Analysis of Factors in Plastic Forming of PET Preforms
PET preform molds are mainly used in the production of PET plastic packaging products to meet the needs of plastic bottle manufacturers.
PET preform mold molding method
1. Extrusion Blow Molding: It is an extrusion blow molding of a parison, which is then heated and drawn into a finished product.
2. Injection Blow Molding: It is an injection molding blow molding of a parison, and then a finished product is produced through a mold.
But whether it is extrusion blow molding or injection blow molding, the parameter selection of each part is the key to plastic molding. Therefore, we need to study and analyze the dimensions of the PET preform mold to obtain the correct data.
Factors in forming PET preform molds
Factor 1: The length of the mandrel in the PET preform mold is generally 10:1. Because the parison receives the maximum injection pressure during the filling process, if the length ratio is large, the mandrel is bent more, which tends to cause uneven distribution of the parison wall thickness. The height of the mandrel is also referred to according to the specific height of the parison. When these parisons of the correct size are produced, the temperature is stabilized at about 145 degrees Celsius to produce a highly transparent plastic part.
Factor 2: The melt temperature of the preform is also a major factor in its formation. For PET molds, the temperature influence in the equipment is very large, so the temperature of the barrel is increased to ensure the temperature of the PET melt. When the temperature of the barrel is 280 degrees Celsius, the temperature of the melt is 290 degrees Celsius, so as to ensure high transparency of the produced plastic parts.
Factor 3: The value of the preform and the inflation ratio is also one of the factors affecting the molding of plastic parts. During the molding of the plastic part, the parison undergoes axial stretching. The smaller the axial stretching, the larger the inflation ratio, and the resulting plastic parts have uneven thickness distribution of the bottle wall and the unevenness of the transition position of the bottle body and the bottle body. The phenomenon.
Factor 4: The size of the preform and the threaded opening should be uniform. When dimensioning the parison, it is necessary to ensure that the size of the preform opening and the threaded opening in the PET mold are uniform, and if it is not uniform, the sealing of the produced plastic part will be poor.