How do grooved break rolls open wheat kernels?

In modern cereal processing, wheat kernels are opened using a series of steel cylinders known as break rolls. These rolls feature grooved surfaces and operate at differential speeds.12

When wheat is directed between the first set of these rolls, the kernels are partially torn open. Rather than performing actual grinding at this initial stage, the process focuses on breaking the grain to release the inner [endosperm]. This action produces a mixture called "chop," which is subsequently sieved to separate the endosperm—often in the form of [semolina]—from the branny outer layers of the grain. This gradual reduction process continues through several sets of break rolls to efficiently separate the endosperm from the bran.1