From press manufacturer to system manufacturer – Press design and manufacturing in large format becomes standard

Interest in production units for large-format molded parts began to tick up at the end of the 1990s and intensified towards the turn of the millennium. Press forces of 100,000 kN and more have long since been achieved. Today, products measuring in excess of 15 square meters are manufactured on WICKERT presses.

The world market leader in elastomer press manufacturing, based in Landau/Pfalz, boasts significant know-how in the development and production of large presses. This article presents examples and special features on the topic of large presses.

As early as 1999, a press used in the production of Teflon semi-finished products in the form of plates and rings set a record for Europe, perhaps even a world record mark: the teflon press from the WKP series can produce plates with a maximum dimension of 3,000 x 3,000 mm or rings with a diameter of up to 3,000 mm.

For high-performance seals with a diameter of 2,000 mm

In 2006, following only 10 months of development and construction, a 5,000 kN WKP S high-pressure downstroke press weighing 122 tons and measuring the size of a small house was installed in the clean room of a customer in Blackburn, UK – a world record for clean room presses.

The press is used to produce high-performance rubber seals up to two meters in diameter. These large seals are primarily manufactured for installation in marine diesel engines and generators, as well as in facilities in the oil and gas industry.

Large presses become standard

In order to be able to build such large machines at all, WICKERT built an additional production hall in 2003 that has since been expanded. With a height of 15 m and the ability to handle weights of 50 tons or more for individual components, WICKERT not only possesses the know-how but also the organizational/technical ability to produce highly efficient large-scale presses. Today, WICKERT designs and builds between 80 and 100 presses per year with upper press force ranges of > 110,000 kN.

The market success of the large presses from Landau is based on a whole series of factors. Thomas Klimpl, Head of Marketing: “By using 3D finite-element design and calculation software early on, we were able to optimize the design of our presses and achieve the highest possible stability with enormous weight savings. In addition, we developed innovative automation concepts for large components, and today we offer not only the ‘press’, i.e. the central component, but all the necessary peripheral components as well. This includes everything from handling and transport systems to heating/cooling systems with up to 5,000 kW of heat output. WICKERT made its way from mechanical engineering to system engineering. Designing our presses to meet the requirements of Industry 4.0 production has been standard for us for many years.”

Customized solutions

The largest vacuum-chamber press working in Germany demonstrates what customized and intelligent large press solutions can look like. The 1,600-ton press produces various products in small batches of 1-50 pieces and is equipped to handle a variety of materials. The press’ double sliding table increases the press capacity significantly. The unusually low operating height for a press of this size – only 875 mm – is achieved thanks to the top ram design and optimized column unit without pit and without platform! The WKP 16000 S 4-cylinder upper ram press has 2,000 mm diameter heating plates and an elastomer special control. Three steam control circuits monitor the temperature setpoint and actual value, as well as the steam pressure. An optimal closing profile as well as the best possible cycle time is achieved by intelligent process control during the changeover to the press motion.

Thanks to two fully autonomous machine programs, two different tools with different press parameters can be run on the WKP 16000 S at the same time. Connected to the WICKERT diagnostic center via a VPN connection, the vacuum-chamber press provides maintenance-relevant data and provides time-saving and cost-saving assistance that ensures high system availability.

For absolute zero-defect manufacture

One of the largest elastomer transfer presses supplied by WICKERT to US customers in the off-shore oil sector is 30,000 kN “heavy” and not one bit sluggish. This largest TM press ever manufactured features custom-fitted top-ram presses for the production of large-diameter parts. The press size was 30,000 kN, with a heating plate format of 3,000 x 3,000 mm. The press was tasked with producing the highest possible production quality. The elastomer components produced on the presses and used in powerful seals in e.g. “blow out preventors” must work in “zero defect” mode.

In these large seals, the parts produced on the presses ensure that a well is securely closed even when an unplanned pressure increase in the borehole threatens to become dangerous.

The classic transfer-molding process is ideal for this task. Since the transfer cylinders tend to tilt when being opened, a very precise synchronization of the hydraulic lifting device is required. To achieve this, a total of four double-acting hydraulic cylinders are hydraulically synchronized so that even extremely different opening forces are unable to cause the transfer cylinder to tilt. With each stroke, automatic zeroing of the entire system takes place to compensate for an accumulation of parallelism errors. The transportation devices provide an idea of the weights of the parts: each one is rated with a capacity of 10,000 kg.

Optimum, precisely controlled temperature distribution

One guarantee for achieving the required top product quality are the electrically heated and very precisely controlled “Iso-Temp” heating plates that are milled from a single piece. In order to prevent uneven degrees of vulcanization or vulcanization times, a uniform temperature level must be established in the tool and mold. Thanks to 9-zone control, the heating plate method continuously developed by WICKERT over decades ensures homogeneous temperature distribution. An accuracy of +/- 2°C in temperature distribution is also achieved for the large heating plates of the 30,000 kN press. Sensors detect the failure of a heating rod and emit an error message so that an imminent change in temperature due to the failure of heating elements on the plates, which are equipped with approximately 500 kW of heating capacity, is registered immediately – not just when a discrepancy appears on the product. The monitoring of the temperature difference in the heating process is also “intelligent”. The maximum temperature difference between transfer ram and transfer pot is limited to 10° C. This prevents damage to the tool or transfer system due to excessive temperature differences. Additional security is provided by the redundant design of the temperature sensor.

Compression presses for the highest demands
WICKERT received the largest single order in its more than 110-year history, for some 5 million euros, for the development and construction of 8 large-format compression presses used to produce highly stressed elastomer components for use in offshore drilling. The order included five WKP 15000 S presses and three WKP 21000 S presses with 1,300 mm and 1,900 mm heating plate diameters.

Energy-saving design
In addition to the buzzwords of digitization and automation, cost efficiency plays an important role in all considerations surrounding any large press design. Individually tailored to the production task, the system is designed to be as energy efficient as possible. WICKERT engineers and technicians see themselves as energy consultants in this regard and design hydraulic and electrical components in accordance with the required process parameters in such a way that optimal energy use and savings are achieved.

The WICKERT WKP press series specializes in the production of molded parts of all kinds. The flexible, modular system fulfills a wide variety of customer requirements, whether compression molding, transfer molding or injection transfer molding – in absolute large format or clean-room version, upon request. The finished production units are quickly developed and manufactured thanks to the special modular concept, measured by facility size and scope.

For further question please contact Mr. Thomas Klimpl, Email: