Methodology for testing the electrical parameters of low-voltage foil
Test procedure:
- 1) Forming etched foil samples
- 2) Measuring forming stress
- 3) Measuring capacity
- 4) Control of oxide layer stability
1. FORMING ETCHED FOIL SAMPLES
Test equipment
-
DC power supply
- ripple ≤ 1%;
- voltage stability ± 3% - DC Voltmeter - Accuracy ± 0.5%
- DC Ammeter - Accuracy ±1.0%
- Stainless steel bath, temperature control
Sampling scheme
Sample size
* The size is determined by the tool.
L is the specimen output length, determined by the equipment used.
The specimen edges must be trimmed without breaks or burrs.
Forming electrolyte
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70 °C: 5.0 - 8.5 Ohm‧cm
- pH, at + 50 °C - 5.2 - 7.2
Forming parameters
- Forming current - 0.3 A/sample
- Electrolyte temperature: 70±2°C
Molding
The test sample should be immersed in the electrolyte so that the top of the measured sample is 10–15 mm below the surface of the solution.
Molding scheme
Forming cycle (F1; F2; F3; F4) – 6 minutes;
Pause between molding cycles (P1; P2) – 1 minute;
Annealing from plus 510 to plus 530 °C (O) – 1 minute.
Flushing
Samples are washed in deionized water at room temperature.
Drying
Drying of samples is carried out at a temperature of <100 °C.
2. Measuring forming stress
Test equipment
-
DC power supply
- ripple ≤ 1%;
- voltage stability ± 3% - DC Voltmeter - Accuracy ± 0.5%
- DC Ammeter - Accuracy ±1.0%
- Stainless steel bath, temperature control
Electrolyte for voltage measurement
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70 °C: 5.0 - 8.5 Ohm‧cm
- pH, at + 50 °C - 5.2 - 7.2
Electrolyte parameters
- Test current - 2.0 ± 0.2 mA/sample
- Electrolyte temperature: 70 ± 2 °C
Voltage measurement
Place the test sample into the electrolyte so that the top of the test sample is below the surface of the solution.
Molding scheme
Note the time to reach 0.9UF and the maximum voltage gained (UM) 180 seconds after TD 0.9UF.
3. Measuring capacity
Test equipment
- Faradmeter - accuracy ± 1%
- Measuring frequency: 100 Hz ± 5% (50 Hz allowed)
- Cell made of inert material
- The counter electrode is etched thermally oxidized foil with a capacitance of ≥ 40,000 μF/dm²
Electrolyte for voltage measurement
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70 °C: 5.0 - 8.5 Ohm‧cm
- Electrolyte temperature: 20 - 25 °C
Measuring capacitance
- 1) Place the molded foil sample in a measuring cell with electrolyte so that only the working part of the sample (without the terminal) is immersed in the electrolyte.
- 2) Keep the sample for 1 minute, then measure the capacity.
- 3) Multiply the capacitance value obtained from the device by 10 to obtain the specific capacitance value in μF/dm².
4. Control of oxide layer stability
Test sample
A sample of formed foil that has passed the tests 2 and 3.
Hydration
- Time: 60 ± 1 minute
- Temperature: ≥ 95 °C
- Number of samples: ≤ 6
- Replace deionized water: after each hydration process.
Electrolyte for voltage measurement
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70 ºС — 5.0 - 8.5 Ohm‧cm
Electrolyte parameters
- Test current - 2.0 ± 0.2 mA/sample
- Electrolyte temperature: 85 ± 2°C
Voltage measurement
- 1) Place the test specimen into the electrolyte so that the upper edge of the protruding area (to be measured) is level with the surface.
- 2) Measure the time to reach 0.9UF.
METHOD FOR TESTING ELECTRICAL PARAMETERS OF HIGH-VOLTAGE FOIL
Test procedure:
- 1) Forming etched foil samples
- 2) Measuring forming stress
- 3) Measuring capacity
- 4) Control of oxide layer stability
1. FORMING ETCHED FOIL SAMPLES
Test equipment
-
DC power supply
- ripple ≤ 1%;
- voltage stability ± 3% - DC Voltmeter - Accuracy ± 0.5%
- DC Ammeter - Accuracy ±1.0%
- Stainless steel bath, temperature control
Sampling scheme
Sample size
* The size is determined by the tool.
L is the specimen output length, determined by the equipment used.
The specimen edges must be trimmed without breaks or burrs.
1.1. FORMING SAMPLES OF ETCHED FOIL FOR SUBSEQUENT FORMING IN ELECTROLYTE No. 4
Forming electrolyte
- Citric acid - 2 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 30ºС — 1000 ± 50 Ohm‧cm
Forming parameters
- Forming current - 0.5 A/sample
- Electrolyte temperature: 90±2°C
Molding
The test sample should be immersed in the electrolyte so that the top of the measured sample is 10–15 mm below the surface of the solution.
Molding scheme
Forming cycle (F1; F2; F3; F4) — 10 minutes;
Pause between forming cycles (P1; P2) — 2 minutes;
Annealing at 250°C (O) — 2 minutes.
Flushing
Samples are washed in deionized water at room temperature.
Drying
Drying of samples is carried out at a temperature of <100 °C.
1.2. FORMING SAMPLES OF ETCHED FOIL FOR SUBSEQUENT FORMING IN ELECTROLYTE No. 1
Hydration
- Time: 15 ± 1 minute
- Temperature: ≥ 95 °C
- Number of samples: ≤ 6
- Replace deionized water: after each hydration process
Forming electrolyte
Forming stage 1:
- Boric acid - 100 g
- Deionized water (≤ 0.1 μS/cm) - 900 ml
Forming stage 2:
- Boric acid - 100 g
- Ammonium pentaborate, tetrahydrate - 0.7 g
- Deionized water (≤ 0.1 μS/cm) - 900 ml
Forming parameters
- Forming current - 0.5 A/sample
- Electrolyte temperature: 90±2°C
Molding
The test sample should be immersed in the electrolyte so that the top of the measured sample is 10–15 mm below the surface of the solution.
Molding scheme
Forming cycle F1 – 10 minutes;
Rinse 1 (P1) – 1 minute;
Annealing from plus 510 to plus 530 °C (O) – 2 minutes;
Forming cycle (F2) – until the forming current drops to 0.03 A;
Rinse 2 (P2) – 1 minute.
Flushing
Samples are washed in deionized water at room temperature.
Drying
Drying of samples is carried out at a temperature of <100 °C.
2. Measuring forming stress
Test equipment
-
DC power supply
- ripple ≤ 1%;
- voltage stability ± 3% - DC Voltmeter - Accuracy ± 0.5%
- DC Ammeter - Accuracy ±1.0%
- Stainless steel bath, temperature control
Electrolyte for voltage measurement
Forming voltage from 200V to 620V:
- Boric acid - 70 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 7,500 ± 300 Ohm‧cm
Forming voltage from 621V to 700V:
- Boric acid - 40 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 19,000 ± 1,000 Ohm‧cm
Forming voltage from 701V to 800V:
- Boric acid - 30 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 28,900 ± 1,500 Ohm‧cm
Forming voltage above 800 V:
- Boric acid - 20 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 46,500 ± 2,500 Ohm‧cm
Electrolyte parameters
- Test current - 4.0 ± 0.2 mA/sample
- Electrolyte temperature: 90 ± 2 °C
Voltage measurement
Place the test sample into the electrolyte so that the top of the measured sample is 4–8 mm below the surface of the solution.
Voltage set circuit
Note the time to reach 0.95UF and the maximum voltage gained (UM) 60 seconds after TD 0.95UF.
3. Measuring capacity
Test equipment
- Faradmeter - accuracy ± 1%
- Measuring frequency: 100 Hz ± 5% (50 Hz allowed)
- Cell made of inert material
- The counter electrode is etched thermally oxidized foil with a capacitance of ≥ 40,000 μF/dm²
Electrolyte for measuring capacity
- Ammonium adipate - 100 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 20 ºС — 16–20 Ohm‧cm
Electrolyte parameters
- Electrolyte temperature: 20 - 25 °C
Measuring capacitance
- 1) Place the molded foil sample in a measuring cell with electrolyte so that only the working part of the sample (without the terminal) is immersed in the electrolyte.
- 2) Keep the sample for 1 minute, then measure the capacity.
- 3) Multiply the capacitance value obtained from the device by 10 to obtain the specific capacitance value in μF/dm2.
4. Control of oxide layer stability
Test sample
Sample of molded foil that passed the tests 2 and 3
Hydration
- Time: 60 ± 1 minute
- Temperature: ≥ 95 °C
- Number of samples: ≤ 6
- Replace deionized water: after each hydration process
Electrolyte for voltage measurement
Forming voltage from 200V to 620V:
- Boric acid - 70 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 7,500 ± 300 Ohm‧cm
Forming voltage from 621V to 700V:
- Boric acid - 40 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 19,000 ± 1,000 Ohm‧cm
Forming voltage from 701V to 800V:
- Boric acid - 30 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 28,900 ± 1,500 Ohm‧cm
Forming voltage above 800 V:
- Boric acid - 20 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte conductivity at + 70 °C: 46,500 ± 2,500 Ohm‧cm
Electrolyte parameters
- Test current - 4.0 ± 0.2 mA/sample
- Electrolyte temperature: 90 ± 2 °C
Voltage measurement
- 1) Place the test specimen into the electrolyte so that the upper edge of the protruding area (to be measured) is level with the surface.
- 2) Measure the time to reach 0.95 UФ and the maximum voltage gained (UМ) 60 seconds after TД 0.95UФ.
METHOD FOR TESTING THE ELECTRICAL PARAMETERS OF CATHODE FOIL
Test procedure:
- 1) Measuring capacity
- 2) Quality control of stabilization
1. MEASURING CAPACITY
Test equipment
- Faradmeter - accuracy ± 1%
- Measuring frequency: 100 Hz ± 5% (50 Hz allowed)
- Cell made of inert material
Sampling scheme
Sample size
* The size is determined by the tool.
L is the specimen output length, determined by the equipment used.
The specimen edges must be trimmed without breaks or burrs.
Electrolyte for measuring capacity
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70°C: 5.0 … 8.5 Ohm×cm
Electrolyte parameters
- Electrolyte temperature: 20 - 25 °C
Measuring capacitance
- 1) Place two controlled samples (located one above the other, according to the sampling scheme) in a cell, as shown in the figure.
- 2) Keep the sample for 1 minute, then measure with a container.
- 3) Multiply the capacitance value obtained from the device by 20 to obtain the specific capacitance value in μF/dm2.
2. STABILIZATION QUALITY CONTROL
Test sample
Samples of cathode foil that passed the test according to test 1
Hydration
- Time: 30 ± 1 minute
- Temperature: ≥ 95°C
- Number of samples: ≤ 6
- Replace deionized water: after each hydration process
Electrolyte for measuring capacity
- Ammonium adipate - 150 g
- Deionized water (≤ 0.1 μS/cm) - 1000 ml
- Electrolyte resistance at + 70 °C: 5.0 - 8.5 Ohm‧cm
Electrolyte parameters
- Electrolyte temperature is 20 - 25 °C.
Measuring capacitance
- Measure the specific capacity according to point 1
METHOD FOR DETERMINING RESIDUAL CHLORINE ON FOIL
Equipment and devices
- Heating plate
- Bath for cooling
- Glasses, flasks, burettes, pipettes as needed
Reagents
- Nitric acid 65%, chemically pure
- Silver nitrate, analytical grade
- Deionized water (≤ 0.1 μS/cm)
Test sample
- Estimated area 0.1 m² (taking into account the surface of both sides), cut into strips 20–25 mm wide.
Test method
- 1) Roll the strips into loose rolls, place them in a flask and pour 100 ml of 5% nitric acid solution into it.
- 2) Heat the flask in a water bath to a temperature of 40-45 °C, hold for 10 minutes, stirring the rolls with a glass rod.
- 3) Remove the rolls from the solution, allowing the solution to drain, and cool the solution.
- 4) Filter the solution until it is completely clear.
- 5) Add 10 drops of 5% silver nitrate solution to the test solution and the standard scale solutions.
- 6) After 10 minutes, compare the opalescence of the test solution with the standard scale solutions.
BENDING TEST METHOD
Equipment
- Setting the foil fold count
Sampling scheme
Sample size
* The size is determined by the tool.
L is the specimen output length, determined by the equipment used.
The specimen edges must be trimmed without breaks or burrs.
Test conditions
| Тип фольги | Радиус изгиба, мм |
|---|---|
| Травленая анодная высоковольтная | 0,5 ± 0,05 |
| Формованная анодная низковольтная | 0,5 ± 0,05 |
| Формованная анодная высоковольтная | 0,5 ± 0,05 |
| 3,5 ± 0,35 | |
| Катодная травленая | 1,0 ± 0,10 |
| Катодная отожжённая |
Test scheme
– One bend is defined as a 90° turn
– The test is carried out until the foil breaks
TEAR RESISTANCE TEST METHOD
Equipment
- Tensile testing machine, measurement range: forces - from 0 to 500 N, measurement error no more than 1%, moving speed of the movable clamp 50 - 60 mm/min.
Sampling
Sample Dimensions
* The size is determined by the tool.
L is the specimen output length, determined by the equipment used.
The specimen edges must be trimmed without breaks or burrs.
Experience
The ultimate tensile strength is determined by applying a tensile force (tensile stress) to the test specimen until the foil specimen breaks. If the foil specimen breaks where it is clamped, the test is not counted and a different specimen is tested.