PET preform molds are mainly production tools for PET plastic packaging products, and then meet the needs of plastic bottle manufacturers.
PET bottle preform mold plastic molding method:
1. Extrusion blow molding: It is an extrusion blow molding of a parison, and then heating and stretching into a finished product.
Second, injection blow molding: It is injection molding blow molding the parison, and then made into a finished product through a mold.
But whether it is extrusion blow molding or injection blow molding, the parameter selection of each part is the key to the molding of plastic parts. Therefore, we must study and analyze the dimensions of PET preform molds, and then obtain the correct data.
The essentials of PET bottle preform moulding:
Element 1: The length of the core rod in the PET preform mold is generally 10: 1. Because the parison is subjected to a large injection pressure during the filling process, if its length value ratio is large, it will lead to a large twist in the core rod, which simply causes the phenomenon of uneven parison wall thickness distribution. The height of the core rod is also referred to according to the specific height of the parison. When these parisons with the correct dimensions are produced, the temperature should be stabilized at about 145 degrees Celsius, and then the highly transparent plastic parts are produced.
Element 2: The melt temperature of the preform is also the main factor for its forming. For PET molds, the temperature effect in the equipment is very large, so the temperature of the barrel must be increased to ensure the temperature of the PET melt. When the barrel temperature is 280 degrees Celsius, the melt temperature should be 290 degrees Celsius, so as to ensure that the plastic parts produced have high transparency.
Element three: The value of the preform and inflation ratio is also one of the factors that affect the molding of the plastic part. During the molding of the plastic part, the parison will experience axial stretching. The smaller the axial tension is, the larger the inflation ratio is. Together, it will lead to the uneven distribution of the thickness of the bottle wall and the unevenness of the transition orientation curve of the bottle body and the bottle body. The phenomenon.
Element four: The dimensions of the preform mouth and the thread mouth must be consistent. When dimensioning the parison, it is necessary to ensure that the dimensions of the preform mouth and the threaded mouth in the PET mold must be consistent. If they are not the same, the plasticity of the produced plastic part will be poor.