WO2014096924A1

WO2014096924A1 - Laminator for solar modules using a tube like pressing member

Info

Publication number: WO2014096924A1
Application number: PCT/IB2013/002745
Authority: WO
Inventors: Christoph GINDRAT; Matthias HÄNL; Michael SIGRIST
Original assignee: Meyer Burger Ag
Priority date: 2012-12-21
Filing date: 2013-12-12
Publication date: 2014-06-26
Also published as: EP2934892A1; CN104884256A

Abstract

An improved and simplified system (1) and method for laminating sandwiched bodies (7), lay-ups, and more particular for the lamination of solar modules is described which can be adapted for mass production inexpensively. The present invention is simple, cost effective, reliable, and environmentally friendly in operation. A tube like inflatable member (4) is used to create a pressing chamber (5) for moving a heating plate (2) toward a base (3) holding the lay-up (7).

Description

Laminator for solar modules using a tube like pressing member

FIELD OF THE INVENTION

[001 ] The present invention relates generally to laminating of sandwiched bodies, preferably having electronic components in the sandwich such as solar cells and in particular the present invention relates to the manufacturing of solar panels and to the panels themselves, as well as to production equipment and methods for carrying out the process of laminating sandwiched bodies such as solar panels.

TECHNICAL BACKGROUND

[002] Manufacturing of sandwiched bodies and solar panels in laminators is known. During lamination a pile (so called lay-up) normally consisting of a front layer (glass plate), an encapsulant layer, active components, a second encapsulant layer and a back layer (another glass plate or back sheet) is pressed together, normally under vacuum and under the influence of heat. The encapsulant layers melt due to the heat the thus form the lay-up into one structure. During lamination, the encapsulant undergoes physical and/or chemical changes and after cooiing forms the sandwiched body. It is also known to use two-component encapsulants that do not require heat to set. In such cases, only vacuum is needed so that no air is trapped inside the module. Additional heat may speed up the setting process though.

[003] Sandwiched body, solar module and lay-up are terms describing the material to be laminated, the end product and intermediate stages and may be used interchangeably.

[004] The sandwiched body may contain no active components or may contain any kind of active components such as solar cells (crystalline, thin film, etc.) as in solar modules or e.g. leds. For thin film, the active component is normally applied to a glass plate. Moreover, one encapsulant layer (the one between the front layer and the active component can be left out.

[005] A lay-up for a solar module is formed before lamination using a carrier material in the production line such as e.g. the glass plate that forms the front layer. It is populated with the encapsulation material (e.g. ethyl vinyl acetate polymer (EVA)). On top of the encapsulation, there are the active components such as a cell matrix. Cell matrices normally consist of strings of cells that in turn are interconnected with cross connectors (ribbons connecting the individual strings into one meandering string, connecting all cells in series). On top of this composition another layer of encapsulant is placed before the final layer that finishes off the lay-up and the later module.

Normally a back sheet or a second glass plate is used. Note that EVA is just one type of encapsulant. It is a thermo setting material. Other materials used are e.g. PVB (Polyvinyl butyral), TPO (Thermo polyolefin) (both thermoplasts) or silicone (thermoplast or 2-component). The back sheet is typically a foil containing PVF or a second glass plate. Other materials and layers can be used, e.g. incorporating insulating or optical properties.

[006] If a two component encapsulant is used, it may not be necessary to heat the lay-up. The materials may simply be pressed together under vacuum. If the inventive laminator is e.g. used as part of a multi-stage lamination process, the already pressed together module may be simply pressed (no heat applied, under ambient pressure) together while it cools down or is actively cooled. If the module is already sealed, e.g. with a butyl sealing or it is placed inside a vacuum bag, heat may be applied to activate/melt the encapsulant while pressing the lay-up together. No vacuum has to be applied.

[007] The invention is not limited to lamination while applying heat or a vacuum.

[008] With vacuum a low pressure is meant that takes enough air (or any other gas) out of the lay- up so that the modules can be formed properly, e.g. not entrapping bubbles.

[009] According to the state of the art, the lay-up may be pressed together using two heating plates: one above and one below the lay-up. Intermediate members may protect the heating plates, e.g. form getting dirty.

[0010] US 4,080,243 which comprises the features of the preamble of claim 1 and claim 15 and is considered the closest state of the art, discloses for example a laminator having two heating plates. One or both heating plates are associated with an inflatable flexible bag for moving the heating plates toward each other. The lay-up is placed on top of the lower heating plate and thus pressed together. The inflatable bags are large and cumbersome to handle. Since such bags need to be replaced regularly (they wear down under influence of the vacuum, gasses set free in the vacuum chamber and the high temperatures), handling should be as easy as possible. In addition the bags are large and therefore expensive. A disadvantage of such bags is that the edges of the modules are compressed more than the centre region. Moreover, since the applied pressure is constant over the complete surface of the module and the edges are compressed more easily (because encapsulant can escape sideways from the lay-up and since the edge regions are only supported from one side), the module will suffer from what is called edge-compression. The present applicant has devised and embodied this invention to overcome these shortcomings and to obtain further advantages.

[0011] From WO2011089474 a laminator is known that uses a membrane for pressing the lay-ups. The membrane is as large as the whole heating plate (lots of material needed). The costs for replacing the membrane (down time and material costs) are high. In addition, edge-compression will be even worst here since there is no upper heating plate that helps the membrane to stay flat.

[0012] From WO2009/114189 A2 a laminator is known having bellows extending between a vacuum system and the space between a pressing plate and a table. These bellows cannot be inflated since the have an opening near their bottom end. They just move along with the plate they are attached to. This system thus having exactly two processing chambers: one above the pressing plate and one underneath it. According to the invention three such chambers are provided for better control of the pressure of the laminates to be formed.

[0013] From US2012/0318856 another two-chamber laminator is known again with bellows extending between the hull or cover and the pressing plate. This bellow is not inflatable as is proposed by the invention.

SUMMARY OF THE INVENTION

[0014] The invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention.

[0015] An object of the present invention is to overcome some of the disadvantages of known laminators and laminating methods, more particularly of the existing solar module laminating methods, systems and production equipment by providing more control over the pressure exerted on the laminate or sandwiched body.

[0016] An improved and simplified system and method for laminating or pressing together sandwiched bodies, lay-ups, and more particular for the lamination of solar modules is described which can be adapted for mass production inexpensively. The present invention is simple, cost effective (shorter down-times), reliable, and environmentally friendly in operation. At the same time, edge-compression is counteracted, thus achieving better module quality. In addition the system can be adapted to the type of sandwiched bodies that are made. Moreover, the pressure distribution can be adapted to the size of say the modules.

[00 7] The further preferred embodiments of the present invention are based on the realisation that using a tube instead of a bag greatly reduces material costs as well as cost of ownership. Since tubes are easier to manufacture, are commonly used (for other purposes) and uses less material, they are more cost-effective. Further, due to special design (see description of the drawing) modern inflatable members or seals are hardly susceptible to wear, which guarantees higher up-times. Since tubes are easier to handle, replacing a tube takes less time, further augmenting up-times.

[0018] In one first basic aspect of the present invention, the system comprises a process-chamber delimited by walls or intermediate members, a first plate member, a second, opposing plate member, and at least one first inflatable member operatively arranged between said first plate member and a first wall portion facing the first plate member for biasing the first plate member towards the second opposing plate member when inflated or between said first plate member and the second plate member for biasing the first plate member away from the second opposing plate member when inflated.

[0019] According to the inventive concept, this system is characterized in that the first inflatable member or seal that at least partially delimits a first pressing chamber further delimited by the first plate member or an intermediate member interposed between that first plate member and the at least one first inflatable member the first wall portion of the process-chamber opposing the first plate or an intermediate member interposed between that wall portion and the at least one first inflatable member or the second plate member or an intermediate member interposed between that second plate member and the at least one first inflatable member and connectors for connecting a pressure or vacuum line (for gases or a fluid) to said process-chamber, first pressing chamber and inflatable member, preferably at least one intermediate member being releasably attached to any of the first plate member, second plate member, the first wall portion or any combination thereof.

[0020] According to the invention, the laminator has (at least) three, independently controllable pressing chambers that allow better control over the local pressure on the work piece to be laminated. Especially near the edges, the pressure may be reduced to counteract edge- compression. Note that during lamination the sandwiched body may be enclosed by the inflatable member or the inflatable member may form a chamber other than the chamber the sandwiched body is placed in. A combination of the two, necessitating two inflatable members, is also possible.

[0021] The inventive laminator may have two pressing plates. In that case a preferred embodiment of the invention comprises at least one second inflatable member operatively arranged between the second plate member and a second wall portion facing the second plate member for biasing the second plate member towards the first plate member when inflated. The second inflatable member at least partially delimits a second pressing chamber further delimited by the second plate member or an intermediate member between the second inflatable member and the second plate member, the second wall portion of the process-chamber opposing the second plate member or an intermediate member between the second inflatable member and the second wall portion and connectors for connecting a pressure or vacuum line (for gases or a fluid) to said second pressing chamber and second inflatable member, preferably at least one intermediate member being releasably attached to any of the second plate member, the second wall portion or any combination thereof.

[0022] The intermediate members may form an airtight unit with the sealing, the sealing preferably forming a closed contour. Preferably the plate members and the inflatable member form a closed chamber, the inflatable member and the intermediate member forming pressing means with two separate chambers. In this way the unit may be removed from the processing chamber easily and the first pressing chamber can be rendered airtight and tested outside of the laminator. Preferably intermediate members are releasably attached to its plate member and its wall portion respectively to make the handling of the unit even easier. Note that the intermediate members may be flexible, so that the pressure in the pressing chamber(s) may exert a force on the wall portion or plate member as it may be.

[0023] The intermediate members may form an airtight unit with the sealing, the sealing preferably forming a closed contour. Preferably the plate members and the inflatable member form a closed chamber, the inflatable member and the intermediate member forming pressing means with two separate chambers. In this way the unit may be removed from the processing chamber easily and especially the first pressing chamber can be rendered airtight and tested outside of the laminator. Preferably, intermediate members are releasably attached to its plate member and its wall portion respectively to make the handling of the unit even easier. The intermediate members may be flexible, so that the pressure in the pressing chamber(s) may exert a force on the wall portion or plate member as it may be, mainly without being hindered by the inflatable member. The intermediate members may for example be made out of a polymer such as used for known pressing membranes or may be metal plates or sheets.

[0024] In this document a "closed" or "airtight" chamber always means with exception of desired openings such as connectors and the like. With "inflatable member" a member is meant that is airtight and can be inflated by introducing air into it through a connector, the inflatable member as such forming an airtight container or reservoir much like a balloon.

[0025] The inventive laminator may be part of a laminator production line consisting of multiple consecutive laminator units, each forming a stage in the production line. It may have heating plates or cooling plates and/or it may be possible to evacuate the processing chamber or not.

[0026] The pressing chamber is used to generate pressure on the good being laminated. The inflatable member at least partially forms a wall delimiting the pressure chamber. The pressure in the inflatable member may be higher than in the vacuum chamber or pressing chamber. Since the surface of the inflatable member abutting the pressing plates is small, the force it exerts on the modules will also be small and may be made negligible.

[0027] Preferably the inflatable member contains at least a tube-like portion, preferably forming a circular tube,, ideally forming a closed contour, together with the adjacent plate or an intermediate member (32, 32', 33, 33') between said inflatable member (4, 4") and that adjacent plate member and an adjacent wall portion ) or an intermediate member (32, 33' ) between said inflatable member (4, 4') and said wall portion (10A, 10B) or the other adjacent plate member (2, 3) or an

intermediate member (32, 32', 33, 33') between said other adjacent plate member (2, 3) and that first adjacent plate (2, 3) member delimiting the pressing chamber or intermediate member between the inflatable member and the wall portion.

[0028] Note that the tube does not have to be round or endless (like a bicycle inner tube). Multiple tubes (whose insides are not interconnected or interconnected by detachable interconnecting tubes or deforming members) may form a ring and thus define or enclose the pressing chamber. Also other members of the press may partially delimit the pressing chamber. The inflatable member has a valve for letting a medium such as a gas or fluid in and out.

[0029] As was explained above, the inventive system is cost-effective (less material needed and standard products may be used) and guarantees high up-times due to the easy handling of the tube and its longer life-time. It is easier to maintain than conventional laminators, as known from e.g. US 4,080,243 and WO2011089474, since it has no large membrane or bag that is difficult to replace and wears off fast (mainly because the tube does not have to bend and stretch as much and does not directly contact the hot layup). The inflatable member may have portions, for example thinner portions, that deform more easily than other portions.

[0030] By using circular tube, the pressing chamber is created in an easy and reliable manner. Here circular means the tube is endless, like the inner tube of bicycle tires. Tubes may be made of polymer or any other suitable material, allowing deformation also for bringing it into the desired shape/contour.

[0031] The inflatable member(s) may essentially follow the contour of the plate member.

Alternatively, a plurality of inflatable members may be provided for at least one plate member and each of the inflatable members at least partly delimiting a pressing chamber. In that case the inflatable members may form a closed contour that encloses an area smaller than the area of the plate member, preferably smaller than one module.

[0032] To prevent loss of pressure in case a seal malfunctions (ideally the pressure in the chambers is monitored to recognize this), multiple concentric tubes may be used. In that case a first inner pressing chamber is formed inside another first pressing chamber. If one seal malfunctions, the other will at least partially ensure pressure on the lay-up so that the module may still be formed correctly. Note that the pressures in concentric chambers have to differ to be able to detect malfunctioning of the inner sealing. This would lead to a higher yield.

[0033] Alternatively multiple tubes may be placed next to each other (non-concentric). In this way, the pressure on the lay-up may be controlled, see also below. Another advantage of using multiple tubes is that they are easier to handle than one large tube and thus easier to replace. Also if more than one module is laminated (heated, cooled or both consecutively) in time parallel in one laminator chamber, one or more tubes may be chosen to correspond to the individual modules. Moreover, each module has associated with it one or more tubes that exerts pressure to it. In this way the same force (distribution) is applied to each lay-up. Also if one seal fails, the modules corresponding to the other seals are not influenced.

[0034] As stated, a known problem is edge compressing: the edges of the lay-up are compressed more than in the middle portion of the module, giving the module a slightly convex shape, introducing undesirable tensions in the module. This edge compressing may be counter acted by choosing the shape of the inflatable members smaller than the size of the modules and especially not having the sealing extend to the corners of the module.

[0035] To heat the lay-up symmetrically it is beneficial if two heating plates are used. This is especially beneficial if the lay-up itself is symmetrical such as is the case for glass-glass modules (glass used as top and back layer). Cooling means may also be provided, maybe as second plate or integrated in a heating plate. For a cooling press (the inventive system for laminating may also be comprised in a press with or without active heating or cooling, as is used in an also called XL- process, see below) one or both pressing plates may be cooling plates. If a two component encapsulant is used, meaning the encapsulant does not have to be softened or cured by heat, one or both plates may be passive. Nevertheless, applying some heat may speed up the setting process.

[0036] Heating plates may have any means of heating the lay-up as known from the state of the art, such as: electrical heating means, hybrid heating means (using heating coils and oil for homogenizing the temperature of the plate), induction heating means (heaters may be outside the plate or even outside the process-chamber), heating means using electro-magnetic radiation or radiant heat sources, air ovens, convection ovens and combinations of two or more thereof.

[0037] To make changing of the inflatable members easier, the inflatable member may be releasably mounted to the associated plate member, the associated wall portion, an intermediate member (32, 32', 33, 33') or any combination thereof. At least one guiding member may be provided for holding the inflatable member that defines the contour of the inflatable member, the guiding member being mountable, as the case may be releasably mountable to any of the associated plate member, an intermediate member, the associated wall portion or any combination thereof or it may be an integral part thereof.Since the guiding member holds the tube is the shape or form the inflatable has when attached to the system, the inflatable member can be easily positioned in the laminator and attached in the correct position. It is for example placed on the upper pressing plate (that is lowered by releasing the biasing means) and the tube can easily be attached to that upper plate because its shape (oval/round shape around the pressing chamber) already agrees with the mountings on the upper plate.

[0038] In order to protect the inflatable member, it may be insulated against the heating or cooling plate for keeping its temperature low or high respectively so that the material is not affected by extreme temperatures. This can be achieved by mounting the inflatable member, the intermediate member associated therewith or its guiding member on an insulating member.

[0039] In order to make the laminator less complex, one of the plate members may be static. It is also possible that the upper and the lower plate are movable by inflatable members. In this way the system can adjust better to thickness variations in the module. Modules, for example, normally have more interconnectors for the strings on one side than on the other side, this side therefore being thicker.

[0040] As stated above, it is known from the state of the art to use laminators consisting of multiple stages, also called XL-process, based on the principle of pipelining: in a first stage the lay-up is e.g. heated under vacuum and pressed together. The lay-up is then moved to a consecutive stage

(leaving the first vacuum or process chamber) where it is actively or passively kept warm and again pressure is applied, not necessarily under vacuum. Then it may be moved to a third stage, leaving the processing chamber of the second stage, where the module is actively cooled, possible under pressure as well. The system for laminating or laminator according to the invention may in fact form or be part of any of these stages. All stages of such pipeline process may use the inventive system or only certain stages or just one stage may use it. At least one plate member may therefore be selected from the group consisting of a passive plate member, a heating plate member, a cooling plate member or any combination thereof.

[0041] By providing biasing elements, preferably spring elements, pneumatic or hydraulic cylinders, for biasing the plate member in a direction opposite to the biasing action of the inflatable member, the initial position of the plates may be defined. In the initial position, the spring elements may hold the plates such that the lay-ups can be introduced into and removed from the process-chamber. If the spring elements should define the position of the inflatable member, the latter must be left open (connected to ambient pressure) so that its internal pressure does not counteract the force of the spring elements. On the other hand, making the springs move the plates toward each other could lead to less defective modules in case of malfunctioning of the system since the lamination process can be completed without pressure. Also the inflatable member is easier accessible this way even if the system is not powered (e.g. during installation).

[0042] When laminating lay-ups, it is beneficial if initially the lay-up does not touch the heating plate(s). Since the heating plates in laminators (or heating stage in a process with multiple stages) normally are not cooled, they stay hot also when no sandwiched bodies are laminated. Putting a glass layer of the lay-up directly on a heating plate would make the former dish or warp: its surface expands under influence of the heat, while the inside still is cool, making the glass bend like a bi- metal. It therefore is beneficial if adjustable distancing members are provided that extend through at least one plate member in a direction towards the opposite plate member for holding the elements of the sandwiched body to be formed at a distance from the plate member the distancing members are extending through. The upper inflatable member may also be used to move the upper heating plate towards the lay-up and hold it just above its surface. In this way the heating from above can be done in a gentle manner.

[0043] In another aspect of the invention, the inventive laminator as described in the preceding paragraphs is used to perform a method for laminating at least one sandwiched body, preferably at least one solar module. Said method comprises placing the lay-up of a sandwiched body to be formed within a process-chamber in between a first plate member and a second, opposing plate member, and pressing together said plate members, including raising or lowering the pressure within a pressing chamber above or below the pressure within the process-chamber respectively as to apply pressure to the sandwiched body at least from a certain time in the process.

According to the essential idea of the present invention, the pressure within at least one inflatable member at least partially delimiting said pressing chamber is raised and held above the pressure within the pressing chamber. If the inflatable member is interposed between the plate members (the pressing chamber containing the sandwiched body), edge-compressing is avoided by counteracting the force on the edge regions. If the inflatable member is located between a wall portion and a plate member, edge compressing is avoided because the pressing chamber (containing the sandwiched body) is smaller than the size of the laminated body. The raised pressing in the inflatable member only ensuring that the pressing chamber remains airtight.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] These together with other objects of the invention, along with the various features of novelty that characterize the invention, will be more clear from the following description of preferential forms of embodiment, given as non-restrictive examples, with reference to the attached drawings wherein:

FIG. 1 illustrates a schematic cross sectional view of an embodiment of the inventive system when the pressing plates are apart; FIG. 2 illustrates a schematic cross sectional view of an embodiment of the inventive system when the pressing plates apply pressure to the lay-up;

FIG. 3 is a cross sectional view of an embodiment of a system with two active plates;

FIG. 4 is a cross sectional view of an embodiment of the inventive system with "pins";

FIG. 5 is a cross sectional view of an embodiment of the inventive system using multiple inflatable members, the pressing plates being apart;

FIG. 6 is a cross sectional view of an embodiment of the inventive system using multiple inflatable members, the pressing plates being moved together;

FIG. 7a is a pan view of the sealing members of figures 5 and 6;

FIG. 7b is a pan view of concentric sealing members;

FIG. 8 is a cross sectional view of a sealing member in retracted state;

FIG. 9 is a cross sectional view of a sealing member in extended state;

FIG. 10 is a cross sectional view of an embodiment of the inventive system with upper and lower inflatable members;

FIG. 11 shows a typical process for laminating a solar module with the inventive press.

FIG. 12 is a cross sectional view of an embodiment of the inventive system with the upper and lower sealing mounted on intermediate members;

FIG 13 is a cross sectional view of an embodiment of the inventive system with the inflatable member mounted between two pressing plates

DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention will be described with reference to exemplary embodiments and the present invention is not limited to a particular system and methods for laminating sandwiched bodies, lay-ups, solar modules, except as defined in the appended claims. Embodiments of the present invention may be used with a variety of lamination methods and systems. It will be apparent to one skilled in the art that the present invention may be practiced in a variety of ways within the scope of the claims. All features shown in relation to the figures may be applied mutatis mutandis to the invention as described in the claims and vice versa.

[0046] As used herein, the indefinite article ("a", "an") denotes the presence of at least one of the referenced item, and the term 'a plurality' denotes the presence of more than one.

[0047] The present invention relates to a system, a method and to production equipment for manufacturing, more precise, laminating solar panels from a lay-up comprising several layers. The module can be a solar module sometimes described as a PV (photovoltaic) module in the form of a sandwiched body, e.g. a lay-up of a plurality of material layers. [0048] Figure 1 shows very schematically a cross sectional view of an inventive system, also called a laminator, laminator unit, press or system for laminating 1 used for producing for example solar modules. These terms are used interchangeably in the complete document. All parts not relevant to the invention have been omitted for clarity and are known to persons skilled in the art. The laminator 1 holds two plates 2, 3 in its vacuum or process chamber 6. The plate 2 shown is a heating plate with heating ducts for heating fluid or heating rods 8 extending therein. The lower plate 3 is a passive plate or base for holding the lay-up 7. The heating plate 2 is attached to a wall portion 0A of the laminator 1 by means of a sealing member, seal or inflatable member 4. The member 4 together with the heating plate 2 and the wall portion 10A of the processing chamber 6 - that may be a vacuum chamber - delimits a pressing chamber 5. Two biasing elements or springs 9 hold the plate 2 in its "opened" position, as long as the pressure within member 4 and/or chamber

5 causes a force on plate 2 smaller than the force of the springs 9. The springs 9 may and may not divide the vacuum chamber 6. Between the process chamber 6, the pressing chamber 5 and the inflatable member 4, the laminator has three airtight chambers in which the pressure can be controlled independently.

[0049] The laminator 1 as shown in figure 1 has an opening for introducing the lay-up in the plain of the drawing that therefore not visible. This opening is closed by a suitable door or lid. Figures 5 and

6 show an alternative way of giving access to the interior of the laminator. The plates 2, 3 as well as the wall portion 10A, 10B may have recesses or engaging members for positioning the inflatable members 4 and/or for ensuring that the formed chambers are airtight. Also shown are connectors 28, 29, 30 for connecting pressure or vacuum lines to the processing chamber 6, the pressing chamber 5 and the sealing for inflatable member 4, respectively.

[0050] The sealing 4 in figure 2 is shown in its expanded or extended state. This is achieved by increasing the pressure difference between processing chamber 6 and pressing chamber 5. The pressure in the sealing 4 is higher than the pressure in pressing chamber 5 so that it presses on both the walls of the processing chamber 6 and the plate 5. In this way the seal 4 seals the processing chamber and the pressing chamber and is not pressed aside. The seal 4 may be attached to the wall 10A, the plate 2, both or neither of them. In the latter case, the seal simply lies on the plate, possibly held in position by a recess (not shown) or a guide member 23 (Fig. 8, 9). Due to the pressure, the springs or biasing elements 9 are elongated enabling the movement of the plate 2.

[0051]

During lamination (complete lamination turning the lay-up into a solar module), the following steps are carried out: • The lay-up 7 is placed inside the vacuum chamber 6 on the base or heating plate 2\ 3;

• The processing chamber 6 is closed to form an airtight processing space;

• The processing chamber 6 is evacuated

• The heating plate 2 is moved towards the lay-up 7. It may be kept at a certain distance for a while in order to come to a more gentle heating of the materials of the lay-up. Also pressing the lay-up too early may entrap air that could form into bubbles in the final module;

• Pressing the pre-heated lay-up together and possibly heating it further; and

• Finally lifting the heating plate 2, opening the vacuum chamber and removing the module from the laminator.

[0052] As was stated above, these steps (as a whole or broken up) may be divided over multiple stages or units of a laminating system. Each stage or unit may comprise an inventive system for laminating solar modules.

[0053] The pressure in the processing chamber 6 may be reduced so that the required pressure difference can be obtained or so that the sandwiched body 7 can be formed properly without entrapping too much air in it. In the former case, instead of evacuating the processing chamber, over-pressure may be applied to the pressing chambers.

[0054] These steps can be done in any order suitable for the desired process/result. The steps are normally at least partially in time parallel. For example, the heating of the lap-up with the heating plate not pressing on it (pre-heating) may be done in time parallel with the removal of the air from the vacuum chamber. The air still in the vacuum chamber may even support heat propagation from the heating plate to the lap-up.

[0055] Figure 3 shows an alternative embodiment according to the present invention. Here plate or base 3 is also a heating plate 2'. Note that in all embodiments the plate 2, 2', 3 may also be part of the wall of the vacuum chamber, rendering it static.

[0056] Figure 4 shows another embodiment according to the present invention. In addition to the embodiments shown in figures 1 through 3, abutment means 11, 12 delimit the vertical movement of plates 2, 2'. Also shown are so-called pins 13: elements that lift the lay-up (which normally has a glass plate as lowest layer) in order to keep it at a distance from the lower heating plate 2'. The pins are mounted on lift members 14 that pull them down so that they disappear in the heating plate 2', as shown in the figure. By applying a pressure over the lift member 14 (under-pressure in pin chamber 15), the pin can be raised thus securing a distance between the lay-up and the heating plate 2'. If the under-pressure is released, the pins move back to the position shown.

[0057] The plates shown in figure 4 are not parallel. This may happen when the lay-up is not equally thick over its complete surface. Since the sealing 4 is isobaric, the upper plate 4 is allowed to adapt to this.

[0058] Figure 5 shows another embodiment of the present invention. Here multiple non-concentric seals or tube members 4a, 4b, 4c are shown. These three members may e.g. be used for laminating one large module (not shown) or for three smaller ones (not shown), each module being associated with one sealing member. A base part 16 and an upper part 18 that are movable relative to each other form the processing chamber 6. An intermediate part 17 with seals 19 render the processing chamber 6 air-tight.

[0059] The plates 2, 2', 3 may be separated by supporting members such as known form e.g. VVO2011089474, reducing the need for reinforcement beams 23 as shown in figure 5. In the same way as shown in this document, multiple vacuum chambers may be formed in one laminator 1.

[0060] Figure 6 shows the same embodiment from figure 5 with the upper heating plate 2 lowered.

[0061] Figure 7a shows the three sealing members 4a, 4b, 4c on the upper face of a heating plate 2 as in figures 5 and 6, but from a direction perpendicular to the plate 2. The sealing members are not concentric. The sealing members do not extend to the comer of the one module (about the size of the heating plate 2) or multiple modules (each module about the size of a sealing 4a, 4b, 4c). This prevents edge compressing that is especially likely to occur in the corners of the module since there the encapsulant has two ways of escaping the lay-up. Since the tubes are round, edge compressing in the corners is counteracted.

[0062] Figure 7b shows a plate 2 with two concentric sealings 4d, 4e. If the sealing 4d is defective, the sealing 4e will keep the inner pressing chamber 5a intact. If sealing 4e is defective, sealing 4d will keep the inner and outer chamber intact. Depending on the defect and the process step, this may be enough to finalize the stage it is in. Making the pressure in outer chamber 5b lower than in inner chamber 5a will further counteract edge-compression.

[0063] Figure 8 shows an embodiment of the sealing or gasket 4. It has an upper part 20, a lower part 22 and a middle part 21. The upper part 20 and lower part 22 are designed such that they do not deform greatly when pressure is applied to the sealing 4. They may be used to attach the sealing 4 to the plate 2, 2', 3, wall portion 10 or guiding member 23. The thinner middle part 21 is designed to deform and can do so without wearing down too fast.

[0064] The sealing 4 is held in a guiding member 23 that is used to give the sealing the right shape when it is not yet attached to the plate 2, 3. In this case, it is also used to secure the sealing to the heating plate 2. Moreover, the sealing is attached to or placed in the guiding member 23 outside of the laminator (not resulting in down-time) and the guiding member 23 is attached to the laminator (mounting means not shown). As the guiding member 23 may be of a hard material such as metal, it is much easier to mount to the laminator than the flexible sealing 4. [0065] Figure 9 shows a cross sectional view of a sealing of figure 8 in the expended state. Inside the sealing a higher pressure is applied than outside. The middle part stretches while the shape of the upper and lower part basically remains unchanged.

[0066] As is shown in figure 10, a system is conceivable that has an upper 4 and a lower sealing 4'. Additional spring elements 9' are used accordingly to keep the lower heating plate 4' in the correct position. The spring may push the plate 4' upwards or pull it downwards against the force applied to it by the lower pressing chamber 5' and the lower seal 4'. Further, in figure 0 the possible mounting of the inflatable member 4 on an insulating member 31 shown. Said insulating members 31 themselves are preferably mounted on the wall portion 10A.

[0067] Figure 12 basically shows the same embodiment as figure 10. In addition the upper inflatable member is sandwiched between an upper 32 and a lower sealing plate 33, also called intermediate member. In this embodiment the lower inflatable member is also sandwiched between an upper 32' and a lower 33' sealing plate, also called intermediate member. In this way respectively the upper 5 and lower 5' chamber form an airtight unit that may be releasably attached to the system 1. In this way such a unit may be removed from the system and replaced by a new one. This may for example be done if a sealing is defective or needs to be maintenance. A second unit may be placed in the system, while the first one is being worked on.

[0068] Figure 13 shows an embodiment where an inflatable member 4 is mounted between two heating plates 2, 3. The upper heating plate 2 in this embodiment is supported by pneumatic cylinders 34 that can lower the upper heating plate 2 onto the lower heating plate 3. According to the invention the component parts 34 may contain an inflatable member delimiting a pressure chamber. In addition, the lower heating plate may be lifted and lowered by the inflatable member 4' underneath it. This embodiment is especially suited for preventing edge compressing. In this embodiment the lay-up is not processed in processing chamber 6 but in pressing chamber 5 enclosed by the inflatable member 4.

[0069] Turning over the embodiment shown in figure 13 will also result in a useful laminator since no the hearting plate 3 is supported by amongst others the inflatable member 4' is that no other active component parts are needed for moving the heating plates relative to each other. Only a support for plate 4 would be needed to hold plate 4.

[0070] Figure 11 shows a typical lamination cycle if the lay-up is laminated completely in one unit or laminator as shown in figure 10. The lay-up and near the end the module temperature is given by the dashed line 25. The pressure in the pressing chamber and the processing chamber are given by the dotted lines 26 and 27 respectively.

[0071] At TO the lay-up is inside the processing chamber 6 and has ambient temperature. It rest on the pins 13 until T2. Then the pins 13 are lowered. The lay-up temperature 25 increases slowly until T2. Since here the lay-up touches the heating plate, the temperature rises more quickly from thereon.

[0072] Up to T2 the pressure in the pressing chamber 5 and the processing chamber 6 is reduced as shown by the lines 26, 27. Since the pressure in both chambers is identical, the lines overlap in this range. At T1 "vacuum", meaning the desired low pressure is reached.

[0073] From T2 on the pressure in the pressing chamber 5 is increased. The force exerted on the plate 2 presses the later down against the upward force of the spring members 9. At T4 the pre- pressing starts: the heating plate 2 presses on the lay-up. At T5 the pre-pressing pressure

(pressure difference between lines 26 and 27) is reached.

[0074] From T6 on the final pressing phase start, ramping up the pressure in the pressing chamber to almost ambient pressure which is reached at T7.

[0075] The lamination is done at T8 and ambient air is introduced into the processing chamber 6 and pressing chamber 5. The module 7 is removed from the processing chamber 6 and introduced into a cooling press or active cooling may be done inside the processing chamber 6 until the module reaches the desired temperature at T9. The cooling press may and may not be a press according to the present invention.

[0076] From T2 on, the pressure in the sealing 4 is kept slightly above the pressure in the pressing chamber so that the pressing chamber does not leak. That is also the reason why the pressure in the pressing chamber 5 is not lifted to ambient pressure before the end of the lamination.

List of reference labels

1 System for laminating a solar module

2 Upper heating plate

2' Lower heating plate

3 Base

4 Upper inflatable member or sealing

4a -4e Non concentric sealings

4d, 4e Concentric sealings

4' Lower inflatable member or sealing

5 Upper pressing chamber

5a Inner pressing chamber

5b Outer pressing chamber

5' Lower pressing member

6 Processing or vacuum chamber

7 Lay-up or module

8 Heating ducts or rods

9, 9' Spring elements

10 Wall portion of the processing chamber

11 Abutment means

12 Abutment means

13 Pin

14 Lift member

15 Pin chamber

16 Base part

17 Intermediate part

18 Upper part of processing chamber

19 Seals of the processing chamber

20 Upper part of the inflatable member

21 Middle part of the inflatable member that is easily deformed

22 Lower part of the inflatable member

23 Guiding member

24 Reinforcement beams

25 Lay-up/Module temperature 26 Pressure in the pressing chamber

27 Pressure in the processing chamber

28 Connectors for connecting a pressure or vacuum line to processing chamber

29 Connectors for connecting a pressure or vacuum line to pressing chamber 30 Connectors for connecting a pressure or vacuum line to sealing

31 Insulating member

32 Upper sealing plate or intermediate member for upper inflatable member 32' Upper sealing plate or intermediate member for lower inflatable member

33 Lower sealing plate or intermediate member for upper inflatable member 33' Lower sealing plate or intermediate member for lower inflatable member

34 Pneumatic cylinders

Claims

A Laminator (1) for laminating at least one sandwiched body (7), preferably at least one solar module, comprising: a process-chamber (6) delimited by walls (10), a first plate member (2), a second, opposing plate member (3), characterized in that at least one first inflatable member (4) is operatively arranged between said first plate member (2) and a first wall portion (10A) facing the first plate member (2) for biasing the first plate member (2) towards the second opposing plate member (3) when inflated or between said first plate member (2) and the second plate member (3) for biasing the first plate member (2) away from the second opposing plate member (3) when inflated, the first inflatable member (4) at least partially delimiting a first pressing chamber (5) further delimited by the first plate member (2) or an intermediate member (33) interposed between that first plate member (2) and the at least one first inflatable member (4) , the first wall portion (10A) of the process-chamber (6) opposing the first plate member (2) or an intermediate member (32) interposed between that wall portion (10A) and the at least one first inflatable member (4) or the second plate member (3) or an intermediate member (32) interposed between that second plate member (3) and the at least one first inflatable member (4), and connectors (28, 29, 30) for connecting a pressure or vacuum line to said process-chamber (6), first pressing chamber (5) and inflatable member (4), preferably at least one intermediate member (32,33) being releasably attached to any of the first plate member (2), second plate member (3), the first wall portion (10A) or any combination thereof.

Laminator according to claim 1 , characterized by at least one second inflatable member (4') operatively arranged between the second plate member (3) and a second wall portion (10B) facing the second plate member (3) for biasing the second plate member (3) towards the first plate member

(2) when inflated, the second inflatable member (4') at least partially delimits a second pressing chamber (5') further delimited by the second plate member (3) or an intermediate member (32') between that second plate member (3) and that inflatable member (4'), the second wall portion (10B) of the process-chamber (6) opposing the second plate member (3) or an intermediate member (33') between said second wall portion (10B) and that second inflatable member (4'), and connectors (28, 29, 30) for connecting a pressure or vacuum line to said second pressing chamber (5') and second inflatable member (4'), preferably at least one intermediate member (32', 33') being releasably attached to any of the second plate member (3), the second wall portion (10B) or any combination thereof.

3. Laminator according to any of claims 1 or 2, characterized in that the inflatable member (4, 4') contains at least a tube-like portion, preferably forming a circular tube.

4. Laminator according to claim 3, characterized in that the tube-like portion of the inflatable member (4, 4') is forming a closed contour, together with the adjacent plate member (2, 3) or an intermediate member (32, 32', 33, 33') between said inflatable member (4, 4') and that adjacent plate member (2, 3) and the adjacent wall portion (10A, 10B) or an intermediate member (32, 33' ) between said inflatable member (4, 4') and said wall portion (10A, 10B) or the other adjacent plate member (2, 3) or an intermediate member (32, 32', 33, 33') between said other adjacent plate member (2, 3) and that first adjacent plate (2, 3) member delimiting the pressing chamber (5, 5').

5. Laminator according to claim 4, characterized in that the closed contour of the inflatable member (4, 4') essentially follows the contour of the plate member (2, 3).

6. Laminator according to any of claims 1 to 5, characterized in that a plurality of inflatable members (4, 4') is provided for at least one plate member (2, 3) and each of the inflatable members (4, 4') is at least partly delimiting a pressing chamber (5, 5').

7. Laminator according to claim 6, characterized in that at least one of the inflatable members (4, A') is forming a closed contour that encloses an area smaller than the area of the plate member (2, 3).

8. Laminator according to any of claims 1 to 7, characterized in that the inflatable member (4, 4') is releasably mounted to the associated plate member (2, 3), the associated wall portion

(10A, 10B), an intermediate member (32, 32', 33, 33') or any combination thereof.

9. Laminator according to any of claims 1 to 8, characterized in that at least one guiding

member (23) is provided for holding the inflatable member (4, 4'), defining the contour of the inflatable member (4, 4'), the guiding member (23) being mountable, as the case may be releasably mountable to any of the associated plate member (2, 3), an intermediate member

(32, 32', 33, 33'), the associated wall portion (10A, 10B) or any combination thereof or it may be an integral part thereof.

10. Laminator according to any of claims 1 to 9, characterized in that the inflatable member or the intermediate member associated therewith is mounted on an insulating member (31).

11. Laminator according to any of claims 1 to 10, characterized in that the plate member (3, 2) opposing the plate member (2, 3) with the inflatable member (4, 4') is static.

12. Laminator according to any of claims 1 to 11 , characterized in that at least one plate member (2, 3) is selected from the group consisting of a passive plate member, a heating plate member, a cooling plate member or any combination thereof.

13. Laminator according to any of claims 1 to 12, characterized by biasing elements (9),

preferably spring elements or pneumatic or hydraulic cylinders, are provided for biasing the plate member (2, 3) in a direction of or opposite to the biasing action of the inflatable member (4, 4').

14. Laminator according to any of claims 1 to 13, characterized in that adjustable distancing members (13) extend through at least one plate member (2, 3) in a direction towards the opposite plate member (3, 2) for holding the elements of the sandwiched body to be formed at a distance from the plate member (2, 3) the distancing members (13) are extending through.

15. A method for laminating at least one sandwiched body (7), preferably at least one solar

module, using a laminator according to any of claims 1 to 14, comprising the steps of: placing the lay-up of a sandwiched body (7) to be formed within a process-chamber (6) in between a first plate member (2) and a second, opposing plate member (3), and pressing together said plate members (2, 3), including raising or lowering the pressure within a pressing chamber (5, 5') above or below the pressure within the process-chamber (6) respectively as to apply pressure to the sandwiched body (7), at least from a certain time in the process,

characterized by raising and holding the pressure within at least one inflatable member (4,

4') at least partially delimiting said pressing chamber (5, 5') above the pressure within the pressing chamber (5, 5').