New laser shearography station for carcass inspection

Thanks to laser technology the RÖSLER Group’s department for carcass inspection can now work even more efficiently when dealing with the retreading of big OTR tyres. After receipt of the carcass by the goods receiving department, the carcass is first subjected to a close inspection. Up until just a few months ago, vulcanisation technician Adam Urbanczyk had to perform this step manually. However, a shearography station is now taking care of the detailed examination carried out before the retreading step.

Shearography is not a technology that is new to the tyre industry, but has long been used for smaller tyres. This technology can reduce the workload significantly, especially when dealing with the retreading of OTR tyres - testing a tyre or a carcass can now be completed within approximately 15 minutes. Meanwhile, testing and evaluation is carried out in parallel by means of special programmes, defects within the tyre structure are depicted in high resolution and directly recorded and archived. Thus, the shearography station ensures higher efficiency and optimal quality assurance when retreading OTR tyres.

RÖSLER uses an SDS ITT 1/2100 shearography station for the carcass inspection which can be loaded with OTR tyre sizes of up to 21.00 R 35. Thanks to its high level of automation, the device is easy to use. Firstly, the tyre to be tested on structural defects is inserted into the machine. Then, the testing step takes place by externally applying a low negative pressure to the tyre so that separations within the tyre material which are not visible on the exterior form minimal bumps. Structural defects are detected by means of laser light (interferometry) and visualised by TV shearography. During the course of this, the device, also known as ITT (Interferometric Tyre Tester), generates images of the different stress-strain and deformation states of the OTR tyre. Consequently, necessary repairs can be performed systematically when subsequently retreading the OTR tyre and the ‘tyre life’ can be increased significantly.