|
Adhesive
Application
courtesy:
Pidilite Industries Ltd.,
PU
Adhesive: Normally a two component, Solvent containing polyurethane (PU)
adhesive is used.
Application
Areas: PU adhesive is mainly used in sole attaching applications viz. bonding
of unit soles made of PVC, Polyurethane to Leather, Synthetic fabric Uppers.
This versatile Resin/adhesive can also be used for bonding soles made of
Thermoplastic Rubber (TPR) & Micro cellular Rubber after halogenating
soles with suitable primer. Similarly EVA soles require pre-treatment with
suitable primer.
APPLICATION
INSTRUCTION:
Prepare the substrates to be bonded appropriately as follows
| SUBSTRATE |
PREPARATION |
| A.
UPPER |
| 1.
Leather |
Roughen
to remove the grain layer upto feather edge. |
| 2.
PVC (Synthetic) |
Lightly
roughen & clean with MEK. |
| 3.
PU Patent Leather |
Roughen
to remove PU film & leather grain to within 3 mm of edge of
sole. |
| 4.
Fabric |
Natural
fabrics do not require any treatment while certain synthetic
fabrics (e.g., Nylon) require special primer treatment. |
| B.
SOLING |
| 1.
Leather |
Roughen
to remove loose flesh fibers. |
| 2.
PVC |
Solvent
wipe with MEK. Change the wiping cloth after every 5-6 pairs to
avoid contamination. Allow to dry for 5 minutes. |
| 3.
Vulcanised Resin or Micro Cellular Rubber |
Roughen
and then halogenate with Primer (Follow the instructions provided
with primer while halogenating) Allow surface to activate for
minimum one hour. |
| 4.
Thermoplastic Rubber (TPR) |
Halogenate
with primer using a soft brush. (Follow all the instruction
provided with primer) Allow the TPR surface to activate for
minimum one hour. |
| 5.
Polyurethane Cellular / Solid |
Light
roughening and solvent wipe with MEK. Two wipes with 5 minutes
gap. |
| 6.
EVA |
Roughen
and then give a primer coat with suitable primer Or Special UV
primer + UV Exposure to get micro surface rupture. |
|
ADHESIVE
APPLICATION:
1. Apply thoroughly mixed Adhesive + Hardener (100 : 5 ratio
by weight) on the upper as well as on sole by brush or
appropriate machine. Second coat may be required on porous
substrates e.g.. Leather upper, which can be given after 5-10
minutes of first coat.
2. On PVC sole the adhesive should be applied within 5-30
mins. of solvent wiping.
3. Allow a minimum drying time of 24-30 minutes, some extra
drying time for sole is advantageous.
4. Heat activation : The sole is generally heat activated in
the high intensity flash activator for 4-5 seconds or any other
type of heating mechanism for appropriate time, while upper is
given a gentle warming The adhesive film should attain temperature
of 80-85degree C before spotting. Spot the upper and sole and bond
them together under appropriate pressure in a sole attaching
press.
5. Chill the bonded unit to cool the glue line. Delast only
when the unit is cooled to room temperature.
6. Remove the excess adhesive carefully within one hour of
pasting/bonding, using crepe rubber roll or any other soft tool.
7. Allow to cure the adhesive for 24 hours.
SAFETY
& PRECAUTION:
Store the adhesive under dry condition below 35degree C. Since the
product is highly flammable, the storage area & shop floor
should be restricted from naked flame. Keep the adhesive container
lid tightly closed when not in use to avoid unnecessary
evaporation or solvent from the adhesive. Proper ventilation must
be provided on the shop-floor.
note:
It is recommended that before using the product in full scale production,
the manufacturer should make his own tests to determine the
suitability of the product under his operating conditions. As the
circumstances under which the products are stored, handled and
used are beyond the control of supplier, one cannot assume
responsibility for their misuse by the manufacturer.
Print |
