QC/T 950-2019Technical requirements and test methods for automobile seat heating pads (English PDF)

3.1 Seat heating

A car electric heating product assembly, which is installed in the interior of the car seat, to make the seat surface generate a certain temperature rise, thereby causing the seat user (occupant) to have a comfortable temperature feeling.

3.2 Heating unit

A sub-assembly of the heating component of the seat heating cushion, which is mainly composed of electric heating materials and base materials.

3.3 Harness

A sub-assembly, which is composed of wires, connectors, terminals, covering materials, etc.

3.4 Seat cushion

The component that supports the occupant's buttocks.

3.5 Seat back

The component that supports the back of the occupant.

3.6 Temperature control unit (TCU)

An electronic control device, which is used to control the working state of the seat heating cushion, under the guidance of the control mode of a bus or physical switch.

4.2 Performance requirements

4.2.1 Flame retardancy

The burning rate shall be less than or equal to 100 mm/min, wherein the passenger car's burning rate shall be less than or equal to 70 mm/min.

4.2.2 Insulation resistance

The insulation resistance shall be greater than or equal to 5.0 Mohm.

4.2.3 Low temperature storage performance

After testing according to 5.5, the product performance shall meet the requirements of 4.1.2 and 4.1.3.

4.2.4 High temperature storage performance

After testing according to 5.6, the product performance shall meet the requirements of 4.1.2 and 4.1.3.

4.2.5 Constant damp heat storage performance

After testing according to 5.7, the product performance shall meet the requirements of 4.1.2 and 4.1.3.

4.2.6 Thermal shock performance

After testing according to 5.8, the product performance shall meet the requirements of 4.1.2 and 4.1.3.

4.2.7 Heating rate performance

When the initial ambient temperature is 0 °C, turn on the heating mode to the highest gear. 5 minutes after the heating starts, the seat surface's temperature shall not be lower than 30 °C.

4.2.8 Saturation temperature performance

When the initial ambient temperature is 0 °C, turn on the heating mode to the highest gear. The temperature of the seat surface shall reach the saturation temperature, within 15 minutes. When the temperature is controlled by the automatic thermostat, the steady-state temperature of the seat surface, at each heating mode, shall be within the range of the set temperature ± 5 °C. When the temperature is controlled by the temperature control unit, the steady-state temperature of the seat surface, at each heating mode, shall be within the range of the set temperature ± 2 °C.

4.2.9 Thermal runaway performance

Short-circuit the temperature control unit or automatic thermostat. Let it work continuously for 2 hours at the rated voltage. The temperature, at any point on the seat surface, shall not exceed 85 °C. After the test, the seat assembly shall be free from ablation, burns, or other thermal damage. The seat heating cushion and surrounding components shall not fail.

4.2.10 Overvoltage performance

After testing according to 5.11, the seat assembly shall show no functional damage; the seat heating cushion and its surrounding components shall not be damaged. After returning to normal working conditions, the seat heating cushion shall function normally.

4.2.11 Thermal uniformity performance

When the heating temperature at each gear reaches a steady state, the maximum temperature difference, BETWEEN each temperature measurement point on the seat surface AND the set temperature value, shall not be greater than 5 °C.

4.2.14 Simulated knee pressure performance

After 5000 tests at each test point in 5.15, the seat heating cushion shall be free from disconnection, short circuit, abnormal heating, leakage, falling off, damage to the covering layer, or various other failures. The product performance shall meet the requirements of 4.1.2.

4.2.15 Simulated road bumps and creep performance

After the seat cushion is subject to 100000 tests AND the seat back is subject to 50000 tests, according to 5.16, the seat heating cushion shall be free from disconnection, short circuit, abnormal heating, leakage, shedding, damage to the covering layer, or various other failures. The product performance shall comply with the requirements of 4.1.2.

4.2.16 Water and liquid resistance

After the test according to 5.17, the product performance shall meet the requirements of 4.1.2.

4.2.17 Adhesion performance

After the test according to 5.18, the foam body shall be peeled off, along with the fixing part of the seat heating cushion (only for sticking fixed seat heating cushion).

4.2.18 Flexural resistance

After the test according to 5.19, the resistance value of the seat heating cushion shall not change more than ±10%. The image detection is carried out by a thermal imager, there shall be no hot spots in the test area.

5.1 Test conditions

5.1.1 The test shall be carried out in an indoor environment; room temperature: 20 °C ± 5 °C.

5.1.2 Test voltage: 13.5V for 12V voltage system; 28V for 24V voltage system.

5.1.3 The requirements for instruments and meters are as follows:

a) For the electrical measuring instrument used in the test, it shall have a standard level of not less than level 0.5;

b) For the temperature measuring instrument used in the test, it has a resolution not greater than 1 °C;

c) For the tensile measuring instrument used in the test, the error shall not be higher than ± 1%.

5.2 Routine inspection

5.2.1 Visual inspection: the appearance of the seat heating cushion is evaluated visually.

5.2.2 Basic parameter test: measure the resistance value of the seat heating cushion by a resistance tester.

5.3 Flame retardant performance test

The test method is carried out in accordance with the provisions of GB 8410.

5.4 Insulation resistance test

Connect the ground electrode (E) of the megohmmeter to the iron plate. Connect the circuit electrode (L) to the terminal of the seat heating cushion's harness connector. Apply a DC 500 V voltage, BETWEEN the terminal of the seat heating cushion's harness connector AND the iron plate. Measure and record the value of the insulation resistance.

5.5 Low temperature storage performance test

Continuously place it in a low temperature environment (-40 °C ± 5 °C) for 96 hours. The test shall be carried out in accordance with the method specified in GB/T 2423.1. Then place it at room temperature for 24 hours. Then connect the power supply, to observe its changes.

5.6 High temperature storage performance test

Continuously place it in a high temperature environment (85 °C ± 5 °C) for 96 hours. The test shall be carried out in accordance with the method specified in GB/T 2423.2. Then place it at room temperature for 24 hours. Then connect the power supply, to observe its changes.

5.7 Constant damp heat storage performance test

Place it in a constant damp heat environment (temperature: 40 °C ± 5 °C, relative humidity: 90% ~ 95%) continuously for 96 hours. The test shall be carried out, according to the method specified in GB/T 2423.3. Then place it at room temperature for 24 hours. Then connect the power supply, to observe its changes.

5.17 Water and liquid resistance test

Water resistance: Lay the heating cushion flat in a plastic container. Cover the heating cushion with a non-woven fabric of about 2 mm. Pour 1.0 L of clean water, at the main heating zone of the heating unit, at a rate of 2.0 L/min. After standing for 24 hours at room temperature to dry, test the performance of the heating cushion.

Liquid resistance (liquid flooding test): Lay the heating cushion flat in a plastic container. Cover the heating cushion with a non-woven fabric of about 2 mm. Pour 200 mL of 5% NaCl aqueous solution (light brine) and cleaning solution, at the main heating zone of the heating unit, at a rate of 1.0 L/min. After standing for 24 hours at room temperature to dry, test the performance of the heating cushion.

5.18 Adhesion performance test

Paste and fix the seat heating cushion on the seat foam. Place a 42 kg seat soft counterweight load, which has a bottom area of 300 mm x 400 mm, along the center line of the seat cushion. After bearing pressure for 24 hours at room temperature, slowly peel off the heating cushion from the foam, at a speed of less than 50 mm/min. Test the adhesion force.

5.19 Flexural resistance test

At room temperature, measure the resistance of the seat heating cushion. After the measurement, fix the heating cushion on the test platform (the test platform is composed of drive, control equipment, movable horizontal sliding bench).

When fixing, it must be ensured that a heating wire is arranged at the bending point position, meanwhile the number of bending points also depends on the heating area. See Figure 6 and Figure 7 for details. After fixing, the heating cushion is bent, at a frequency of 0.5 ~ 1 Hz; each bending point is subject to 50000 bending cycles. During each bending cycle, the heating cushion moves 50 mm horizontally along the sliding bench. After the test, measure the heating unit; use an infrared thermal imager to perform imaging detection of the heating cushion.

7.1 Identification

Each set of products shall have model specifications, part numbers, manufacturer names, markings, trademarks.

7.2 Packaging

7.2.1 It is packed in a plastic bag inside and a carton outside.

7.2.2 There shall be a product certificate on the product packaging box, which shall meet the following basic requirements:

a) Conclusion of inspection.

b) Product's inspection date, inspector's signature or seal (it can be indicated by inspector code).

7.2.3 The packaging box shall be manufactured in accordance with the drawings and technical documents, which are approved by the prescribed procedures.

7.2.4 The mark on the outside of the packing box shall meet the following basic requirements:

a) The marks of each part of the packaging box must comply with the corresponding national or industry standards.

b) Product name, specification model, product quantity, date of exit-factory, manufacturer name, production address.

c) Box size (length x width x height).

7.3 Transportation

The seat heating cushion shall be protected from rain and squeezing, during transportation.