1. What kind of material is memory foam? Why is it increasingly widely used in bedding?
A: Memory foam, also called space cotton, slow rebound, inert cotton or viscoelastic foam material, is a soft polyurethane slow rebound foam. Polyurethane (full name: polyurethane) is a polymer synthetic material, which is formed by the chemical reaction between the isocyanate in the organic isocyanate compound and the hydroxyl group in the polyether (or polyester) polyol to form many --NHCOO -- A polymer compound composed of groups. The slow rebound polyurethane foam is a special polyether added to the synthesis of ordinary flexible polyurethane foam, so that the foam has both a soft segment and a hard segment, showing two states at room temperature (soft segment - high elastic state; hard segment - —glass state), when subjected to external force, the soft segment of the foam is easily deformed, while the hard segment prevents deformation, resulting in slow rebound, so we can all see that the slow rebound foam is generated by external force Deformation, and the force-applying object will still leave traces (such as fingerprints, etc.) after the force is removed, and then slowly return to its original shape. The physical properties of slow-rebound foams also change with temperature. This is because when the temperature rises, more molecular chains become soft segments, which are easier to deform and recover, making people feel that the foam is softer and rebounds faster; otherwise As the temperature decreases, more molecular chains are "frozen" into hard segments, and the foam becomes stiffer. Polyurethane slow-rebound foam material has excellent shock resistance, decompression, cushioning, sound insulation and other properties. It was first developed by NASA and used in astronauts' seats to reduce the burden on astronauts when they lift off and return to the ground. Huge pressure, is also widely used in bedding, toys and transportation tools for earthquake resistance and noise prevention and so on. Pillows and mattresses made of high-quality slow-rebound foam (that is, memory foam) can disperse to the maximum extent, reduce and eliminate the pressure of the human body, and at the same time fit the human body and have a certain support for the human body, which makes people feel very comfortable. Comfortable, it helps to improve sleep and protect the spine. Therefore, memory foam is one of the most ideal bedding materials at present.
02. Memory foam is also a chemical, so is it safe? How is the toxicity to the human body?
Answer: Memory foam, that is, polyurethane slow-rebound foam, is a polymer synthetic material. The polymer material itself is non-toxic and has now been flooded in all aspects of our life (such as plastics, rubber, fibers, etc.), but synthetic polymer materials The toxicity of raw materials varies greatly, such as highly toxic raw material residues in the finished product, which will damage our health. There are two main raw materials for synthetic polyurethane slow rebound foam (memory foam), polyether and isocyanate. Polyethers are almost completely non-toxic raw materials, and isocyanates depend on what kind of compounds they are. All compounds containing NCO groups are called isocyanate compounds, but due to different chemical structures, their toxicity is also completely different. At present, toluene diisocyanate (TDI) is mostly used in the synthesis of polyurethane foam materials on the market. Toluene diisocyanate (TDI) is recognized as a highly toxic chemical in my country. The transportation, storage and production must be handled in strict accordance with dangerous goods. During the production process, it will cause harm to production operators and the environment. The residual toluene diisocyanate (TDI) in the final product ( TDI) is also bad for the health of consumers. Another isocyanate compound that has appeared in recent years for the synthesis of polyurethane slow-rebound foam: diphenylmethane diisocyanate (MDI) is much safer and more reliable, it is just a common chemical, and diphenylmethane diisocyanate (MDI) ) The late reaction rate with the hydroxyl group is 4 times that of TDI, so the residual amount of the common chemical MDI in the final product made from MDI is much smaller than that of the highly toxic chemical TDI in the TDI product, that is, relatively For TDI, MDI products are almost non-toxic and consumers can use them with confidence. Of course, new MDI products will also have some odors, mainly from a small amount of volatile additives in the manufacturing process. These additives are not toxic themselves, and the smell will disappear in 3-4 days under ventilation. In addition, MDI products are less affected by temperature, and their physical properties are relatively stable. That is to say, when the temperature changes, the hardness and slow rebound of the products do not change much, and they can better meet the individual's spine conditions all-weather.
03. In addition to the chemical structure of the main raw materials of memory foam products, what other factors will affect the safety of the product?
A: In addition to the chemical structure of the main raw materials of memory foam products, the following factors will affect the safety of the product:
(1) Quality of raw materials: The quality of starting materials, production process and control will affect the quality of polyurethane raw materials. The raw materials of internationally renowned large companies have high purity, few impurities, few harmful substances and high safety.
(2) Foaming agent: Memory foam is a foam product, and a foaming agent is used in the production process. Although most of the foaming agent is volatilized during the production process, the use of a safe foaming agent will still improve the final product. For example, water as a foaming agent must be safer than other physical foaming agents (volatile substances such as dichloromethane).
04. How to evaluate the quality of memory foam products?
Answer: First of all, the density of memory foam should not be too low, because the density is too low, the physical properties are poor, and the service life is short; secondly, talcum powder should not be added in the manufacturing process of memory foam. In order to reduce costs, many polyurethane manufacturers add talc powder to memory foam, because the price of talc powder is only 1/10-1/20 of the price of polyurethane raw materials. After adding talcum powder, the weight of memory foam Increase in order to deceive consumers and make people feel that the density of this product is not low. However, the hand feeling and physical properties of the memory foam added with talcum powder are very poor, it is easily deformed, and the service life is very short.
05. How does the production process of the memory pillow affect the quality of the product?
A: There are currently two production processes for memory pillows on the market: cutting and molding. The cutting process is to first make a large memory foam foam, and then use a cutting machine to cut out many pillows on the large foam; the molding process is to directly inject the reaction raw materials into a single pillow mold, and after the reaction is completed, then Take out the pillows one by one from the mold, and each pillow is formed independently. The resulting pillow has a thin skin on the outside, good hand feeling, good physical properties, long life, and must reach a certain density, otherwise it cannot be produced. Of course, this process is labor-intensive and expensive, but the quality of the product is far better than cutting pillows.
06. What conditions must a consumer-responsible memory foam product have?
A: Memory foam products that are responsible to consumers must meet the following conditions:
a. Use low-toxic or non-toxic raw materials, such as MDI (diphenylmethane diisocyanate)
b. Using the raw materials of major international companies, with high purity and less harmful substances
c. Do not use chemical substances as foaming agents
d. No talc added
e. The pillow adopts molding process
f. The product has reasonable density, hardness and slow rebound performance
