1, the size of the amount of dispensing
According to work experience, the size of the dot diameter should be half of the product spacing. This ensures that there is sufficient glue to bond the components and avoid excessive glue. The amount of dispensing is determined by the length of time. In practice, the dispensing time should be selected according to the production conditions (room temperature, glue viscosity, etc.).
2, dispensing pressure
Dispenser equipment to the needle (glue gun) to provide a certain pressure to ensure that the glue supply, the size of the pressure to determine the amount of glue and glue out of the speed. Pressure is too easy to cause glue overflow, glue too much; pressure is too small will appear dispensing intermittent phenomenon and leakage, resulting in product defects. Should be based on the nature of the glue, the working environment temperature to select the pressure. High ambient temperature will make glue viscosity smaller, better mobility, then need to lower the pressure value, and vice versa.
3, needle size
In the actual work, the size of the needle should be the size of the point of plastic dot diameter of about 1/2, dispensing process, according to the size of the product to choose dispensing needle. Size difference between the products to choose a different needle, so that both can guarantee the quality of plastic dot, but also can improve production efficiency.
On - line jet dispenser SD950
4, the distance between the needle and the face
Different dispenser equipment with different needles, some needles have a certain degree of stop. The calibration of the distance between the needle and the face should be made before the start of each work, ie the Z axis height calibration.
5, the viscosity of glue
The viscosity of the glue directly affects the quality of the dispensing. Viscosity, the plastic point will become smaller, or even drawing; viscosity is small, plastic spots will become larger, and thus may be infiltration products. Dispensing process, should deal with different viscosity of the glue, select a reasonable pressure and dispensing speed.
6, glue temperature
General epoxy glue should be stored in 0 ~ 5℃ refrigerator, use half an hour ahead of time to make the glue temperature and work environment consistent. Glue the use of temperature should be 23℃ ~ 25℃; ambient temperature on the viscosity of the glue a great impact, the temperature decreases viscosity increases, the corresponding amount of plastic flow smaller, more prone to drawing phenomenon. Other conditions of the same circumstances the same ambient temperature difference of 5℃, will cause the amount of plastic volume changes occur 50%, so the ambient temperature should be controlled. While the ambient temperature should also be given to ensure that the temperature is too high glue point easy to dry, affecting the cohesive force.
7, curing temperature curve
For the curing of the glue, the general manufacturer has given the temperature curve. In practice should be as much as possible to use a higher temperature to cure, so that the glue after curing enough strength.
8, bubble
Glue must not have bubbles. A small bubble will cause many products without glue; each time the replacement hose should be empty at the junction of the air to prevent the phenomenon of air play.
9, need special set of fluid
Instant glue: the use of water-based instant glue with a safe piston and Teflon lined with metal needles, the use of thick instant glue, the use of tapered oblique needle, for flexible use of PP needle.
UV glue: the use of amber syringes, white pistons and oblique needles (can be covered with ultraviolet light) if the use of other types of needles, please customize the needle can be covered with UV.
Light curing adhesive: use black opaque syringes, to avoid the light.
Anaerobic Adhesive: Use 10CC syringe and white PE universal piston.
Sealant and paste fluid: If you use a white piston rebound serious, please use a safe type, the use of oblique needle.