Information

ELECTRICAL SOLUTIONS
B1.100
B2.
Cable
Accessories
C1.
Wiring
Duct
C3.
Abrasion
Protection
C4.
Cable
Management
D1.
Terminals
D2.
Power
Connectors
E1.
Labeling
Systems
E2.
Labels
E3.
Pre-Printed
& Write-On
Markers
F.
Index
B3.
Stainless
Steel Ties
C2.
Surface
Raceway
E5.
Lockout/
Tagout
& Safety
Solutions
B1.
Cable Ties
A.
System
Overview
D3.
Grounding
Connectors
E4.
Permanent
Identification
Material Failure Testing
Property decay can lead to three different modes of failure: loss of strength, loss of toughness, or change in
appearance. The critical mode for any given application would depend upon the application and the
requirements it places upon the material itself.
Loss of strength is monitored by tensile testing samples of the material before and after it has been weathered.
This test will reveal the decreasing strength accompanied by extended weathering.
Loss of toughness can be monitored by measuring changes in elongation and impact strength. As ultraviolet
light exposure time increases and the material becomes brittle, its elongation and impact strength are greatly
reduced. It is important to note that brittle failures can occur even when the tensile strength shows no change.
Although change in appearance is normally not a failure mode for cable ties, the plastic does tend to discolor
and lose its surface gloss as exposure increases. These changes can be measured by color difference using
Adams units, which are similar to National Bureau of Standard units.
Panduit has its own weathering test program to determine estimated life of various cable tie materials. This
includes examining many previously aged samples obtained throughout the world.
In all cases, the amount of property decay increased with increasing exposure to ultraviolet light. The principal
signs of degradation were found to be brittleness, cracking, and loss of surface gloss. It was also determined
that the time for failure to occur was shorter than indicated from industry tests performed on material samples.
This discrepancy is in part due to the fact that cable ties were tested in an end use, stressed condition, while
most plastic resin suppliers conduct weathering tests using unstressed test bars.
Five cable tie materials have superior ultraviolet light resistance: TEFZEL
■
, HALAR
▲
, Weather Resistant Acetal,
Nylon 12 and Stainless Steel.
Determining the outdoor life expectancy of any material is difficult since there are other factors, besides
ultraviolet light stability, which have to be considered. These factors are listed below and should be considered
before specifying a cable tie material.
*Based on the assumption of minimum loading, no chemical attack and
impact-free conditions.
■
TEFZEL is a registered trademark of E.I. du Pont de Nemours and Company.
▲
HALAR is a registered trademark of Ausimont USA, Inc.
Factor
Chemicals
Bundle
diameter
Loading
Thickness
Vibration
Degree of
exposure
Moisture
Galvanized
metals
Effect on Cable Tie Life
Applications which have chemicals present can
reduce the life of a tie. This is the most detrimental
factor to the life of a tie.
As the bundle diameter is reduced, the tie has more
bending stress. A thick strap on a small bundle
diameter has more stress.
If the tie is under high loading, this will add additional
stress on the tie body.
A thinner tie will have a decreased life since surface
cracks will penetrate the thickness of the tie faster.
Applications with high vibrations will cause impact,
which will propagate any surface cracks.
No shield or shade, southern exposure, higher
altitudes and high temperatures, decrease the life
of a cable tie.
High humidity plus high temperature can result in
degradation due to hydrolysis in nylon.
Acid rain and acid moisture acting on galvanized
metals release chemicals known to attack Nylon 6.6.
Weathering Life Expectancy
Material, Color (Part Number Suffix)
Polypropylene, Green (109)
Nylon 6.6, Natural (No suffix)
Flame Retardant Nylon 6.6, Black (60)
Flame Retardant Nylon 6.6, Ivory (69)
Heat Stabilized Nylon 6.6, Natural (39)
PEEK, Polyetheretherketone, Translucent Brown (71)
Heat Stabilized Nylon 6.6, Black (30)
Weather Resistant Polypropylene, Black (100)
Weather Resistant Nylon 6.6, Black (0 and 00)
Heat Stabilized Weather Resistant Nylon 6.6, Black(300)
Weather Resistant Nylon 12, Black (120)
TEFZEL
■
, Aqua Blue (76)
HALAR
▲
, Maroon (702Y)
Weather Resistant Acetal, Black
Stainless Steel
Years*
1
1 – 2
1 – 2
1 – 2
1 – 2
1 – 2
4 – 5
7 – 9
7 – 9
7 – 9
12 – 15
>15
>15
>20
>30
Weathering (continued)
Table A – External Factors That Affect the Life of a Cable Tie