VW 50133 PA66 - Material Requirements for Finished Interior and Exterior Parts of Vehicles

The “VW 50133 PA66 - Material requirements for finished parts outside the vehicle interior” standard, developed by the Volkswagen automotive company, describes the requirements for unreinforced, glass fiber reinforced, or mineral reinforced PA66 materials used in engine, chassis, transmission, and body sections (unpainted). For coolant conveying parts, the VW TL 52682 standard applies.

The requirements in this standard are specified as follows:

• Initial delivery and modification approval must comply with VW 01155 standard.
• Material suitability must be in accordance with the VW 91101 standard.
• Tests should be performed on samples made from finished parts. If testing on the part itself is not possible due to geometry, data sheets or measurements taken on test plates can be used.
• Measured properties on finished parts may differ from standard properties. Deviations must be agreed upon with the buyer and indicated in the drawing if necessary.
• The surface of the finished parts must be free from defects resulting from the manufacturing process, such as voids, cracks, and cold closures.
• For parts subjected to high loads or those of particularly critical functionality, porosity and properties must be examined according to the VW 50093 standard. Once satisfactory test results are obtained, the measured properties must be recorded in a drawing. The buyer decides whether a porosity specification is necessary.
• The parts must allow for flawless assembly. There should be no functional risk or risk of injury to assembly workers due to loosening of burrs, chips, or particulate matter.

The materials are designed for injection molding or blow molding processes. If PA66 is not modified for impact resistance, up to 30% by weight of homogeneous regrinding from the initial machining operation is permitted. Parts must be verified with the expected maximum regrinding percentage. The use of recycled materials (i.e., raw materials from non-process sources) is only permitted after consultation with the buyer and must be clearly indicated in the drawing.

A distinction is made between dry and conditioned conditioning states. Samples taken from dry-condition parts are dried until their weight remains constant and are continuously aged in a dry atmosphere before testing. Conditioned-condition samples are dry-condition samples that are kept in a waterproof bag filled with water at 70 degrees until they reach the equilibrium state shown in the table. Alternatively, samples can also be conditioned according to the DIN EN ISO 1110 standard.

When evaluating measurement results, the required numerical values ​​​​are valid for each measurement.

In the high-risk world of automotive engineering, where every component must withstand extreme temperatures, relentless vibrations, and corrosive fluids, material specifications are much more than just technical documentation; they are the unsung heroes that ensure vehicles operate reliably for years to come. In this context, the VW 50133 standard regulates the use of polyamide 66 (PA66) plastics in non-interior vehicle parts. This standard is not just a checklist, but a rigorous blueprint for creating lightweight, heat-resistant, and mechanically robust components that power everything from engine manifolds to chassis reinforcements. As electric and hybrid vehicles become more widespread, understanding the VW 50133 standard is becoming increasingly important for suppliers, engineers, and enthusiasts alike, highlighting Volkswagen's commitment to quality and sustainability.

The VW 50133 standard is essentially a group of standards detailing material requirements for PA66-based finished parts used outside the vehicle interior. This standard targets unreinforced, glass fiber reinforced, and mineral reinforced variants of PA66, a semi-crystalline thermoplastic known for its high melting point (approximately 260 degrees), excellent tensile strength, and resistance to oils, fuels, and coolants.

This standard applies particularly to components in harsh environments: engine compartments, chassis, transmissions, and body structures. These are areas where parts are exposed to extreme heat (150 degrees or higher), mechanical stress, and aggressive substances such as transmission fluids and fugitive gases. These environments can cause lower-quality materials to warp, crack, or fail prematurely. The VW 50133 standard specifically excludes painted parts and interior applications, recommending the VW 50132 standard for painted exteriors or the VW 50136 standard for interior PA66.

Unlike PA6, PA66 offers superior thermal stability and hydrolysis resistance, making it an ideal material for under-hood applications. The VW 50136 standard ensures that these materials are not only durable but also optimized for mass production, recyclability, and cost efficiency, aligning with the industry's shift towards lighter vehicles to meet emission targets.

The VW 50133 standard consists of a series of tests that blend general and application-specific criteria. Parts must be approved according to the VW 01155 standard for initial supplies and modifications. These tests ensure consistency between batches.

• Moisture content: ISO 1133 standard test method. Requirement: maximum 0,2%. The aim is to prevent hydrolysis in humid environments.
• Melting point: ISO 11357-3 (DSC) standard. Requirement: minimum 255 degrees. Aim: To withstand engine compartment temperatures.
• Yield strength (23 degrees): ISO 527 standard. Requirement: minimum 100 MPa. Intended to withstand tensile loads on the chassis.
• Elongation at break: ISO 527 standard. Requirement: at least 3 percent. The aim is to prevent brittle fracture.
• Notched impact resistance (minus 30 degrees): ISO 179 standard. Requirement: at least 8 kJ/m2. Aim: to provide durability in cold climates.
• Aging of transmission fluid (150 degrees, 96 hours): ISO 527 standard. Requirement: Retaining at least 70 percent yield stress after exposure. The aim is to ensure compatibility with transmission oils.

The requirements are specified for GF30 (30% glass fiber). Values ​​vary depending on the class and application area (e.g., higher for motors and housings).

The VW 50133 standard adapts the classes according to regions:

• Engine compartment (e.g., intake manifolds): High GF content (25-35%) for heat and pressure resistance. Must withstand PV 3936-A gas leak tests.
• Chassis/transmission: Mineral reinforced for vibration damping, low bending after 150-degree aging.
• Body (unpainted): Balanced filler materials for collision energy absorption according to ISO 178 bending tests.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, 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 in accordance with the VW 50133 standard.