Q/SQR S1-33-2012 Polyamide (PA6/66) Materials

The “Q/SQR S1-33-2012 Polyamide (PA6/66) Materials” standard, developed by Chery Automobile, one of China's leading global automotive brands, defines polyamide (PA6/PA66) materials used in automobiles, and describes their application range, technical requirements, and test methods. This standard applies to the identification of polyamide (PA6/PA66) materials and automotive parts (injection molded). This standard primarily contains technical requirements related to the scratch resistance of automotive part coatings.

PA6/66 is an engineering plastic widely used in modern automobiles, particularly Chery vehicles. It is not a single type of nylon, but rather a blend or copolymerization of two different polyamides.

• PA6 (Polycaprolactam): Made from caprolactam.
• PA66 (Polyhexamethylenediopamide): Made from hexamethylenediamine + adipic acid

The most common applications in Chery vehicles are as follows:

• Engine air intake manifolds
• Radiator end tanks (upper and lower sections of the radiator)
• Engine covers / acoustic covers
• Cooling fan housings and fan blades
• Some engines have cylinder head covers (valve covers)
• Throttle body housings
• Reservoir tanks (coolant, windshield washer)
• Door handle bases (inner and outer)
• Pedal brackets
• Battery trays and holders
• Various under-hood brackets and clips.

Chery Automobile develops standards for a wide range of technical specifications, covering everything from material requirements to performance testing. Examples of such standards include:

• The Q/SQR S1-27-2012 standard includes classification, identification codes, and technical requirements for polypropylene (PP) materials used in automobiles, including homopolymeric, copolymeric, hardened, filled, or reinforced PP properties.
• The Q/SQR S1-16-2012 standard includes specifications for paint coatings on interior parts, including adhesion, durability, and environmental resistance tests.
• Other Q/SQR standards cover topics such as pole sheathing assemblies, cable harnesses, odor emission tests, and scratch resistance.

These standards ensure consistency in part quality, safety, and performance across Chery’s supply chain and vehicle production.

The Q/SQR S1-33-2012 standard follows the S1 series model, which generally focuses on materials or surface treatments for automotive components. It follows the numbering sequence within the S1 group (e.g., S1-16 for interior paint, S1-27 for PP plastics). This standard primarily deals with:

• Specific material requirements (e.g., a type of plastic, rubber, coating, or composite for indoor/outdoor use).
• Durability performance tests such as resistance to scratches, UV rays, chemicals, or extreme temperatures.
• Technical specifications of a particular part, such as gaskets, trims, or adhesives.

Chery's standards generally align with or exceed national/international norms, supporting export-quality vehicles.

The Q/SQR S1-33-2012 standard is considered important for the automotive industry for the following reasons:

• Suppliers: To provide Chery with reliable and high-quality parts.
• Quality control: To ensure vehicles meet safety, emission, and reliability requirements.
• After-sales/repair: Technicians refer to these standards for original part specifications.

The following tests are performed under the Q/SQR S1-33-2012 standard:

• Cross-cut adhesion test: This test is performed in accordance with the “GB/T 9286-1998 Paints and varnishes - Cross-cut test for films” standard. A 1 mm or 2 mm cross-cut tool is used in the tests (depending on the coating thickness). Rating: 0 to 5 (0, best, no separation).
• Pencil hardness test: This test is performed in accordance with the “GB/T 6739-2006 Paints and varnishes - Determination of film hardness by pencil test” standard. Pencils with hardness grades from 6B to 9H are used in the tests. Chery's requirement is generally a minimum hardness of HB or 2H (depending on the part's location).
• Scratch resistance test with Erichsen needle: This test is the main test for this standard. The Erichsen 318 scratch hardness tester (or equivalent) is used in the tests. Needle, tungsten carbide spherical tip, diameter 1 mm. Load, 10 N (most common for Chery internal parts). Speed, 100 mm/s. Scratch length, 100-150 mm. Evaluation: visual evaluation under defined light (D65). Acceptance criteria are as follows (typical Chery limits):
• Level 1 (best): No visible scratches or only very slight change in shine.
• Level 2: Slight white marks, no material lifting.
• Level 3: Clear white trace, acceptable for some areas.
• Levels 4-5: Deep scratches, peeling coating, rejected.
• Color difference measurement after scratching: Measurements are taken with a spectrophotometer. The requirement is that the value should be at most 1,5 or 3,0 (depending on the part and color).
• Brightness change before and after scratching: 20-degree, 60-degree, or 85-degree geometry. The requirement is that at least 80-90% brightness retention should be achieved.
• Environmental aging before scratch testing (aging + scratching): The scratch test is repeated after the following aging cycles:
• Heat aging: 80 degrees or 90 degrees x 168 hours or 500 hours.
• Humidity: 40 degrees Celsius, 95% relative humidity x 168 hours.
• Thermal shock: Between -40 degrees and +80 degrees, 3-5 cycles.
• Xenon arc exposure (according to GB/T 250-2008 or ISO 105-B06 standards): 500-1000 kJ/m2.

Chery uses this standard very strictly, especially for the following:

• Piano black upholstery (glossy black).
• Interior decorative elements (door panels, center console, etc.).
• Soft-touch painted surfaces.
• Exterior chrome or black coated parts (where scratch resistance is required).

Most first-tier suppliers are required to provide test reports conforming to the Q/SQR S1-33-2012 standard when supplying Chery.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the “Q/SQR S1-33-2012 Polyamide (PA6/66) materials” standard.