Characterisation of cut and chip behaviour for NR, SBR and BR compounds with an instrumented laboratory device

Abstract

Understanding the cut and chip (CC) effect in rubber is important for successful product development for tires used in off-road or poor road conditions and for other demanding applications of rubber. This research describes a laboratory testing method for characterising the CC fracture behaviour of rubber using a device that controls and records multiple applied loads and displacements during cyclic impact to the surface of a solid rubber specimen to mimic and quantify the CC damage experienced by tire tread compounds. To study the capabilities of the instrument, three model compounds were studied that are based on carbon black reinforced compounds of common elastomers used in tire treads: natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR). These polymers have well-established CC tendencies in field performance of tire treads, with NR exhibiting the best CC resistance followed by SBR and finally BR. The same trend was found with the rubber impact testing approach that allowed the CC behaviour to be quantified using a new physical parameter which is the CC propensity (P). The relative ranking for CC resistance for the three compounds followed the fatigue crack growth resistances of the materials but was exactly opposite to the ranking of DIN abrasion resistance. This provides evidence that CC damage from impact by mm-scale asperities and abrasion of rubber against μm-scale asperities exhibit distinct characteristics in rubber.

Trends in particulate matter generation from truck and bus radial tires using a wear tester

“…However, NR rubber generally has better cut and chip properties than other synthetic rubbers. This is in contrast to the wear test results and appears to be owing to the difference between the millimeter‐scale asperities of cut and chip evaluation and the μm‐scale asperities of abrasion 18 . Since PM results from microscale wear from tires, it can be hypothesized that the BR in NR matrix effectively prevents the microscale wear.…”

Effect of Crosslink Density on Cut and Chip Resistance of 100% SBR Based Tire Tread Compound

“…The diameter loss Di was measured for 20 min, and the loss was divided by the number of strokes n to represent the average rate of cut and chip per stroke Rcc. This value was adopted as the measure of cut and chip characteristics [19][20]. The radial impact force Fi was constant for each stroke.…”

Modelling of elastomeric materials and products

“…The second paper looks at the failure mechanisms that are often present in large tyre type application. Radek Stocek et al [2] discuss what they refer to as 'chipping and chunking', while trying to develop a methodology to measure this behaviour under laboratory conditions. This type of rubber failure is often seen in off-road tyre applications or other conditions where the road surface is poor.…”