What is Shotblasting?

Shotblasting is a method used to clean, strengthen (peen) or polish metal. Shot blasting is used in almost every industry that uses metal, including aerospace, automotive, construction, foundry, shipbuilding, rail, and many others. There are two technologies used: wheelblasting or airblasting.

Wheelblasting

Wheelblasting directly converts electric motor energy into kinetic abrasive energy by rotating a turbine wheel. The capacity of each wheel goes from approximately 60 kg per minute up to 1200kg/min. With these large amounts of accelerated abrasive, wheelblast machines are used where big parts or large areas of parts have to be derusted, descaled, deburred, desanded or cleaned in some form.

Often the method of transportation of the components to be blasted will define the type of machine: from simple table machines to integrated, fully automatic manipulator machines for full series automotive manufacturers, through to roller conveyors and strip descaling systems.

Airblasting

Airblast machines can take the form of a blastroom or a blast cabinet, the blast media is pneumatically accelerated by compressed air and projected by nozzles onto the component. For special applications a media-water mix can be used, this is called wet blasting.
In both air and wet blasting the blast nozzles can be installed in fixed positions or can be operated manually or by automatic nozzle manipulators or robots.
The blasting task determines the choice of the abrasive media, in most cases any type of dry or free running abrasive media can be used.

What is Shotblasting www.wheelabratorgroup.com

Leopad Group a leading provider of corrosion protection services ranges from the scope of blasting and painting, insulation, thermal spray application, passive fire protection, refractory and other services such as scaffolding, cable tray systems and cathode protection. 

We are a Malaysian company with close to 3000 staff and over 10 offices and fabrication yards throughout the country. Leopad Group is dedicated to being the market leader for corrosion protection and provide the highest standards in the industry with the convenience of providing multi-disciplinary services through a single point of contact.

For further enquiries on our services, please contact our Business Development Department at +603-22600200 , website www.leopad.com or email at hq@leopad.com

 

BLASTING TECHNIQUE FOR PAINTING SURFACE PREPARATION (Part2)

Types of Abrasive Blasting

b) Wet

Wet-abrasive blasting is used to control the amount of airborne dust. There are two general types of wet abrasive blasting. In one, water is injected near the nozzle exit into the stream of abrasive (Figure 2). In the other, water is added to the abrasive at the control unit upstream of the nozzle and the mixture of air, water, and sand is propelled through the hose to the nozzle. For both types of wet-blasting, the water may contain a corrosion inhibitor. Inhibitors are generally sodium, potassium, or ammonium nitrites, phosphates or dichromates. Inhibitors must be chosen to be compatible with the primer that will be used. After wet blasting, the surface must be rinsed free of spent abrasive. (The rinse water should also contain a rust inhibitor when the blasting water does.) Rinsing can be a problem if the structure contains a large number of ledges formed by upturned angles or horizontal girders since water, abrasives, and debris tend to collect in these areas. The surface must be completely dry before coating. When leaded paint is present, the water and other debris must be contained and disposed of properly. This waste may be classified as a hazardous waste under Federal and local regulations, and must be handled properly.

Schematic Drawing of Cross Section of Typical Water-Injected Wet Abrasive Blasting Nozzle

c) Vacuum

Vacuum blasting systems collect the spent abrasives and removed material, immediately adjacent to the point of impact by means of a vacuum line and shroud surrounding the blasting nozzle. Abrasives are usually recycled. Production is slower than open blasting and may be difficult on irregularly shaped surfaces, although shrouds are available for non-flat surfaces. The amount of debris entering the air and the amount of cleanup is kept to a minimum if the work is done properly (e.g., the shroud is kept against the surface). This procedure is often used in areas where debris from open air blasting or wet blasting cannot be tolerated.

d) Centrifugal

Cleaning by centrifugal blasting is achieved by using machines with motor-driven bladed wheels to hurl abrasives at a high speed against the surface to be cleaned. Advantages over conventional blasting include savings in time, labor, energy, and abrasive; achieving a cleaner, more uniform surface; and better environmental control. Disadvantages of centrifugal blasting include the difficulty of using it in the field, especially over uneven surfaces, although portable systems have been developed for cleaning structures such as ship hulls and storage tanks. Robots may be used to guide the equipment. In many cases, the abrasive used is reclaimed and used again.

http://theconstructor.org/building/blasting-technique-for-painting-surface-preperation/5631/

Leopad Group a leading provider of corrosion protection services ranges from the scope of blasting and painting, insulation, thermal spray application, passive fire protection, refractory and other services such as scaffolding, cable tray systems and cathode protection. 

We are a Malaysian company with close to 3000 staff and over 10 offices and fabrication yards throughout the country. Leopad Group is dedicated to being the market leader for corrosion protection and provide the highest standards in the industry with the convenience of providing multi-disciplinary services through a single point of contact.

For further enquiries on our services, please contact our Business Development Department at +603-22600200 , website www.leopad.com or email at hq@leopad.com