PSA D14 1428 Anti-Splintering Products Plastics-Rubbers - Resistance to Sandblasting Process

When it comes to dry abrasive blasting, the efficiency of the blasting device is usually measured by how much area it can cover in a given amount of time and the amount of abrasive it uses to do so. A procedure for determining this is described in the standard “PSA D14 1428 Anti-chip products plastics-rubbers - Resistance to sandblasting”, developed by PSA, a French multinational automotive company that produces cars and motorcycles under brands such as Peugeot, Citroën and Opel.

It is widely accepted within the industry that 7 bar (102 psi) pressure is required at the nozzle to achieve optimum blasting performance. Anything below this pressure will result in reduced blasting efficiency as the abrasive velocity is reduced.

Compressor pressure setting, the often misunderstood compressor air capacity and blast nozzle selection are all interconnected and will increase the abrasive rate but will also make it increasingly difficult for the blast device to grip the nozzle due to the higher pressure.

Sandblasting is a surface treatment technique that uses particulate grains propelled under high speed. This process is a highly effective solution for removing contamination from metal substrates or changing the roughness or smoothness of a surface prior to coating. The force with which the abrasive is propelled can be generated centrifugally using a high-speed rotating wheel or pneumatically via a compressed liquid or air medium. Technically, sandblasting refers to a process that specifically uses spherical particles.

Several characteristics are used to describe an abrasive. These characteristics determine the type of abrasive: grade (size), hardness (measured in Mohs units), shape (spherical or angular), and mineral composition. Each of these factors affects the finished surface profile.

The main sandblasting methods are:

• Grit blasting is sometimes used as a general term for the cleaning or profiling of a hard surface. Grit blasting refers specifically to blasting with angled or sub-angled particles. The effect of using grit abrasives is similar to using sandpaper, but grit blasting produces a smoother surface and is a much faster process as a result.
• Wet blasting is preferred for marine and outdoor applications due to the cushioning effect of water, which reduces the amount of dust generated. However, wet blasting has a much slower cleaning effect than air-only systems and can cause flash rusting on certain iron surfaces.
• Bead blasting or shot blasting is the process of using circular media to create dimples in the surface of an object. This method is similar to sand blasting but works on the mechanism of plasticity rather than abrasion, which removes less material and produces less dust. Additionally, this method is used to relieve tensile stresses and increase compressive strength of metals and composites. This process is usually reserved for precision machine components such as gear parts, suspension springs, and turbine blades.
• Wheel blasting uses centrifugal force to push media against a surface. A rotating wheel spins at extraordinary speeds to launch the abrasive into a self-contained cage. Wheel blasting is often described as an airless blasting process due to the lack of a pressurized ejector. It is a highly efficient form of processing that uses recyclable media for long-term operation. However, this form of blasting lends itself to repetitive shapes and products and is not as versatile as a blast chamber.

The main equipment used in these tests includes:

• Blast Pots: Mobile blasting systems, or blast pots, are compressor-fed, pneumatic machines filled with abrasive material. The abrasive is held in a pressurized pot and expelled through a hose that is controlled by the operator. The operator can control the flow of media with a lever.
• Blast booths: These are small closed-loop systems designed for smaller component processing. Booths use only recyclable abrasive and have four separate modules: the enclosure (booth), the abrasive recycling system, the blast abrasive, and the dust collector. Operators can manipulate components and the blast hose inside using rubber gloves integrated into the booth wall. A viewing window on the gloves allows the operator to see what they are working on. Blast booths can operate with a pressurized vessel or an extraction system that introduces the media into an air stream and blasts at lower pressures.
• Sandblasting chambers: These are a much larger version of a sandblasting booth used for heavy industrial applications. Operators must be trained to work in these chambers. Inside, the operator roughens, smooths, or cleans the surfaces of a component depending on the needs of the finished product. Sandblasting chambers come in a variety of sizes. As a result, they can accommodate very large or uniquely shaped objects such as rail cars, commercial or military vehicles, construction equipment, ship sections, and aircraft. Sandblasting chambers can be automated. To do this, a conveyor system is required and robotic nozzles are installed inside.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also testing services in accordance with the standard “PSA D14 1428 Anti-chip products plastics-rubbers - Resistance to sandblasting”.