109 Production quantities and types have greatly changes during recent years. Glassworks now need to adapt to these different needs and demands by producing smaller but varied batches of products. In response to the needs of its clients and the market, Forvet has, since the introduction of its NC workcentre in 1989, moved on to create flexible, versatile, high-tech machinery for the processing of various types, thicknesses and dimensions of glass sheets. or over 15 years, Forvet, based in Piedmont, northern Italy, has been designing, manufacturing and installing special plants for glass processing. All the company s production has always been realized with the aim of offering the market and clients innovative solutions. The first important project carried out by Forvet was dedicated to drilling, and was presented at the 1989 edition of Vitrum - the prototype of the Francesca FC CN workcentre for drilling, flaring and milling. At that time, many of the plants manufactured for glass process- Franco Scanavino* FORVET SRL The premises of Forvet, in Piedmont, northern Italy
110 ing were manual or semi-automatic and, therefore, the introduction of Numerical Control on a Forvet workcentre raised considerable curiosity among operators of the sector, but also perplexity towards a machine that was completely different from those normally used. Moreover, Francesca FC was the only machine to use a rotating spindle head and was also the only machine that did not need any manual adjustment or intervention from the operator. Francesca FC has always been a special machine, dedicated to an elite market, distinguished for its sophisticated equipment, sturdy, reliable, high-tech, and above all for its flexibility and capability to guarantee in a short time any kind of particular process, even in small batches. From the prototype of the Francesca FC, different models have been developed, according to the various different needs of processing, thicknesses and dimensions of the glass sheets. Detail of the Francesca FC 32M 3200 DRILLING The glass processing market is now moving towards important needs regarding drilling of glass. Small batches of production can be managed perfectly on single machines, but for medium to large production batches, an inline connection with grinding and drilling machinery is essential, in order to avoid double and triple handling and washing. The dimensions of glass are continuously increasing, with widths from 2,500-2,800 millimetres up to 3,210 millimetres, and with lengths up to 6,000 millimetres. The handling of these glass sheets requires plants of impressive dimensions, that have optimum performance with large sized glass sheets, but are very slow with small to medium sizes, because of the considerable distances that these pieces must cover on large transporters. From these considerations and other analyses, Forvet has designed and constructed a
111 machine that solves these problems - the Francesca FC 32M 3200. Francesca FC 32M 3200 Thanks to its technology, this machine can process glass sheets of up to 3,210 x 6,000 millimetres with milling, flaring and drilling, completely automatically, without contact with the upper surface of the glass sheet. This latter feature enables the processing of low-e magnetronic glass without damaging the treated surface. The machine is equipped with 32 tools, divided over four work heads, thus enabling the simultaneous use of four different tools on the same glass sheet, drastically reducing work times. The real flexibility of Francesca FC 32M 3200, however, is its ability to process two different types of glass at the same time, enabling to exploit to the full the versatility of the machine. Support of the glass during movement and its immobilization during processing, obtained Francesca FC 32M 3200 with a new system of glass transport (patented by Forvet), are based on a dynamic vacuum concept, that holds the glass in position on its longitudinal axis in movement. Moreover, this system has been realized in such a way that it adapts to the different widths of the glass sheets, thus optimizing support and hold of the glass during processing. Francesca FC 32M 3200 is the only workcentre that enables to include processes of milling and drilling in automatic production lines, since it is equipped with completely automatic loading, positioning, zero setting and unloading. Moreover, thanks to its high speed and the possibility of processing two glass sheets at the same time, it eliminates the usual slowing down that is necessary on drilling lines of traditional plants with different glass types and sizes. Francesca FC 32M 3200 is equipped with the most advanced electrical technology available
112 at the moment, 32 numerical control, as per the positioning of each working axis. GRINDING The second important project of Forvet is dedicated to grinding. The approach to the problems connected to grinding has been carried out after careful analysis of the specific needs of the market. This research has highlighted some fundamental points: first of all, the decrease in requests for large series: production batches are always more frequently made up of limited quantities and with different dimensions. Moreover, special magnetronic, ceramic, and laminated glass, are not easily processed with traditional machinery. The same research has highlighted even more the need for high quality finished products, perfect in dimensions and finishings, differentiated from lower cost products. Last but not least, the space taken up by the plants, which is considered as a problem by many of today s glassworks. The result of this analysis is that the production flow in glassworks is always more complex, disjointed, and tied to programming that does not follow production optimization. This leads to consequent cost analysis, which refers exclusively to requested delivery times, to the detriment of the production of the machinery used for processing. In fact, with the present conditions of the market, it is much more important to satisfy delivery times in the shortest time possible at any cost. Production batches of 50 pieces with 8-10 Chiara 2500 different dimensions are the norm of the present market. How can the different pieces of these batches be produced exploiting to the full the potentiality of the machines installed in each glassworks? Analyzing the various phases of the process needed, it can be said that, until the glass is loaded onto the cutting table, marked, sheared, and placed on the internal transport racks, problems with efficiency do not exist. When the glass is ready to be processed, a choice must be made: the use of a bilateral grinder for 50 pieces with 15 different sizes, or to process the same glass pieces on a straight-line edger? In these two different situations, there are different problems: in the first, production times connected to the need of the bilateral grinder to open and close for each different size, in the second, the manual handling needed for each piece with extremely longer times needed. From these considerations, Forvet has developed a grinder that responds to this new market, combining flexibility, speed, precision, and quality, also occupying the smallest space as possible. A machine, therefore, that has high speed changeover times, that can handle nonhomogeneous dimensions, that is not slowed down by different glass thicknesses, that guarantees dimensional precision and quality on all glass types; a machine where glass is immobilized in complete safety during process phases. The prototype of the Chiara quadrilateral grinder was delivered to the first client at the start of the new millennium, underlining the
new era of grinding. The first Chiara carried out finishings such as course ground e dges and seams, with thicknesses from 3 to 15 millimetres. Today, there are various models available, including the Chiara MTP, with polished finishings of the edges and seams. Chiara MTP Flexibility is the most important characteristic of this machine. It can grind glass thicknesses of 5 millimetres with dimensions of 500 x 800 millimetres, immediately followed by glass thicknesses of 15 millimetres with dimensions of 2,500 x 4,500 millimetres, without stopping or slowing down for adjustments. An important advantage of the Chiara MTP is the fact that each grinding wheel is controlled electronically, with regards to positioning (as well wear), processing and working speed, that can vary as per the different glass to be processed. This enables to carry out grinding with different finishings, simply by using numerical control. It is also possible to differentiate the type of finishing for each side of the same glass sheet. In other words, to carry out one side with polished edges and seams, another side with course edges and seams, and even a side not ground. Last, but not least, the advantage of being able to exploit to the full a new generation user interface, which, as support during maintenance, has a video that highlights to technicians all operations to be carried out in order to The control panel and video of the Chiara MTP conclude the work quickly and precisely. By means of an online connection, it is possible to order spare parts, etc. directly using the numerical control of the machine. The availability of this kind of plant enables glassworks to evolve in a way never even thought of before regarding glass processing. Thanks to the flexibility of Chiara, it is possible to transport a batch of glass sheets of any dimension in the pre-programmed production, having the information regarding the impact that this will have on the main batch in advance. This enables to accept orders with just in time delivery dates or orders that, for problems regarding small quantities, previously had to be turned down. Moreover, Chiara can handle different types of product, with different needs, thus creating production improvements and satisfaction of the client. *Process and Quality Manager Forvet Srl Strada Piossasco 46 10040 Volvera (TO) Italy Tel: +39-011 - 9855200 Fax: +39-011 - 9853032 E-mail: forvet@tin.it www.forvet.it 113