Yet More Handy Tricks: Volume 5

Step 16 Identify Different Types of Plastic

for purposes of welding plastic. The large pieces they deal with are usually not marked with recycling codes.
from: http://www.malcom.com/downloads/techtips/tips.pdf

PLASTICS RECOGNITION
So that you can recognize which plastic you are dealing with, the following simple test is recommended:

1. A short test weld with the available welding rod. If the welding rod or tape is fixed firmly,
the problem is solved.

2. Take a small sliver or shaving of the material to be welded and light it with a match,
observe the flame and smell the smoke.
On PVC blackish smoke and acrid smell
On Polyethylene no smoke, the material drips like a candle and also smells of wax
On Polypropylene no smoke, the material drips like a candle and smells of burnt oil
On Polyamide no smoke, pulls to form thread, smells of burn horn
On Polycarbonate yellowish sooty smoke. Sweetish smell
On ABS blackish smoke, soot flakes, sweetish smell

The welding rod and tape has the following colors: Welding temperature in °C
Hard PVC rod grey and red 300°C
Soft PVC rod transparent 400-500°C
Soft PVC tape grey 400-500°C
Hard Polyethylene rod black and white 300°C
Hard Polyethylene tape white 300°C
Soft polyethylene rod black 270°C
Soft Polyethylene tape transparent 270°C
Polypropylene rod grey 300°C
Polypropylene tape natural 300°C
Polymide rod black 400°C
Polycarbonate rod transparent 350°C
Xenoy tape grey 350°C
ABS rod white 350°C
ABS tape white 350°C

Because containers, pipes and foils are available in many different colors, it is not possible to judge from the color of an Article from which thermoplastic it is made. Since however 50% of goods are made of types of polyethylene this eases your recognition problem.

If contrary to expectations you have problems when welding, contact the service center at the address

Comments

[wsni]

Sniffing fumes from burning plastic is not a good way to retain your health.

[thepelton]

PVC, or Polyvinyl Chloride, releases chlorine when it overheats, which is poisonous.

[pfred2]

Oxygen and water are poisonous in too great quantity so what exactly is your point?

[eric m]

Polyamide is NYLON.

[pfred2]

Nylon is a DuPont trade name.