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

Users of small cable carriers with very narrow bending radii used to frequently ask us for a cable suitable for this type of application, as well as very high numbers of cycles.

At bending radii of less than 5xd, copper quickly reaches its physical limits, which meant we had to research substitute conductor materials or fundamentally different conductor superstructures.

We carried out many series of tests with a variety of conductor superstructures and materials. The aim was to find out how cables should be manufactured to ensure they would operate efficiently over several millions of cycles at bending radii as small as 4xd inside a cable carrier.

Test set-up: short, horizontal travel

Test parameters
Distance of travel:	S = 2.62 ft
Speed, approx.:	V = 4.92 ft/s
Acceleration, approx.:	a = 1.64 ft/s²
Radius, approx.:	0.71 inches

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 and different core numbers and cross-sections 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 identically to test item A, with the exception of 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 cycles. Test item B, however, only achieved approx. 1.4 million cycles, before it was determined that the conductors had been completely destroyed. This test also demonstrates 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	Cross section	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

Conductivity of alloys

However, the outstanding mechanical properties of this alloy are because of a reduced conductivity versus copper, which can be compensated by slightly increasing the 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-filling extruded TPE outer jacket, the oil resistance and the UV resistance as well as the absence of any PVC and halogen compounds. The igus® cable offers an increased degree of operational safety and efficiency, especially in applications with minimal space but a high number of cycles. Areas of application include the semiconductor, automation, automotive and packaging industries. Other applications can also be found in banking machines, automatic doors on cars and trains, as well as in automatic food and self-service machines.