What items are included in leather testing
November 12, 2021
Some items of leather testing:
Physical performance test: tensile strength, elongation, tear strength, tensile strength, shrinkage temperature, burst height, burst strength, apparent density of leather, coating fold fastness (normal temperature/low temperature), bottom leather fold fastness , Water absorption, heat resistance, oil resistance, friction resistance, flame retardancy of fur
Chemical performance test: pH value, hexavalent chromium content, formaldehyde content, banned azo dyes, smell, fur volatile content, leather moisture content and volatile matter
Color fastness: color fastness to rubbing, color fastness to water stain, color fastness to perspiration, color fastness to light
Content determination: formaldehyde content, hexavalent chromium, azo, heavy metals, PCP, TeCP, OPP, free fatty acid content, organotin compounds
Material identification: material identification (leather, fur/artificial leather/synthetic leather, etc.)
Analysis items: component analysis, toxic and hazardous substance testing, environmental protection testing, azo testing.
Leather testing significance
Leather is the main raw material of the leather products industry, mainly used for shoe uppers, shoe soles, clothing, luggage and so on. Therefore, the quality of leather products mostly depends on the raw materials used-the quality of leather. The quality of leather is evaluated through visual inspection, wearing test, microstructure inspection and physical and chemical analysis inspection.
Boxes, bags, gloves, ticket holders, belts, etc. are indispensable daily necessities in people's lives. Generally speaking, the fabrics of medium and high-end bags and bags are mainly made of natural leather materials. As the end product of leather, leather goods are closely related to the development of the two. Leather development is a prerequisite for the development of leather goods, and the speed of leather development restricts the development of leather goods.
Leather products are products processed with fur and leather as the main raw materials, including boots, gloves, coats and hats, bags, cultural and sports goods, and leather products for furniture. The production and processing technology of leather products and the selection of materials determine that the finished products may produce some chemical hazards, such as dimethyl fumarate, hexavalent chromium, azo dyes, formaldehyde, pentachlorophenol and so on. Nowadays, my country's current leather products have stipulated the limit requirements for azo dyes and formaldehyde, but there is no limit requirement for the hexavalent chromium index. This index is also the main reason for product recalls in the world. Chromium is a multivalent metal ion, which mainly exists in two forms: trivalent and hexavalent. Different valences have different impacts on the environment and biological effects. The second form of chromium (hexavalent chromium) has been proven to have health risks to human health. Studies have shown that hexavalent chromium remaining in leather can be absorbed by the human body through the respiratory tract, causing damage to the gastrointestinal tract, liver and kidney function, and may also damage the eyes, causing retinal hemorrhage, optic nerve atrophy, etc.; hexavalent chromium is easy to penetrate The skin enters the body, causing a series of health hazards.According to the medical statistical dose-response results, the allergic reaction threshold on normal skin is 10mg/kg, and among the 14 chromium allergic patients, the allergic threshold for 1 patient is 1mg/kg; If there is an irritant, in 17 chromium allergy patients, the allergy threshold for 2 patients is 1mg/kg. Based on the above research, Denmark proposed to the European Union to strictly control the content of hexavalent chromium in leather products, and this proposal was recognized by the European Union.