Company manager Hans-Joachim Bender mentions: "We have reached to reduce process times to 3 ½ minutes". An annual capacity of up to 110 MWp can be reached with the new, three-step single-opening laminators (e.a.sy-Lam SL). On the highest level, a ten-opening laminator can produce an annual capacity of up to 265 MWp. This is an increase in capacity of more than 100% contrary to the current standard process.
The annual capacity of Bürkle machines sold since market launch is very interesting in this context. In 2009 the same was with 1,6 GWp - up to this day it has more than doubled and almost reached 4 GWp. By the end of 2012, two gigawatts more shall be added worldwide. The lion’s share for lines for producing crystalline modules is almost with 2,8 GWp. Bürkle machines for producing thin film modules have an annual capacity of 1,2 GWp at the moment.
Product Manager Dagmar Metzger explained that the development has been realized by focusing on a number of important process parameters. “Among others, we have increased the temperature for laminating glass-foil modules”. Depending on the foil type, an increase of the operating temperature by ten degrees Celsius to for example 160 degrees can double the cross-linking speed. Combined with a higher pressure and a reduction of the evacuating time, it is possible to reduce the process to 3 ½ minutes, explains Metzger.
With these enormous production outputs, the relilability of the lines is getting more and more important. For reaching this, a regular heating is very essential. Bürkle laminators ensure the same through the external heating-up of the thermal oil so that the module quality is not affected by local temperature deviations in the heating platen. This differs from the process of most competitor models. The heating elements of the competitors are integrated into the heating platen so that a failure can damage the modules in the affected area, says Metzger. This results in the following: with an annual reject rate of only 0,1 per cent, the reject costs are almost the same as the annual energy costs of a lamination line.
At the moment Bürkle is carrying out several test series on a laboratory laminator at their headquarters in Freudenstadt, says the PV expert.
At the end of next February Bürkle plans to install a lamination line at their headquarters in the Black Forest on which the solar module manufacturer can test the new process from top to bottom and for producing modules for certification. Moreover the company has received a certificate of the test laboratory Cetecom ICT Service GmbH from Saarbrücken confirming the good quality of the modules produced via the SL process.
The unit costs per solar module are reduced by up to 25 per cent thanks to the shortened lamination times of the SL production, since the costs depending on the machine such as energy, maintenance and staff costs, can be considerably lowered.
For example the use of one three-step e.a.s.y-Lam SL system could replace up to four single-opening laminators. Another example of cost savings and higher quality finished product using the three-step process.
It is anticipated that most existing systems can be upgraded to the new SL technology at extra cost.
The solar modules presented on the Intersolar consisting of two glass panels with a thickness of 1,3 mm were highly approved on the fair. Standard thicknesses are between three and four millimeters. Metzger explains: “Handling these thin glass panels is very challenging, but it can be well achieved with today’s handling systems".
At the same time completely new doors are opened for module manufacturers through weight reduction of the panels by around one third. The Freudenstadt company operates a production line in their test center for pushing processes.
Finally, as part of Burkle’s coating experience of 90 years they are leading the development of coating new Anti-Reflective liquid material to Glass Modules. An important development within the manufacturing process of Glass PV Modules is the application of very thin liquid anti-reflective coatings. The Roller Coating process, unlike spray coating, deposits a consistent and uniform layer of material in high volume production environments. Process control and uniform coating are important aspects of any coating process, but the Bürkle Roller Coater is an ideal tool for this high volume application. Oliver Meisriemel, Bürkle Coating Product Manager, says “that roller coating is an ideal tool minimizing material loss and providing a predictable coating thickness.” The transmission rate is increased by 2 to 3 per cent through the anti-reflective coating for a better exploitation of solar energy. The capacity increase per module is with approx. 5 Wp.