Sleeping Bag Testing

Sleeping bag inspection mainly conducts scientific testing and analysis on thermal insulation performance testing, filling quality testing, fabric physical property testing, structural process evaluation, safety and hygiene testing, and comfort and size 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

Thermal insulation performance testing: This is the most core testing item of the sleeping bag, usually evaluated by determining the thermal resistance (R value) or the clo value (CLO value). The testing is carried out on a thermal manikin simulating the heat dissipation of the human body. By measuring the heating power required to maintain the constant surface temperature of the manikin, the overall thermal insulation performance of the sleeping bag is precisely calculated, and the result directly determines the applicable temperature grade of the sleeping bag.

Filling quality testing: For the down-filled or synthetic cotton-filled sleeping bags. The main tests are the down content, cluster content, fill power (expansion height), oxygen index and cleanliness of the filling. For example, the high fill power down means a better warmth-to-weight ratio, and the oxygen index is the key indicator for measuring the hygiene and safety of the down, usually required to be lower than a specific value (such as 10.0).

Fabric physical property testing: Including the breaking strength, tearing strength, abrasion resistance, anti-pilling and the colour fastness (to rubbing, washing and light) of the fabric. These items evaluate the durability of the sleeping bag in the outdoor use, ensuring that the fabric is not easily damaged or faded after the force, friction and repeated use.

Structural process evaluation: Checks the sewing process, quilting methods (such as the vertical baffle, diagonal baffle and overlapping), zipper smoothness and durability, windproof strip design, and the firmness of the accessories such as the drawstrings and fasteners of the sleeping bag. A good structural process can effectively prevent the filling from shifting to form cold spots, and improve the convenience of use.

Safety and hygiene testing: In accordance with the relevant regulations, the chemical safety indicators such as the formaldehyde, decomposable carcinogenic aromatic amine dyes, pH value and odour in the sleeping bag are detected. For the children's sleeping bags, special attention also needs to be paid to the physical safety of the small parts (such as cords and buttons), ensuring compliance with the children's product safety specifications, and avoiding the risks of strangulation or accidental swallowing.

Comfort and size testing: Measures the key dimensions of the sleeping bag such as the total length, shoulder width, hip width and foot width, evaluating whether it conforms to the ergonomic design. At the same time, the air permeability and moisture permeability of the fabric are detected, to ensure that the sleeping bag has a certain moisture discharge ability while keeping warm, improving the sleep comfort.

Testing Scope

Classification by filling type: The testing scope covers the down sleeping bags (including the duck down and goose down), synthetic fibre cotton sleeping bags (such as the hollow cotton, Primaloft and Thermolite) and the mixed-filling sleeping bags. Due to the material characteristics of the different types, the key testing items (such as the fill power and compression resilience) and the standards will be different.

Classification by use season and environment: The testing needs to cover the full series of products from the summer lightweight sleeping bags to the winter extreme low-temperature sleeping bags. The different temperature ratings and environments (such as the alpine, polar and humid environments) have completely different requirements for the thermal insulation, waterproofness and moisture permeability of the sleeping bag, and the testing needs to simulate the corresponding conditions.

Classification by applicable population: The testing objects include the adult universal sleeping bags, women's dedicated sleeping bags (usually designed to better fit the female body curves), children's sleeping bags and infant sleeping bags. Different populations have specific testing specifications in the size, safety requirements (such as the cord restrictions of the children's sleeping bags) and thermal insulation needs.

Classification by product design and function: Covering the various structural designs such as the mummy type, envelope type, splittable type (couple sleeping bag) and expandable type. In addition, the sleeping bags with special functions are also included, such as the ultralight sleeping bags emphasizing the lightweight, the sleeping bags with waterproof shells, and the integrated products of the "sleeping bag pad" combining the functions of the moisture-proof pad.

Classification by the relevant regulations and supply chain: The testing scope runs through the entire industry chain, from the incoming inspection of the raw materials (down, fabric and zippers), to the semi-finished product sampling inspection in the production process, until the ex-factory inspection of the final finished products and the type inspection of the third-party laboratories, ensuring that the products meet the quality requirements in the whole process.

Testing Methods

Thermal manikin test method: This is the internationally recognized and the most scientific method for evaluating the overall thermal resistance (or clo value) of the sleeping bag. The constantly heated thermal manikin (simulating the heat production and dissipation of the human body) is placed in the sleeping bag, placed in a climate chamber with specific temperature and humidity, and by measuring the heating power required to maintain the constant surface temperature of the manikin, the thermal resistance value of the sleeping bag is precisely calculated, thereby calibrating its temperature ratings such as the comfort temperature and limit temperature.

Fill power test method: Mainly for the down filling. In accordance with the IDFB (International Down and Feather Bureau) or the national standards of various countries (such as GB/T 10288), the pretreated quantitative down is placed in a dedicated cylinder, allowed to recover naturally under a standard pressure, and the volume it occupies is measured, expressed in cubic inches per ounce (in³/oz) or cubic centimetres per gram (cm³/g). The higher the value, the better the warmth retention.

Oxygen index test method: Used to evaluate the hygiene and safety condition of the down and feathers. The sample is burned in a high-temperature oxygen flow, and the oxygen index is calculated by measuring the amount of oxygen consumed. This index reflects the level of the residual organic matter (such as microorganisms and oils) in the down. The lower the index, the more fully the down has been washed and disinfected, and the less prone it is to breed bacteria and produce odours.

Fabric physical property test methods: An electronic fabric strength tester is used for the breaking strength and tearing strength testing (such as the tongue method and trapezoid method); a Martindale abrasion tester is used to test the number of abrasion cycles of the fabric; and a rubbing fastness tester and washing fastness tester are used to evaluate the colour retention ability of the fabric. These methods are all executed in accordance with the corresponding national standards of the textile.

Size and process inspection methods: Usually under a standard light source environment, tools such as the steel tape measure and callipers are used to precisely measure the dimensions of the various parts of the sleeping bag. The process inspection evaluates the stitch density, stitch flatness, whether the quilting is uniform, zipper smoothness and the installation firmness of the accessories through the visual inspection combined with the handle, and may carry out the simulated use tests.

Chemical safety indicator test methods: A high-performance liquid chromatograph (HPLC) is used to detect the formaldehyde content and the decomposable carcinogenic aromatic amine dyes; a pH meter is used to determine the acidity and alkalinity of the aqueous extract of the fabric; and the odour is judged by the sense of smell of the trained inspectors in a specific environment. These methods strictly follow the national mandatory standards such as GB 18401 and GB 31701 (children's products).

Testing Standards

Domestic Standards:

1. GB 18401-2010, National general safety technical code for textile products

2. GB/T 10288, Testing method for down and feather

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

4. GB/T 3921-2008, Textiles — Tests for colour fastness — Colour fastness to washing with soap or soap and soda

5. GB/T 3922-2013, Textiles — Tests for colour fastness — Colour fastness to perspiration

International Standards:

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

2. ISO 105, Textiles — Tests for colour fastness

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

Thermal manikin system: The core of this system is a heating manikin that can simulate the heat dissipation of the various parts of the human body (torso, arms and legs), equipped with high-precision temperature sensors and power control units. The manikin is placed in an environmental climate chamber that can precisely control the temperature, humidity and wind speed. Through the data acquisition and analysis software, the overall thermal resistance or clo value of the sleeping bag is automatically calculated and output.

Fill power tester: Mainly composed of a graduated cylindrical measuring cylinder, a pressure plate of a known weight and a lifting mechanism. During the operation, the down of a standard mass is placed into the cylinder, the pressure plate is allowed to naturally fall within a standard time and compact the down, and the final stable graduated volume occupied by the down is read. It is the key equipment for assessing the quality grade of the down.

Oxygen index tester: A dedicated analytical instrument, usually including a high-temperature tube furnace, high-purity oxygen supply system, gas flow controller and oxygen concentration detection sensor. The instrument automatically controls the combustion process of the sample in the oxygen flow, and precisely calculates the amount of oxygen consumed per unit mass of the sample, thereby obtaining the oxygen index. It is crucial for ensuring the hygiene and safety of the down.

Fabric strength testing machine: i.e., the electronic universal material testing machine, equipped with the dedicated fabric grips. It can be used for various tests such as the breaking strength, tearing strength, seam slippage and repeated zipper pulling. The equipment precisely records the force value change and displacement during the test through the sensors, and the computer software plots the stress-strain curve, outputting the data such as the maximum force and elongation.

Abrasion and colour fastness testers: The Martindale abrasion tester evaluates the abrasion resistance by making the sample carry out the Lissajous figure friction motion with the standard abrasive under a standard pressure. The rubbing fastness tester evaluates the degree of the colour transfer by making the dry or wet standard white cloth carry out the linear reciprocating friction with the sample. These are the core equipment for evaluating the durability of the sleeping bag fabric.

Chemical analysis instruments: Including the high-performance liquid chromatograph (HPLC) and gas chromatography-mass spectrometer (GC-MS), used to precisely analyse the hazardous chemicals such as the formaldehyde and prohibited azo dyes. In addition, the pH meter is used to measure the acidity and alkalinity of the extract, and the constant temperature water bath shaker is used for the extraction operation in the sample pre-treatment, jointly constituting the technical basis of the chemical safety testing of the sleeping bag.