ASTM D202 - Untreated Paper Slide Angle Coefficient of Friction

Untreated Paper Used for Electrical Insulation
SURFACE FRICTION

Accurately assessing the surface properties of electrical insulation paper is vital for ensuring consistent performance in demanding applications. ASTM D202, the Standard Test Methods for Sampling and Testing Untreated Paper Used for Electrical Insulation, provides a comprehensive guideline for measuring the slide angle coefficient of friction—a critical factor in the paper’s handling, especially in high-speed processing environments.

Importance of ASTM D202 in Paper Testing

ASTM D202 focuses on untreated electrical insulation paper used in apparatus such as motors, transformers, and cables. Among several mechanical tests, surface friction testing holds particular significance.

Frictional properties directly impact:

Tape winding efficiency during insulation assembly
Ease of conductor wrapping
Mechanical integrity during bending and folding
Slip resistance during processing and stacking

Poorly controlled friction can result in wrinkling, misalignmentatau material failure during insulation application.

Testing Procedure: Untreated Paper COF Test

To perform the untreated paper COF test per ASTM D202:

Prepare specimens: Cut samples in machine direction (MD) – 63 mm × 170 mm for block; 200 mm × 250 mm for plane.
Condition the paper: Follow ASTM and TAPPI guidelines to stabilize moisture and temperature.
Attach samples: Smoothly apply paper onto the inclined plane and the sliding block.
Begin testing:

- Place block at plane base and begin tilting the surface.
- Lightly tap to initiate movement as angle increases.
- Final friction angle is recorded once the block slides unassisted.

Multiple measurements ensure statistical reliability, with the average friction angle reported.

Slide Angle Coefficient of Friction Tester in ASTM D202

The slide angle coefficient of friction tester plays a central role in ASTM D202. The test evaluates how one piece of untreated paper slides over another or over smooth surfaces like metal, which simulates actual handling conditions in electrical insulation.

Test Apparatus Highlights:

Inclined Plane: Adjustable between 0° and 30°, surfaced with smooth, rigid material.
Sliding Block: 235 g ± 10 g, hardwood with rounded edges, used to hold the specimen.
Friction Angle Measurement: Angle is recorded when the block slides without external tapping.

The slide angle directly correlates to the static coefficient of friction, calculated using the tangent of the measured angle.

Why Friction Testing Matters

The friction between untreated papers or between paper and winding metals influences:

Tape feed reliability
Wrapping speed consistency
Prevention of overlapping or tearing
Safety and performance of insulated equipment

By using ASTM D202, manufacturers and quality control engineers gain a quantifiable measure of paper frictional performance, enabling them to meet customer specifications and optimize production processes.

Aplikasi di Seluruh Industri

The ASTM D202 COF testing method benefits multiple sectors:

Electrical equipment: Ensures safety and durability of insulation layers.
Pengemasan: Helps select papers that won’t shift or slide during shipment.
Textile and adhesives: Verifies the material’s grip and bonding interaction.
Paper manufacturing: Supports process optimization based on surface behavior.

Whether in R&D or production, understanding and controlling surface friction is essential.

Cell Instruments COF-03

For precise and efficient execution of ASTM D202, Cell Instruments’ COF-03 Inclined Plane COF Tester is a top-tier choice. Designed specifically to evaluate the slide angle coefficient of friction, the COF-03 offers:

High measurement accuracy (±0.01°)
PLC-controlled automatic lifting
Real-time friction angle and COF display
Versatile sled options (200g, 235g, 1300g)
Compliance with ASTM D202, TAPPI T815, T548

Professionals in electrical insulation paper manufacturing, jaminan kualitasdan material testing laboratories rely on the COF-03 for its repeatability and ease of use.

Pertanyaan Umum

1. What is the purpose of ASTM D202?

ASTM D202 defines methods for testing untreated paper used in electrical insulation, focusing on properties like surface friction to ensure reliable application.

2. Why is surface friction important in electrical insulation paper?

Friction affects how the paper wraps around conductors, its behavior during bending, and performance in tape-wrapping equipment.

3. What equipment is used for the slide angle COF test?

A precise inclined plane, sliding block, and angle measurement device are used, such as those featured in Cell Instruments’ COF-03 tester.

4. How is the coefficient of friction calculated in ASTM D202?

It is the tangent of the angle at which the paper starts to slide on the inclined plane without external force.

5. Who benefits from ASTM D202 testing?

Manufacturers of electrical insulation, quality assurance professionals, and testing labs all use ASTM D202 to ensure material compliance and performance.

Untreated Paper Used for Electrical InsulationSURFACE FRICTION