Delving into the Working Principles and Selection of Blow Molding Machines

What is a Blow Molding Machine

A blow molding machine is a machine that blows bottles. The simplest explanation is a machine that can blow plastic particles (softened into liquid) or pre-made bottle preforms into bottles through certain processing methods. A blow molding machine is a device that uses blow molding process to produce hollow containers from plastic particles. Commonly used models include single-step hollow extrusion blow molding machines using PP and PE, two-step injection-stretch blow molding machines using PET, PC, or PP, as well as newly developed multi-layer hollow extrusion and stretch blow molding machines.

Types of Blow Molding Machines

Blow molding machines are mainly divided into three categories: extrusion blow molding machines, injection blow molding machines, and special structure blow molding machines.

The processing technology is mainly divided into one-step and two-step methods. Currently, most blow molding machines are still two-step blow molding machines, which means that plastic raw materials must first be made into preforms and then blown. PET, an environmentally friendly plastic material, is commonly used today. Blow molding machines: Machines that blow bottles, the simplest explanation is a machine that can blow plastic particles or pre-made bottle preforms into bottles through certain processing methods.

Most blow molding machines today are still two-step blow molding machines, which means that plastic raw materials must first be made into preforms and then blown. PET, an environmentally friendly plastic material, is commonly used today.

Blow molding machines: Machines that blow bottles, the simplest explanation is a machine that can blow plastic particles or pre-made bottle preforms into bottles through certain processing methods.

Blow Molding Machine and Blow Molding Machine: Differences

Broadly speaking, an extrusion blow molding machine is also a type of blow molding machine! Fully automatic blow molding machines include blow molding machines, hollow molding machines, injection blow molding machines, and the more commonly used two-step blow molding machines!

In simple terms, it's a machine, specifically a machine for producing hollow containers. Generally, there are two types: pneumatic blow molding machines, which generally produce bottles within 10L, and hydraulic blow molding machines, which are generally considered for use above 10L because of their high energy consumption.

Blow molding machines: Machines that blow bottles, the simplest explanation is a machine that can blow plastic particles or pre-made bottle preforms into bottles through certain processing methods.

Currently, most blow molding machines are still two-step blow molding machines, which means that plastic raw materials must first be made into preforms and then blown. PET, an environmentally friendly plastic material, is commonly used today.

Blow molding machines: Machines that blow bottles, the simplest explanation is a machine that can blow plastic particles or pre-made bottle preforms into bottles through certain processing methods.

Blow Molding Machine Working Principle

1.Preheating

The bottle preform is irradiated by infrared high-temperature lamps to soften the defective part of the bottle preform. To maintain the shape of the bottle mouth, the bottle mouth does not need to be heated, so a certain cooling device is needed to cool it.

2.Blow Molding

In this stage, the preheated bottle preform is placed in a pre-made blowing mold, and high-pressure inflation is carried out inside it. The bottle preform is blown and stretched into the desired bottle.

Fully automatic blow molding machines combine the two operations of blowing bottles through the operation of a manipulator, eliminating the process of manually placing preheated bottle preforms into the blowing mold. This greatly speeds up production rates.

Selecting a Blow Molding Machine

1. Strictly check the quality issues, inspect the safety performance and technical performance of the product, which is the most important step in the selection process.
2. Understand the after-sales service situation. Products with guaranteed quality must have good after-sales service. When choosing, everyone can pay more attention to the after-sales service of the merchants.
3. When selecting a blow molding machine, everyone must carefully check relevant technical documents, such as user manuals, operation instructions, qualification certificates, packing lists, software operation instructions, and operate in accordance with the instructions.
4. Understand the quality management level of the production enterprise. For manufacturers certified by ISO9000 quality management system and safety certification, their product performance and technology are reliable.

Blow Molding Machine Installation

Machine Layout

The layout of the machine in the workshop should facilitate mold replacement and maintenance. Generally, leave a space of 1~1.5 meters around it, and there should be about 2 meters of space between two machines.

Installation Base Requirements

In order to avoid vibration during work, the machine should be placed on a cement foundation. The foundation thickness should be ≥459mm, the concrete grade should not be less than 200#, and the horizontal error of the foundation should be 1/1000. The exposed part of the pit in the foundation should be equipped with appropriate cover plates (for installation of duct pipelines) to prevent accidents. The bearing capacity of the installation base should not be less than 8MPa.

Installation Sequence

Installation is divided into fixed installation and movable installation.

1. Fixed installation means moving the machine to the foundation and installing anchor screws, preliminarily adjusting the level, then pouring concrete into the anchor screw holes, and finely adjusting the level after the concrete is dry. Alternatively, anchor bolts can be directly fixed on the foundation. The inclination angle of the machine is not more than 3°.
2. The method of fine-tuning the level is to use a level gauge to measure the upper surface of the locking template and the dovetail groove of the plug frame. After adjusting the horizontal direction, tighten the anchor screws evenly.
3. Movable installation allows the equipment to be moved at any time. Just place the shockproof pad (standard size, but not a standard part of LES), adjust the level with a level on the upper edge of the template, adjust the shockproof pad, and then tighten the nut. The inclination angle of the machine is not more than 3°.

Using a Blow Molding Machine

Blow Molding Machine Usage

1.When using a blow molding machine, people should carefully check whether the power supply, control system, heating system, etc., are all in normal condition, and for parts that need to be lubricated, an appropriate amount of lubricating oil should be added to ensure the normal use and operation of the equipment.

2.When using a blow molding machine, the mold should be accurately installed on the blow molding machine. Carefully check whether the buttons are in the correct position and start, debug, or operate according to the specified requirements to ensure that the machine is running and working under normal conditions.

Blow Molding Machine Maintenance

1.Before starting the plastic blow molding machine every shift, lubricate all moving parts once. (Manipulator, manipulator guide rail, opening and closing mold guide rail)

2.The swing arm can be lubricated every (3-4) days. The large chain and small chain of the heating machine can be lubricated once a month. Regularly check whether the main engine reducer and heating machine reducer lack oil. The main engine bearing can be lubricated every (2-3) months.

3.Check whether various moving parts are firm, whether screws are loose or missing, especially the center with strong impact, and whether there are any abnormalities in the belt drive area before consumption.

4.Check whether the high-pressure air source, low-pressure air source, power supply, and water source are normal.

5.Check whether various emergency stop switches, safety door switches, maintenance installation detection switches are normal.

6.Check whether the heating head enters the embryo and the local work of dropping the embryo can be normal. If the plug is not in place, adjust the pressure embryo installation nut.

7.Check whether the lamp tube is damaged or broken. Change it in time.

8.Check whether various pneumatic components leak air and whether the actions are flexible...

Temperature Adjustment of Fully Automatic Blow Molding Machine

When processing with a fully automatic blow molding machine, it is necessary to pay attention to controlling some temperatures to ensure the production of suitable plastic bottles.

1. Melting temperature TM: For crystalline polymers, it refers to the temperature at which the three-dimensional ordered state of the molecular chain structure changes to an unordered viscous flow state, also known as the melting point. It is the lower limit of the processing temperature of crystalline polymers.
2. Glass transition temperature TG: It refers to the temperature at which amorphous polymers (including the non-crystalline part of crystalline polymers) transform from the glass state to the high elastic state or from the latter to the former. It is the lowest temperature at which the molecular chain segments of amorphous polymers move freely, and also the upper limit of the working temperature of the product.
3. Non-flowing temperature: The highest temperature at which no flow occurs under a certain pressure. The fully automatic blow molding machine adds a certain amount of plastic into the barrel at the upper end of the capillary viscometer.

Equipment Maintenance of Blow Molding Machine

Fault 1: Poor transparency of PET bottle

Reasons:

1. The heating temperature is too high.

2. The heating time is too long.

3. The compressed air contains moisture.

4. The injection preform itself is not transparent.

5. The design of the preform is not suitable.

6. The blow ratio is too small.

Exclusion methods:

1. Reduce the temperature.

2. Shorten the heating time.

3. Use a dryer to remove water.

4. Improve the quality of preforms, select materials, and increase the drying degree of raw materials.

5. Improve the size design of the preform.

6. Reduce the diameter of the preform.

Fault 2: Pearl luster and whitening of PET bottles

Reasons:

1. The heating temperature is too low.

2. The wall thickness of the preform is uneven.

3. The preform thickness is too thick, and the heating penetration is insufficient.

Exclusion methods:

1. Increase the temperature or slow down the rotation speed.

2. Improve the quality of the preform.

3. Reduce the thickness of the preform, or try to increase the outer casing of the heating device to increase the surface temperature of the preform

TAG:  Blow Molding Machine  PET Blow Molding Machine

                       

Update：Feb, 23 /2024

                       

Author：HZM Machinery

Pageviews：310