Urea-formaldehyde resin can be obtained through a certain chemical reaction between formaldehyde and urea under the action of a catalyst. Urea-formaldehyde resin can be used to make plastics, synthetic fibers, coatings, adhesives and other materials.
Due to its abundant raw materials, simple production process, low cost and high bonding strength, urea-formaldehyde resin is widely used in urea-formaldehyde resin adhesives. Especially in the wood processing industry, 90% of the adhesives used to manufacture various artificial boards are made of urea-formaldehyde resin and its modified products.
In order to improve the stability of urea-formaldehyde resin in adhesive production, appropriately increasing the proportion of formaldehyde consumption will produce some formaldehyde residues that do not participate in the reaction, resulting in the release of formaldehyde in the future.
In addition, the process of formaldehyde and urea forming urea-formaldehyde resin is reversible, that is, under certain conditions (such as heat, aging, etc.), urea-formaldehyde resin can decompose formaldehyde, so artificial panels are made into urea-formaldehyde resin. Releases formaldehyde. The cycle will be longer, lasting 3 to 15 years.
Urea-formaldehyde resin-based artificial boards are the main source of indoor formaldehyde pollution, such as cabinets, wardrobes, bookcases, partitions, etc. In addition, coatings, wallpaper glue, etc. containing urea-formaldehyde resin will release large amounts of formaldehyde.
The dangers of formaldehyde
We all know that formaldehyde is harmful to the human body, but what are the dangers? According to research, the harmful effects of formaldehyde on the human body involve multiple systems and organs.
Respiratory system: Since formaldehyde is soluble in water, most of the formaldehyde inhaled into the human body is absorbed by the upper respiratory tract, and a small part will enter the lungs. Therefore, short-term exposure to formaldehyde is mainly due to symptoms of upper respiratory tract infection, such as sneezing, coughing, etc. Long-term exposure to formaldehyde may also cause rhinitis and asthma.
According to the indoor air formaldehyde hygienic standards, the maximum allowable concentration is 0.08 mg/m3. Research shows that when the formaldehyde content in indoor air is 0.1mg/m3, there will be a slight smell, which can cause discomfort; when the concentration exceeds 0.5mg/m3, it will irritate human eyes and cause tearing; the concentration reaches 0.6mg At/m3, people may experience symptoms of throat discomfort or pain; when the concentration reaches 12mg/m3-24mg/m3, people may feel difficulty breathing, coughing, chest tightness and headache; when the concentration is greater than 60 mg/m3, May cause pneumonia, emphysema, and even death.
Nervous system: Experiments have shown that formaldehyde can cause degeneration and necrosis of the nervous system. Long-term exposure to formaldehyde (as in anatomists) may cause symptoms such as headaches, memory loss, reduced sensitivity, decreased coordination, and sleep disturbances.
Formaldehyde is seriously harmful. In addition to formaldehyde, you must be careful to choose the correct method!