Photovoltaic Glass Reflective White Enamel

• Warranty: <5 Years
• Material: Glass Enamel
• Transport Package: 25kg/Drum
• Model NO.: PV-22-001
• Specification: 20kg/drum
• Trademark: Belleview
• Origin: China
• HS Code: 320710000

Product Description

Photovoltaic glass high reflection white enamel
BJ-HP1-8W is a lead-free water-based environmentally friendly highly reflective white coated enamel. specially developed for use on the back panel glass of photovoltaic double glass modules.
The product has passed the performance test, the certification issued by the National Photovoltaic Quality Inspection Center. The product has excellent high reflectivity, which can effectively improve the power generation efficiency of photovoltaic modules. The product composition does not contain heavy metal lead, and the use of water-based enamel medium oil meets various environmental protection requirements.

1. Use of highly reflective white enamel

The highly reflective white enamel is silk screen printed on the photovoltaic backplane glass, and then the organic solvent in the enamel ( medium oil) is volatilized by drying and curing at 180 ~ 220 ° C, then tempered by the tempering furnace at 680 ~ 720 ° C, holoding time at  80 ~ 160s, so finaly the enamel coating is firmly attached to the glass surface. Figure 1 shows the photovoltaic backplane glass, and the white grid line is a highly reflective white enamel printed by silk screen.


Figure 1 the photovoltaic backplane glass
Figure 2 shows a single photovoltaic cell module. Its dark part is a battery sheet, and the white grid lines are highly reflective white enamel coating.


Figure 2 Single photovoltaic cell module
 Figure 3 shows a solar power base station. It is made up of multiple battery modules spliced together.

Figure 3 Solar power base station
The principle of high reflection white enamel to improve the power generation efficiency of photovoltaic modules
Crystalline silicon solar cell modules are composed of glass, EVA or PVB, cells, back panels, frames and other materials. They are packaged into a "sandwich" structure in the order of glass-EVA-cell-EVA-back panel glass, the structural diagram as shown in Figure 4.


Figure 4  Diagram of the battery module structure

Fig. 5 Schematic diagram of double-glass optics
Optical diagram of the double glass component as shown in Figure 5. Most of the incident light shines through the front and back panel glass onto the cells. A small part is projected from the gap between the cells onto the back panel glass, and if the back panel glass is not coated in anything, the light directly penetrates the back panel glass, causing a loss of light. Coat the back panel glass with a layer of highly reflective white enamel.
The enamel coating will re-reflect the light through the gap to the cell, so make full use of the light energy, and the power generation efficiency of the battery module can be increased by 3% to 6%.

1. Composition and characteristics of BJ-HP1-8W high reflection enamel

The high reflection enamel is composed of three parts: glass flux, functional whitening powder, and water-soluble enamel medium oil

1. Glass flux is an important part of the enamel, mainly composed of a variety of inorganic non-metallic minerals and chemical raw materials, etc.,

According to a certain proportion of full mixing, through the converter high temperature melting, and then through water quenching, and finally grind into a fine powder. The main role of the glass flux is to form a coating through the tempering process. The functional whitening powder adheres to the glass surface. The composition of the glass flux acts as  a very important role on the gloss, reflectivity, corrosion resistance. The flux melting temperature will affect enamel adhesion with the glass . And its expansion coefficient will affect the impact resistance of the tempered back panel glass. Our company has carefully blended the composition of the flux, so that the enamel has high reflectivity, the best roasting temperature, excellent corrosion resistance and a suitable coefficient of expansion.

1. Functional whitening powders usually use titanium dioxide as the main raw material. In the case of a harsh outdoor environment, solar photovoltaic modules need to ensure a service life of 25 years, so our company only use the best titanium dioxide as our raw materails
2. Water-soluble medium oil is composed of polymer resin and solvent, and the additives include dispersants, defoamers, leveling agents, thickeners and curing agents. Our company uses water-soluble environmentally friendly resins, and makes the enamel have good printing performance and good adhesion.

TEST REPORT

ITEM	High diffuse reflection photovoltaic glass enamel
CODE	BJ-HP1-8W
TEST DATE	2022/4/4

TEST ON THE BASIS OF

GB/T 9286-1998 CROSS KNIFE TEST (2) GB 15763.2-2005 TOUGHENED GLASS TEST (3) GB-T2790-1995 180 PEEL STRENGTH OF ADHESION (4) JC⁄T 2170-2013 ANTIREFLECTION FILM GLASS FOR SOLAR PHOTOVOLTAIC MODULES

 

CODE

ITEM

UNIT

PARAMETERS

BJ-HP1-8W

1	Solid contain	%	78±2	78.02
2	Particle size	um	<10	<10
3	Wet film thickness	um	20±8	22~26
4	Adhesion	/	0 grade cross knife test	0 grade
5	Reflection rate	%	450nm,550mm,650nm≥79% (white grid)	81.15
6	Gloss	/	2.7±0.5 Glossmeter	3.1
7	Optical density	/	1.00±0.2 Optical densitometer	0.954
8	Peel off EVA film strength test	N	≥70N Tensile testing machine	77.184
9	Potential Induced Degradation test	/	-1500V,85ºC,85%RH,96h No discoloration in appearance	No discoloration in appearance
10	Pressure Cook Test aging test		PCT aging test chamber 121ºC,100%RH,96h △R≤1% adhesion level peeling force ≥40N	Grade 0 △R=0.8% adhesion Peel strength 70.092
11	Intensity test	MPa	>100( glaze up )	121.3
12	Ball drop test	%	227g steel ball height 70cm , 10 glass pass rate>70%	95cm heigh pass rate >90%

Figure 6 : Peeling off EVA film strength test

Figure7 Potential Induced Degradation test 96H

Figure 8 Ball drop test of 227g ball height 95cm