The global energy transition is accelerating in the direction of efficiency, cleanliness and sustainability, and the development of clean energy is also an important factor affecting the global economy and ecological environment. Photovoltaic solar energy has the advantages of low carbon, environmental protection and high efficiency, and has gradually developed into the main force of green energy.
In the solar photovoltaic power generation system, photovoltaic solar panels are mainly composed of:Tempered glassPhotovoltaic adhesive filmCellsAmong them, the photovoltaic encapsulation film plays a vital role in improving the quality of photovoltaic modules and maintaining the efficient operation and power stability of the cell
However, at present, the production technology of adhesive film on the market has not yet reached a mature level, and film manufacturers and module manufacturers are still in the production stageThere will be different difficultiesThis article will discuss this with you.
Problems that film manufacturers and module manufacturers need to solve
The following is a summaryThreeCase study of the problem and ideas for solving the problem.
Case 1
The POE membrane adopts the traditional process scheme
Ingredients: POE Liquid: (Silane Acrylate Auxiliary Crosslinker Crosslinker).
Problem:The scrap rate is high and the PID is average.
Traditional POE film soaking (silane, acrylate crosslinker, crosslinker) and pre-mixing will produce a long liquid adsorption time at this stage, which may take eight hours or even longer, affecting the production efficiency. Assuming that the precipitation is incomplete, it will lead to slippage of the discharge port.
When the module factory encapsulates the cast adhesive film, incomplete adsorption will cause the liquid to leak and migrate to the surface, resulting in sticky and thickening, and easy to block the vacuum port.
After the module is finalized, it is cured at a high temperature of 160 degrees, and the silane monomer cannot be fixed for a short time, which will affect the PID and deteriorate the aging resistance.
Solution ideas
The POE membrane adopts the grafted masterbatch scheme
Ingredients: POE silane graft masterbatch Silane (small amount) Acrylate (small amount) Acrylic graft masterbatch Crosslinker.
The total amount of liquid is reduced, the soaking time is shortened, and the squeezing slippage is improved.
After 80 degrees of extrusion casting molding, because the grafting is relatively stable, the silane is fixed on the POE, which is not easy to migrate, which means that the vacuum is blocked, slipping and displaced, and the scrapping phenomenon will also be improved.
Finally, in the high-temperature stage, because the grafted silane will share the action that needs to be completed for curing, the adhesive efficiency will be improved, and finally the PID aging resistance of the whole module will be improved and improved.
Case 2
EVA membranes are made using traditional processes
Problem:After high temperature and high humidity aging, the adhesion decreases significantly.
The traditional practice is EVA plus silane, and then add acrylate crosslinker, the traditional practice will have some problems, when doing PCT experiments, under high temperature and high humidity, the acrylate bond is easy to hydrolyze and break, resulting in a decrease in peeling force, which in turn affects aging and PID performance.
Solution ideas
EVA membranes are grafted with a masterbatch scheme
Ingredients: EVA silane graft masterbatch silane (small amount) acrylate (small amount) crosslinker.
We will choose some oligomers or other types of silane grafting EVA, which is not easy to plug the vacuum, and finally this component in the process of PCT testing, because the silane is relatively stable and fixed on the EVA after grafting, so the hydrolysis resistance will be greatly improved.
Case 3
EPE films use traditional methods
Problem:The degree of cross-linking of the e, P layer is difficult to match, and it is easy to blister.
When making three-layer co-extrusion, it is expected that the middle POE layer and the upper and lower EVA layers can achieve similar viscosity or gluing speed, and the traditional method is to add liquid acrylic co-crosslinker to the POE.
POE is non-polar, and the acrylate adsorption is not reliable, placed for a long time, the acrylate is easy to move outward, and is absorbed by the upper and lower layers of EVA, resulting in the degree of cross-linking deviation, wrinkling, and blistering.
Solution ideas
Acrylic graft masterbatch is used in the P layer instead of the direct addition of acrylate
Three-layer co-extrusion, acrylate graft masterbatch has a promoting effect on cross-linking, prevents migration, completes cross-linking, and improves the results.