Effectiveness of Antivibration Gloves When Used with a Light Electric Hammer. Differences Among Different Methods of Measurements

Abstract

The capability of antivibration (AV) gloves to reduce the vibration's transmissibility is not always proven, especially with percussive tools. Additionally, laboratory test results are sometimes dissimilar from the real field's one. The present paper investigates the properties of three different types of gloves air bubbles, gel, neoprene -specifically designed for vibration reduction, and of an ordinary working leather glove, during their use with a light (3 kg) electric hammer, in a real field, while chiseling a limestone block. Outcomes reveal that AV gloves could provide benefits in reducing vibration when used with that type of tool, even though the protection is different to the one determined in laboratory test according to the ISO 10819 Standard. The statistical analysis does not reveal differences for the triaxial transmissibility in the AV gloves in the range (6.3-1250 Hz), showing an average overall reduction of 26%, calculated with the corrected method specified by the ISO 10819:2013 Standard. The leather glove provides a reduction of around 8%. Similarly, statistical differences are not found with reference to transmissibility through the three main axes for the same type of glove, both in air and neoprene gloves. On the contrary, gel and leather gloves differ in transmissibility along the axes, showing a better reduction on the x-and z-axes, respectively. The transmissibility estimated with the direct method shows an average decrement of around 10% when compared to that resulting from the corrected one. The air glove provides the best triaxial transmissibility reduction at middle frequencies (25-200 Hz), while at high frequencies (200-1250 Hz), the best reduction is provided by the neoprene glove. At the peak percussion frequency of 63 Hz, measured on this tool, all the AV gloves provide some vibration attenuation -an average of 27% -with no statistical differences, while leather gloves show a little transmissibility increment (1.02). Although the accelerometers used for the study are positioned as closely as possible, there are still differences between the acceleration measured on the bare-hand adaptor and the one directly on the handle, highlighting the importance of the corrected method application for better evaluating the gloves' transmissibility.

Efficacy of Antivibration Gloves When Used with Electric Hammers of about 10 kg for Chiseling Limestone Rocks

“…In our case, both the gloves in neoprene and gel performed better along the x-axis than along the z-axis. The capability of the gel glove to reduce better in shear than in compression was found also in another measurements campaign we made using a lightweight hammer (3 kg) for chiseling a limestone block [27]. These results are also consistent with those reported in another study made using simulated laboratory tests (McDowell et al, 2013) [18].…”