The Indian Standard, IS 18929: 2024, titled "Textiles- Synthetic Filament Yarns- Electrostatic Propensity Evaluation by Measuring Electrical Resistance," is an essential guideline for evaluating the electrostatic behaviour of synthetic yarns. This standard is a modified adoption of the ISO 24180: 2021, issued by the International Organization for Standardization (ISO). The Bureau of Indian Standards (BIS) adopted it after the recommendation of the Physical Methods of Test Sectional Committee and approval from the Textiles Division Council.

Understanding IS 18929: 2024

The IS 18929: 2024 standard, a modified adoption of ISO 24180:2021, specifies the method for evaluating the electrostatic propensity of synthetic filament yarns by measuring their electrical resistance. This is especially important for industries that manufacture anti-static clothing, as it is important to control electrostatic build-up. The standard applies to threads that are conductive and actually designed to reduce static electricity, preventing unwanted sparks or damage. This thread is mainly used in the production of anti-static textiles, but it is also particularly suitable for electromagnetic shielding, power supply and heating.

--------------Blog Contact Form-------------

The standard test kit provides detailed instructions, including the required equipment to validate the test, including a DC high-resistance meter, insulating sample holder and strain weight. To ensure reliable results, the actual test environment must be carefully controlled at 20 ± 2°C temperature and 40 ± 4% relative humidity. The yarn sample go through conditioning and pre-conditioning to obtain the specific tension required for both textured and non-textured yarns.

Scope of IS 18929: 2024

This standard specifies methods for electrostatic propensity evaluation by measuring electrical resistance of synthetic filament yarns. It applies to synthetic filament yarns that are basically used in textiles to minimize electrostatic charge accumulation. Conductive yarns covered in this document are used for anti-static fabric. They are not used for transmission of electric signals, supply of electric power and electromagnetic shield and heating.

Benefits of IS 18929: 2024

The IS 18929: 2024 is a modified standard, adopted for assessing the electrostatic tendency of synthetic filament yarns. There are several benefits of this standards, some includes:

• Enhanced Product Quality Assurance: IS 18929:2024 provides a standardized method for assessing the electrostatic tendency of synthetic filament yarns. By evaluating electrical resistance, manufacturers can certify that yarn meets particular electrostatic standards, thereby improving product quality. This adds to a more stable and reliable end product that fulfills demands of the industry and customers.  
• Enhanced Safety Standards: The evaluation of electrostatic properties of synthetic threads is vital to prevent the build-up of static electricity, which can be dangerous in many environments. The application of IS 18929: 2024 helps in the identification of yarns which are likely to static build- up, therefor, ensuring safe production process and minimizes the risk of sparks, fire or any other safety concerns related with electrostatic discharge. 
• Compliance with Global Standards: This standard is based on ISO 24180:2021, permitting manufacturers to integrate their own practices with international best practices. Adoption of IS 18929:2024 has helped in achieving global textile standards compliance, which may be necessary to reach international markets and maintain valid competition in the global textile industry.
• Process Optimization and Cost Efficiency: Manufacturers can optimize the production process by selecting appropriate threads for specific applications and using electrostatic tendency evaluation. This can cause reduction in defects and waste due to electrostatic problems. In addition, producers can avoid the expensive consequences of creating defective or hazardous products, improving overall cost efficiency.  
• Increased Durability and Performance: Synthetic filament yarn with low electrostatic tendency often exhibits better long-term performance in different applications. By following the guidelines of IS 18929:2024, manufacturers can produce yarns that are not only safe but also durable, delivering customers with high-value products that conserve their performance over time.
• Better Customer Satisfaction: Adopting the electrostatic tendency test as specified in IS 18929:2024 ensures that the yarn performs optimally in different end uses. The result is fewer complaints, improved customer satisfaction, and higher demand for products that consistently exhibit quality and functionality, particularly in areas where static resistance is serious, such as in electronics or high-tech textile applications.

Also Read: IS 19059: 2024 Continuously Transposed Conductor (CTC) Copper Winding Wires

Normative References

The standard depends on several documents, including ISO 139 for conditioning procedures and ISO 24180:2021 for its adopted methodology. These references provide the necessary guidelines for testing and ensure that procedures are in line with global standards.

Terminology

Some key terms outlined in IS 18929:2024 include:

• Electrical Resistance per Unit Length: The resistance exhibited by a material per unit length.
• Volume Resistivity: This is the quotient obtained when the potential gradient is divided by the current density, describing a material’s ability to resist electric current.

Principles of IS 18929: 2024

• The principle behind the evaluation of the electrostatic tendency in synthetic filament yarns is based on measuring the electrical resistance of the yarn under specific conditions.
• The resistivity values obtained help to understand the conducting properties of the yarn material, which is critical for determining its suitability in anti-static applications.

Apparatus of IS 18929: 2024 

To perform the electrostatic propensity evaluation, the following apparatus are required:

• DC High-Resistance Meter:

1. Resistance range: 1×10^6 Ω to 1×10^13 Ω.
2. Accuracy: ±5% for measurements less than 1×10^12 Ω and ±20% for higher measurements.

• Open circuit voltage: (100 ± 5) V.

1. Insulating Specimen Holder: The holder must have a resistance greater than or equal to 10^14 Ω and be equipped with copper clamps spaced at (10 ± 0.1) cm apart. The clamps should have flat jaw faces to hold the test specimen securely.

• Tensioning Weight: Tension is applied to the test specimen using clamps, ensuring the specimen is properly tensioned during measurement.

Also Read: IS 18879 (Part 15): 2024 ISO 8536-15: 2022 + AMD 1: 2023 Infusion Equipment for Medical Use Part 15 Light-Protective Infusion Sets for Single Use 

Testing Conditions

The test environment plays an essential role in obtaining accurate results. The following conditions must be maintained:

• Temperature: 20 ± 2°C
• Relative Humidity: 40 ± 4%

If different conditions are used, they must be documented in the test report.

Test Specimen Preparation

The test specimen is prepared as follows:

• Specimen Preparation: Yarn should be cut to a length between 400 mm and 500 mm. The outer layer of the package is discarded to eliminate any irregularities. A minimum of three specimens should be tested, with a total of no less than 30 specimens if resistance uniformity testing is required.
• Pre-conditioning: The yarn specimens must undergo pre-conditioning according to ISO 139 standards to remove moisture and prepare the yarns for consistent measurement.

Conclusion

The electrostatic propensity evaluation of synthetic filament yarns is a key factor in the design of anti-static fabrics. By measuring electrical resistance, IS 18929: 2024 provides a standardized method to assess yarns for their ability to resist static charge build up, ensuring the development of safe, functional textiles. The precision of the methods described in the standard ensures that manufacturers can create fabrics suitable for specific anti-static applications, promoting safety in environments where static discharge can be hazardous.

Electrical resistance is measured using a high-resistance meter, with results recorded after a one-minute period under 100 V of voltage. The measured resistance values allow manufacturers to assess whether the yarn is suitable for anti-static applications. This method helps ensure that textiles produced for sensitive environments meet the necessary standards for electrostatic safety.

Understanding and adhering to this standard will help textile manufacturers produce high-quality, anti-static yarns, contributing to the broader goal of reducing electrostatic hazards in various industries.