First, the preform is exposed to high-temperature infrared lamps to soften its body; however, the neck finish generally does not require heating in order to maintain its shape, necessitating specific cooling equipment to keep it cool.
In the actual blow-molding stage, the preheated preform is placed into a prepared blow mold. High-pressure air is then injected into the preform, stretching and blowing it into the desired bottle shape.
Beverage companies face two urgent demands regarding blow-molding equipment. First, driven by the continuous rise in plastic raw material costs, companies constantly seek to minimize packaging expenses and maximize profits, requiring advanced equipment capable of producing lighter-weight bottles. Second, the rapidly changing market requires beverage producers to respond flexibly to increasingly short product lifecycles; this entails frequent product updates during PET bottle production, necessitating minimal downtime when switching preform molds. These two pressing needs present a significant challenge for blow-molding equipment suppliers.
Closed-loop technology integrates in-line process parameter monitoring into the stretch blow-molding machine's control system, creating an automated production cycle that combines automatic control and adjustment. Intelligent machine control technology aims to enhance the machine's quality assurance capabilities. For instance, the AgrPETWallplus monitoring system is used to track various preform data points, such as wall thickness.
During operation, any data deviating from the system's set values is immediately identified. This information is promptly transmitted to the control system of the preform heating unit, which reacts quickly to independently adjust the settings for individual heating lamps within the oven. Consequently, even if data varies between individual preforms, the quality of the finished bottles remains stable and reliable without requiring changes to the initial process parameters.