Definition of Wide-Mouth Bottle Blow Molding Machines and Factors Affecting Production
Bencheng Machinery2026-01-23 08:25:04
A wide mouth bottle blowing machine refers to a machine that blows bottles. Simply put, it is a machine that can blow plastic particles (softened into liquid) or pre made bottle preforms into bottles through a process. Plastic hollow containers are widely used in the beverage, pharmaceutical, cosmetics, food, and chemical industries due to their lightweight, low cost, and high safety. They have attracted many manufacturers to choose plastic containers instead of traditional glass containers.
Preform
Bottle preforms, also known as preforms, are PET pellets that are injection molded. They require a recycling ratio of no more than 10% and a recycling frequency of no more than two times. After injection molding, the bottle blank or the bottle blank used after heating should be cooled for more than 48 hours, and the storage time of the used bottle blank should not exceed 6 months. Different production dates, especially bottles with long intervals, should not be mixed. The main reasons are the different types of raw materials used for the bottle blank, the proportion of secondary materials mixed in, and the residual stress inside the bottle blank. These factors have a significant impact on the blowing molding process and should be treated specifically according to the actual situation.
Heat
The heating of the preform is completed by a heating furnace, which is manually set and automatically adjusted. The height of the heating furnace should be around 25mm, and it should be around 19.6mm away from the conveyor wheel. The preform runs continuously through the entire oven on the conveyor wheel, so that the preform is heated more evenly and can be formed well, overcoming the previous disadvantages of stationary heating and uneven heating caused by manual rotation. However, if the heating furnace is not adjusted properly, it can cause uneven distribution of the wall thickness of the blown bottles (light above and heavy below), excessive enlargement of the bottle mouth, hard neck and other product defects, and even torque failure of mechanical components. The temperature in each area can be adjusted according to the molding situation of the product, while considering the opening of the oven light tube. In addition, the setting of the output power of the oven also has a significant impact on the heating of the preform, as it controls the overall heat output of the oven. When the wide mouth bottle blowing machine is not turned on for a long time and restarted, the initial output power should be set higher accordingly, and gradually reduced to normal during normal production. The output power is generally around 80%, especially when the ambient temperature is below 5 ℃, the effect is obvious.
The production process of blow molding is also related to the production environment temperature, and the ambient temperature is generally suitable at room temperature (around 22 ℃). If the temperature is too high, the product is prone to condensation and clumping; The temperature is too low, and the product performance is unstable when the machine starts. The specific operation should be adjusted according to the actual situation and experience.
Pre blowing
The role of pre blowing in the blowing process is to shape the preform and increase its longitudinal strength by stretching it longitudinally with a stretching rod. The entire process involves the pre blowing cam pushing the three-way valve to the pre blowing position during the bottle blowing process, and the one-way valve cooperating to complete it. The pre blowing position, pressure, and flow rate can all affect the quality of the bottle.
Position: If the pre blowing position is advanced, defects such as deviation and thinning of the center point at the bottom of the bottle, uneven thickness and whitening of the foot wall, heavy weight at the top and light weight at the bottom, hard neck, and even bottom penetration may occur; If the pre blowing position is incorrect, defects such as light up and heavy down, thickening of the center point, and indentation may occur.
The pre blowing air flow rate is controlled by a one-way valve, and it is generally recommended to open it 3-4 times. Large airflow, heavy bottom, thin and skewed center point, white feet, uneven wall thickness; The airflow is small, the center point becomes thicker, and the weight of the segmented parts exceeds the standard.
Pressure: The recommended pre blowing pressure is 0.8-1MPa. When the pressure is high, it may cause the top to be heavy and the bottom to be light, the center point to be skewed, uneven foot wall thickness, whitening, etc; When the pressure is low, it cannot be fully stretched, the bottom is heavy, and the center point is thick.
The forming condition of the bottle feet and center point has a significant impact on the quality of the bottle, and improper adjustment often causes fatal defects such as bottle bursting (under normal experimental conditions) and leakage.
Preform
Bottle preforms, also known as preforms, are PET pellets that are injection molded. They require a recycling ratio of no more than 10% and a recycling frequency of no more than two times. After injection molding, the bottle blank or the bottle blank used after heating should be cooled for more than 48 hours, and the storage time of the used bottle blank should not exceed 6 months. Different production dates, especially bottles with long intervals, should not be mixed. The main reasons are the different types of raw materials used for the bottle blank, the proportion of secondary materials mixed in, and the residual stress inside the bottle blank. These factors have a significant impact on the blowing molding process and should be treated specifically according to the actual situation.
Heat
The heating of the preform is completed by a heating furnace, which is manually set and automatically adjusted. The height of the heating furnace should be around 25mm, and it should be around 19.6mm away from the conveyor wheel. The preform runs continuously through the entire oven on the conveyor wheel, so that the preform is heated more evenly and can be formed well, overcoming the previous disadvantages of stationary heating and uneven heating caused by manual rotation. However, if the heating furnace is not adjusted properly, it can cause uneven distribution of the wall thickness of the blown bottles (light above and heavy below), excessive enlargement of the bottle mouth, hard neck and other product defects, and even torque failure of mechanical components. The temperature in each area can be adjusted according to the molding situation of the product, while considering the opening of the oven light tube. In addition, the setting of the output power of the oven also has a significant impact on the heating of the preform, as it controls the overall heat output of the oven. When the wide mouth bottle blowing machine is not turned on for a long time and restarted, the initial output power should be set higher accordingly, and gradually reduced to normal during normal production. The output power is generally around 80%, especially when the ambient temperature is below 5 ℃, the effect is obvious.
The production process of blow molding is also related to the production environment temperature, and the ambient temperature is generally suitable at room temperature (around 22 ℃). If the temperature is too high, the product is prone to condensation and clumping; The temperature is too low, and the product performance is unstable when the machine starts. The specific operation should be adjusted according to the actual situation and experience.
Pre blowing
The role of pre blowing in the blowing process is to shape the preform and increase its longitudinal strength by stretching it longitudinally with a stretching rod. The entire process involves the pre blowing cam pushing the three-way valve to the pre blowing position during the bottle blowing process, and the one-way valve cooperating to complete it. The pre blowing position, pressure, and flow rate can all affect the quality of the bottle.
Position: If the pre blowing position is advanced, defects such as deviation and thinning of the center point at the bottom of the bottle, uneven thickness and whitening of the foot wall, heavy weight at the top and light weight at the bottom, hard neck, and even bottom penetration may occur; If the pre blowing position is incorrect, defects such as light up and heavy down, thickening of the center point, and indentation may occur.
The pre blowing air flow rate is controlled by a one-way valve, and it is generally recommended to open it 3-4 times. Large airflow, heavy bottom, thin and skewed center point, white feet, uneven wall thickness; The airflow is small, the center point becomes thicker, and the weight of the segmented parts exceeds the standard.
Pressure: The recommended pre blowing pressure is 0.8-1MPa. When the pressure is high, it may cause the top to be heavy and the bottom to be light, the center point to be skewed, uneven foot wall thickness, whitening, etc; When the pressure is low, it cannot be fully stretched, the bottom is heavy, and the center point is thick.
The forming condition of the bottle feet and center point has a significant impact on the quality of the bottle, and improper adjustment often causes fatal defects such as bottle bursting (under normal experimental conditions) and leakage.
