The main factors that affect the dispensing effect of the dispensing machine include the size of the needle, the amount
of dispensing, the distance between the needle and the working surface, dispensing pressure, viscosity of the glue,
curing temperature curve, glue temperature, bubbles in the glue, and fluids that require special settings. So the editor
of Helishi believes that improving the effect should also start from these areas.
1: Selection of Needles for Different Glues Instant glue: Use
a safe piston and lined metal needle for water-based instant glue; For thick instant glue, a conical
oblique needle is required, and if flexibility is required, a PP needle is used
UV glue: Use an amber
syringe, white piston, and angled needle tip
UV curable adhesive: Use a black opaque syringe to avoid
photosensitivity
Anaerobic adhesive: use a 10CC syringe and a white PE universal piston
Sealant
and paste fluid: If using a
white piston with severe rebound, please switch to a safe movable type and use an angled needle
2: the amount of glue applied is generally considered to be half the diameter of the product
spacing, which ensures sufficient glue to bond the components and avoids wasting glue.. The length
of time determines the amount of glue applied, so the glue application time should be determined based on temperature
and the characteristics of the glue In terms of glue filling pressure, usually too much pressure
can cause glue overflow and excessive amount of
glue; If the pressure is too low, intermittent glue filling and leakage points may occur, leading to product defects.
Therefore, it is necessary to adjust according to factors such as environmental temperature and glue viscosity
3: Besides the factors of the glue dispenser itself, the viscosity of the glue also directly
affects the
quality of the glue dispensing If the viscosity is high, the adhesive point will decrease, and
even wire drawing may occur; When the viscosity is
low, the adhesive point will increase, which may lead to infiltration of the product, and the adhesive temperature
should be between 23 ℃ and 25 ℃; The environmental temperature has an impact on the viscosity of the adhesive. As
the temperature decreases, the viscosity increases, and the adhesive flow rate correspondingly decreases, making it
easy for wire drawing to occur. The curing temperature curve of adhesive is generally provided by the manufacturer,
and in practice, higher temperatures should be used as much as possible to solidify the adhesive, so that it has
sufficient strength after curing
4: The needle of the glue filling machine usually needs to be
selected with an inner diameter of about
half of the diameter of the glue filling point. During the glue filling process, the glue filling needle should be
selected based on the size of the produced product
5: The distance between the needle and the working
surface needs to be well controlled, and it is important to know
that different dispensing machines use different needles, each with a specific stopping degree. Therefore, before
each operation, the distance between the needle and the working surface needs to be calibrated, that is, the Z-axis
height calibration
Finally, the editor of Helishi reminds everyone that glue must not have bubbles. A small
bubble can cause many
products to lack glue; When replacing the rubber hose midway, the air at the connection should be emptied to prevent
the phenomenon of the glue dispenser hitting empty.