ARTIFICIAL VISION FOR PIPE EXTRUSION LINES

Over the last few years, the Artificial Vision (from now on, Vision) has made enormous strides both from the point of view of the improvement of technology (devices and software algorithms) and of economics of scale of its components. All this made it possible to extend the field of application to areas where the use of the Vision was previously considered too expensive or too complicated. Today, this change of scenery is combined with a growing demand for processing quality control systems even on extrusion lines, no longer just upstream, immediately after the extruder, but also downstream where a typical example is the need to control the quality of the “socket” as a result of the thermoforming process to which the pipe is subjected in one of its ends. SICA has always been careful to meet market needs by combining the most advanced technologies with Italian design, and has developed a Vision based quality control system to be applied to its Belling machines or stand-alone to evaluate the quality of the produced sockets and discard those that do not fall within the acceptance thresholds.

The system, based on the use of multiple cameras and sophisticated optics, allows you to check, for each pipe produced with the socket, whether:

• the gasket has been correctly positioned;
• there are aesthetic defects such as spots of color (typically light or dark streaks) or any writings / logos are not visible as desired;
• there are macro-defects;
• the measurement of the inner diameter of the gasket (D2e) is within the acceptable range.

The system is equipped with its own operator interface, very powerful but at the same time easy to use, by which it is possible:

• display the acquired images and the inspection result for the single tube (also in the case of multi-socketing);
• set the parameters required for inspection through the configuration pages;
• monitor the inspected products, defective products, inspected quantities, etc.

The system has been designed so as not to interfere in any way with the productivity of the line, relying on fast and performing Vision algorithms that allow its use even on the latest generation SICA belling machines which can reach 1200 pieces/h (for 32-40-50 mm diameter pipes wall thickness 1.8 mm). It can be easily integrated alongside belling machines or stand-alone, in cases where the manipulation of the pipes can be done by anthropomorphic robots downstream of the line, of which a typical example is the applications of putting pipes in a box.

The benefits deriving from the SICA Quality Control System are numerous and undoubtedly profitable:

• the defective product (deformed, without seal etc.) is identified and managed automatically;
• eliminates the need for operators dedicated to quality control of production;
• allows an increase in productivity where the need to visually check the quality of the product previously prevented from increasing the line speed;
• avoids the problem of replacing any defective tubes inside already formed and strapped packages;
• drastically reduces the probability that defective pipes reach the end user because they are not identified by the operator.

The SICA offer in terms of automation is thus increasingly complete. Thanks to the numerous experiences in the design and installation of complex systems, SICA is today a leader in the supply of automated systems for plastic pipe extrusion lines, from pulling to packaging systems, which can now be equipped with a powerful and reliable quality control.

Since most of the pipe manufacturers’ investments have concentrated on automating the packaging of the pipes themselves, the very high performance of the SICA plants have pushed productivity to unimaginable values (eg approx. 20 m / min of line speed for pipes with an average length of 1.5m) even just 5 years ago, highlighting what is a new need: to ensure that the automated system requires the minimum number of operators dedicated to the qualitative verification of the product so that the performance obtained upstream will not vanish. SICA’s response is immediately ready: a Quality Control system based on artificial vision technology. The SICA Quality Control system described has again raised the bar of technological know-how in the field of plastic pipe production, confirming that it is increasingly the right technological partner to face the challenges of today and tomorrow.