Automotive Seat Cover Testing

Automotive seat cushion inspection mainly conducts scientific testing and analysis on physical and mechanical property testing, burning characteristic testing, volatile organic compounds, toxic and hazardous substances, material composition and performance analysis, and weatherability and aging performance testing, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Physical and mechanical property testing: Evaluates the structural stability of the seat cushion under the long-term use, mainly including the fatigue resistance, impact resistance, compression set and recovery rate testing. These items simulate the actual working conditions such as the sitting pressure and bumping, ensuring that the seat cushion will not collapse, deform or produce the abnormal noise too quickly, affecting the riding comfort and support.

Burning characteristic testing: In accordance with the relevant safety regulations, the vertical burning, horizontal burning and smoke density testing are carried out on the seat cushion assembly (including the fabric, foam and frame). This item aims to evaluate the flame retardant performance of the material, measuring its burning rate, self-extinguishing time and smoke release amount. It is an important indicator of the passive safety of the vehicle.

Volatile organic compounds (VOC) and odour testing: The quantitative analysis is carried out on the hazardous substances such as benzene, toluene, xylene, formaldehyde and acetaldehyde released by the seat cushion materials under the specific temperature and humidity environment. At the same time, the professional odour assessors carry out the subjective odour grade evaluation, to control the air pollution in the vehicle and safeguard the health of the occupants.

Toxic and hazardous substance (ELV/REACH) testing: Screens whether the seat cushion contains the hazardous chemicals prohibited by the regulations, such as the polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), phthalates (such as DEHP and BBP) and heavy metals (lead, mercury, cadmium and hexavalent chromium), ensuring that the product meets the environmental protection regulatory requirements.

Material composition and performance analysis: The component identification, thickness, grammage, colour fastness, abrasion resistance (Martindale method) and tear resistance testing are carried out on the raw materials used in the seat cushion, such as the fabrics (genuine leather, fabrics and synthetic leather), foam (polyurethane and memory foam) and frames (metal/plastic), controlling the quality from the source.

Weatherability and aging performance testing: Simulates the internal environment of the vehicle, carrying out the accelerated aging tests such as the high temperature, low temperature, damp-heat, UV light (QUV) and temperature and humidity cycling on the seat cushion. The colour change, gloss retention, material cracking, chalking and physical performance attenuation are evaluated, predicting its service life.

Testing Scope

Original and aftermarket seat cushions of the passenger cars: Covering the seat cushion assemblies of the front row, rear row and third row of all the M1 class vehicles (passenger cars with nine seats and below), including the OEM supporting products and the modified and replacement seat cushions in the market circulation, all of which need to meet the corresponding technical specifications and certification requirements.

Driver and passenger seat cushions of the commercial vehicles: Including the driver seat cushions and passenger area seat cushions of the commercial vehicles such as the trucks and buses (M2, M3 and N class vehicles). In addition to the conventional performance, the testing items focus more on the dynamic comfort under the long-time driving, vibration damping performance and higher durability requirements.

Child safety seat cushions: As the core component of the child restraint system (CRS), the testing scope strictly follows the ECE R44/04 or the newer standard i-Size (ECE R129), emphatically focusing on the crash safety, flame retardancy and hazardous substance limits, with the requirements much higher than the ordinary automotive seat cushions.

Special vehicle dedicated seat cushions: Such as the seat cushions of the special vehicles such as the construction machinery, agricultural machinery and military vehicles. The testing scope needs to consider their special operating environments, adding the evaluation of the items such as the oil resistance, corrosion resistance, anti-static and extreme high and low temperature adaptability.

Seat cushion component materials and parts: The testing is not only for the finished assembly, but also goes deep into its components, including the surface fabric, middle cushioning layer (foam, springs and support plates), bottom base fabric, sewing threads and adhesives, implementing the all-round quality control.

Functional seat cushions: For the electric or intelligent seat cushions with the additional functions such as the heating, ventilation, massage and posture adjustment, the testing scope needs to be extended to the special items such as the electrical safety (insulation resistance and voltage resistance), EMC electromagnetic compatibility, functional reliability and noise testing.

Testing Methods

Static load and fatigue testing (GB/T 11550/ISO 11346): A buttock form model or loading pad is used to apply the specified static load and dynamic cyclic load (usually tens of thousands to hundreds of thousands of times) to the seat cushion, and after the testing, the residual deformation of the height is measured, evaluating its long-term support performance and durability.

Vertical burning testing (FMVSS 302/GB 8410): The seat cushion material specimen is vertically fixed in a specific burning chamber, ignited from the bottom with a standard Bunsen burner for a certain time, and after the fire source is removed, the burning rate, self-extinguishing time and damaged length of the material are precisely determined, assessing its flame retardant grade.

Volatile organic compound sampling and analysis (VDA 276/HJ/T 400): The seat cushion or its material samples are placed in a sampling bag or environmental chamber under the specific temperature and ventilation conditions, enriched for a certain time, and then the gas in the chamber is sampled and analysed with a thermal desorption-gas chromatography/mass spectrometry system (TD-GC/MS), quantitatively detecting the concentrations of the various VOCs.

Toxic and hazardous substance chemical analysis (ICP-MS, GC-MS): The inductively coupled plasma mass spectrometry (ICP-MS) is adopted to precisely determine the heavy metal element contents in the material; the gas chromatography-mass spectrometry (GC-MS) or high-performance liquid chromatography (HPLC) is used to analyse the contents of the specific hazardous substances such as the organic flame retardants and plasticizers.

Material physical property testing: An electronic fabric strength tester is used for the tensile and tearing strength testing of the fabric; a Martindale abrasion tester is used to evaluate the abrasion resistance of the fabric; and the colour fastness tester (such as the xenon lamp aging chamber combined with the grey scales) is used to rate the colour fastness to light, perspiration and rubbing of the fabric.

Artificial climate aging testing (ISO 4892/GB/T 16422): The specimen is placed in a climate aging test chamber that can precisely control the temperature, humidity, UV light intensity and spray cycle, carrying out the accelerated aging of hundreds to thousands of hours. Through the regular sampling comparison, the aging degree of the material is quantitatively evaluated.

Testing Standards

Domestic Standards:

1. GB 8410, Burning behaviour of interior materials of motor vehicles

2. GB/T 11550, Motor vehicles — Seat cushioning materials and upholstery — Test methods

3. HJ/T 400-2007, Determination of volatile organic compounds and aldehydes and ketones in the cabin of vehicles

4. GB 27887, Restraining devices for child occupants of power-driven vehicles

5. GB/T 16422, Plastics — Methods of exposure to laboratory light sources

International Standards:

1. FMVSS 302, Flammability of interior materials — Passenger cars, multipurpose passenger vehicles, trucks and buses

2. ECE R44/04, Uniform provisions concerning the approval of restraining devices for child occupants of power-driven vehicles

3. ISO 4892, Plastics — Methods of exposure to laboratory light sources

4. Regulation (EC) No 1907/2006 (REACH)

5. Directive 2000/53/EC on end-of-life vehicles (ELV)

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Seat comprehensive performance testing machine: A professional equipment integrating the functions such as the static pressure, dynamic fatigue and slippage testing. It can simulate the human sitting posture, precisely apply the loads through the servo motor and hydraulic system, and record the data such as the displacement and force value in real time, used to evaluate the durability and comfort of the seat cushion.

Automotive interior material burning test chamber: Specially used to execute the vertical burning testing of the standards such as FMVSS 302 and GB 8410. The equipment is equipped with a precision Bunsen burner, specimen fixture, timing device and backboard scale, can provide the stable and repeatable flame conditions, and automatically record the key parameters of the burning process.

Gas chromatography-mass spectrometer (GC-MS) and thermal desorber (TD): Constituting the core analysis system of the VOC testing. The thermal desorber is used for the desorption and enrichment of the volatile organic compounds in the sampling tubes, and the GC-MS carries out the efficient separation and precise qualitative and quantitative analysis of the complex organic compounds, with the sensitivity reaching the ppb level.

Inductively coupled plasma mass spectrometer (ICP-MS): The cutting-edge equipment for detecting the trace and ultra-trace heavy metal elements in the seat cushion materials. The principle is to ionize the sample with the high-temperature plasma, and carry out the separation and detection through the mass spectrometry, with the advantages of the low detection limit, wide linear range and simultaneous multi-element analysis.

Universal material testing machine and Martindale abrasion tester: The universal material testing machine can complete the mechanical tests such as the tensile, compression, bending and shear through the different fixtures; the Martindale abrasion tester evaluates the abrasion resistance of the materials such as the fabric and leather through the relative friction motion between the specimen and the standard abrasive under the specified pressure.

High and low temperature damp-heat test chamber and xenon lamp aging test chamber: The high and low temperature damp-heat test chamber can simulate the extreme temperature and humidity environments; the xenon lamp aging test chamber simulates the solar spectrum through the filter system, and controls the temperature, humidity and spraying. It is the key equipment for the light aging and climate aging testing of the materials.