TSH1519G Test Method for Gloss of Paint Film

The "TSH1519G Test Method for Gloss of Paint Film," a Toyota engineering standard, describes the procedure for measuring the gloss (specular gloss or luster) of paint films applied to automotive components and parts.

In the automotive industry, paint appearance is critical for both aesthetic appeal and perceived quality. Gloss level affects how a vehicle's exterior or interior surfaces appear under different lighting conditions. The TSH1519G standard is part of a broader quality control system that includes paint coatings on vehicles, trim parts, and related materials.

• TSH1501G Dye film printing resistance
• TSH1503G Paint film adhesion properties
• TSH1504G Paint film flexibility
• TSH1508G Solvent resistance of paint film
• TSH1509G Chemical resistance of paint film
• TSH1539G Paint film hardness
• TSH1585G Xenon arc weather resistance

These methods, together, ensure that automotive coatings meet the requirements for appearance, durability, and environmental resistance.

This test evaluates the specular reflectivity (mirror-like sheen) of a cured paint coat. High-gloss finishes are typically used for exterior body panels, while lower gloss levels are used for matte or interior applications. Consistent gloss ensures a uniform appearance across production batches and helps detect issues such as orange peel appearance, cloudiness, or deterioration due to environmental factors.

The TSH1519G standard is closely aligned with international gloss measurement practices such as “ASTM D523 Standard test method for reflective gloss” or “ISO 2813 Paints and varnishes - Determination of gloss value at 20 degrees, 60 degrees and 85 degrees angles”.

Measurements are typically taken using a gloss meter at standard angles: using 20 degrees (high gloss), 60 degrees (half gloss), or 85 degrees (low gloss/matte) geometry depending on the expected gloss range.

Test reports provide gloss units that meet the acceptance criteria defined in specific Toyota part specifications (e.g., higher for Class A exteriors).

It is generally required for qualifying paints on interior and exterior parts, bumpers, and decorative trim.

The main areas of application of this standard are:

• Exterior paint systems (e.g., clear coating over primer on body panels).
• Interior coating components where gloss affects perceived quality.
• Supplier approval processes for paint materials and application processes.
• Durability assessments after weathering, chemical exposure, or abrasion tests.

TSH1519G is frequently listed in the following locations:

• Toyota supplier quality guidelines and test method compilations.
• Accreditation scope of independent testing laboratories.
• Automotive material conformity documentation.

In short, the Toyota TSH1519G standard test method is primarily used for quality control and material suitability of painted surfaces, ensuring that coatings used on interior and exterior components have a consistent appearance and meet Toyota's visual and durability requirements.

The primary purpose of the TSH1519G standard is to measure the specular gloss of a paint film, which refers to the amount of light reflected from a surface at a given angle. Gloss is a critical aesthetic characteristic for automotive coatings because it affects how a vehicle's surface appears to the human eye.

This standard provides:

• The painted surfaces meet Toyota's aesthetic specifications.
• The coatings exhibit consistent reflectivity and gloss.
• Differences in brightness between production batches are minimized.
• Automotive components maintain a uniform visual quality across the entire vehicle.

Gloss testing is particularly important for the following parts:

• Interior trim panels
• Plastic decorative components
• Painted metal parts
• Exterior decorative trims

The TSH1519G standard is based on measuring specular reflectance using a luminescence meter. In this method:

• A beam of light is directed onto the painted surface at a specified angle.
• The amount of light reflected in the direction of the mirror is measured.
• The device calculates the brightness value, which is usually expressed in units of brightness (GU).

The measured value indicates how glossy or matte the surface is. Higher values ​​represent more reflective and shiny surfaces, while lower values ​​indicate matte or dull surfaces.

Similar measurement approaches are also used in widely accepted gloss standards such as ASTM D523 and ISO 2813, which utilize measurement angles such as 20 degrees, 60 degrees, or 85 degrees depending on surface properties.

The TSH1519G standard test method generally follows these steps:

• Sample preparation: Painted samples must be clean and free of contamination. The paint film must be fully cured according to the coating specification.
• Device calibration: The brightness meter is calibrated using standard reference plates with known brightness values.
• Brightness measurement: The measuring head is placed on the surface. Measurements are taken at one or more points. For accuracy, an average of multiple readings is usually taken.
• Evaluation: Measured gloss values ​​are compared to the specified Toyota acceptance criteria for the component or coating system.

The TSH1519G standard is commonly used in the following situations:

• Paint development: Automotive paint suppliers use this method to verify that new coating formulations meet Toyota's appearance standards.
• Production quality control: Manufacturers measure the gloss of finished parts to ensure consistency between production batches.
• Supplier qualification: Component suppliers must demonstrate compliance with Toyota standards in order for parts to be approved for Toyota vehicles.
• Appearance matching: Gloss measurements help maintain visual consistency between adjacent parts such as bumpers, trims, and body panels.

The TSH1519G standard is considered important for the following reasons:

• It maintains consistent visual quality across vehicle components.
• It helps ensure the perceived quality of automotive coatings by the customer.
• Toyota supports global supplier quality control for its parts.
• It provides an objective method for measuring a subjective aesthetic quality.

In conclusion, the TSH1519G standard standardizes gloss measurement, ensuring that painted surfaces meet stringent aesthetic and performance expectations.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with the TSH1519G standard to businesses.