Introduction to Fabric Thickness Testing and ASTM D1777 Standard

 

 

One of the fundamental physical properties of textile materials is their thickness. This parameter plays a crucial role in evaluating the bulk, thermal insulation, and structural qualities of fabrics. In this article, we explore the concept of fabric thickness in detail — highlighting its importance, practical applications, and the widely recognized test method ASTM D1777, frequently adopted in professional textile testing laboratories.

 

Introduction to ASTM D1777

Fabric Thickness

Textile structures consist of interwoven or bonded fibers with minute air spaces between them. These air pockets are delicate and compressible — meaning that even slight applied pressure can affect fabric thickness measurements. Notably, fabric thickness is inversely proportional to the applied pressure during testing. Therefore, it is essential to specify the pressure used whenever reporting fabric thickness.

Thickness significantly influences fabric performance, including its thermal resistance, abrasion durability, shrinkage behavior, and dimensional stability. It also plays a pivotal role in industrial applications where precise thickness tolerances are necessary for processing and product quality.

 

 

What is ASTM D1777?

ASTM D1777 is a standardized test method used internationally for determining the thickness of textile materials. The procedure involves placing a fabric specimen between a weighted presser foot and a base plate, gradually lowering the presser foot, and measuring the distance between the two surfaces to determine the material’s thickness.

 

Alternative Test Methods to ASTM D1777

In addition to ASTM D1777, various regional and international standards are employed for measuring the thickness of textiles and nonwovens. Some commonly used alternatives include:

• GB/T 3820 — Thickness measurement of textiles and textile products
• GB/T 24218.2 — Test methods for nonwoven fabrics, Part 2: Thickness determination
• ISO 5084:1996 — International standard for determining the thickness of textile materials

Each standard has its procedural nuances and must be reviewed carefully prior to implementation.

 

Test Conditions – Temperature and Relative Humidity

Before testing, fabric specimens should be conditioned in a controlled environment at 21 ± 1°C and 65 ± 2% Relative Humidity for a minimum of 4 hours. The same conditions must be maintained throughout the testing process to ensure accuracy and consistency.

 

Apparatus for ASTM D1777

The primary instruments required for this method include:

• Fabric Thickness Tester (Thickness Gauge) — available in multiple configurations; for example, Darong offers two ASTM D1777-compliant models.
• Cutting Dies or Fabric Templates — to prepare samples at least 20% larger than the presser foot’s diameter.

 

ASTM D1777 Testing Procedure

1. Power on the fabric thickness tester.
2. Configure the appropriate test parameters according to ASTM D1777.
3. Select a pressurization time of 10 seconds or 30 seconds, as applicable.
4. For standard testing, use a 2000 mm² presser foot applying 1000 Pa of pressure (corresponding to a 200 g weight).
5. Calibrate the tester by zeroing the display without a sample.
6. Place the fabric sample flat and wrinkle-free on the test base.
7. Initiate the test by pressing the start button.
8. After the set pressurization time, record the thickness value as indicated.
9. Repeat the procedure for each sample.
10. Calculate and document the results as per the standard’s requirements.

 

Report Formation

A comprehensive thickness test report should include:

• Material details (fiber type, yarn count, weave/knit type, treatments, etc.)
• Sampling methodology
• Applied test pressure
• Test date
• Statement confirming adherence to ASTM D1777

 

Conclusion

Fabric thickness is a vital material property influencing various textile characteristics such as insulation, compactness, breathability, and structural integrity. Precise measurement of thickness provides valuable insights for product development, quality assurance, and industrial processing. Professionals should always account for testing conditions and applied pressure to ensure reliable and repeatable results.

 

Expert Advice & Industry Insights

• Avoid stretching fabrics during preparation, as this alters thickness values.
• Always condition samples in controlled environments before testing.
• Use circular presser feet for most materials, but rectangular options may be necessary for specific applications.
• Always document the applied pressure when reporting fabric thickness.

 

FAQs

What is ASTM D1777-96?
A globally recognized test method for measuring the thickness of textile materials, also applicable to leather products and packaging substrates.

What unit is used to measure fabric thickness?
Typically measured in millimeters (mm) for accuracy and consistency.

 

About Cell Instruments

Since our establishment in 2014, Cell Instruments has rapidly distinguished itself in the field of material testing equipment. Our comprehensive product lines span Packaging, Medical, Food, Pharmaceutical, Adhesion, Paper, Board, and Textile Testing, with custom solutions tailored to specific industry needs.

With a footprint in over 70 countries, Cell Instruments is committed to supporting global industries through reliable, standards-compliant, and innovative testing equipment. As a pioneer in engineering-driven solutions, we strive to be an integral partner in enhancing our customers’ quality control and R&D processes worldwide.