Textiles (such as clothing, furniture fabrics, bedding, etc.) may come into contact with fire sources (such as open flames, high-temperature electrical appliances, cigarettes, etc.) during daily use. Their combustion characteristics are directly related to fire risk and personal safety. Therefore, imparting flame-retardant properties to textiles is of great significance in eliminating fire hazards, preventing the spread of fire, and reducing loss of life and property.

1. Vertical burning method: Mainly used for flame retardancy testing of clothing textiles, curtains, and other fabrics. This testing method requires the test sample to be placed vertically (with the length direction of the test sample perpendicular to the horizontal line). The ignition source is located below the test sample to initiate combustion. Key indicators related to flame-retardant performance include the minimum ignition time, sustained burning time, smoldering time, flame spread rate, char length (damaged length), and char area (damaged area) of the test sample.

Common testing standards for the vertical burning method:

GB/T5455 Test method for flammability of textiles;  

GB/T8745 Determination of vertical damage length, flame retardancy, and sustained burning time of textiles;  

16CFR1615/1616 Flammability test for children's sleepwear.

2.45° Burning Method: This testing method specifies that the test sample is placed at a 45° angle (with the length of the test sample forming a 45° angle with the horizontal line), and measures the time required for the sample to burn upward over a certain distance, or measures post-flame burning time, smoldering time, flame spread rate, char length, char area, or the number of times the sample must come into contact with the flame to burn to a certain distance below the sample, among other indicators related to flame-retardant performance.

Common testing standards for the 45° burning method:

GB/T14644 Determination of burning rate in the 45° direction for textile burning performance;  

ASTM D1230 Standard test method for flammability of apparel textiles;  

16 CFR PART 1610 Flammability test standard for apparel textiles;  

CAN/CGSB-4.2 No. 27.5 Canadian textile 45° flame burning performance.

3. Horizontal Burning Method: Primarily used for testing the flammability performance of children's sleeping bags and blankets. This testing method involves exposing the sample surface to a standardized flame for a specified period of time, observing the burning rate, damage extent, or color change of the sample, and subsequently grading the tested fabric.

Common testing standards for the horizontal burning method:

CPAI75 Children's Sleeping Bag Flammability Test

ASTM F1955 Sleeping Bag Flammability Test Method

ASTM D4151 Blanket Flammability Test Method

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Yarn friction tester is the quality and performance of knitted fabrics depend on the characteristics of the knitted raw materials, the structure and specifications of the knitted fabrics, dyeing and finishing, and other factors. Among these, the performance of the knitted raw materials is the primary factor influencing the characteristics of knitted fabrics. Different types of knitted fabrics require different raw materials. Currently, most knitted fabrics used for underwear are made from cotton yarn; the raw materials for sock products include cotton yarn, wool, and chemical fibers. Wool sweaters are primarily made from wool, acrylic, acrylic blended yarn, etc. The main raw materials for knitted jackets are polyester, nylon, acrylic, blended yarn, and new textile materials (such as staple fibers, differentiated fibers, etc.); raw materials for special industries are primarily glass fiber, metal wires, and aromatic fibers. Raw material components can be pure yarn, which contains only one type of fiber, or blended yarn, which contains two or more types of fibers; (e.g., colored yarn, slub yarn, knotted yarn, core-spun yarn, etc.). Additionally, the emergence of new raw materials, such as special-shaped chemical fibers, composite fibers, and especially ultra-fine denier fibers, has opened up new methods for knitted yarn production.

During the process of forming knitted fabrics on a knitting machine, yarn is subjected to complex mechanical actions such as stretching, bending, twisting, and friction. To ensure normal production and product quality, knitting yarn must meet various requirements:

1. Yarn should have sufficient strength and extensibility

2. Yarn should have good softness

3. Yarn should have a certain degree of twist

4. The linear density of yarn should be uniform, and yarn defects should be minimal

5. The yarn should have good moisture absorption properties

6. The yarn should have a good finish and low friction coefficient

Knitting yarn should be free of impurities and oil stains and should be very smooth. Rough yarn can cause severe wear on parts, which are easily damaged. There are many flying sparks in the workshop, which not only affect workers' health but also impact the productivity of the knitting machine and the quality of the fabric.

Additionally, during the weaving process, yarn comes into friction contact with various mechanical components to impart a certain degree of resistance, thereby generating yarn tension. Therefore, when passing through ring machines, yarn with rough surfaces or coarse yarn will produce higher yarn tension, which will affect the uniformity of yarn tension and result in uneven loop structure. To reduce the yarn's friction coefficient, the yarn surface can be treated with anti-adhesive agents, lubricants, or wax.

When friction occurs as the yarn slides over other surfaces, tension is generated due to friction. In practical applications, the yarn passes through several sinkers and hooks. As the friction coefficient increases, yarn tension increases significantly. The increase in tension depends not only on the friction coefficient but also on the yarn guidance and the total wrapping angle when the yarn slides.

During textile processing, relative movement typically occurs between yarns, as well as between yarns and machine components, resulting in friction between yarns or between yarns and other materials. Sufficient friction between yarns is a necessary condition for good dimensional stability of the fabric; however, excessive friction can cause pounding during weaving and adversely affect fabric quality. The magnitude of the friction coefficient also directly influences the appearance and style of the fabric. For example, friction between yarns to some extent determines the fabric's interlacing resistance. If the interlacing resistance is too high, the fabric typically feels hard and rough, and distortion is likely to occur. Additionally, the friction force between yarns plays a decisive role in the fabric's shear deformation resistance, and the circular shape of the chest and back areas requires the fabric to have good shear deformation capability. Therefore, determining the yarn friction coefficient is of significant importance.

UTSTESTER's Y019A/B Yarn Friction Tester (ASTM D 3108) is used to measure the friction characteristics of yarns. This tester is suitable for determining the dynamic friction coefficient of chemical fiber filaments and other material yarns, and can also be used for textiles such as top rolls. The friction coefficient measurement of the device is an indispensable testing tool for evaluating the friction coefficient of filaments and textile equipment.

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Salt is one of the most common compounds in the world and can be found in oceans, the atmosphere, on land surfaces, in lakes, and in rivers. When salt enters tiny droplets in the atmosphere, it forms a salt fog environment whose main component is sodium chloride.

1. What is salt spray testing?

Salt spray testing is used to evaluate the resistance of products or metal materials to salt spray corrosion. The results of salt spray testing are used to determine product quality, and whether the results are correct and reasonable is key to accurately measuring the resistance of products or metals to salt spray corrosion.

2. Classification of Salt Spray Test Methods Artificial simulated salt spray tests include three different test methods with varying requirements.  

(1) Neutral Salt Spray Test (NSS Test) is the earliest developed and currently most widely applied accelerated corrosion test method. It uses a 5% sodium chloride saltwater solution with a pH value adjusted to the neutral range (6.5–7.2) as the spray solution. The test temperature is set at 35°C, with a required salt fog deposition rate of 1–2 ml/80 cm/h.  

Application scope: metals and alloys, metal coatings, conversion coatings, anodized coatings, and organic coatings on metal substrates.

(2) The Acetic Acid Salt Spray Test (ASS Test) was developed based on the neutral salt spray test. It involves adding some glacial acetic acid to a 5% sodium chloride solution, lowering the solution's pH to around 3, making the solution acidic, and resulting in acidic salt spray instead of neutral salt spray. Its corrosion rate is approximately three times faster than that of the NSS test.

Application scope: decorative coatings of copper + nickel + chromium or nickel + chromium, anodized films on aluminum, and organic coatings.

(3) The Copper-Accelerated Acetic Acid Salt Spray Test (CASS Test) is a newly developed rapid salt spray corrosion test abroad. The test temperature is 50°C, and a small amount of copper salt (copper chloride) is added to the salt solution to strongly induce corrosion. Its corrosion rate is approximately 8 times that of the NSS test.

Application scope: decorative coatings of copper + nickel + chromium or nickel + chromium, anodized aluminum films, and organic coatings.

3. How long is the conversion time between salt spray testing and natural environment exposure?

Based on existing industry standards (theoretical values), the conversion relationship between 24-hour salt spray testing and natural environment exposure is as follows:

Neutral salt spray testing for 24 hours ⇌ 1 year of natural environment exposure

Acetic acid salt spray testing for 24 hours ⇌ 3 years of natural environment exposure

Copper salt accelerated acetic acid salt spray testing for 24 hours ⇌ 8 years of natural environment exposure

There is no uniform standard for salt spray test duration, which should be flexibly selected based on product type, industry standards, and testing objectives. It is primarily divided into three categories:  

(1) Short-term testing (24–72 hours)  

Purpose: Rapid screening of the basic corrosion resistance of materials or coatings, such as small appliance housings, connectors, etc.  

Example: Exposed automotive hardware: 24-hour neutral salt spray test (NSS); Electronic component factory testing: 24–48 hours.

(2) Medium-term testing (72–168 hours)

Purpose: To assess durability in moderate corrosion environments, such as automotive components and outdoor building materials.

Example: Hardware fittings (doors, windows, railings): 96–168 hours; photovoltaic mounting brackets: 72–240 hours.

(3) Long-term testing (over 168 hours)

Purpose: Reliability verification in extreme environments (e.g., marine engineering, aerospace), with durations up to 1,000–2,000 hours.  

Examples: Ship components: starting at 500 hours, some exceeding 2,000 hours; aerospace fasteners: 480–1,000 hours of neutral or alternating salt spray testing.

Salt spray test duration is a dynamic parameter that requires flexible design based on product application, environment, and standards. Short-term tests (24 hours) are suitable for production line spot checks, while thousand-hour-level tests serve as the “quality gatekeepers” for marine and aerospace equipment. Reasonable time planning can avoid the cost waste of excessive testing while accurately exposing corrosion protection shortcomings.

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Nonwovens are widely used in daily life and industry due to their unique properties. From medical and hygiene products to filter materials and geotextiles, nonwovens have a wide range of applications. To ensure that nonwoven products meet the needs of various industries, the ISO 9073 testing standard was developed to provide a comprehensive assessment method for nonwovens quality control.

1. Introduction to ISO 9073 Testing Standards

ISO 9073 is a series of standards developed by the International Organization for Standardization for nonwoven fabric testing. They cover a wide range of test methods, from raw material properties and finished product physical properties to specialized properties. These standards are designed to ensure that the quality and performance of nonwoven products meet specific requirements and protect the interests of end users.

2. Key Contents of the ISO 9073 Testing Standard

The ISO 9073 testing standard series consists of multiple parts, each addressing different testing requirements. The following are some key ISO 9073 standards and their explanations:

（1）ISO 9073-1: Sample Collection and Preparation

This part of the standard specifies the sampling and preparation methods for nonwoven fabric samples prior to testing to ensure accurate and reproducible test results.

（2）ISO 9073-2: Measurement of Thickness

The thickness of nonwoven fabrics directly affects their water absorption, air permeability, and other properties. This part of the standard describes methods for accurately measuring the thickness of nonwoven fabrics.

（3）ISO 9073-3: Determination of Mass and Mass Variability

Specifies standard test methods for determining the mass (weight) of nonwoven fabrics and their variability over a specified area.

（4）ISO 9073-4: Determination of Tear Strength

This standard provides a test method for measuring the tear strength of nonwoven fabrics, a key indicator of their mechanical properties.

（5）ISO 9073-10: Determination of liquid breakthrough time and absorption rate

For nonwovens used as absorbent materials, the absorption rate and amount of liquid absorbed are extremely important. This part of the standard describes test methods for evaluating these properties. Given that certain applications require special flame retardancy for nonwovens, this part of the standard specifies test methods for the flammability of nonwovens.

（6）ISO 9073-13: Flammability test

3. Application and Significance of ISO 9073 Standards in the Nonwovens Industry

ISO 9073 testing standards provide a scientific and systematic evaluation method for the production, inspection, and application of nonwoven products. Through these standards, manufacturers can comprehensively evaluate and control the performance of nonwovens, improving product quality and gaining an advantage in the fiercely competitive market. For consumers, the application of ISO 9073 standards ensures they can obtain reliable nonwoven products that meet their needs in various scenarios.

4. Conclusion

As the application areas of nonwovens continue to expand, the performance requirements are becoming increasingly stringent. The ISO 9073 testing standard provides a scientific and systematic testing method to ensure that nonwoven products can meet increasingly stringent application requirements. In the future, as technology advances and the market develops, the ISO 9073 standard may be updated and improved accordingly to adapt to new challenges and demands. For companies in the nonwovens industry, understanding and strictly adhering to the ISO 9073 testing standard is undoubtedly key to promoting sustainable development and enhancing competitiveness.

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Twist not only affects the tensile properties of yarn but also influences its diameter, specific volume, softness, and stiffness. These factors, in turn, impact the fabric's coverage performance, thermal insulation, wrinkle recovery ability, dye absorption rate, and permeability. Twisting also affects the fuzziness of the yarn surface, making twist an important indicator of yarn structural characteristics.

In addition to using twist and twist coefficient to describe yarn twist characteristics, the twist direction within the yarn is also crucial. Twist direction refers to the inclined direction of fibers or individual yarns within a twisted yarn after twisting. There are two types of twist direction in yarn: S-twist (clockwise twist) and Z-twist (counterclockwise twist). Single yarns are generally twisted in the Z-direction, while S-twist is commonly used in plied yarns.

The commonly used twist testing methods are direct counting and untwisting and twisting. The direct counting method is generally used for short fibers and yarns, while the untwisting and twisting method is used for fine yarns. In addition, there are also secondary and tertiary untwisting and twisting methods, slip methods, etc.

1. Direct counting method

One end of the sample is fixed, while the other end is rotated in the direction of untwisting until the fibers in the yarn are completely straightened and parallel. The untwisted twist is then counted to determine the twist count per unit length of the sample. The direct counting method is the most basic method for determining yarn twist, and its results are relatively accurate, often serving as a standard for evaluating the accuracy of other methods.

However, this method has low work efficiency. If the fibers in the yarn are twisted, they are difficult to separate into parallel strands, and separating the fibers can cause the yarn to break easily. The direct counting method is generally used to count the twist count of coarse yarn or plied yarn, while the black-and-white yarn counting method can be used to test fine yarn. This involves feeding a black coarse yarn and a white coarse yarn into the same spindle to produce a fine yarn with alternating black and white stripes. The sample is clamped on the twist meter and untwisted in the same manner as the direct counting method. As the untwisting progresses, the distance between the black and white sections on the yarn increases, making it easier to count manually. Generally, untwisting to approximately half of the total twist count allows for manual counting of the remaining twist count. The total twist count on the yarn is the sum of the untwisted twist count from the twist meter and the remaining twist count from manual counting.

2. Twist removal and twist addition method

The twist removal and twist addition method is based on the assumption that, under a certain tension, the elongation of the yarn after twist removal is equal to the shortening of the yarn during reverse twist addition. A typical testing apparatus.

3. Factors Affecting Twist Testing  

3.1 Pre-tension  

The pre-tension for the untwisting and retwisting method varies between countries and regions. Excessive pre-tension can cause the pointer to return to zero slowly during reverse twisting, thereby increasing the twist during reverse twisting. In the slip method, this can lead to premature fiber slippage. Conversely, insufficient pre-tension can result in relatively reduced twist during reverse twisting, causing the test values to be lower during the untwisting and twisting method. In the slip method and the secondary untwisting and twisting method, since the errors caused by tension changes are taken into account, the method of subtracting the errors of two samples is adopted, thus minimizing the influence of tension.

3.2 Allowable elongation value  

After yarn untwisting, the elongation of the sample is measured. The allowable elongation value set for the elongation limit plays a role in preventing fiber slippage during the untwisting process. Experiments have shown that in untwisting and twisting tests, the larger the allowable elongation value, the larger the measured twist value. However, if the allowable elongation value is too large, fiber slippage at the weak points of the yarn strand will significantly affect the accuracy of the experiment. The allowable elongation value is related to the twist coefficient; the larger the twist coefficient of the yarn, the larger the allowable elongation value can be selected; conversely, it should be smaller. Generally, the variation range of yarn twist coefficients is not large, so the differences in allowable elongation values will also not be excessive.

3.3 Yarn unevenness

Yarn unevenness can affect twist testing. If the yarn contains defects such as neps or slubs, during the untwisting process, the original twist on the yarn may not be fully removed before reverse twisting begins, leading to increased testing errors. If there are long sections of unevenness on the yarn, it will affect the accuracy of the applied tension, ultimately causing additional testing errors.

In yarn twist testing, if the data deviates significantly, the above three factors affecting the test can be used as references to identify the cause, and human factors cannot be ruled out as a source of data inaccuracy. Regardless of the type of test, it must be conducted carefully and meticulously to ensure the scientific accuracy of the data.

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1.Test Scope  

Applicable to various types of sole materials, including rubber soles such as natural rubber and synthetic rubber-made sports soles, casual soles, etc.; plastic soles made of materials like polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), etc., commonly used in various fashion shoes, sandals, etc.; polyurethane soles, which are widely used in high-end leather shoes and sports shoes due to their excellent wear resistance and elasticity; and composite soles made from multiple materials, such as rubber-polyurethane composites or fabric-rubber composites, whether for adult shoes or children's shoes, During quality inspection of newly produced soles, or during the evaluation of sole performance in shoe product R&D, as well as during market supervision spot checks, it is necessary to test the tensile strength of the soles to ensure they do not easily break during normal wear and use, thereby ensuring the quality and safety of shoe products.

2.What are the test items?

Horizontal tensile strength test of the sole, longitudinal tensile strength test of the sole, comparative tensile strength test of different parts, tensile strength change test of the sole material after aging, tensile strength determination of the sole after wear treatment, tensile strength test of the sole under different temperature conditions, tensile strength assessment of the connection between the sole and the upper, analysis of the effect of additives (such as fibers, fillers, etc.) on tensile strength, Tensile strength testing between multiple layers of the sole structure, study on the relationship between sole tensile strength and sole thickness, repeatability and reproducibility testing of sole tensile strength, tensile strength change testing of the sole under humid conditions, tensile strength testing of the sole after chemical corrosion, and deformation characteristic testing of the sole during the tensile process.

3.Testing Instruments  

Tensile Testing Machine: Capable of precisely applying tensile force and measuring changes in force values during the stretching process of shoe soles, thereby determining tensile strength values; Constant Temperature and Humidity Test Chamber: Capable of adjusting and maintaining different temperature and humidity environments, used to test the tensile strength of shoe soles under special environmental conditions; Aging Test Chamber: Simulates the aging process of sole materials to assess changes in tensile strength after aging; Abrasion Tester: Subjects soles to simulated abrasion treatment and then measures their tensile strength; Microscope: Observes the microscopic structure of sole materials and their fracture patterns during tensile testing; Vernier caliper, used to measure the thickness and other dimensional parameters of shoe soles, assisting in studying their relationship with tensile strength; Electronic balance, used to weigh shoe sole samples to ensure consistency of test samples; Data acquisition system, used to record real-time force values, displacement, and other data from the tensile testing machine during the testing process, facilitating subsequent analysis.

4.Testing Methods and Standards

Testing methods typically begin by cutting a suitable-sized sample from the sole of the shoe product. A Vernier caliper is used to measure its thickness and other relevant dimensions, which are then recorded. The sample is secured in the clamps of a tensile testing machine, and parameters such as tensile speed and direction (transverse or longitudinal) are set according to testing requirements. The testing machine is then activated to perform the tensile test, while a data acquisition system records force and displacement data until the sample breaks. The tensile strength is then calculated using a formula. For tests under special conditions, such as aging, wear, or different temperature and humidity conditions, the sole samples must first be treated under the corresponding environmental conditions for a specified period of time before conducting the tensile strength test. The testing standards are based on relevant standards such as “Footwear - Whole Shoe Test Methods - Upper-Sole Adhesion Strength” (GB/T 21396 - 2008), These standards provide detailed specifications for sample preparation, testing environment, instrumentation requirements, testing procedures, criteria for determining the acceptability of test results, and reporting requirements for tensile strength testing of shoe soles. This ensures the accuracy, consistency, and reliability of test results, ensuring that the tensile strength of shoe soles meets the quality requirements for footwear products and providing consumers with reliable footwear products.

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1. Circular Track Fabric Pilling Test

According to the specified method and test parameters, use a nylon brush and abrasive, or abrasive alone, to cause the fabric to rub and pill. The fabric is then compared to a sample photo under specified lighting conditions to assess the pilling grade.

Testing equipment: Circular Track Pilling Tester, abrasive, foam plastic spacer, sample cutting tool, standard sample photo (5-grade scale), and rating box.

During measurement, the friction body can evenly abrade the fabric surface in multiple directions, following either a straight or elliptical trajectory. Therefore, the resulting pilling is similar to the pilling that occurs when the fabric is actually worn (e.g., on sleeves, elbows, knees, etc.). This method is applicable to all types of textile fabrics.

2. Martindale Fabric Pilling Test

A sample mounted on the abrasive head is rubbed against the fabric abrasive on the abrasive table a specified number of times under a specified pressure. The pilling grade is assessed by comparing the sample to a photograph under specified lighting conditions.

Testing equipment: Martindale abrasion tester, woven felt, sample spacer, punch, standard photograph, and rating box.

This method is suitable for most fabrics, but is particularly effective for wool fabrics.

3. Pilling Box Method Fabric Pilling Test

According to the specified method and test parameters, a fabric sample is placed on a polyurethane plastic tube and rolled in a rotating square wooden box lined with plastic cork. The pilling grade is assessed by comparing the sample with a photograph under specified lighting conditions.

Testing equipment: a pilling box tester, polyurethane plastic tube, sample punch, sewing machine, tape, standard sample, and rating box.

The pilling produced by this test method is similar to the pilling effect experienced during actual clothing, but the test time is longer.

This method is suitable for most fabrics, but is particularly suitable for wool knitted fabrics.

4. Sample Pilling Grade Example

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Does your clothing fade after washing? Does it turn yellow after prolonged exposure to sunlight? Does it stain when wet with sweat? These are all issues related to the color fastness of textiles, which are closely linked to the raw materials, production, and processing of textiles and clothing. They are also one of the items with a high failure rate in quality inspections. Therefore, testing the color fastness of textiles is a routine testing item in many standards.

1. What is colorfastness of textiles?

Textiles are subjected to various external influences during use, such as compression, friction, and washing. Some dyed textiles also undergo special finishing processes, such as resin finishing, flame-retardant finishing, sandwashing, and brushing. In such cases, it is essential that the colorfastness of dyed textiles remains relatively stable. This is referred to as colorfastness, and testing for colorfastness is an important method for assessing the degree of color fading.

2.What are the standards for textile colorfastness testing?

Colorfastness to washing: DIN EN ISO 105-C06, AATCC 61

Colorfastness to water: DIN EN ISO 105-E01, AATCC 107

Colorfastness to perspiration: DIN EN ISO 105-E04, AATCC 15

Resistance to artificial saliva and sweat: DIN 53160-1/-2

Resistance to friction: DIN EN ISO 105-X12, AATCC 8

Resistance to sublimation: DIN EN ISO 105-P01, AATCC 117

Lightfastness (sunlight): DIN EN ISO 105-B02, AATCC 16

Chlorine (pool) water fastness: DIN EN ISO 105-E03, AATCC 162

Saltwater fastness: DIN EN ISO 105-E02, AATCC 106

Dry cleaning colorfastness: DIN EN ISO 105-D01, AATCC 132

Heat pressing colorfastness: DIN EN ISO 105-X11, AATCC 133

Organic solvent colorfastness: DIN EN ISO 105-X05

Chlorine bleaching colorfastness: DIN EN ISO 105-N01, AATCC 188

Resistance to peroxide bleaching: DIN EN ISO 105-N02, AATCC 172

Resistance to water stains: DIN EN ISO 105-E07, AATCC 104

Resistance to alkali spots: DIN EN ISO 105-E06, AATCC 6

What is the significance of textile colorfastness testing?

The quality of colorfastness directly impacts human health and safety. If, during wear and use, dyes in textiles break down and fade due to the action of enzymes in sweat or saliva, this not only contaminates other garments or items but also allows dye molecules and heavy metal ions to be absorbed by the skin, thereby posing a risk to human health. Therefore, textile colorfastness testing is of great significance in evaluating the quality, usability, and health impact of textiles.

UTSTESTER — Textile Testing, Certification, and Research

UTSTESTER was established in 2005 as an exporter of laboratory testing instruments. All testing instruments comply with international testing standards, including ISO, AATCC, EN, DIN, JIS, ASTM, SATRA, GB, QB, BS, etc. The company has successfully obtained calibration certificates such as ISO 17025 and CE. To ensure continuous quality, UTS operations have been certified to the ISO 9001 standard.

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Colorfastness to perspiration measures a textile fabric's ability to maintain color stability without fading or bleeding when exposed to human sweat. It is a critical parameter in textile quality testing. Human sweat is a complex mixture containing water, salts (such as sodium chloride), lactic acid, urea, and other components. These elements may chemically react with dyes in the fabric or cause dye migration under the influence of sweat's moisture and temperature, thereby affecting the fabric's appearance and lifespan. This indicator directly impacts the wear experience and durability of garments, being particularly critical for intimate apparel (such as underwear and sportswear) and infant/toddler clothing.

1. Purpose of Sweat Resistance Testing

Sweat resistance testing methods evaluate a material's color durability when exposed to prolonged contact with human perspiration. This is critical for products in close contact with the body, such as apparel, footwear, and accessories. The test simulates the effects of sweat on materials over time, enabling manufacturers to assess colorfastness under real-world usage conditions.

2. Operating Procedure for Sweat Color Fastness Tester

The GT-D09 Sweat Color Fastness Tester is suitable for assessing the sweat color fastness of various textile materials, dyed fabrics, and colored textiles. It evaluates resistance to sweat, water, seawater, saliva, chlorine bleach, and phenolsulfonated ethylamine.

Sweat fastness testing follows various international standards, such as ISO 105-E04, AATCC 15, and JIS L 0848. The test involves immersing textile or leather samples in a synthetic sweat solution containing specific concentrations of salts and acids to mimic human sweat composition.

The samples are then placed in an oven at a set temperature and humidity for a specified duration (typically 4-24 hours). After the sweat exposure period, samples are rinsed and dried, then evaluated for color change or staining using a gray scale or colorimeter. This test assesses color transfer from the material to other surfaces, as well as fading or discoloration of the material itself.

Sweat colorfastness test results are reported on a scale of 1-5 or 1-8, with higher numbers indicating greater resistance to sweat staining. This test is commonly used in the textile and leather industries to ensure products maintain their appearance and quality during use.

3. Significance of Sweat Testing in Textile Testing Methods

Sweat testing within textile testing methods holds significant importance in the textile and leather industries, as it provides manufacturers and consumers with valuable information regarding material quality and performance under real-world usage conditions. High levels of sweat colorfastness indicate that materials are less likely to fade or stain when exposed to perspiration, making them more durable and long-lasting.

Sweat fastness testing methods are standardized to ensure consistency and accuracy across different laboratories and testing facilities. This enables manufacturers to ensure their products meet industry standards and comply with regulations. Furthermore, this testing method can be used to identify potential quality issues in materials before incorporating them into finished goods, allowing manufacturers to address and correct any problems before they reach consumers.

4. Features of Sweat Fastness Testing Equipment

4.1. Steel frame and weight bags are constructed from 316L stainless steel, offering acid and alkali resistance with long-term corrosion resistance.

4.2. The sweat fastness tester provides ISO and AATCC acrylic separator plates.

4.3. The perspiration tester supplies ISO and AATCC standard pressing weights.

4.4. Perspiration testing requires the use of a high-precision drying oven.

5. Other Colorfastness Tests

Sweat resistance testing instruments represent only one of several methods used to evaluate the colorfastness of textiles and leather goods. Additional tests, such as wash fastness, lightfastness, and rub fastness, can be conducted to gain a more comprehensive understanding of a material's color durability.

Wash fastness testing involves subjecting materials to repeated washing cycles to assess resistance to fading or staining. Lightfastness testing exposes materials to artificial or natural light to evaluate resistance to fading. Rub fastness testing involves rubbing one material against another surface to assess resistance to color transfer.

6. Conclusion

In summary, the perspiration colorfastness test method is a crucial assessment technique used in the textile and leather industries to evaluate a material's resistance to fading or staining when exposed to human perspiration. This standardized test ensures consistency and accuracy, providing manufacturers and consumers with valuable information about a material's quality and performance under realistic conditions. Manufacturers can thereby ensure their products meet and comply with industry standards.

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1. What is yarn evenness testing?

Yarn evenness testing, in simple terms, is the measurement of the uniformity of yarn thickness along its length. As the basic raw material for textile products, the quality of yarn directly impacts the performance and appearance of subsequent textile products. Yarn evenness, as one of the key indicators of yarn quality, directly affects the quality of textile products.

2. The significance of yarn evenness testing

Conducting yarn evenness testing serves multiple important purposes. On one hand, it helps assess the quality level of yarn. Yarn with even thickness ensures clear fabric patterns, uniform color, and reduced defects during subsequent processing. For example, in weaving processes, uneven yarn may cause defects such as horizontal bands or clouding in the fabric, severely affecting its aesthetic appeal and practicality. On the other hand, testing can promptly identify issues in the spinning process, helping manufacturers adjust process parameters, optimize production workflows, improve production efficiency, and reduce production costs. For instance, if test results indicate that uneven yarn evenness is caused by a malfunction in the draw-off mechanism of the ring spinning machine, the company can target repairs or adjustments to the draw-off mechanism to improve yarn quality.

3. Yarn Evenness Testing Methods

In practice, there are several methods available for testing yarn evenness.

Among these, the traditional visual inspection method involves experienced inspectors directly observing the appearance of the yarn with the naked eye to assess its evenness. While this method is simple and straightforward, it is highly subjective, as different inspectors may have varying criteria for judgment, and it may be difficult to accurately detect subtle unevenness in the yarn.

The capacitive yarn evenness tester method utilizes the difference in dielectric constants between yarn and air. As yarn passes through capacitive plates, the capacitance value changes with yarn thickness. By detecting changes in capacitance, the method reflects yarn evenness. This method offers fast testing speed and high precision, accurately measuring unevenness in short yarn segments.

Another method is the photoelectric yarn evenness tester, which is based on the varying degrees of light obstruction by the yarn. It converts light signals into electrical signals through photoelectric conversion and then analyzes the yarn's evenness. This method is sensitive to changes in the yarn's surface morphology and can effectively detect defects such as yarn fuzz and details.

4. Yarn Evenness Testing Criteria  

In yarn evenness testing, there are a series of important criteria used to quantify the test results. The Average Deviation Coefficient (U%) is one of the commonly used criteria, reflecting the degree of deviation between the actual linear density of each segment of the yarn and the average linear density. The smaller the U% value, the more uniform the yarn evenness. The coefficient of variation (CV%) is also used to measure yarn unevenness, similar to the average deviation coefficient, but with a slightly different calculation method. A lower CV% value indicates better yarn quality. Additionally, there is the blackboard yarn evenness test, which involves winding the yarn around a blackboard and comparing it to a standard sample to evaluate the yarn's evenness grade, categorized into superior, first-class, second-class, etc. A higher grade indicates better yarn evenness.

In the entire textile industry, yarn evenness testing plays a crucial role. From spinning mills to weaving mills, and then to garment processing factories, each stage has strict requirements for yarn evenness. For spinning mills, good yarn evenness test results indicate that the yarn they produce is of high quality, capable of meeting the needs of downstream enterprises, thereby enhancing the company's market competitiveness. Weaving mills use yarn with uniform evenness to produce stable-quality, aesthetically pleasing fabrics, reducing defect rates and improving economic efficiency. Garment processing plants utilize high-quality yarn fabrics to create comfortable, stylish clothing products that appeal to consumers. In summary, yarn evenness testing runs throughout the entire textile supply chain, serving as a critical component in ensuring textile quality and promoting the healthy development of the textile industry.

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