<span style=";font-family:Microsoft Yahei;color:rgb(51,51,51);letter-spacing:1px;font-style:normal;font-size:17px;background:rgb(255,255,255 ; Due to technical bottlenecks and differences in equipment, the density of domestically produced polyurethane is generally lower than 100D, while the highest abroad can reach 150D. Secondly, even products with the same density will vary greatly, mainly in terms of formula, process and raw materials. Caused by the difference, that is to say, high-end slow rebound materials must be high-density, but high-density materials are not necessarily high-end materials.
2. Slow rebound time: Most internationally renowned brands of memory foam have a slow rebound time of more than 10 seconds, such as the "Big Three". However, the rebound time cannot directly determine its quality, because the rebound time can be adjusted by adding chemical raw materials. The simple way to identify good and bad sponges is: see whether their complete rebound time is the same under the same pressure extrusion, such as a If it can fully rebound within the same time after being squeezed tens of thousands of times, it is a good sponge. Many businesses on the market add chemical raw materials in order to achieve a rebound time of 3~5 for numbing. Most of these sponges will have a slower and slower rebound time after being squeezed, and even the sponges cannot fully rebound and recover.
3. Manufacturing process: There are two manufacturing processes for slow rebound: cutting and molding. Cutting is to buy the finished slow rebound sponge and cut it into the shape of a pillow. Because the molding relies on cutting rather than mold + additives, no other additives are added, so even the density of pure polyurethane can only reach 40~70 density; Molding is made from a mold through a series of processes such as foaming and vacuuming, which is much more complicated. The density increases to about 70~100, the hand feels good, and the service life is related to this;
4. Feel and Temperature sensing: The high-end slow-rebound sponge feels very comfortable to the touch. It feels like kneading dough when you pinch it. If it rebounds slowly, it will either feel a bit shaky or stiff. At the same time, this high-end slow rebound also has good temperature sensing and will become softer as the temperature rises. When the human body comes into contact with the slow rebound material, as the body temperature is transferred, the pillow will become softer and can Better wrapping and supporting the human body;
5. Service life: Slow rebound generally will not deform after more than 5 years of use, and top slow rebound can It will not deform for about 15 years. On the contrary, the ones made by cutting process or the quality are poor, and usually can only be used for 1 to 2 years.