GMW 14867 Performance Requirements for Paints on Indoor Plastic Surfaces

Developed by General Motors Worldwide (GMW), the “GMW 14867 Performance of Paints on Interior Plastic Surfaces” standard is an engineering specification that defines the performance requirements for paint and coating systems on plastic surfaces used in automotive interiors. Its aim is to ensure that interior painted components maintain their appearance, adhesion, durability, and resistance to environmental and chemical influences throughout the vehicle's lifespan.

This specification covers coatings applied to rigid plastics, flexible surfaces, and integrated surface foam systems. It may encompass both metallic and non-metallic coating systems, including various tactile or soft-touch technologies.

Automotive interior components such as instrument panels, consoles, door trims, frames, switches, and other decorative plastic parts are subjected to significant mechanical, environmental, and chemical stresses. A coating may be exposed to:

• Repeated use and contact
• Cleaning agents
• Skin oils and lotions
• Sunscreen and insect repellent
• temperature changes
• Gender
• Impact and deformation
• Wear and scratches
• Long-term environmental exposure

The GMW 14867 standard establishes a common performance framework for evaluating these coating systems. Previous versions of this standard aimed to replace regional requirements and unify internal coating performance requirements into a single specification.

The GMW 14867 standard applies to painted or coated plastic interior components. Coatings can be used on a variety of substrate configurations, including:

• Rigid plastic substrates
• Flexible plastic substrates
• Integrated skin foam systems
• Other plastic components used inside vehicles

This standard may encompass both metallic and non-metallic colors and coating systems designed to provide distinct tactile or touch-sensitive properties. Typical automotive applications might include:

• Instrument panel components
• Center consoles
• Door trim components
• Inner frames
• Decorative moldings
• Key and control circles
• Other painted plastic interior parts

One of the key features of this standard is that it evaluates the coating as a complete performance system, rather than simply checking its initial appearance. Important performance areas include:

• Coating curing: The coating must reach a suitable degree of curing before being subjected to further testing. This standard includes a curing test, specifically defined in the section describing a test for paint curing. Proper curing is crucial because insufficiently cured coatings may indicate:
  • poor adhesion
  • Softening
  • chemical attack
  • Staining
  • Loss of brightness
  • Scratching
  • Surface deformation
• Adhesion: Coating adhesion is a fundamental requirement for painted interior plastics. The aim is to determine whether the coating remains firmly adhered to the plastic substrate when subjected to mechanical stresses. Poor adhesion can lead to:
  • Peeling
  • Exfoliation
  • Layer separation
  • Local coating failure

Good adhesion is important, especially where the component will be subjected to repeated handling or deformation.

• Environmental resistance: Internal components are exposed to temperature and humidity changes throughout their service life. Therefore, this standard includes environmental durability requirements. For example, an accredited laboratory might list this standard among its methods for high/low temperature environmental simulation testing. Environmental tests help determine whether the coating retains its properties after being exposed to extreme temperatures and associated environmental stresses.
• Chemical resistance: Chemical resistance is a particularly important aspect of this standard. Interior coatings may come into contact with:
  • Cleaning products
  • hand creams
  • Skin oils
  • suntan cream
  • Insect repellents
  • Other consumer chemicals

This standard includes requirements regarding the effects of cleansers and lotions. Chemical exposure can cause:

• color change
• Brightness change
• Softening
• Swelling
• Staining
• Bubble formation
• Loss of adhesion
• Surface degradation

This is especially important for modern soft-touch and decorative finishes.

• Sunscreen and insect repellent resistance: A particularly challenging application is resistance to sunscreen and insect repellent products. Resistance to chemical attack at high temperatures is identified as a significant requirement. This specification is also referenced for coating systems requiring resistance to sunscreen and insect repellent exposure. This requirement is extremely important for components frequently touched by vehicle occupants.
• Impact resistance: Interior plastic parts can be subjected to accidental impacts from passengers, luggage, tools, or other objects. As a result, the coating system must have sufficient impact resistance without leading to the following situations:
  • Cracking
  • Break
  • Peeling
  • Excessive deformation
  • Separation from the lower stratum

GMW 14867 is defined by testing laboratories as a standard containing impact-related performance requirements.

The testing process generally follows these steps:

• Preparation of the plastic substrate
• Application of the specified paint/coating
• Curing under specified conditions
• Initial visual and physical assessment
• Adhesion or mechanical test
• Environmental conditioning
• Chemical exposure
• Cleansing/lotion exposure
• Impact or durability assessment
• Final visual and performance evaluation

The exact dimensions of the sample, conditioning parameters, chemicals, exposure times, temperatures, grading, and acceptance criteria are all included within this standard.

The GMW 14867 standard is often used as a basic coating performance specification for more specific coating requirements. For example, the GMW 15543 standard specifies interior metallic paint systems resistant to sunscreen lotion and requires the paint system to first meet the GMW 14867 standard before being approved to that specification. Similarly, specific specifications for sunscreen-resistant coatings on materials such as polyurethane, TPO, and polypropylene refer to the GMW 14867 standard as a prerequisite.

In short, the GMW 14867 standard provides a basic performance baseline before a coating system can be qualified for more specialized applications. This standard is important because interior painted plastics are highly visible and frequently touched components.

A coating that performs well immediately after manufacturing may deteriorate during vehicle use. For example, repeated contact with sunscreen or cleaning chemicals can cause the coating to fade, swell, soften, or be damaged. This standard helps General Motors and its suppliers achieve the following by implementing standardized performance requirements:

• Consistent coating quality.
• Improved appearance durability
• Better chemical resistance
• Improved adhesion
• Resistance to environmental influences.
• Better customer perceived quality.
• Reducing field failures related to coatings.

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 in accordance with the GMW 14867 standard.