GME 60301 Test Method for Determining Weight Per Unit Area

The “GME 60301 Test Method for Determining Weight Per Unit Area” standard, developed by General Motors Europe (GME), is a materials testing standard. This standard specifies a laboratory procedure for measuring the mass per unit area (area density or basis weight) of sheet materials used in automotive applications. It is commonly applied to textiles, nonwoven fabrics, coated fabrics, leather substitutes, films, and other flexible materials used in vehicle interiors.

Weight per unit area is one of the most fundamental physical properties of a material and directly affects component weight, thickness, strength, durability, cost, and manufacturing consistency.

The primary purpose of the GME 60301 standard is to establish a uniform method for determining the weight per unit area of ​​automotive materials. By using the same procedure across suppliers and manufacturing facilities, General Motors ensures:

• Consistently meeting material specifications.
• Suppliers must deliver products of a uniform quality.
• Vehicle components should have predictable performance.
• Material consumption and production costs remain under control.
• Lightweight vehicle design goals are verifiable.

The GME 60301 standard applies to numerous automotive materials, including:

• Woven fabrics
• knitted fabrics
• Nonwoven materials
• Seat cover fabrics
• Carpet materials
• Ceiling fabrics
• Door trim fabrics
• Coated textiles
• PVC and PU films
• Faux Leather
• Laminated composites
• Flexible interior flooring materials

The described test method is designed for flat sheet materials where weight can be expressed in grams per square meter (g/m²). This test is based on a simple measurement principle ^:

• A sample of known dimensions is cut.
• The sample is conditioned under controlled environmental conditions.
• The sample is weighed using a precision balance.
• The measured mass is divided by the sample area.
• The result is weight per unit area (g/m²).²(reported as)

This standardized approach minimizes measurement variations between laboratories.

Equipment used in tests typically includes the following:

• Precision analytical balance
• Circular or square sample cutter
• Steel ruler or cutting template
• Conditioning room
• Cutting mat
• Calibration weights

The sample cutter ensures the same sample size for every measurement.

To obtain reliable results, the sample is prepared as follows:

• Samples must be wrinkle-free.
• Damaged or contaminated areas should not be tested.
• Typically, multiple samples are taken from different locations.
• Samples are conditioned before testing.

Testing several samples helps to account for material variability.

The standard defines precise dimensions and conditions for testing, and the general procedure includes the following:

• The material is conditioned.
• Samples with a known area are cut.
• The sample mass is measured.
• Weight is calculated per unit area.
• The average of the individual results is calculated.
• The final value is reported.

Weight per unit area is calculated according to the following formula: Weight per unit area = Area * Mass.

Area density affects many engineering properties:

• Vehicle weight: Even small differences in material weight can significantly affect a vehicle's overall weight when multiplied by hundreds of components.
• Production consistency: Variations in material weight may indicate the following:
  • Irregular coating
  • Incorrect fiber content
  • Inconsistent production
  • Lamination defects
• Material cost: Many automotive textiles are purchased based on weight specifications. Monitoring weight per unit area helps suppliers ensure consistent production and control material usage.
• Mechanical performance: Weight is generally related to the following:
  • Tensile strength
  • Tear resistance
  • Wear resistance
  • Dimensional stability
  • Durability

The GME 60301 standard is commonly used in the following automotive components:

• Seat upholstery
• Door trim fabrics
• Ceiling tiles
• Floor carpets
• Luggage covers
• Packaging trays
• Sound insulation materials
• Non-woven backing layers
• Decorative laminates
• Protective coatings

The GME 60301 standard is often used in conjunction with other General Motors Europe material standards for complete material characterization. Testing organizations also note its similarity in purpose to international methods such as EN 12127 (mass per unit area of ​​textiles), ISO 2286-2 (coated fabrics), and ISO 29073-1 (nonwoven fabrics), depending on the type of material.

Implementing the GME 60301 standard offers several advantages:

• Standardized testing among suppliers.
• Improved quality control.
• Better production consistency.
• Easier supplier selection
• Reliable specification verification.
• Improved material traceability.
• Lightweight vehicle development support
• Improved reproducibility between laboratories.

Although developed for General Motors Europe, this testing method is applicable to all industries that use sheet metal materials, including:

• Automotive production
• Automotive interiors
• Textile production
• Nonwoven fabric production
• Synthetic leather production
• Plastic film production
• Composite materials
• Industrial fabrics

Independent testing laboratories list the GME 60301 standard among the original equipment manufacturer methods they support for evaluating automotive textiles and plastic films.

In conclusion, the GME 60301 standard is a fundamental material testing standard used to determine the weight per unit area of ​​automotive sheet materials. While the process is simple, this standard provides critical data for quality assurance, supplier verification, material specification compliance, and vehicle weight optimization. Consistent measurement of area density helps manufacturers ensure uniform performance and supports the production of durable, lightweight automotive interior components.

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 compliant with the GME 60301 standard.