What are the reasons for the increase in the defect rate in dispensing machines?

During the use of dispensing machines, have you ever wondered which factors contribute to the high defect rate in fully automatic dispensing machines? After careful analysis, we have summarized the following key points:

1. Improper Dispensing Volume   

Generally, when dispensing on any product, one principle should be followed: the dispensing volume of the fully automatic dispensing machine should not exceed half the spacing between solder points. Exceeding this volume may lead to an increase in defect rates.

2. Control of Dispensing Pressure   

In fully automatic dispensing machines, higher dispensing pressure results in a larger dispensing volume, while lower pressure reduces the volume. It is essential to set the pressure appropriately by considering factors such as adhesive properties, temperature, and environmental conditions.

3. Selection of Nozzle Size   

Typically, the diameter of the dispensing nozzle should be about half the diameter of the dispensing volume. This is the most suitable nozzle size. Using an incorrect size may cause excessive or insufficient adhesive output, increasing product defect rates.

4. Control of Adhesive Temperature   

Epoxy adhesives are generally stored at temperatures around 0–5°C and used at around 23°C. During application, it is crucial to allow the adhesive to acclimatize to the ambient environment to avoid issues like filamentation during dispensing.

5. Adhesive Viscosity   

In fully automatic dispensing machines, high adhesive viscosity results in smaller dispensing volumes, while low viscosity leads to larger volumes. Proper control of adhesive viscosity before dispensing is essential to ensure smooth operation.

6. Prevention of Air Entrapment   

The surrounding environment plays a critical role. Before dispensing, the machine should be placed in a dry, enclosed environment to prevent air ingress and avoid issues like air dispensing, thereby reducing the defect rate.

Shenzhen Jiuju Industrial Equipment Co., Ltd. has been engaged in the research and production of dispensing machines for many years. Its main products include fully automatic dispensing machines, precision dispensing machines, circular dispensing machines, and related peripheral equipment.