Polyethylene (PE) has excellent physical, chemical and mechanical properties, good toughness, flexibility and cushioning properties, electrical insulation, heat insulation and other characteristics, widely used in packaging, chemical and construction fields. PE foaming material is one of the most widely used foaming materials.
PE foaming materials can be divided into high foaming, low foaming and microporous foaming materials according to the foaming ratio, bead, sheet and profile foaming materials according to the shape, and closed and open foaming materials according to the morphology of the bubble. At present, the output of PE foaming material is only inferior to polyurethane (PU) and polystyrene (PS), but it is more widely used than PU and PS. More than 1000 kinds of products have been developed, and the development is rapid, and it has a great tendency to take the lead in the future.
Development of 1 PE foam materials
The patent of PE foaming material * was proposed by DuPont Company in 1941. The patent uses nitrogen as foaming agent to foam near the melting point of PE, but because it can not be continuously produced, it has not been widely used in industry. In 1958, Dow realized the industrialized production of high foamed PE materials with tetrafluorodichloroethane as foaming agent by non-crosslinking extrusion foaming method for the first time. At present, most of high foamed PE materials in the United States are still produced by this method.
In the early 1960s, Japan Sanhe Chemical Co., Ltd., Guhe Electric Co., Ltd. and Waterlogged Chemistry Co., Ltd. developed and developed cross-linked high foaming PE materials, and began to produce high foaming PE products in 1965. This method mainly uses cross-linking agent to improve the strength of PE melt and foaming properties.
Europe began producing crosslinked PE foams in 1970s. At present, most manufacturers produce PE foamed materials based on the technology developed in Japan. However, the products after crosslinking can not be used repeatedly, and are easy to cause environmental pollution. PE foamed sheet obtained by non-crosslinking physical foaming technology is generally known as pearl cotton in China. It has non-crosslinking closed-cell structure and is a new type of environmental protection packaging material. It is composed of countless independent bubbles produced by physical foaming of low-density PE. It overcomes the shortcomings of common foamed plastics such as fragility, deformation and poor recovery, and has separation. Water-proof, shock-proof, sound insulation, heat preservation, good plasticity, strong toughness, recycling, environmental protection, strong crashworthiness and good chemical resistance and many other advantages, is an ideal substitute for traditional packaging materials.
Since the end of the 20th century, in order to solve the demand for the production of special-shaped multi-functional products, Japanese JSP and Kaneka companies have developed intermittent production of PE foamed beads (EPE) process, through the molding device can be met with the requirements of various shapes and properties of EPE foam. The reactor impregnation method is widely used in the production of EPE. However, the autoclave foaming process is complex and the cost of equipment is high. At present, only a few companies, such as JSP Corporation of Japan, Kaneka Company, BASF Company of Germany, Korea, Korea, Korea, Korea, and Korea, have mastered the technology.
Deqing Sanhe Rubber Plastic Co.,Ltd