Summer Quilt Inspection

Summer quilt inspection mainly conducts scientific testing and analysis on fibre content and composition testing, formaldehyde content determination, pH value testing, decomposable carcinogenic aromatic amine dye testing, colour fastness to perspiration testing and colour fastness to water testing, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Fibre content and composition testing: This testing item aims to accurately determine the fibre types and percentage contents of the filling and fabric of the summer quilt through technical means such as the chemical dissolution method, microscope observation method or infrared spectroscopy method. The result is directly related to the authenticity and value of the product, and is the key basis for judging whether the product conforms to the labelling provisions and whether it is adulterated with inferior products. It is crucial for safeguarding the rights and interests of consumers and the market fairness.

Formaldehyde content determination: As a hazardous chemical substance, formaldehyde may remain in the textile during the printing and dyeing and finishing processes. For this item, in accordance with the relevant standards, the free formaldehyde in the sample is extracted by the water extraction method or the steam absorption method, and quantitatively analysed with a spectrophotometer. Strictly controlling the formaldehyde content is a necessary link to ensure the product safety and avoid the irritation or harm to the human skin and respiratory system.

pH value testing: Tests the pH value of the aqueous extract of the summer quilt fabric, to evaluate whether its acidity and alkalinity are within the range suitable for the human skin. If the pH value of the textile is excessively high (alkaline) or low (acidic), it may destroy the weakly acidic environment of the skin surface, causing discomfort such as skin itching and allergies. This indicator is an important parameter for measuring the skin-friendliness and safety of the product.

Decomposable carcinogenic aromatic amine dye testing: Some azo dyes can be reductively decomposed to release carcinogenic aromatic amines under certain conditions, posing a serious threat to human health. For this item, precision equipment such as gas chromatography-mass spectrometry is used for the pre-treatment and analysis of the sample, strictly screening whether it contains the more than twenty kinds of decomposable carcinogenic aromatic amines prohibited by the national regulations. It is the bottom-line testing of the product safety.

Colour fastness to perspiration testing: Simulates the human perspiration environment, evaluating the colour retention ability of the summer quilt fabric under the action of perspiration. The specimen is combined with a standard adjacent fabric, immersed in a simulated perspiration solution containing histidine, pressed and dried, and then the change in colour of the specimen and the staining of the adjacent fabric are rated with the grey scales. Products with poor colour fastness are prone to dye transfer, contaminating the skin or other clothes.

Colour fastness to water testing: Evaluates the colour stability of the summer quilt fabric under the condition of immersion in clean water. The specimen is attached to the adjacent fabric, immersed in distilled water or deionized water, a certain pressure is applied and maintained for a specified time, and after drying, the change in colour and staining grades are rated. This testing is particularly important for evaluating the colour fading risk caused by sweating or contact with moisture in summer.

Colour fastness to rubbing testing: Divided into the dry rubbing and wet rubbing tests, used to evaluate the degree of colour transfer of the summer quilt fabric to other fabrics through friction. A standard rubbing finger is used to rub the sample surface back and forth under a specified pressure, and then the staining grade of the white cotton cloth is rated with the staining grey scale. This indicator directly reflects the fading and staining situation of the product in daily use.

Pilling performance testing: Simulates the phenomenon of pilling formed on the fabric surface due to friction during the long-term use and washing of the summer quilt. A Martindale abrasion tester or a circular locus pilling tester is usually adopted, so that the specimen is rubbed with a standard abrasive under a specific pressure. After the test, the pilling grade is assessed by comparison with the standard photos or visual evaluation under standard lighting conditions, which is related to the appearance retention of the product.

Testing Scope

Filling material identification: The testing scope covers the common filling materials of summer quilts, including but not limited to polyester fibre (such as seven-hole and ten-hole fibres), regenerated cellulose fibres (such as lyocell and modal), natural fibres (such as silk and down) and various functional fibres (such as cool-feel fibres and antibacterial fibres). Their specific types and mixing ratios need to be clarified.

Fabric analysis: Covering the testing of the outer and inner fabrics of the summer quilt, including their weave structures (such as plain weave, twill weave and satin weave), yarn density, grammage and fabric composition (such as pure cotton, tencel-cotton blend and polyester fibre). Different fabrics directly affect the touch, air permeability and durability of the product.

Full coverage of the safety and hygiene indicators: The testing scope strictly follows the national mandatory standards, fully covering the chemical safety items directly related to human health, such as formaldehyde, pH value, decomposable carcinogenic aromatic amine dyes, heavy metals (lead and cadmium), phthalate plasticizers and pesticide residues, ensuring that the product has no hazardous substance hazards.

Colour fastness series testing: For the different media and environments that the summer quilt product may contact, the testing scope includes the colour fastness to soaping, perspiration, water, rubbing (dry/wet), light and saliva (especially applicable to infant products) and other dimensions, comprehensively evaluating the colour durability.

Physical property and durability evaluation: This scope includes the testing of the dimensional stability (shrinkage after washing), breaking strength, bursting strength, pilling, abrasion resistance, and the uniformity and compression resilience of the filling of the summer quilt, comprehensively judging the mechanical properties and long-term use quality of the product.

Functional claim verification: For the summer quilts claimed to have special functions, the testing scope needs to be extended to the relevant functional indicators. For example, for the claimed "cool-feel" function, the contact cooling coefficient (q-max value) needs to be tested; for the claimed "antibacterial" function, the antibacterial performance needs to be quantitatively or qualitatively tested in accordance with the standards; and for the claimed "anti-mite" function, the anti-mite effect needs to be evaluated.

Labelling conformity inspection: This scope belongs to the sensory and normative inspection, and it is necessary to check whether the information on the durable label (washing label) and the hang tag of the product is complete and accurate, including the fibre composition and content, maintenance methods, safety category, executed standards and manufacturer information, ensuring its conformity with the provisions of the standards such as GB/T 5296.4.

Testing Methods

GB/T 2910 (all parts), Textiles — Quantitative chemical analysis: This standard series is the core method for determining the fibre content. One or more components in the blended fabric are dissolved by selective chemical solvents, and the remaining undissolved part is washed, dried and weighed, calculating the mass percentage of each component. There are specific test procedures for different fibre combinations (such as cotton/polyester and silk/wool).

GB/T 2912.1, Textiles — Determination of formaldehyde — Part 1: Free and hydrolysed formaldehyde (water extraction method): The specimen is extracted in water at a constant temperature for a certain time, and the extract reacts with the acetylacetone reagent to form a yellow compound. The absorbance is determined with a spectrophotometer at the wavelength of 412 nm, and the free formaldehyde content in the sample is calculated by comparison with the standard working curve.

GB/T 7573, Textiles — Determination of pH of the aqueous extract: The specimen is cut into pieces and extracted with grade 3 water or potassium chloride solution under the specified temperature, liquor ratio and time conditions. The pH value of the extract is directly measured with a calibrated pH meter. This method is used to evaluate the residual acidic and alkaline substances in the textile after treatment.

GB/T 17592, Textiles — Determination of prohibited azo dyes: This method adopts gas chromatography-mass spectrometry (GC-MS) as the confirmation means. The specimen is reductively decomposed with sodium dithionite in a citrate buffer solution, to cleave the possibly present prohibited azo dyes. The released aromatic amines are subjected to liquid-liquid extraction or column extraction, and then analysed by instruments, with qualitative and quantitative comparison against the spectra of the reference substances.

GB/T 3922, Textiles — Tests for colour fastness — Colour fastness to perspiration: Acidic and alkaline simulated perspiration solutions are respectively prepared. The specimen is sewn with a standard adjacent fabric, fully soaked in the perspiration solution, and after removing the excess droplets, placed in a test device and kept in an oven for a certain time under constant pressure. After being taken out and dried, the change in colour of the specimen and the staining of the adjacent fabric are respectively rated with the grey scales.

GB/T 3920, Textiles — Tests for colour fastness — Colour fastness to rubbing: The specimen is laid flat on the base of the rubbing fastness testing machine and fixed. A standard dry rubbing cloth or wet rubbing cloth (soaked with distilled water and squeezed to maintain a 100% moisture content) is wrapped on the surface of the rubbing finger, rubbing back and forth on the specimen with the specified pressure, number of times and trajectory. Finally, the staining grade of the rubbing cloth is rated with the staining grey scale.

GB/T 4802.1, Textiles — Determination of the pilling resistance of fabrics — Part 1: Circular locus method: The specimen is fixed on the sample tube, and rubbed with the standard abrasive under a certain pressure in a circular motion trajectory. After the specified number of frictions, the specimen is removed and compared with the standard photos under the specified lighting conditions, assessing its fuzzing and/or pilling grade, usually divided into grades 1-5, with the higher the grade, the better the performance.

GB/T 35263, Textiles — Testing and evaluation for instantaneous cool feeling property: This method uses a flat-plate steady-state thermal property tester. The specimen is placed on a hot plate, and a cold plate with a lower temperature is placed above the specimen. The temperature rise curve of the cold plate is measured, and the contact cooling coefficient (q-max value) is obtained by calculating the heat flux per unit area, thereby objectively evaluating the cool-feel performance.

Testing Standards

Domestic Standards:

1. GB/T 2910, Textiles — Quantitative chemical analysis

2. GB/T 2912.1, Textiles — Determination of formaldehyde — Part 1: Free and hydrolysed formaldehyde (water extraction method)

3. GB/T 7573, Textiles — Determination of pH of the aqueous extract

4. GB/T 3922, Textiles — Tests for colour fastness — Colour fastness to perspiration

5. GB/T 3920-2024, Textiles — Tests for colour fastness — Colour fastness to rubbing

International Standards:

1. ISO 105, Textiles — Tests for colour fastness

2. ISO 3071, Textiles — Determination of pH of aqueous extract

3. ISO 13934-1, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and elongation at maximum force using the strip method

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Fibre content analysis system: This system usually includes a Soxhlet extractor, a constant temperature water bath, an analytical balance (with an accuracy of 0.0001 g), a vacuum filtration device, an oven and a dryer. The Soxhlet extractor is used to dissolve the specific fibres through the solvent circulation; the analytical balance is used to precisely weigh the sample mass before and after dissolution, and is the core equipment for the quantitative analysis by the chemical method.

UV-visible spectrophotometer: In the formaldehyde content determination, this instrument is used to measure the absorbance of the extract after colour development with acetylacetone at a specific wavelength (usually 412 nm). The instrument needs to have good wavelength accuracy, repeatability and stability, and the absorbance value is converted into the formaldehyde concentration through the standard curve method. It is a common quantitative tool in chemical analysis.

pH meter: Used to precisely measure the acidity and alkalinity of the aqueous extract of the textile. During the testing, a laboratory-grade pH meter precisely calibrated with the pH standard buffer solutions (such as pH 4.00, pH 6.86 and pH 9.18) needs to be used. Its electrode performance is stable, and the measurement accuracy can reach ±0.01 pH unit, ensuring the accurate and reliable test results.

Gas chromatography-mass spectrometer: This is the key high-end instrument for detecting the prohibited azo dyes (carcinogenic aromatic amines). The GC is responsible for separating the components in the complex mixture, and the MS carries out the qualitative (through the characteristic ion fragments and library searching) and quantitative analysis of the separated components. Its high sensitivity and high selectivity are the basis for ensuring the reliability of the test results.

Perspiration fastness tester: This equipment is usually composed of a set of stainless steel clamps, weights (providing a constant pressure) and a constant temperature oven. Its design can ensure that the combined specimen fully acts with the perspiration solution under the specified pressure (such as 12.5 kPa) and temperature (37±2 ℃), simulating the real wearing environment and ensuring the standardization of the test conditions.

Rubbing fastness testing machine: The instrument has a rubbing finger that can vertically apply a specified pressure (usually 9 N) downward, and can carry out reciprocating linear motion with a fixed stroke (such as 100 mm) and speed (such as once per second). Its mechanical structure ensures the consistency of the rubbing action, and it is the standard equipment for evaluating the rubbing staining performance of textiles.

Martindale abrasion/pilling tester: The instrument drives the specimen holder and the standard abrasive to carry out relative friction motion in a Lissajous trajectory through a vertical shaft. It can precisely control the number of frictions, pressure and motion trajectory, and is widely used for the testing of the fuzzing and pilling, abrasion resistance and felting shrinkage of fabrics, simulating the long-term use effect.

Fabric cool-feel performance tester: This is a dedicated instrument based on the heat flow principle, and its core components are the hot plate (simulating the skin) and the cold plate (or sensor). The instrument can precisely control the initial temperature difference, and quickly and accurately measure the heat flux density change, thereby calculating the contact cooling coefficient (q-max value), providing objective cool-feel data for the functional summer quilts.