May 30th, 2019
Automotive polishing is a multi-step process that typically requires the application of several distinct compounds in a sequence. The initial polishing phase requires a higher-cut rate to remove scratches and swirls that have been etched into the car’s clearcoat through sanding. Particles in a high removal rate abrasive (HRRA) solution are typically large with multiple cutting-points to maximize the material removal rate and accelerate this first aggressive step. After the macro surface has been suitably leveled, engineers will typically take another pass over the car with a fine particle compound engineered to eliminate the swirls and holograms generated by rotary buffers with an HRRA polish.
This ideal two-step process is complicated by the wide variations in the chemical compositions of abrasive solutions and clearcoats, as well as the chromatic properties of the vehicle’s paint and the severity of flaws. A black car will display minor scratches more vividly than another color, for example. Additional polishing steps are often required to achieve the optimal surface finish, particularly for vehicle recoveries and body shop applications. In reality, this two-step process typically expands into a three or four-step procedure.
Conventional abrasive compounds are loaded with blocky calcined alumina (Al2O3) particles and other earthen minerals. This is a cheap abrasive solution for automotive polishing that contributes towards the lengthy and subjective nature of automotive polishing.
Recognising the limitations of established polishing compounds, Saint-Gobain Surface Conditioning has undergone significant research and development into particle technology to explore the possibilities of a single step abrasive solution for automotive polishing.
Abrasive Solutions: IDEAL Hybrid Alumina Particles
Our IDEAL range of engineered alumina particles was envisaged as a unique abrasive solution for long-established problems in automotive polishing. The coarse particles of calcined alumina offer very limited control over surface finish. Hence the requirement for multiple compounds with sequentially diminishing particle loads.
By manipulating the particle size distribution (PSD), morphology, and microstructures of high purity alumina particles, we have developed a novel morphing technology. This hybrid alumina exhibits excellent cutting action at the outset before reaching an improvised state enabling a good surface finish. This has effectively enabled us to reduce the number of mandatory steps in automotive polishing from 3-4 to 1-2.
Single step automotive polishing is the ideal that particle engineers have been consistently striving towards. This requires extremely tight control of the PSD and morphology of the particles within the abrasive solutions. We have successfully developed an innovative alumina particle with realistic single step finishing capabilities.
Centered on a mean particle size of around 5 microns with an alumina purity exceeding 99%, IDEAL Hybrid powders offer the perfect combination of cut and finish. These capabilities can be finely tuned to achieve a unique position between the two, with good affinity for a range of fluids and solvents for integration into polishing slurries. The IDEAL Hybrid G abrasive solution PSD is centered at the finer dimension of 0.75 microns, providing a high gloss finish in shorter time frames and reduced loading requirements.
The performance of an abrasive solution is dependent upon the skill and experience of the engineer operating the rotary buffer, alongside the unique conditions of the polishing application. Yet we are confident that our IDEAL range represents an objective measure of high quality for automotive polishing applications. While further engineering is required to guarantee single-step polishing every time, our IDEAL Hybrid product range represents the leading edge of rapid paintwork correction for even demanding vehicle recovery jobs.
Abrasive Solutions from Saint-Gobain Surface Conditioning
Saint-Gobain is an institution in the field of particle engineering and surface conditioning. We have developed an expansive range of surface leveling and finishing products for numerous demanding applications. Our abrasive solutions are routinely used in chemical mechanical planarization, sapphire finishing, and fixed-diamond wire sawing.