How to make the dispensing effect of the dispenser better?
Date：2022-04-26
The dispensing effect of the dispensing machine is mainly affected by the size of the needle, the size of the dispensing amount, the distance between the needle and the working face, the dispensing pressure, the viscosity of the glue, the curing temperature curve, the glue temperature, the bubbles in the glue, and the fluid that needs special settings, etc. So, how to make the click effect of dispensing machine better?
Glue difference
Instant glue: for water-based instant glue, use safety piston and Teflon lined metal needle. For thick instant glue, use conical oblique needle. If you need flexibility, use PP needle;
UV glue: use amber syringe, white piston and oblique needle (UV shielding). If you use other kinds of needles, please order needles that can block UV;
UV curable adhesive: use black opaque needle cylinder to avoid photosensitivity;
Anaerobic glue: 10cc syringe and white PE universal piston are used;
Sealant and paste fluid: if the rebound of white piston is serious, please use safe movable type and inclined needle;
The adjustment of various parameters should be carried out from point to surface. The change of any parameter will affect other aspects. At the same time, the defects may be caused by multiple aspects. Possible factors should be checked one by one.
Size of dispensing amount
The size of the dispensing amount is generally considered to be half of the product spacing, which not only ensures that there is enough glue to bond components, but also avoids wasting glue. The length of time determines the amount of dispensing, so the dispensing time should be determined according to the temperature and the characteristics of the glue.
Dispensing pressure
Secondly, in terms of dispensing pressure, usually too much pressure is easy to cause glue overflow and too much glue; If the pressure is too small, intermittent dispensing and leakage will occur, resulting in product defects. Therefore, it needs to be adjusted according to environmental temperature, glue viscosity and other factors.
Viscosity of glue
If the viscosity is large, the glue point will become smaller, or even wiredrawing; If the viscosity is small, the glue point will become larger, which may dye the product, and the glue temperature should be 23 ℃ ~ 25 ℃; The ambient temperature has an impact on the viscosity of glue. When the temperature decreases, the viscosity increases, and the glue flow decreases accordingly, which is also prone to wiredrawing. The glue curing temperature curve has been given by the manufacturer. In practice, it should be cured at a higher temperature as far as possible to make the glue have sufficient strength after curing.
Needle size
The needle of dispensing machine usually needs to choose the needle whose inner diameter is about 1/2 of the diameter of dispensing point. In the process of dispensing, we should choose the dispensing needle according to the size of the product.
Distance between needle and working face
The distance between the needle and the working face needs to grasp the dispensing distance. We need to know that different dispensing machines need to use different needles, and each kind of needle has a specific stopping degree. Therefore, before each work, we need to calibrate the distance between the needle and the working face, that is, Z-axis height calibration.
As a friendly reminder, the glue must not have bubbles. A small bubble will cause many products without glue; When replacing the rubber hose in the middle of each time, the air at the connection shall be emptied to prevent the phenomenon of empty beating.
