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Example 4: Tested, tested, tested! CF98 with < 4xd!

For users of very small energy supply chains with mostly very narrow bending radiuses, the question for a suitable cable for very high stroke numbers has come up frequently in the past.

At bending radiuses of less than 5xd, copper quickly reaches its physical limits, which necessitated the search for suitable substitute conductor materials or for fundamentally different conductor superstructures.

Many series of tests with a variety of conductor superstructures and materials were performed in order to find out how cables must be manufactured in order to be able to endure several millions of bending operations in EChains®, even at bending radiuses of less than 4xd.

Test set-up: Horizontal, short distance of travel

Test parameters  
Distance of travel: S = 0,8 m
Speed, approx.: V = 1,5 m/s
Acceleration, approx.: a = 0,5 m/s2
Radius, approx.: 18 mm

Test 1:

Inspection of four different cable designs

Test item A – conductor with special conductor alloy
Test item B – conductor same as test item A, but in copper
Test item C – conductor in braided structure
Test item D – conductor in stranded construction

This long-term inspection, which was carried out over a period of 2 years, provided the following results:

Test 2:


Two different cable designs were tested, whereby different core numbers and cross-sections were selected in comparison with test 1:
Test item A – conductor with special conductor alloy
Test item B – conductor in copper

In this case, test item B was manufactured completely identical to test item A except for the conductor material. The test showed that not a single case of wire breakage could be detected for test item A even after 28 million double strokes. Test item B, however, only achieved approx. 1.4 million double strokes before complete destruction of the conductor was determined. This test also demonstrates that the alloy concept clearly surpasses the life of the copper conductor by more than 19 times and achieves these extraordinary results in the mechanically critical area of very small cross-sections!

  Number of
double strokes
Cross section d [mm] Testradius
Test item A 31.268.000 7x0,20 5,8 3,1xd = 18
Test item B 450.000 7x0,20 5,6 3,2xd = 18
Test item C 638.000 7x0,25 7,3 2,5xd = 18
Test item D 2.350.000 7x0,25 7,3 2,5xd = 18

  Number of
double strokes
d [mm] Testradius
Test item A 28.267.000 2x0,14 3,9 4,6xd = 18
Test item B 1.450.000 2x0,14 2,9 6,2xd = 18

Number of double strokes
Number of double strokes

Conductivity of alloys

However, the outstanding mechanical properties of this alloy have to do with a reduced conductivity versus copper, which can be compensated by means of slightly increased cross-sections. This means that the cross-sections mentioned in the catalog meet the electrically defined cross-sections defined using the conductivity value. The conductor diameter of the alloyed conductor increases slightly compared to the conductor diameter of a copper conductor.

This compromise results in a 10% greater external diameter for the CF98 series versus a comparable CF9 type, although the service life differences to be expected between the CF98 versus the CF9 speak for themselves and increase by a multiple factor in comparison with other so-called chain-suitable cables.

As in the case of the CF9 series, further characteristics of the chainflex® CF98 include the highly abrasion-resistant, gusset-filled extruded TPE outer jacket, the oil resistance and the UV resistance as well as the absence of any PVC and halogen compounds. Especially in areas of application that only possess minimum construction space but also demand a large number of strokes, the igus® cable offers an increased degree of operational safety and efficiency. Areas of application are available in the semiconductor and component parts industry, in the automation sector as well as in the automotive and bank sector. New possibilities of application can also be found in automatic doors for motor vehicles and trains as well as in automatic food and selfservice machines and in the packaging industry.

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