What are the differences between fully automatic dispensing machines and fully automatic dispensing machines? What is the principle

The fully automatic dispensing machine is a unique adhesive that is pre applied to the surface mounted parts of the PCB board to fix the fixed surface mounted components. After drying and solidifying, it is then subjected to a wave soldering machine. The dispensing process is fully automated according to the program flow.

1. Tube shaped rotation and glue dispensing control; General, digital time control.

2. The dispensing pen tip is set to touch the power switch on the axis, making it easy to operate in practice; No gas pressure is required, and it can be plugged in to work.

Archimedean drip pump:

1. Principle: Air is compressed and fed into the rubber bottle (injection needle), and the glue is embedded into the cutting tube. The glue flows through the extruder screw that rotates at a fixed time and a special speed. The rotation of the extruder screw generates shear stress on the adhesive, causing the adhesive to flow down the external thread. The rotation of the extruder screw continuously charges pressure on the adhesive, allowing it to be discharged from the drip nozzle.

2. Features: Possess the ability to coordinate the diameter of adhesive dots without fixed or fixed limitations. Adjustments can be made based on mobile software. However, when dripping large glue points, the screw rotation time of the extruder is long, which will reduce the production volume of the entire equipment. In addition, the viscosity and flowability characteristics of the adhesive can jeopardize its reliability.

The principle of fully automatic glue dispenser is that the fully automatic dispensing machine and glue dispenser use a piston rod to control the amount of glue produced. The size and flow speed of the strong adhesive are determined based on the movement trajectory of the piston rod inside the rubber cylinder. The displacement of the piston rod inside the rubber cylinder will result in a corresponding change in the amount of rubber produced.

When operating the dispensing and dispensing machine equipment throughout the entire process, in order to accurately control the dispensing amount, it is necessary to achieve that goal based on precise calculations. General packaging manufacturers often use electronic rulers to accurately measure the trajectory of the piston rod, and then based on its specific volume of colloidal solution and the proportion of strong adhesive, after professional and standardized precise calculations, obtain the size of the adhesive output.

The control of the dispensing volume of automatic dispensing and dispensing machines is an eternal and unchanging scientific research topic in the field of packaging. The size of the adhesive output and the length of the adhesive output time have significant practical implications for the quality hazards of packaged goods.

What are the differences between fully automatic dispensing machines and fully automatic dispensing machines? What are the key factors that affect the amount of glue produced

Setting the dispensing time

The size of the adhesive dot diameter should be half of the product spacing. That way, it can ensure that there is sufficient strong adhesive to bond the components and prevent too much strong adhesive. The amount of glue to be dispensed is determined by the time length set by the fully automatic glue dispensing machine. Specifically, the dispensing time should be selected based on the production and manufacturing conditions (indoor temperature, viscosity of strong glue, etc.).

Glue dispensing pressure setting

The dispensing machine equipment provides a certain pressure to the needle cylinder or oil distributor to ensure the supply of strong adhesive, and the pressure size determines the amount of adhesive supplied and the rate of strong adhesive discharge. High pressure can easily lead to the overflow of strong adhesive and excessive clamping force; If the pressure is too low, intermittent dispensing and leakage may occur, resulting in product defects. The pressure should be selected based on the characteristics of the strong adhesive and the working temperature during operation. If the working temperature is too high, the viscosity of the strong adhesive will decrease and the flowability will improve. At this time, it is necessary to reduce the pressure value, and the opposite is also true.

Needle or nozzle size

In practical work, the inner diameter of the needle should be around half of the diameter of the dispensing point. Throughout the dispensing process, the selection of the dispensing needle should be based on the size of the product. Products with significant differences in size should choose different needles, which can ensure the quality of adhesive points and improve productivity.

When dispensing, the distance between the dispensing needle and the circuit board, as well as the inner diameter of the needle, are important parameters. If there is an error in the spacing between the needle and the base steel plate, the actual operator will never be able to obtain the appropriate dispensing result. Under the condition that other main parameters do not change, the larger the distance between the dispensing needle and the circuit board, the smaller the diameter of the dispensing point, and the higher the aspect ratio of the dispensing point; The smaller the distance between the dispensing needle and the circuit board, the larger the diameter of the adhesive point, and the lower the aspect ratio of the adhesive point.

The diameter of the adhesive point is determined by the inner diameter of the needle and the distance between the needle and the base steel plate. When the inner diameter of the needle is the same, if the distance between the needle and the base steel plate is changed, even if the clamping force of the points is completely the same, it is very likely to obtain different adhesive spot diameters and shapes.

However, changing the diameter of the adhesive point based on the aspect ratio of the adhesive needle also has certain scope limitations. The diameter of the adhesive point is unlikely to be lower than or even equivalent to the inner diameter of the applied needle. It is caused by the relative interaction force between the interfacial tension (f1) between the adhesive and the needle and the interfacial tension (F1) between the adhesive and the base steel plate.

To achieve good dispensing results, it is crucial for F1 to exceed f1, that is, Fl>fl.

The basic parameters for determining the size of F1 and F1 are the diameter of the adhesive point and the inner diameter of the needle. Generally, it is specified that the diameter of the adhesive point is greater than 2 times the inner diameter of the needle.

Reasonable operation of the dispensing machine and the clamping force must pay attention to the hazards of different pressures, dispensing times, needle or nozzle sizes on dispensing volume.

A

Reducing pressure, reducing dispensing time, and needle size can all reduce dispensing volume. Thinner and more dilute liquids, such as sulfonic acid acrylate adhesives or paint thinners, should reduce pressure, reduce dispensing time, or use thinner needles;

B

Increasing pressure, dispensing time, and needle size will increase the amount of glue produced. Thicker and thicker liquids, such as mud like or lubricating grease, with higher pressure, longer dispensing time, or thicker needles;

High pressure or reduced dispensing time can accelerate dispensing speed and result in higher production volume;

Reducing pressure or increasing the dispensing time will improve the accuracy of the adhesive point size.

Suggest selecting based on the specific quality regulations of the product itself.