Ubiquitous automation is a process we take for granted in today’s world. Improving productivity, guaranteeing quality and repeatability or personnel problems, are the main determinants affecting the progressive mechanization of production cycles. The situation is no different among companies in the woodwork industry, which, with the widespread increase in competition, are looking for solutions to make their products more attractive and improve the productivity of the company.
An unquestionably important stage, undoubtedly affecting the entire production and having a direct impact on its dynamism, is the moment of cutting PVC profiles. The right machine – the cutting center, is able to guarantee the smoothness of the entire manufacturing process. Successive machine manufacturers are outdoing themselves in technical solutions to guarantee the uniquenes and usability of their centers. Some of them are better, others leave a lot to be desired. Window manufacturers themselves, on the other hand, have a tough nut to crack, as they have to choose from among many a technology that will meet their expectations and perform well.
PREZ-MET, while working on its cutting center, wanted to know the opinion of those directly involved in the manufacture of doors and windows.
Through conversations and meetings with joinery manufacturers, the pains and expectations that accompany a modern cutting device were learned. The fruit of mutual dialogue and work is the CT 500 center – a machine, which, despite its uniqueness, does not differ in size from others of its kind. Its distinguishing feature is its speed – the center is capable of supplying 3.5 sealing and cleaning lines.
In comparison, a standard cutting center supplies 2 such lines, and in some cases is able to handle 2.5 lines – however, these machines are already characterized by much larger dimensions. High productivity for many is key, and if you add to that the savings in production space, you get a combination capable of truly satisfying. In the case of the CT 500, this is only the beginning of the positives, because at each of its stations – profile feeding station, profile cutting station, profile receiving station – we encounter solutions that set them apart from the competition.
The feeder is the first component mentioned. The feeder itself is characterized by a robust design, which ensures stable operation and prevents the carriage from falling into oscillations and vibrations during fast operation.
Reliable operation of the machine is ensured here by a griper (gripper) equipped with a profile presence sensor. It allows protecting the profile from improper cutting or ejection. In addition, the positioning of the gripper is carried out in two axes directly from the program – an innovative solution, since, as standard with centers of other manufacturers, its determination takes place only in one axis. Determination of the position of the other axis takes place with a bumper, and in some cases we have Z- and Y-axis positioning with bumpers. The CT 500 is also distinguished by the way it controls the dimension of the cut piece, as this is done in two ways – with a ruler, as well as an encoder. This is a solution that is not commonly used, because usually checking the dimension comes down to downloading data only from the encoder.
Another aspect worth mentioning is the way the profile is fed, for it is done simultaneously with the cutting of the previous lagi. Thanks to this, the CT 500 is characterized by the previously mentioned high working speed. Noteworthy is also the method of guiding the bar through the pressure rollers, which eliminates the common problem associated with the cutting of curved profiles, commonly known as “bananas” due to their curvature.
“Saw against saw” technology is a PREZ-MET patented solution worth exploring, applied to another CT 500 station, namely the cutting station. Its name can be translated as saw against saw, and this translation somewhat perfectly reflects the work itself and the layout of the heads with cutting discs – the upper (rotary) and lower (fixed) slides are opposite each other. The cutting process itself begins with the entry of the profile into the center and its basing. Then the lower unit is the first to clamp the lag to the desired angle, after which it returns to its original place.
At this time, the profile is moved according to the entered dimension, and the upper aggregate cuts it. The moment of cutting is also the moment of receiving the profile. The return of the upper slide into position is accompanied by the simultaneous following of the lower slide, which cuts the next piece.
What is worth emphasizing in the case of the lower disc, we do not have to deal with rotary motion, thus easily eliminating the problem of blocking and incorrect positioning of the cutting disc.
The innovative system discussed above in itself guarantees very fast profile cutting.
If we add to this the short passage of the slides themselves – 2 x 180 mm, while it can be more than 1,000 mm in the machines of other manufacturers, we can easily understand where the CT 500 comes from the cutting speed enabling performance almost twice as fast as competitive solutions. Also worthy of mention is the way of solving the issue of non-utility waste and various cuttings. The machine is equipped with a unit pushing unwanted elements outside the cutting station area, as a result of which the CT 500 is protected against uncontrolled blocking or failure.
Another innovation introduced by PREZ-MET at this stage is an automatically controlled way of basing profiles in two axes with additional clamping. This innovation ensures the stability of the lagi during cutting and avoids the situations that occur when using a standard system of two clamps – horizontal lower and upper. We are talking about skewing of flush profiles, which directly affects their improper cutting and failure to maintain angles on the cut piece (the profile does not have any angle – for example, 45˚ or 90˚in the other plane). Floating angles then give rise to a number of problems, which include: difficulties in cleaning and fitting, failure to maintain the parameters of the window and lack of aesthetics of the weld. All this, unfortunately, measurably translates into less profit for the company through the occurrence of complaints and a decrease in orders.
The receiver of cut profiles is the last station of the cutting center, and also here we are dealing with an out-of-the-box solution. Unique is the very technology of receiving the cut profile, which is lowered below and thus creates space for the next component. As a result, the cut piece is pushed down and the next piece is cut at the same time.
The machine features a simple program with an intuitive interface for its operation. Work is certainly facilitated by the visualizations included in it and the preview of the entire process on the monitor screen. Any correction of cut profiles or cutting an element from usable waste are not a problem. The cutting itself can be done in two ways – by editing the cutting list or manually entering the dimension. In addition, the program is able to collect data on usable waste and basic statistics, and the extended error report and the aforementioned visualizations make it significantly easier to locate and remove failures.
In addition, an equally important, and for some the most important, argument for the in favor of the CT 500 cutting center is the fact that PREZ-MET, while ensuring efficiency and cutting quality, has not forgotten about people and their safety. Operator protection, for that is what we are talking about here, is an aspect to which special attention has been paid. In the case of the machine in question, fixed guards, movable guards with safety interlocks, sensitive protective equipment, protective fencing, emergency stops or a bumper with locking confirmation were used. However, the array of safety features used does not impinge in any way on the efficiency or culture of the center. The best of the sophistication of the solutions that translate into a high level of safety is evidenced by the CT 500’s certification in 2019 by the Accredited Laboratory of the Institute of Advanced Manufacturing Technologies in Krakow.
In summary, the CT 500 cutting center is a strict leader of machines of this type in the European market. Thanks to the use of a number of innovative solutions, an extremely fast and precise machine was obtained, which, despite its high performance, is safe for the operator, easy to operate and does not take up a relatively large area.