2014MarchHP

Toolfix Monthly
Plastic Welding Solutions

Plastic Welding Process
Plastic welding is the process of welding or joining softened plastic materials
using heat. It is widely used for plastic fabrication, manufacture and
repair of plastic tanks, surface vehicle repair, shrinking and forming
thermo plastic parts and much more.
Normally, there are 3 stages in the plastic welding process:
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Surface Preparation
It is very important that all plastic components to be welded are clean. This
may include: removing all paints, molds, oils etc. Wearing a face mask and
gloves is recommended.
Tools Preparation
At this stage, you will need to turn on and preheat the hot air gun and put
the correct welding rod into the welding nozzle. It is necessary that the
substrate and the welding rod are of identical material. Polypropylene
(PP), Polyethylene (PE) and Polyvinyl chloride (PVC) are the three most
common thermo plastics.
Working Heat Temperatures:
Each plastic has it's own working heat temperature:
Polyethylene (PE): It has low water absorption and high tensile strength.
Suitable for tanks, liners etc.
Polypropylene (PP) : Most common, suitable for tanks, equipment, pipes
ect. It has high tensile strength and good chemical resistance.
PVC (polyvinyl chloride): It has good weather strength and is to corrosion
resistant. Suitable for pipe, fume hoods and equipment etc.
Note: WT - Working Temperature.
Errors and omissions excepted

Know how to choose
the correct plastic
welding tool?
1) Identify the material which your customer is
going to weld. See chart on right and next page.
This is important, because if the incorrect material
are welded together, they will not bond.
Know how to identify plastic?
Normally you can find the identification sign
on the surface of the material:
This means the plastic is
High Density Polyethylene.
This means the plastic is
Vinyl or Polyvinyl Chloride.
This means the plastic is
Low Density Polyethylene.
Based on the working temperature of the material
you will be able to determine the maximum
temperature and airflow required to weld the
plastic.
2) It is important to identify how often the
customer will be using the gun to weld. If the gun
is to be used on a daily basis it will be necessary
to recommend the industrial tool range over the
professional range, which is ideal for
small or irregular jobs.
Tools and Accessories
for Plastic Welding
This means the plastic is
Polypropylene.
Learn how to identify the material without
the sign, see next page.
Professional Heat Gun Welding rod
Welding Nozzles Water-based solvent
Die Grinder Sandpaper Rags
Mask Safety Glasses Foil tape
Errors and omissions excepted

Test Identification for
Common Thermo Plastics
Small Piece
in Water
Burn
Test
Touch
Test
HDPE
Working Temperature
+/- 300 C
Float
Blue Flame
Yellow Tip
Wax Smell
Hard, Can be Scratched
by Fingernail
LDPE
Working Temperature
+/- 250 C
Float
Blue Flame
Yellow Tip
Wax Smell
Soft and Flexible,
Easily Scratched
PP
Working Temperature
+/- 250 C
Float
Blue Flame
Yellow Tip
Burnt Oil Smell
PVC
Working Temperature
+/- 300 C
ABS
Working Temperature
+/- 350 C
Sink
Sink
Yellow Flame, Green Tip
White Smoke, Acitic Smell
Self-Extinguishable
Blue Flame
Yellow Tip
Acitic Smell
HDPE - High Density Polyethylene
Steinel Part No. 071 219
LDPE - Low Density Polyethylene
Steinel Part No. 073 312
PP - Polypropylene
Steinel Part No. 073 411
PVC - Polyvinyl Chloride
Steinel Part No. 073 114
ABS - Acrylonitrile Butadiene Styrene
Steinel Part No. 074 210
Errors and omissions excepted