Wood furniture is a large variety of furniture. There are many kinds of products. There are also many raw and auxiliary materials used in the production of wood furniture. It basically involves forestry, chemical, metal, textile and other fields. The harmful substances in the products are mainly summarized into the following categories. . Free formaldehyde Formaldehyde (molecular formula CH2O) aqueous solution is also called formalin. Formaldehyde is a volatile substance. When the air contains a small amount of free formaldehyde, it will cause eye irritation and tearing. When the concentration of formaldehyde increases, people will feel itchy throat, nasal pain, chest tightness, cough, difficulty breathing, weakness and headache. Long-term work or living in a high concentration of formaldehyde, people will be chronically poisoned and can cause digestive disorders, visual impairment, and even nerve paralysis, respiratory mucosa and conjunctival ulceration. The main source of free formaldehyde produced in wood furniture comes from three aspects: 1 artificial board, currently mainly medium density fiberboard, particle board, plywood and blockboard, etc., generally used as the substrate of furniture, of course, also including decorative wood-based panels . The 2 parts of the adhesive contain free formaldehyde. 3 The end faces of the parts of the wooden furniture are not edge-sealed and some of the connecting holes are installed in the section, and these parts are easy to release free formaldehyde. In the manufacture of wood-based panels (including veneered wood-based panels), a large amount of synthetic resins such as urea-formaldehyde phenolic resin is used as an adhesive. Since urea-formaldehyde resin itself has good water solubility, low price, fast curing speed, high bonding strength, and good storage stability, it is widely used. Used in the processing and production of wood-based panels. The urea-formaldehyde resin is a condensate of urea and formaldehyde. When the artificial board or the processed veneer is hot pressed, the pre-condensed urea-formaldehyde resin is reticulated by the curing agent and heat, that is, cured. After the hot pressing, a small amount of free formaldehyde remains in the artificial board. The linear resin in the artificial board which is not reticulated when solidified, and the partially cured resin will still decompose into free formaldehyde under certain temperature and humidity conditions. These free formaldehyde will continue to emanate during the use of furniture, causing environmental pollution and harm to human health. 2. Soluble heavy metals such as lead, cadmium, chromium and mercury Lead, cadmium, chromium and mercury are common toxic substances that are clearly harmful to humans. In particular, lead can damage human nerves, hematopoiesis and reproductive system, which is very harmful to children and adolescents, affecting children's growth and development and intellectual development. Therefore, the control of heavy metal pollution such as lead has become a worldwide hot spot and development trend. Long-term inhalation of cadmium dust can impair kidney or lung function. Long-term exposure to chromium compounds causes dermatitis wet diagnosis. Chronic mercury poisoning mainly affects diseases such as the central nervous system. The soluble heavy metals in wood furniture products mainly come from the paint film on the surface of the product. Especially in some color paint furniture, children's furniture occupies a certain proportion. The coating is mainly the color pigment of paint, such as red dan, lead and chrome. Yellow, lead white, etc. In addition, since inorganic pigments are usually made from natural minerals and processed through a series of chemical and physical reactions, it is inevitable to entrain trace amounts of heavy metals. 1.cylindrical milling cutter End Mill,Roughing End Mill,Carbide Square Drill Bit,Coating Machine Tools Behappy Crafts (suzhou)Co.,Ltd , https://www.haoyuebehappy.com
Used for processing flat surfaces on horizontal milling machines. Cutter teeth are distributed on the circumference of the milling cutter, and are divided into straight teeth and spiral teeth according to tooth shape. According to the number of teeth and coarse teeth and two kinds of fine teeth. The helical tooth rough tooth milling cutter has fewer teeth, high tooth strength and large chip space, which is suitable for rough machining. Fine-tooth milling cutters are suitable for finishing.
2. face milling cutter
Also known as disc milling cutter, used for vertical milling machine, end milling machine or gantry milling machine processing plane, end face and circumference have cutter teeth, also have coarse teeth and fine teeth. The structure has three kinds: integral type, insert type and transferable type.
3. End milling cutter
Used for processing grooves and step surface, knife teeth in the circumference and end face, can not work along the axial feed. When the end mill has end teeth through the center, axial feed can be provided.
4. Three-side edge milling cutter
Used for processing all kinds of grooves and steps, its two sides and circumference are provided with cutter teeth.
5. Angle milling cutter
For milling grooves at a certain Angle, there are two kinds of single Angle and double Angle milling cutters.
6.Saw Blade milling cutter
Used for machining deep grooves and cutting off workpieces, there are more cutter teeth on the circumference. In order to reduce the friction during milling, there are 15 '~1° auxiliary Angle on both sides of the cutter teeth. In addition, there are keyway milling cutters, dovetail slot milling cutters, T - shaped slot milling cutters and various forms of milling cutters.