Plastics in general are very problematic to work with. From one grade to the other grade of the same material, you may need to re-adjust your processing parameters to avoid degradation, surface defects, mechanical properties drops and so on. In the service life, they are also very vulnerable materials so they need to be protected from UV, Humidity, Temperature variations, and other environment conditions. Some plastics are more sensitive and very tricky to work with, similar to a pampered teenager kid at home. Nylon and PVC are among these sensitive plastics. That is why, we tried to explain the reasons for their degradation and provided a remedy for all that. Read through the article to understand more.

1. Nylon Degradation in Processing,
Recycling and Service Life
& How To Avoid It.
Dr. A Zad
© AxiPolymer Inc. 2018.
A Full Portfolio of Solutions to Plastics Industry
April 2018

2. © AxiPolymer Inc. 2018.
Nylons in general
• Nylons were amongst the new and
exciting materials in 1930s. Their
application has undergone a steady and
remarkable growth since then.
• Nylon is used in clothing, nonwovens,
carpets, hosiery, rope tire cord, brush
bristles, industrial conveyor belts, hot air
balloons, airbags for cars, zips, gears,
wire insulation and piping and etc.

3. © AxiPolymer Inc. 2018.
Advantages Disadvantages
 High Toughness
 High Abrasion Resistance
 High and Low Temperature
resistance
 Low Coefficient of Friction
 High Tear Resistance
 Resistant to Oil, Solvents and
Alcohols
 Not affected by Fungi and
molds
X Hydrophilic nature (adsorbs
moisture in molecular level and
swells)
X Decompose under sunlight
X Subject to attack by strong
acids and oxidizing agents
X High shrinkage in molded
sections
X Electrical and mechanical
properties influenced by
moisture content
X Hard to Recycle and maintain
properties

4. © AxiPolymer Inc. 2018.
Degradation Mechanism
The process of degradation happens whenever a change
occurs to the main chain, side chain or substituent groups of
Nylon molecules. These can happen in any of the forms
below:
• Change in one or more end-groups;
• Disruption of the side-chains;
• Chain scission of the backbone.
This can be caused in different ways such as Mechanical,
Thermal, Photo- and Chemical degradation.
R. Shamey et al. Rev. Prog. Color.. 33 (2003)

5. © AxiPolymer Inc. 2018.
Degradation Mechanism
Different parameters cause Nylon to degrade.
• Intermolecular Forces
• Processing Conditions
• Storage
• UV Radiation
• Weathering
• Heat
• Moisture
• Dyestuff
• Chemicals

6. © AxiPolymer Inc. 2018.
Degradation in Process and Recycling
• Combination of Mechanical forces and heat during
processing will result in various changes in the molecular
structure of polymers. Chain scission is one of the effects
which will produce free radicals.
• Free radicals, due to their highly reactive nature, will react
again with Oxygen and result in further degradation.
W Dong et al. Polymer Degradation and Stability 95 (2010) 1054e1062

7. © AxiPolymer Inc. 2018.
Degradation in the Environment
• Under photolytic and/or thermal ageing
conditions, Nylon undergoes undesirable
changes in mechanical properties, becomes
brittle and becomes yellow in color. The
behavior of aliphatic polyamides on exposure
to heat and irradiation has therefore attracted
a significant amount of attention.

8. What to do to avoid many of these
problems?
 Use the right grade for every application
 Find the right processing conditions (rpm, temperature,
screw design)
 Use of appropriate process stabilisers (To avoid
degradation during the process)
 Include the right UV and Antioxidant packages in the
formulation (To protect the Nylon molecules from
degradation in service life)

9. One of the solutions is
 Let’s check some case studies to realise
what it is capable of…
Process Enhancer 701
An Innovative Additive Compound for
Processing & Service Life

10. © AxiPolymer Inc. 2018.
UV Stability
Nylon 6 fibers QUV340 exposure, 380 hrs.
(8 hrs 70C; 4 hrs 50C Conditioned)
Control 0.28 % 701 0.35 % 701

11. © AxiPolymer Inc. 2018.
UV Stability
Nylon 6 containing 0.5% TiO2
QUV340 exposure, 1200 hrs.
Control 0.35 % 701

12. © AxiPolymer Inc. 2018.
UV Stability
1% Pigment 180 in Nylon 6 fibers,
QUV340 exposure: 1550 hrs.
Control
DEGRADED 0.1 % 701 0.2 % 701

13. Injection Molding Trial with DSM
Nylon 4,6
© AxiPolymer Inc. 2018.

14. © AxiPolymer Inc. 2018.
MOLDING WITH 6:1 RATIO OF PRIME
TO RECYCLED NYLON 4,6
CIRCULAR DISC. SPRUE IN CENTER OF DISC.

15. © AxiPolymer Inc. 2018.
Warpage
With 3% 701,
No Warpage
Control

16. © AxiPolymer Inc. 2018.
Nylon 6 with 33% Fiberglass
Control With 3% 701

17. © AxiPolymer Inc. 2018.
Nylon 6 with 33% Fiberglass
Control

18. © AxiPolymer Inc. 2018.
Nylon 6 with 33% Fiberglass
With 3% 701

19. © AxiPolymer Inc. 2018.
Control
Nylon 6 with 33% Fiberglass

20. © AxiPolymer Inc. 2018.
With 3% 701
Nylon 6 with 33% Fiberglass

21. Dupont Zytel 70G33 HSIL 33% Glass Filled Black
Nylon 6,6 Molded 310C
© AxiPolymer Inc. 2018.
With 2% Cel-Span 701Control

22. Injection Molding Trial with DSM
Nylon 4,6 with Regrind Material
© AxiPolymer Inc. 2018.

23. © AxiPolymer Inc. 2018.
MOLDING WITH 6:1 RATIO OF PRIME
TO RECYCLED NYLON 4,6
CIRCULAR DISC. SPRUE IN CENTER OF DISC.

24. © AxiPolymer Inc. 2018.
Warpage
With 3% 701,
No Warpage
Control

25. © AxiPolymer Inc. 2018.
Advantages of Enhancer 701 in
Nylon processing/products
 Enhanced Processability
 Extended UV resistance
 Decrease in cycle time
 Reduction in processing temperature (10 to 40F)
 Decrease in Yellowing
 No Warpage
 Allows using regrind back into the system

26. © AxiPolymer Inc. 2018.
Contact us to explore this opportunity for your product line:
info@axipolymer.com
www.axipolymer.com
Tel: (438) 929 4900
(647) 491 7979
A Full Portfolio of Solutions to Plastics Industry