Abrasive Blast Machines and Sandblasters Information
About Abrasive Blast Machines
Abrasive blast machines and sandblasters clean and prepare surfaces by directing a stream of abrasive particles against a part or a surface. Blast wheels, pressurized water or compressed air drive the abrasive or blasting media. Blasting is used for finishing, surface texturing, roughening, frosting / etching, degreasing, deburring, deflashing, descaling, stripping coatings, and surface preparation of products made of metal, wood, plastic, glass or other materials. Specialized micro-blast or micro-jet machines are available for applications requiring selective surface preparation, material removal and finishing. Blasting provides a surface suitable for subsequent coating operations such as thermal spraying, painting or plating.
Abrasive blast machines and sandblasters contain several major components. The pressure generator uses a crankshaft or plunger pump to increase the pressure of the carrier. Abrasive injectors deliver the abrasive from a hopper or tank to either a blasting wheel, or directly to a nozzle, gun, head or lance. Blast cabinets hold smaller workpieces, while blast rooms are used for larger ones. The dust collection / filtration system removes fine particles of abrasive, media, and blasting waste from the air. Similarly, the media separator / reclaimer removes undersized abrasive, media, or coarse waste.
There are several important specifications for abrasive blast machines and sandblasters. The media flow is the rate at which the abrasive grain feeds into the system. The blast pressure is the water or air pressure used to create a jet or blast stream for cutting or propelling abrasive particles. The abrasive linear speed is the particle velocity of abrasive grains as first projected from the blast wheel or nozzle. Abrasive particle velocity applies mainly to blast wheel machines.
Abrasive blast machines and sandblasters vary in terms of size and mounting. Some equipment is small enough for portable or handheld use, or can be mounted on a bench, pedestal, cart, handtruck, floor, or skid. Other systems are large enough to be mounted onto a trailer or vehicle that can be driven to the worksite requiring blasting, such as the side of a steel tank, ship's hull, or building wall. Crawler or track mounted units can uniformly clean or roughen a surface by scanning a surface in a controlled and repeatable fashion. Crawlers are small vehicles that grab onto a surface with magnetic or vacuum feet mounted on a set of tracks. Track mounted units use a track to guide the jet cutter head across the surface.
On large fixed surfaces, operators guide abrasive blast machines and sandblasters across the surface for cutting or cleaning. By contrast, smaller surfaces often require workpiece loading. For example, parts can be mounted on a conveyor, tumbler, or spinner. They can also be held by hand or placed on a gantry or rotary table. CNC controllers and PC interfaces can be used in conjunction with abrasive blast machines and sandblasters to automate and regulate the delivery of the abrasive.
Abrasive Blast Machine Application
Finally, abrasive blast machines and sandblasters vary by application. Some machines refine, roughen or clean surfaces while others debur sharp edges, remove flashing, wash parts, or strip unwanted materials such as heat-treat scale. Other machines peen or burnish glass beads, metal shot or other smooth, rounded shaped media. For example, shafts and turbine blades are sometimes peened or shot blasted because peening improves the fatigue strength of metallic materials by imparting a residual compressive stress on the parts.