Multilayer Solar Module Sealing Sheet Without Crosslinking Bottlenecks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sealing material sheets for solar-cell modules, particularly double-sided glass protecting substrate type modules, face challenges in achieving high tensile shear adhesion force at normal temperature while maintaining heat resistance and molding characteristics without crosslinking processing, which affects productivity and durability.
Innovation Solution
A multi-layer sealing material sheet with a core layer and skin layers made from silane-modified polyethylene-based resin, where the core layer has a density of 0.880 g/cm3 to 0.930 g/cm3 and a melting point of 70° C. or higher, and the skin layer has a density of 0.880 g/cm3 to 0.900 g/cm3 and a melting point of 90° C. or lower, with a specific molecular weight range for the silane-modified resin, ensuring high tensile shear adhesion force and improved molding characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If crosslinking treatment is performed to improve heat resistance, then heat resistance is reliably improved, but molding characteristics deteriorate and followability to surface irregularities cannot be maintained
Solution Approach 1:
The sealing material sheet is divided into a core layer and skin layers with different functions. The core layer provides heat resistance through crosslinking, while the skin layers maintain molding characteristics and followability without crosslinking, thus resolving the contradiction between heat resistance and molding characteristics
Solution Approach 2:
Different regions of the sealing material sheet have different properties: the core layer is crosslinked for heat resistance, while the skin layers remain non-crosslinked for good molding characteristics and followability to surface irregularities
2Temperature
If crosslinking treatment is performed to improve heat resistance, then heat resistance is improved, but productivity decreases due to additional processing steps and film formation ability loss
Solution Approach 1:
The sealing material sheet is divided into a core layer and skin layers with different functions. The core layer provides heat resistance through crosslinking, while the skin layers maintain molding characteristics and followability without crosslinking, thus resolving the contradiction between heat resistance and molding characteristics
Solution Approach 2:
The crosslinking treatment is performed preliminarily on the core layer before final assembly, allowing the skin layers to maintain their molding characteristics. This preliminary crosslinking of only the necessary portion reduces the impact on overall productivity while achieving the required heat resistance
3Ease of operation
If density of polyethylene-based resin is decreased to improve transparency and flexibility, then transparency and flexibility are improved, but heat resistance becomes insufficient
Solution Approach 1:
The density of the polyethylene-based resin is optimized to balance transparency, flexibility, and heat resistance. By controlling the density parameter within a specific range, the sealing material achieves adequate flexibility for molding while maintaining sufficient heat resistance for solar cell module application
Solution Approach 2:
The sealing material uses a composite structure with a core layer and skin layers made of polyethylene-based resin with optimized density. This composite structure allows the material to exhibit both flexibility from the optimized density and heat resistance from the crosslinked core layer
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a sealing material sheet with high productivity, high tensile shear adhesion force at normal temperature, and balanced heat resistance and molding characteristics, effectively addressing the limitations of existing materials by eliminating the need for crosslinking processing.
Implementation Method 1
the heat resistance is imparted by a crosslinking agent. In this case, the heat resistance is reliably improved. However, when a crosslinking treatment is performed to an extent that is sufficient and necessary for providing sufficient heat resistance
Implementation Method 2
a problem arises in that followability (hereinafter, referred to as 'molding characteristics') to irregularities on a surface of a facing member cannot be maintained
Data Source
AI summary
To provide a sealing material sheet for a solar-cell module that has high productivity without performing crosslinking processing, and has a high tensile shear adhesion force at normal temperature at a high level in addition to heat resistance and molding characteristics. A sealing material sheet is a multi-layer sheet using a polyethylene-based resin as a base resin, a core layer has a density of 0.880 g/cm3 to 0.895 g/cm3 and a melting point of 70° C. or higher, a skin layer has a density of 0.880 g/cm3 to 0.910 g/cm3 and a melting point of 90° C. or lower and contains a silane-modified polyethylene-based resin, a weight average molecular weight of the silane-modified polyethylene-based resin contained in the skin layer 11 in terms of polystyrene is 70000 to 120000, and a polymerized silane amount of the skin layer in the whole resin component is 300 ppm to 2000 ppm.