Changzhou Comay Three Heating System Crosslinking Degree Tester

1Changzhou Comay Three Heating System Crosslinking Degree TesterPrinciple of action

EVA adhesive, due to heating, bonding and curing in the application process, part of EVA is cross-linked into gel. The solvent xylene is used to extract the uncrosslinked portion of the sample, allowing for the determination of crosslinking degree.

IIChangzhou Comay Three Heating System Crosslinking Degree TesterTechnical Specifications

Model: KM-EVA-JLD2000L

Specification: 850x1800x2350mm

Power supply: single-phase three wire AC 220 ± 10%, 50 ± 0.5Hz;

Installation power: approximately 4.5KW.

IIIChangzhou Comay Three Heating System Crosslinking Degree TesterSub item configuration

Ventilation cabinet:

Adopting a three-stage exhaust structure to effectively discharge harmful gases.

Streamlined handle, with a gap between the handle and the glass. Due to the rotating flow of air on the table, effective air intake is ensured from the surface.

Set up anti drop pins for windows. In case the steel wire rope falls off and the glass window accidentally falls, the anti drop pin will catch it and prevent injury to personnel.

The glass window adopts tempered glass, so even if the glass is accidentally damaged or exploded, there will be no injury accidents.

Ventilation holes are installed on the upper part of the fume hood to allow air to enter even if the glass window is closed, avoiding the generation of greater negative pressure.

instrument

Large mouth round bottom flask and stopper. Connect with a grinding mouth or cork stopper. It is advisable to use 500mL for the determination of 1-2 samples; It is advisable to use 1000mL for the determination of 2-3 samples; If several but not more than 6 are used, a 2000mL flask is more suitable.

Heating sleeve or constant temperature oil bath, requiring sufficient heat capacity to add boiling xylene with a boiling point of 135-144 ° C.

Reflux condenser tube, with a grinding mouth or connected to the flask with a cork. The grinding mouth size of the condenser tube is appropriate for the round bottom flask, and the length is appropriate.

Bracket and clamp, used to secure the flask and condenser tube.

Vacuum oven, equipped with a vacuum source capable of producing a vacuum degree of 0.87MPa.

120 mesh stainless steel mesh

A tray electronic analytical balance with an accuracy of 1/10000.

Drying agent:

Xylene A.R., analytical or chemically pure.

Antioxidant

4Changzhou Comay Three Heating System Crosslinking Degree TesterPrinciple Introduction:
The crosslinking degree tester mainly extracts the un bonded EVA from the sample using xylene, and the remaining undissolved substances are the already bonded EVA. Assuming the total amount of the sample is W1 and the weight of the undissolved substances is W2, the crosslinking degree of EVA is W2/W1 * 100%.

1. It has excellent flexibility, impact resistance, elasticity, optical transparency, low-temperature bending, adhesion, environmental stress cracking resistance, weather resistance, chemical resistance, and heat sealing.
2. The performance mainly depends on the molecular weight (expressed as melt index MI) and the content of vinyl acetate (expressed as VA). When MI is constant, the elasticity, flexibility, adhesion, solubility, and transparency of VA increase, while the content of VA decreases, approaching the performance of polyethylene. When the VA content is constant, the decrease in MI leads to a decrease in softening point, while the processability and surface gloss improve, but the strength decreases and the molecular weight increases, which can improve impact resistance and stress cracking resistance.

3. Different temperatures have a significant impact on the bonding strength of EVA, which directly affects the performance and service life of the components. In the molten state, EVA adheres to crystalline silicon solar cells, glass, and TPT through both physical and chemical bonding. Unmodified EVA is transparent, soft, has hot melt adhesion, low melting temperature, and good melt flowability. However, its heat resistance is poor, it is prone to elongation but has low elasticity, low cohesive strength but poor creep resistance, and it is prone to thermal expansion and contraction, leading to chip fragmentation and delamination of the adhesive. Therefore, by adopting chemical bonding to modify EVA, the method is to add organic peroxide crosslinking agent to EVA. When EVA is heated to a certain temperature, the crosslinking agent decomposes to produce free radicals, triggering the binding between EVA molecules and forming a three-dimensional network structure, resulting in the crosslinking and curing of the EVA adhesive layer. When the bonding degree reaches over 60%, it can withstand atmospheric changes and no longer undergo thermal expansion and contraction.

5、 Configuration List:

1. Large mouth round bottom flask and stopper. Connect with a grinding mouth or cork stopper. It is advisable to use 500mL for the determination of 1-2 samples; It is advisable to use 1000mL for the determination of 2-3 samples; If several but not more than 6 are used, a 2000mL flask is more suitable.
2. Heating sleeve or constant temperature oil bath. Require sufficient heat capacity to add boiling xylene (boiling point 135-144 ° C).
3. Reflux condenser tube. Connect the condenser tube with a grinding mouth or a cork to the flask. The grinding mouth size of the condenser tube should be the same as that of the round bottom flask, and the length should be appropriate.
4. Bracket and clip. Used for fixing flasks and condenser tubes.
5. Vacuum oven. Equipped with a vacuum source capable of generating a vacuum degree of 0.87MPa.
6. 120 mesh stainless steel mesh
7. A tray electronic analytical balance with an accuracy of 1/10000.
8. Drying machine

6、 Test project requirements:
1. Appearance inspection of crosslinking degree testing system: EVA surface has no creases, stains, flatness, translucency, stains, and clear embossing

2. Using a thickness gauge with an accuracy of 0.01mm, measure at least five points in the amplitude direction, take the average value, and ensure that the thickness meets the agreed thickness, with an allowable tolerance of ± 0.03mm

Measured with a steel ruler with an accuracy of 1mm, the amplitude conforms to the agreed thickness, and the allowable tolerance is ± 3.0mm

3. Transmittance test

a、 Take the adhesive film size of 50mmX50mm, use 50mmX50mm X1mm glass as the carrier, and laminate the glass/adhesive film/glass in three layers

b、 Place the above sample in a laminating machine, heat it to 100 ℃, vacuum it for 5 minutes, then apply pressure of 0.5Mpa, maintain it for 5 minutes, and then place it in a curing box. Perform adhesive bonding curing according to the required temperature and time of the product, and then take it out and cool it to room temperature

c、 Conduct testing according to GB2410 regulations

4. Crosslinking degree test

a、 Instrument devices and instruments

Capacity of 500ml~1000ml, 24 'ground mouth round bottom flask; Reflux condenser tube with 24 'grinding mouth; Electric heating sleeve or electric heating oil bath equipped with temperature controller; Vacuum oven; Use 0.125mm (120 mesh) stainless steel wire mesh, cut 80mm x 40mm, fold it in half into a 40mm square, fold both sides into 6mm and fix them to make a bag with an open top

b、 reagent

Xylene A, R-grade

c、 sample preparation

Take a piece of adhesive film, stack the TPU/adhesive film/glass, and cure and crosslink it according to the usual one-time curing process (or according to the manufacturer's process requirements). Cut the crosslinked adhesive film into small pieces for later use

d、 Inspection steps

Wash the stainless steel wire mesh bag, dry it, weigh it to W1 (accurate to 0.01g), take 0.5g ± 0.01g of the sample, place it in the stainless steel wire mesh bag, weigh it to W2 (accurate to 0.01g), seal the bag mouth to make a sample package, weigh it to W3 (accurate to 0.01g), suspend the sample package with a fine wire in a flask under a reflux condenser tube, add 1/2 xylene solvent to the flask, heat it to about 140 ℃, and when the solvent boils and refluxes for 5-6 hours, maintain a reflux speed of 20 drops/min~40 drops/min, cool and remove the sample package, suspend it to remove solvent droplets, and then place it in a vacuum oven with a temperature controlled at 140 ℃ and a vacuum degree of 0.08Mpa, dry for 3 hours, * remove the solvent and take out the sample package from the vacuum oven. After cooling in a dryer for 20 minutes, take out the sample and weigh it as W4 (accurate to 0.01g). The result is calculated as C=[1- (W3-W4)/(W2-W1)] x100. In the formula: C - degree of adhesion (%) W1- Empty bag weight (g) W2- bag weight with sample (g) W3- sample package weight (g) W4- sample package weight after solvent extraction and drying (g)
e、 Glass strength test
1. Take two pieces of adhesive film with a size of 300mmX20mm as samples, and stack them separately according to the TPT/adhesive film/adhesive film/glass
2. Cure according to the usual one-time curing process
3. Inspect according to GB/T2790 regulations
f、 UV aging resistance test
Place the adhesive film in a UV aging chamber and irradiate continuously for 100 hours. Compare visually
g、 Uniformity detection
Weigh 10 films of the same size and compare the weight of each film. The difference between the largest and smallest films should not exceed 1.5%.

5、 Material Introduction:
1. Melt index: affects the melting rate of EVA
2. Softening point: the temperature point at which EVA begins to soften
3. Transmittance: Different spectral distributions have different transmittance, mainly referring to the transmittance under the spectral distribution conditions of AM1.5
4. Density: density after bonding
5. Specific heat: The specific heat after bonding, reflecting the magnitude of the temperature increase when EVA absorbs the same amount of heat after bonding.
6. Thermal conductivity: The thermal conductivity after bonding, reflecting the thermal conductivity of EVA after bonding
7. Glass transition temperature: reflecting the low-temperature resistance of EVA
8. Tensile strength at break: The tensile strength at break of EVA after bonding reflects the mechanical strength at break of EVA after bonding
9. Fracture elongation rate: The fracture elongation rate of EVA after bonding reflects the elongation performance of EVA after bonding
10. Tension coefficient: The tension coefficient of EVA after bonding reflects the magnitude of the tension after bonding EVA
11. Water absorption: directly affects its sealing performance on battery cells
12. Adhesive bonding rate: The adhesive bonding degree of EVA directly affects its water resistance
13. Glass strength: reflects the bonding strength between EVA and glass
14. UV aging resistance: affecting the outdoor service life of components
15. Heat aging resistance: affecting the outdoor service life of components
16. Low temperature environment aging resistance: affecting the outdoor service life of components

VIChangzhou Comay Three Heating System Crosslinking Degree Testerafter-sales service

On site installation and debugging of equipment, and training of operating personnel for customers.

If the product cannot function properly due to manufacturing quality issues within twelve months from the date of shipment, provided that the user complies with the product installation and usage rules, our company will provide free repairs for the user.

For products outside the warranty period, our company provides long-term technical services.