Application of Powder Coatings in the Field of Photovoltaic Panels

"A new acrylic powder coating based on the GMA acrylic system and its application in photovoltaic panel assemblies

This article mainly discusses a novel acrylic powder coating based on GMA acrylic system and its application in photovoltaic panel assemblies

• This acrylic powder has a light transmittance of 94% and is as transparent as glass coatings online at coatingol.

  
  

• 20min@170℃ can be fully cured and formed

  
  

• It has excellent weather resistance and humidity and heat resistance.

  
  

• This new type of powder coating is a brand-new attempt in the powder coating industry, whether it is raw materials, technology, process, or application, and it is a major breakthrough in the research and development, manufacturing, performance and application of powder coatings

  
  

Lightweight requirements

In recent years, the photovoltaic industry has developed rapidly, and technological updates have gradually accelerated.

The weight of traditional glass photovoltaic modules is more than 10kg per square meter.

Therefore, it is necessary to seek a novel encapsulation material for photovoltaic modules to solve the problem of heavy weight of encapsulation materials in the existing encapsulation structures of photovoltaic modules

Schematic diagram of packaging material structure

It is a good choice to make the powder coating into a transparent, weather-resistant, water-resistant, chemical-resistant, soft and thin packaging material instead of traditional glass by hot pressing directly instead of spraying to form a film
.
After many demonstrations and preliminary theoretical research, we decided to use acrylic system to develop this product
.
Acrylic powder coatings have the advantages of high transparency, good weather resistance, good chemical resistance, good wettability, and high reactivity, which can meet the requirements of the solar industry
.
Since most of the acrylic resins for powder coatings on the market are aimed at the automotive wheel industry, their weather resistance, chemical resistance, and reactivity do not meet the requirements of the solar industry
.
Together with domestic professional acrylic resin suppliers, we have developed special acrylic resins for the solar industry
.

After unremitting efforts, acrylic products have been mass-produced stably by customers, and customers have reported stable performance after use, and various performance indicators can meet the packaging standards of the photovoltaic industry
.
Among them, the light transmittance reaches 94%, and it can be completely cured at 170 °C.
The color difference after 3000 hours of UVB irradiation is less than 1.
5, and the gloss retention rate is greater than 95%, reaching the outdoor weather resistance level of 20 years.
After 1000 hours of damp heat, the color difference is less than 1.
5, and the The light rate is greater than 90%, and the mechanical properties after the rapid freezing test and the cold-heat cycle test meet the requirements of the photovoltaic industry
.

Performance Testing

Acrylic resin for photovoltaic modules is GMA type acrylic resin.
This resin has the advantages of good transparency, high reactivity and low viscosity, which is very suitable for the application requirements of solar photovoltaic panels
.
In terms of transparency, the customer's use results show that the transparency of the modules laminated with acrylic powder is quite high, with a light transmittance of 94%, which is consistent with the light transmittance of conventional photovoltaic glass panels, and the photoelectric conversion efficiency is no different from conventional glass modules
.
Since there are other components in photovoltaic modules, these components are not resistant to high temperature.
When the lamination temperature is higher than 170 °C, these components become unstable and decompose, so the powder coating system for photovoltaic modules must be able to withstand 170 °C.
Curing and molding below degree
.
Acrylic powder for photovoltaic modules can be completely cured under the curing conditions of 170 °C for 20 minutes, and the gelation time at 170 °C is about 270 seconds, and the reaction speed is fast
.
At the same time, the powder must have good compatibility, binding force and wettability with other components, so that the components will not be separated during use
.
This acrylic powder for photovoltaic modules has good fluidity at 170 ℃, and the oblique flow is up to 230 mm, which can well infiltrate and coat the substrate
.
Acrylic powder for photovoltaic modules has relatively good mechanical properties, and has certain flexibility and toughness after curing, which enables the modules to be applied to the facades of different buildings and greatly expands the application scope of photovoltaic modules
.

Basic properties of acrylic powder for photovoltaic modules

Solar photovoltaic applications have very high weather resistance requirements for photovoltaic modules, because the modules need to be exposed to the sun all year round, especially in those areas with rich light energy, such as deserts and Gobi, where the sun exposure time is long and the intensity is high.
If there is no excellent weather resistance performance, components will lose transparency, lose gloss, turn yellow or even chalk in a short period of time
.
Acrylic powder for photovoltaic modules has excellent weather resistance.
After 1500 hours of UVB irradiation, the color difference is less than 0.
5, and the gloss retention rate is close to 100%, which is better than most of the acrylic powders on the market, including automotive acrylic powders
.
After 3000 hours of UVB irradiation, the color difference is less than 1.
5, and the gloss retention is still close to 100%, which has reached the weather resistance of fluorocarbon powder, which is higher than all acrylic products on the market
.

Weather resistance of acrylic powder for photovoltaic modules - UVB test

The xenon lamp test also shows that after 1500 hours of xenon lamp irradiation, the color difference is less than 0.
5, the gloss retention rate is close to 100%, and the performance is excellent
.
After 3000 hours of xenon lamp, the color difference is only about 1, and the gloss retention rate is still higher than 90%, which is also close to the performance of fluorocarbon powder
.
In summary, this product can meet the 20-year outdoor weather resistance requirements for solar photovoltaic applications
.

Weather resistance of acrylic powder for photovoltaic modules - xenon lamp test

Solar photovoltaic panels need to be placed outdoors in the wind and rain all year round, especially in summer, when the humidity is high and the temperature is high, so the photovoltaic panel components have very high requirements for high temperature and humidity resistance
.
The usual powder coating systems, such as polyester, are not very good in heat and humidity resistance, especially the problem of discoloration.
Usually, the yellowing of the coating film becomes serious after the high temperature and high humidity test
.
The acrylic system itself has good moisture and heat resistance, and this acrylic resin for photovoltaic modules is specially designed to avoid factors that may cause moisture and heat yellowing in the monomer selection and synthesis process
.
On the other hand, the introduction of raw materials that are prone to yellowing is also avoided in the formulation design of powder coatings, which makes this powder quite excellent in moisture and heat resistance
.
After 1000 hours of storage at 85 ℃ and 85% relative humidity, the color difference is only 1.
3, and the gloss retention rate is about 95%, which is far superior to other systems such as polyester, and also superior to most acrylic system products
.

Moisture and heat resistance of acrylic powder for photovoltaic modules

Epilogue

Powder coatings based on GMA acrylic systems are suitable in every respect for photovoltaic panel assembly applications
.
It can be completely cured and formed at 170 ℃, which can meet the requirements that photovoltaic modules cannot be processed at high temperature
.
The transparency is good, and the light transmittance reaches 94%, which is consistent with glass
.
Acrylic powder for photovoltaic modules has good weather resistance and moisture and heat resistance
.
After 3000 hours of UVB irradiation, the color difference is less than 1.
5, and the gloss retention rate is greater than 95%.
harsh requirements
.
Traditional powder coatings are used in the solar photovoltaic industry, no matter from raw materials, technology, process, or application, for powder coatings, it is a brand new attempt, which is the research and development, manufacturing, performance and application of powder coatings.
major breakthrough
.
This cross-border expansion has injected new vitality into the traditional industry of powder coatings, and has also given a lot of good inspiration.
Maybe powder coatings can be used in fields other than coatings.
We will rethink the application scope and application fields of coatings, actively explore and strive to develop
.