Shrinkage test

1) Purpose: To determine the dimensional stability of woven or knitted fabrics after repeated washing in a household washing machine.

2) Principle: Before washing, mark the size on the sample, and judge the size change of the sample by measuring the change of the mark after washing.

3) Process: Select the washing and drying method, cycle and drying times according to the type of fabric and customer requirements, add standard detergent and appropriate water level to start washing and drying, and finally get the test results.

Physical performance testing

1) Main projects:

Yarn count, density, weight, tensile strength, tearing strength, seam slippage, seam strength, bursting strength, wear resistance, pilling resistance, etc.

2) Specific instructions:

Yarn count: refers to the thickness of the yarn. Most of the current ones use the British count, expressed as Ne. It is defined as a multiple of 840 yards of the length of a 1-pound cotton yarn when the public moisture regain is 9.89%.

Density: The number of yarns per inch.

Gram weight: The weight in ounces of cloth per square yard or the weight in grams of cloth per square meter.

Tensile strength: The force used when a fabric of a certain size is stretched by a tensile strength machine at a constant rate until it breaks is the measured tensile strength. Tensile strength testing includes grab sample method and strip method. Specific test methods are selected according to different testing standards and customer requirements.

Tear strength: A sample of a certain size is clamped on a tear strength meter, and an incision is made in the middle to determine the tearing direction. The tear strength meter uses a pendulum descending method to tear the sample from the incision. Measured tearing strength.

Seam slippage: After folding a fabric of a certain size, sew it along the width direction, cut it at a certain distance from the suture line, and then use a tensile strength meter to stretch it at a constant rate to a certain suture opening. The opening distance when stretched to a certain strong force is the joint slippage we measure. There are two ways to measure joint slippage: fixed opening force measurement and constant force opening measurement. When testing, select the specific test method according to different testing standards and customer requirements. Seam slippage is generally only used for testing woven fabrics.

Seam strength: Just like seam slippage, fold the fabric of a certain size and sew along the width direction. After cutting it at a certain distance from the seam, use a tensile strength meter to stretch at a constant rate to break the seam. The force used is the measured seam strength. The seam strength can be measured at the same time as the seam slippage. It is generally only used for testing woven fabrics.

Bursting strength: Under certain conditions, an expansion force is applied to a flat fabric at an appropriate angle until it breaks. This force is the bursting strength.

Wear resistance: Under known pressure, rub the sample mounted on the sample clamp and the standard friction cloth against each other in a certain trajectory under a certain pressure until the fabric has the number of broken yarns or holes required by the customer. , record the number of frictions at the end of the experiment, which is the measured wear resistance value.

Anti-pilling: Roll and rub the fabric under specific conditions for a certain period of time to observe the pilling on the surface. Pilling refers to the pile balls formed by entangled fibers standing on the surface of the fabric. Pilling refers to the roughness and unevenness of the fibers on the surface of the fabric and (or) fiber fluffing, which leads to changes in the appearance of the fabric. The pilling and pilling are evaluated by comparing the rating sample or the original fabric.

Color fastness test

1) Main projects:

Color fastness to washing, color fastness to dry cleaning, color fastness to rubbing, color fastness to sunlight, color fastness to perspiration, color fastness to water stains, color fastness to chlorine bleaching, color fastness to non-chlorine bleaching, color fastness to hot pressing Degree etc.

2) Basic content:

Color fastness to washing: The sample is sewn together with a standard backing fabric, washed, cleaned and dried, and washed under appropriate temperature, alkalinity, bleaching and friction conditions, so that the test results can be obtained in a shorter time . The friction is accomplished through a small liquor ratio and the tumbling and impact of an appropriate number of stainless steel beads. Finally, the standard lining fabric and sample are rated using a special gray card for color fastness to obtain the test results. Different testing methods have different temperature, alkalinity, bleaching and friction conditions and sample sizes. The specific selection should be based on the testing standards and customer requirements. Generally, colors with poor color fastness to washing include green blue, brilliant blue, black red, navy blue, etc.

Color fastness to dry cleaning: The same as color fastness to water washing, except that washing is changed to dry cleaning.

Color fastness to rubbing: Place the sample on the rubbing fastness meter and rub it with a standard rubbing white cloth for a certain number of times under a certain pressure. Each group of samples needs to be tested for dry rubbing color fastness and wet rubbing color fastness. The color stained on the standard rubbing white cloth is rated with a gray card, and the obtained grade is the measured color fastness to rubbing. Rubbing color fastness requires two tests, dry rubbing and wet rubbing, and all colors on the sample must be rubbed.

Sunlight color fastness: Textiles are usually exposed to light when used. Light energy destroys dyes, causing the well-known "fading", causing colored textiles to change color, generally becoming lighter or darker, and some will also change the color and light. Therefore , it is necessary to test the color fastness. The color fastness test is to put the sample and the blue wool standard cloth of different fastness levels together under the specified conditions for sunlight exposure, and put the sample with the blue wool Compare the blue wool standard cloth to evaluate the light fastness. The higher the grade of the blue wool standard cloth, the more light fast it is.

Color fastness to perspiration: Sew the sample and the standard backing fabric together, put them in the perspiration solution, then clamp them on the perspiration color fastness meter, place them in an oven at constant temperature, and then separate the backing fabrics of the sample. After drying, the standard lining fabric and the sample are finally rated with a special gray card for color fastness to obtain the test results. Different testing methods have different sweat liquid ratios, different sample sizes, and different testing temperatures and times.

Color fastness to water stains: Sew the sample and the standard lining fabric together, fully soak them in water under certain conditions, clamp them on the perspiration color fastness tester, place them in an oven at constant temperature, and then stick the sample The lining fabrics were dried separately, and finally the standard lining fabrics and samples were rated using a special gray card for color fastness to obtain the test results. Different testing methods have different sample sizes, different testing temperatures and times.

Color fastness to chlorine bleaching: After washing the fabric in chlorine bleach under certain conditions, the degree of color change is evaluated. This is the color fastness to chlorine bleaching.

Non-chlorine bleaching fastness: After the fabric is washed under non-chlorine bleaching washing conditions, the degree of color change is evaluated. This is the non-chlorine bleaching fastness.

Hot pressing color fastness: After covering the dry sample with cotton lining fabric, press it for a certain period of time in a heating device with specified temperature and pressure, and then use a gray sample card to evaluate the discoloration of the sample and the staining of the lining fabric. . The color fastness of hot pressing includes dry pressing, tidal pressing and wet pressing. The specific test method should be selected according to different customer requirements and testing standards.

Chemical performance test

1) Main test items:

Formaldehyde test, pH value test, water repellency test, oil repellency test, antifouling test, flame retardant test, fiber composition analysis, banned azo dye test, etc.

2) Basic content:

Formaldehyde test: Extract free formaldehyde or released formaldehyde from a certain amount of fabric in a certain way, and then calculate the formaldehyde content through colorimetric testing.

In today's market, textile products can be treated with resin to improve their wrinkle resistance. This resin finishing agent is synthesized directly from formaldehyde, so fabrics treated with these resins will retain a certain amount of formaldehyde. In addition, in order to improve the dye fastness, the cross-linking agent in the pigment printing paste and the fixing agent used after dyeing with direct dyes and reactive dyes will leave a certain amount of formaldehyde remaining on the clothing materials. These formaldehydes can be measured through certain testing methods.

pH value test: Use a pH meter to accurately measure the acidity and alkalinity of the fabric solution. The value read on the pH meter is the measured pH value.

Water-repellent, oil-repellent, and anti-fouling test: Use a certain method to measure the resistance of fabrics to water, oil, and stains, mainly for fabrics that have undergone three-proof finishing.

Flame retardant test: Place the sample on the flame retardant tester according to regulations and burn it to see the flame spread time.

Fiber composition analysis: First, qualitatively analyze the fibers of the fabric. There are many kinds of qualitative analysis, including combustion method, melting point method, visual inspection method, microscope section analysis method, etc. Generally, the microscope section analysis method is used, that is, using a microtome to slice the fibers. Afterwards, it is observed under a microscope to determine the type of fiber based on its appearance. Then different solvents are used for qualitative analysis based on different fibers to calculate the specific ingredient content.

Banned azo dye testing: It is one of the most important quality monitoring items in the international textile and apparel trade, and is also one of the most basic quality indicators of ecological textiles. Currently, it is mainly analyzed and tested through gas chromatography. There are three methods for testing azo dyes, textiles (textiles except polyester and genuine leather), polyester (polyester), and leather (genuine leather), so the ingredients of the product must be provided when doing azo testing.

Email: hello@utstesters.com

Direct: + 86 152 6060 5085

Tel: +86-596-7686689

Web: www.utstesters.com