(Reported by Zhang Yunzhong) A new-type composite polyurethane memory cotton material has been invented by Liming Research Institute recently. With the common features of structural memory cotton and air-bag-type memory cotton, the new material is comfortable to feel, durable to use, low in temperature sensitivity, and high in process tolerance compared with the conventional memory cotton. The Institute has filed an invention patent application for this technology.
Industrialized production of this new material has been realized. Waist pillows and seat cushions made of it have been successfully used in ejection seat of a certain series of jet fighters, providing good protection and comfort to the pilot.
While developing the formulas of memory cotton materials to be used for different purposes, the developers need to consider both physical properties and process performance of the material. Different applications require the foam to have different physical properties. For instance, pillows must be soft and comfortable; mattresses require high hardness and good bearing capacity; cushions used in planes and other vehicles require the memory cotton to be flame retardant. In addition, the formulas need to be adjusted according to subtle changes in and actual conditions of the production process so as to meet production requirements.
Mainly made of polyether polyol that contains a lot of PO, the conventional memory cotton is significant in permanent deformation and sensitive to temperature change. For the present invention, however, the inventors developed a special kind of polyether that is dedicated to memory cotton and a kind of polyether that is rich in EO, combined the two kinds of polyether, and synthesized a high-porosity low-molecular-weight polyether polyol that is matched with high-activity foam stabilizers. The memory cotton thus prepared is much less in permanent deformation, more durable, softer and more comfortable than the conventional memory cotton. As composite material, it has the characteristics of both structural memory cotton and air-bag-type memory cotton, featuring a higher shape memory index and being non-sticky, among other advantages.