CPS+ a Big Plus for Performance and Precision

After 25 years of CPS, Dieffenbacher has brought a completely reworked version of the successful product to the market, taking the industry completely by surprise by unveiling the new CPS+ to the public at LIGNA 2015. 150 CPS presses have been built. However, in order to meet the future demands of the wood-based panels industry, Dieffenbacher has decided to completely rework and redesign the press, with the aim of considerably enhancing its performance and ensuring even better panel quality. Together with INSERCO, customers were updated at Ligna about this new development.

New Arrangement of the Pressure Cylinders

The most visible change is the new positioning of the press cylinders. This change was borrowed from the Dieffenbacher ContiPlus SWPM press. The press cylinders now impact directly on the heating plates from above. The cylinders can still be set individually, in pairs, or in groups as with the multipots. The cylinder banks are also fitted with different numbers of cylinders in the longitudinal direction. They sit offset in relation to one other and so homogenize the surface of the produced panels.

Rigid yet Flexible

The modular frame, consisting of four frame elements, has been retained. This modular design offers several advantages over one-piece window frames. Firstly, it reduces maintenance and repair times. Secondly, it enables subsequent extension of the press with minimal downtime, provided the foundation and press pit have been prepared. The main advantage of the modular design is the excellent pressure distribution in the longitudinal direction, which produces a parallel press gap almost innately, without the need for additional components for pressure distribution.

Optimal Pressure Distribution in the Longitudinal Direction

This parallel press gap concept — the Parallel Press Gap System (PPS) — minimizes any "breathing out" effect in the as yet unhardened panels between the cylinder banks. The forces of the top cylinder and the opposing forces of the lower frame elements are offset in a longitudinal direction. To do this, the thicknesses of the heating plates and roll plates, the number of cylinder banks and the top and bottom frame intervals are defined and coordinated so that the press gap between the frames only has minimal variation and always runs in parallel. Uniform pressure distribution in the longitudinal direction saves huge amounts of glue. Further consequences are excellent thickness tolerances and outstanding surface quality of the wood-based panels.

Product Changeover without Interruption

A unique feature of the CPS proven over decades is the extrainment of the frames while thermal expansion. This concept is also an important quality characteristic of the CPS+. When the heating platens expand due to increased temperature, all frames move along with the heating platens, including the internally mounted cylinders. This allows product changeovers that also entail a change in temperature of the heating platens to be carried out without interruption, i.e. without being run out. Tilting of the cylinders or oil leaks can only be excluded if the cylinders move in case of changes of heating temperature.

Quick and Safe

The new maximum speed of the CPS+ in thin panel production is 2500 mm/s. This is an increase of 25% over its predecessor. However, this planned speed takes many existing components to their limits. "In comparison with today's CPS, which runs at a maximum speed of 1800 mm/s, drives now have to undergo completely different acceleration and deceleration speeds. For this reason, a speed testing bench was installed in the laboratory in Eppingen, Germany, to enable the engineers to test their calculations when designing the circulation system.

THDF production using the new press is safer than ever despite the high speed. The patented Press Infeed Protection (PIP) safety package is included in the CPS+ standard equipment for panels under 6 mm thick and speeds of over 1200 mm/s. An X-ray sensor monitors the mat a few centimeters before the double hinge press infeed. If mat flaws or distortions are identified, a quick-stop is activated on the press. For even thinner boards below 3 mm in thickness and at production speeds of over 1500 mm/s, the pressure cylinders are also released at that moment. Additional multipot cylinders, which are arranged on the first three frames beneath the lower heating plate, are also pulled downward at the same time. Earlier models can of course also be retrofitted with the safety package.

Faster Heat Transfer

Mats are subjected to high pressure, even in the press infeed. The load on the heating platen is correspondingly high. Dieffenbacher heating platens are protected from damage by hardened protection platens. A new feature is that the first protection platens with which the mat comes into contact are also equipped with heating ducts. This enables heat, as well as pressure, to be transferred from the press to the mat at an earlier stage. The benefit of the heated protection platen was easily demonstrated with the help of a small sensor which was placed in the mat to record the temperature, pressure and moisture of the mat at any position. The effect is considerable. The resulting surface temperature of the steel banding is around 10 Kelvin higher right at the infeed of the CPS+. This allows the mats to be heated through to the desired temperature 10 to 20 seconds earlier and speeds up the glue curing in the calibration zone. The pressure factor is lowered and the cost-effectiveness of the CPS+ increased accordingly.

Safe Steel Belt Operation

A further important innovation of the CPS+ is the automated orthogonal adjustment for flawless steel belt operation, which is continuously measured. If the steel belt is operating under load, a mechanism affects the operation of the rolling rods. The direction of the rolling rods is altered by tenths of a millimeter so that the steel belts automatically return to their ideal running position. Time-consuming manual adjustment of the steel belt tracking is a thing of the past. This not only increases the operational reliability and service life of the steel belt and machine parts, but also the availability of the plant.

The new, smoother steel belt guidance is particularly obvious in the backward direction. The CPS+ is now lower. A reduction of unwanted buckling and bending influences on the steel belt ensure a longer service life. Dieffenbacher has also increased the diameter of the steel belt drums on the press outfeed to allow the use of thicker steel belts of up to 3.5 mm. This has advantages for the manufacture of panels at high pressure, such as OSB panels or particularly dense panels.

A Clean Machine

Ease of maintenance was also considered when developing the CPS+. The supply side and maintenance side of the press are clearly separated. This makes it much easier to access the press and its internal components. Wear parts can be replaced very quickly. The press pit is also tidy and clean. Valve blocks and the switch cabinet are installed at ergonomic working heights to simplify maintenance and care of the continuous Dieffenbacher press.

Dieffenbacher together with INSERCO hopes to set new benchmarks with the CPS+ for North and South America as well, using a combination of innovations as well as tried and tested components, and believes it is now well-equipped for the future. This assumption seems to be paying off. Just four months after the unveiling, Dieffenbacher has already received three orders for a CPS+ — two of them for a customer who has not used a Dieffenbacher plant before. Among this, a first CPS+ for the Latin American market was ordered in 2015 already. The collaboration with Inserco during the project development and after, has an complementary effect for the investments in this region.

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