaging that would be lighter than the glass bottles previously used. One of the drinks giant's partners developed a plastic bottle but failed to find a tool manufacturer for its production. Plastic bottles are blown into a mould but the material is loaded into the blow moulding machine in the form of a premoulding. This injection moulded premoulding is made up of the bottle thread and a profile similar to a test tube, with this material then being blown into the final shape of the bottle. Otto Hofstetter's 40 employees at the time made the best impression in the subsequent selection process and won themselves a major new customer. For the next ten years, the company was the exclusive producer of injection moulding tools for the Coca-Cola bottle premouldings in the USA.

When the exclusivity agreement expired, it was another few years before the boom in plastic bottles made its way to Europe in the mid-1990s. Sales of the relevant tools exploded and the son of founder Otto Hofstetter, who took over the running of the company in 1997, decided to massively increase production capacity. However, the partners who produced the master moulding plates were unable to make the required investments to ramp up their own production capacities.

As a result, the Hofstetter board took a very brave decision, namely to set up in-house production capacity for the plates previously produced externally. Of course, this involved procurement of new machines, as the existing milling centres were far too small in terms of the maximum workpiece size. Depending on the tool, the plates can be up to 1.5 x 1 metre in size, 20 centimetres thick and weigh 2500 kilogrammes, with stringent precision requirements. A tool can have up to 144 cavities, and the tolerance between the five plates that make up a tool is less than a hundredth of a millimetre. Ultimately, the plates not only have to be individually exact, they have to match one another exactly too.

In addition to a large number of machining centres from another manufacturer, Hofsstetter purchased Heckert machining centres with horizontal spindles in 1995 and 1997. This horizontal spindle makes the chip discharge easier, particularly important as up to 70 percent of the unmachined part is cut away on many workpieces. 

Stefan Zatti, board member and the head of Sales & Marketing, recalls: "We bought the two Heckert machines because they offered such excellent value for money. In the following years, the two CWK 800 proved to be reliable machines with high availability, which is why we returned to the Starrag Group when we were looking for larger machines for plate production. Another important factor was that we had found Starrag to be a reliable and stable partner."

The decision makers from Hofstetter were so impressed by their visit to Chemnitz, where the Starrag Group subsidiary Heckert is based, that instead of the one type CWK 1250 machine originally planned, they bought two. Alongside the high quality of the machines, the crucial features included the pallet changing system, which allows automatic removal and loading of workpieces. Instead of an expensive pallet interchange, the CWK 1250 provides two pallet positions, and two workpieces can be secured on each pallet. This enables a sequence of up to four workpieces to be processed without human intervention. Zatti says that the CWK 1250s enabled the company to go "from 100 percent outsourcing to 100 percent in-house plate production" within a year. After eight years, the machines' production capacity was exhausted due to the high number of operating hours, and it was time to think about investing in replacements.

"There was no question that we would buy from Starrag again", Zatti recalls. "We had got to know one another well over the years and developed a close partnership that goes beyond a normal supplier relationship. When problems occurred, as they inevitably do over the years, we always worked well together. The other factor that was important for us was that both department managers and machine operators - the people who use the equipment every day - were totally behind the decision to use Heckert."

So, in 2009, Hofstetter ordered the first of three HEC 1250s, each with three pallet positions. The other two machines followed at intervals of a year, bringing the company up to full capacity by 2011. Thanks to the third machine, they have capacity for in-house production of other components that were previously subcontracted to suppliers.
The three machines stand next to one another in a specially constructed hall. Albert Kuster, plate production foreman, says: "We mainly use one of the three machines for rough machining, not because it's not capable of fine work, but because it can transport the chips directly into large troughs. On the other two machines, we use normal chip collectors, we would be too small to hold the chips produced in the rough work during an unmanned night shift or at the weekend."

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Kuster is particularly impressed with the tool magazines on the HEC 1250

"On other machines we have chain magazines, where the tools are hard to get to and you have to discharge them at a removal station first. The Heckert machines use magazines with four towers each, in which the tools are stored vertically on the side in four sections. You can simply look for the appropriate tool on an operator station and turn the tower, then open a door and remove the tool. We have enough space for 320 tools per machine, of which around 90 percent always stay in the magazine, with just a few special tools being used for specific jobs."

The three machines are equipped with wear monitoring systems, which measure the required torque on the spindle when milling and use this to determine the condition of the machining tool. In addition, break monitoring is carried out using laser measuring systems for tool measurement, allowing long periods of unmanned machining to be performed. If a tool breaks, the machine continues working automatically with a replacement tool where possible, or sends an alarm by mobile phone to the employee on duty. As a result, up to twelve hours of continuous machining can be carried out on a workpiece very efficiently at night or at the weekend without the need for shift work - a crucial factor in a high wage country like Switzerland. "On average, we achieve 21 hours of operation, 7 days a week," says Zatti, "and the other three hours are used for setup and maintenance. We are very satisfied with this excellent machine availability."

hec 1250

"Right from the start, we were impressed with the assembly by Heckert staff.  We were able to choose the service team and chose the Heckert employees we'd been working with for a long time. Commissioning took six weeks for each machine, which is very good for such large machining centres. Another very positive point for me was that Heckert was responsive to our comments and suggestions for improvements. The second machine incorporated improvements that we had suggested based on our experiences with the first machine - and the first machine was updated alongside commissioning of the second one."

"Our concerns were addressed," Zatti continues, "and that feels good. The three machines - and the new hall to house the machines - was a major investment for our company, and with the CWK 1250s we have more than doubled our capacity. The fast commissioning meant that we could start getting a return from the machines right away. This is important in terms of our return on investment Our injection moulding tools produce up to a million premouldings per day, and this can only be achieved if the tool and its production meet the very highest standards.

There is a good reason why we are number two in the world for PET tools - we have reached this position thanks to our premium quality and short lead times, and the HEC 1250 machines contribute to our success in both of these areas."

Zatti has only positive things to say about cooperation with the manufacturer: "The product is right, the price is right, the service is right - this has been confirmed over many years and now with seven Starrag machines. We do not have a typical supplier relationship with our suppliers, we see it as a partnership and this has always worked outstandingly well with the Starrag Group, even at times when we had a difference of opinion. If you want to move mountains, you need a partner you can rely on - and that's exactly what we have found in the Starrag Group."

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Company profile

Otto Hofstetter Senior founded Otto Hofstetter AG, a tool and mould producer, in 1955 and ran the company for four decades. Since 1997, the company has been run by Otto Hofstetter, the son of the company's founder, as operations director and owner.

Otto Hofstetter AG is based in Uznach at the Eastern tip of Lake Zurich, just an hour away from Zurich airport by rail or car. The company has a strong international focus, with almost 100% of the products being exported. Their customers and partners are based all over the world. 

They are a reliable partner, offering quality tailored tools that deliver maximum precision, stable design and a long service life. To cope effectively with the rapid developments in the tool production market, the company has been split into three independent divisions.

High performance injection moulding tools for PET premouldings

  • Up to 192 cavities for mono-layer premouldings
  • Up to 72 cavities for multi-layer premouldings
  • Horizontal and vertical systems

High performance injection moulding tools for various packaging applications, including

  • Thin wall and garden products 
  • Cartridges and tubes

Service centre (customer service, ASS)

  • For preventive maintenance and repair of tools
  • For reliable spare parts supply
  • For rapid breakdown assistance by telephone or on site


The new structure has a flat organisation, resulting in efficient decision making processes. The strategy is to concentrate on the core competences. This is a key factor for the success in the current environment.

Their plant covers 11’000 m2 and they have currently around 190 employees, with another 23 apprentices.

For more than 50 years, Otto Hofstetter AG has been developing and producing its own standard parts and hot runner systems. Example: To date, more than 85,000 Otto Hofstetter hot runner nozzle systems have been supplied. They have proved their quality in the toughest of practical applications. 

Before tools are delivered, they undergo a precisely specified testing programme in their in-house test department (5 injection moulding machines). The customers only receive tested and ready-for-production tools. All the products are supplied with technical documents, drawings, operating manuals, logs and sample parts. By agreement, they can also commission the tools at the customers' plants.

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