Abstract: The present invention provides a method for manufacturing ethylene-vinyl alcohol copolymer pellets, which comprises passing a solution of ethylene-vinyl alcohol copolymer through a die plate of an extruder and cutting into pellets while cooling the ethylene-vinyl alcohol copolymer pellets by a coagulating fluid under flowing, and then charging into a solid-liquid separating device to separate the ethylene-vinyl alcohol copolymer pellet. According to the method of the present invention, it can produce pellets continuously in a stable manner and ethylene-vinyl alcohol copolymer pellets having uniform size and shape can be obtained.

Abstract: The present invention relates to a method for increasing the heat-resistant of ethylene-vinyl alcohol copolymer (EVOH), the method is characterized by using a mixture of acetic acid, magnesium dihydrogen phosphate, and potassium dihydrogen phosphate at a certain ratio as an acid-treating solution in the acid-treating procedure of a process for preparing EVOH. The EVOH produced by the method of the present invention exhibits an excellent heat-resistance and does not become yellowing attributed to the elevated processing temperature. Also, the EVOH generated by the method of the present invention exhibits a uniform heat-resistance since the additives are dispersed evenly in the EVOH.

Abstract: A process for continuously preparing ethylene-vinyl acetate (EVAc) copolymer, by subjecting ethylene and vinyl acetate to a solution polymerization by introducing the gaseous phase of the polymerization reaction into an impurity scrubbing column and washing the gas phase with a solvent used in the reaction, then recycling it into the reaction system, thereby impurity generated in the reaction will be removed. A reactive system having a reaction tank for co-polymerizing ethylene with vinyl acetate, an ethylene recovering tower connected with the bottom of the reaction tank, a line connecting with the bottom of the recovering tower for recovering ethylene-vinyl acetate copolymer; and an impurity scrubbing column connecting with the top of the reaction tank for removing impurity generated in the polymerization reaction.