How appropriate is called soft and hard? The simplest measure is: lying up, hand to neck, waist, and buttocks to the thigh was bent between these three places inside Stretch to see if there are no gaps; again a roll around and the same way to try the body parts and sag curves no gap between the mattress, if not, to prove that the mattress and the person during sleep neck, back, waist, buttocks, and legs adapt to a natural curve, so that the mattress can be said to softness and hardness.
Everyone’s hard and soft mattress preferences vary, some people like to sleep on hard beds, while others like the soft bed to sleep, what good is the hardness of the mattress it? In three decades ago, in Germany has triggered off a really good hard or soft mattress good discussion, that was caused by Germany to discuss the involvement of human engineering degree sector and triggered the study of human sleep posture.
Results of the study are: whether strong or too soft mattress sleep all adverse to human health, the right mattress should be the highly elastic mattress. That is when the force applied to the large mattress, the mattress should decline much more supportive and the human body, and vice versa. This is because the human body is a curve, only in the high elasticity of the mattress to make the human body and the back have been supported, in particular, the waist should be strong support so that the ministries of human relax and get enough rest.
S-pale as a human spine, lie down and when the need for the proper hardness of the supports, so flexible mattress on the human body comfort and quality of sleep is essential. The election can not simply rely on feel the mattress, too soft or too hard are not appropriate, but differences based on height and weight. Lighter weight soft bed to sleep so little into the mattress shoulder hip, waist, full support. Shen-weight hard mattresses are suitable for sleeping, spring will give the body strength of appropriateness of each site, especially the neck and waist are well supported. You can refer to the height, weight and soft and hard mattress comparison table, it will be more scientific.
What makes Mattress spring hard or soft?
Different types of spring steel wire have different production methods, requires certain common characteristics are the strength, high toughness and good performance of coiled spring. Spring steel wire commonly used in a variety of fabrication methods are as follows:
Health and spring steel wire drawing process: (steel) wire rod – Surface treatment – drawing (wire mattress can this method)
Patented spring steel wire: wire rod size or drawing in the middle of the specification lead bath quenching, surface treatment and then drawing.
Galvanized spring steel wire: normally finished size of hot-dip or electroplating, also used pickling hot-dip rod to the required size after the drawing.
Oil hardened spring steel wire: carbon steel or alloy steel can be used as needed, surface treatment and cold drawing to finished size after quenching and tempering treatment, this process in the automotive suspension springs and valve spring wire used on the more common spring, of course, can also be used.
Surface treatment: general use of acid phosphate, iron oxide skin removal, the formation of phosphate coating; also a few mechanical approaches. The goal is to meet the requirements of cold drawn wire drawing process to obtain a smooth surface. Fatigue life for demanding spring steel wire, such as valve spring wire, wire rod should be Flayer, decreases the surface defects, if the steel mill in grinding on steel billets, but also beneficial to reduce the defects.
Drawing: Drawing Process finished drawing process a great impact on product performance, generally about 90% of the total cut surface of the larger rate (see area reduction rate) and a smaller surface pass rate of reduction (about 10% – 20%), to ensure product toughness. For the high-strength spring steel wire, drawing wire of each pass should control the export of temperature below 150 ℃, to prevent the wire due to the emergence of the strain aging to reverse the crack, which is mainly caused by defects in steel scrap.
To this end, drawing lubricant must have good and adequate cooling, a smaller pass rate and reduce side wire drawing speed can help reduce the temperature rise. Heat treatment: steel spring wire lead used quenching bath, get very small pearlite (sorbate), for improving the performance of deep drawing performance, and springs are beneficial, alternative processes lead bath bed yet promotion, currently, there are some small diameter applications.
Annealed alloy steel wire commonly used to make to adapt to drawing deformation microstructure. Stainless steel wire heat treatment by solution heat treatment, which also aims to improve the organization to meet the needs of drawing. Quenching oil used in the finished steel, the use of induction heating or gas, fuel oil furnace, the steel is heated to austenitizing temperature insulation for some time, once the temperature quenching after tempering. Although nominally called the oil quenching, basically by water quenching or water quenching plus polymer materials.