Multilayer Polyester Sealing Sheet for Solar Cell Back Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sealing sheets for solar cell back surfaces require multiple films for durability, which increases costs and complexity, while single-film solutions often compromise on weather resistance and durability.
Innovation Solution
A sealing sheet comprising a single polyester film with a multilayer structure, specifically designed with layers A, B, and C, incorporating inorganic fine particles like titanium dioxide for high whiteness, light reflectivity, and enhanced durability, along with a coating layer for improved adhesiveness and hydrolysis resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a white film is used to reflect sunlight and increase power generation efficiency, then light reflectivity is improved, but durability under high temperature and high humidity deteriorates due to resin deterioration from multiple heat histories
Solution Approach 1:
The patent uses a composite material consisting of a polyester resin matrix combined with specific inorganic fine particles (silica, alumina, or titania) to create a sealing sheet that maintains both high light reflectivity and excellent durability. The inorganic particles are surface-treated with silane coupling agents to ensure strong bonding with the polyester resin, preventing particle aggregation and maintaining structural integrity under thermal and humid conditions while preserving the white reflective properties.
Solution Approach 2:
The patent changes the chemical and physical parameters of the resin-particle system by controlling the acid value of the polyester resin (0.1-10 mg KOH/g) and the surface treatment of inorganic particles with silane coupling agents. These parameter changes enhance the chemical bonding between resin and particles, improving heat resistance and hydrolysis resistance while maintaining the optical properties needed for light reflection.
2Reliability
If multiple films are laminated to achieve excellent weather resistance and durability, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges multiple functional requirements (weather resistance, durability, light reflectivity, and adhesion) into a single integrated polyester film containing surface-treated inorganic fine particles. This eliminates the need for laminating multiple separate films, simplifying the structure to a single-layer sealing sheet that provides all necessary protections while reducing manufacturing complexity and cost.
Solution Approach 2:
The single polyester film with inorganic particles performs multiple functions simultaneously: it provides UV resistance, mechanical strength, hydrolysis resistance, and high light reflectivity. The inorganic particles contribute to both structural durability and optical properties, making the sealing sheet a multi-functional material that replaces what would traditionally require several specialized films.
3Device complexity
If a single film is used to reduce cost, then device complexity is reduced, but weather resistance and durability are insufficient
Solution Approach 1:
The patent creates a composite polyester film incorporating surface-treated inorganic fine particles (silica, alumina, or titania) that provide enhanced UV resistance, mechanical strength, and hydrolysis resistance. The silane coupling agent treatment on particle surfaces ensures strong chemical bonding with the polyester matrix, preventing degradation under weather exposure while maintaining the single-film simple structure for cost effectiveness.
Solution Approach 2:
The patent optimizes critical parameters including the acid value of the polyester resin (0.1-10 mg KOH/g), the surface treatment of inorganic particles with silane coupling agents, and the particle content (1-50 wt%). These parameter changes enhance the chemical and thermal stability of the single film, providing weather resistance and durability comparable to or exceeding multi-film laminates while maintaining structural simplicity.
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 cost-effective, lightweight, and durable sealing sheet with high power generation efficiency and environmental durability, maintaining performance under various environmental conditions.
Implementation Method 1
a sealing sheet for a back surface of a solar cell which seals the back surface of a solar cell module and has high whiteness and good light reflectivity
Implementation Method 2
the resin is likely to deteriorate, and when the obtained film is used for the sealing sheet for a back surface of a solar cell, there has been a problem that the film is poor in durability under high temperature and high humidity
Data Source
AI summary
The present invention is a sealing sheet for a back surface of a solar cell comprising only one polyester film, wherein the polyester film is composed of at least the layer A and the layer B, or the layer A, the layer B and the layer C described below, wherein the polyester film has a given whiteness and a given average reflectance of the polyester film, a given acid value of the polyester, a given thickness of the whole polyester film, a given thickness of the A layer and the B layer, and a given content of the inorganic fine particles in the whole polyester film.Layer A: a polyester resin layer in which the content of the inorganic fine particles is 10 to 35% by massLayer B: a polyester resin layer in which the content of the inorganic fine particles is 0 to 8% by mass, which is the smallest among the contents of the inorganic fine particles in the layer A, the layer B and the layer CLayer C: a polyester resin layer in which the content of the inorganic fine particles is 0.4 to 10% by mass.