Tests show that the same viscosity of the PET material forming the preform, the entrance of the raw materials than the domestic material easy to blow molding; and uniform batch of preforms, the date of production differences, blow molding process may also be quite different. The preform's black and white resolution of the blow molding process is difficult, the request for the preform is pure, transparent, no impurities, no color, point length and around the halo fit. 2.2 heating the preform heating by the heating oven to complete, the temperature set by the manual, active adjustment. Oven in the oven by the far infrared light tube far infrared radiation on the preform radiation, the bottom of the oven by the fan for the heat cycle, so that the average temperature inside the oven. The preform is moved forward in the oven while the veneer wall is heated to an average. Lamp arrangement in the oven from top to bottom was generally "area" shape, both ends of the more, the center). The heat of the oven is controlled by the number of lamps, the overall temperature setting, the oven power and the heating ratio of each section. The opening of the lamp should be carried out in conjunction with the pre-blowing bottle. To make the oven better display their role, its height, cooling plate and other adjustments are very important, if the swap is not correct, easy to show when the expansion of the mouth of the bottle (bottle larger), hard neck (neck material pull not open) And other shortcomings. 2.3 pre-blowing pre-blowing is a two-step blowing method is a very important step, it refers to the process of blowing in the stretch bar at the same time start

Blowing, so that the initial shape of the preform. Pre-blowing in this process, pre-blowing pressure and blown flow are three major process identities. The pre-blown shape of the black and white resolution of the blow molding process is easy with the bottle function black and white. The shape of the pre-blowing bottle is usually spindle-shaped, abnormal bell-shaped, handle-like, etc., resulting in abnormal shape of the reasons for local heating is not appropriate, pre-blowing pressure or blown flow is insufficient, and pre-blowing The size of the bottle depends on the pre-blowing pressure and pre-blowing position. In the production to keep the whole equipment all the pre-blowing the size and shape of the same, if different will have to find specific reasons, according to the pre-blowing situation adjustment heating or pre-blowing process. Pre-blowing pressure with the size of the bottle specifications, equipment can be different, the general capacity, pre-blowing pressure is small; equipment production can be high, pre-blowing pressure is also high.