FABRICATION
Prepared By:
Presented On:
Group 22B2473-86
June. 2, 2023
GRIT
BLASTING
Grit blasting is a process where
abrasive particles are accelerated
and forcefully directed against a
surface. The resulting texture is
influenced by the shape, size,
hardness, and velocity of the shot
particles using high-speed
particles.
03
Scope / Objective
04
Process
05
Specifications
06
Analysis
07
Outcome
08
Challenges
09
Improvements that can be made
10
Key Learnings
Objectives
Surface Preparation
By accelerating abrasive particles
against a surface, it effectively removes
contaminants, rust, scale, old coatings,
and other unwanted substances.
Texture Modification
The shape, size, hardness, and velocity of
the shot particles used in the blasting
process influence the resulting texture.
Surface Cleaning &
Restoration
By forcefully propelling abrasive
particles
Removal of Surface
Defects
Grit blasting can effectively remove
surface defects, such as weld spatter,
burrs, or sharp edges.
The process typically involves
1.
1. SELECTION OF ABRASIVE MATERIAL
2. PRESSURIZED AIR OR WATER
Different types of abrasive materials can be
The abrasive material is fed into a blasting system,
used for grit blasting, including sand, aluminum
which is usually a specialized blasting gun or nozzle.
oxide, garnet, glass beads, steel grit, and plastic
Compressed air or water is used to propel the
media. The choice of abrasive material depends
abrasive material towards the surface being
on the specific application and the desired
treated.
outcome.
3. IMPACT ON THE SURFACE
4. COLLECTION AND RECYCLING
As the abrasive material is propelled at high
velocity, it impacts the surface, effectively
removing contaminants, coatings, or imperfections.
The force of the impact can vary depending on the
application, and different blasting techniques (such
as direct pressure blasting, suction blasting, or wet
blasting) can be employed.
To control dust and prevent environmental
contamination, proper containment systems or
blasting booths are often used. Additionally, many
grit blasting operations incorporate recycling
systems to collect and reuse the abrasive material,
reducing waste and costs.
We used the Ducom
Air Jet Erosion
Tester for testing
the process.
The Ducom Air Jet Erosion Tester is a unique
and feature rich erosion tester that is
capable of testing bulk materials and
coatings under erosion. Its capabilities range
from subjecting samples to tightly controlled
gentle erosion to some of the harshest
erosion conditions seen on the field.
Machine usage
specifications
PROPERTY
VALUE
Particle Velocity
30 to 100 m/s
Erodent Feed Rate
1 to 10 g/min
Angle of Impingement
45°& 90°
Nozzle Diameter
1.5 mm
Sample Size
25 x 25 x 5 mm
Temperature Options
Ambient
Standard Erodent
Alumina Al2O3
Requirements:
1. Safety goggles
2. Mask
3. Weighing
machine
(sensitive to
0.0001 g)
ANALYSIS
: Readings
SAMPLE 2 ANGLE = 90°
INITIAL WEIGHT(g)
FINAL WEIGHT(g)
MASS LOSS(g)
7.6707
7.6144
0.0565
7.6144
7.6117
0.0027
7.6117
7.6099
0.0018
7.6099
7.6085
0.0014
7.6085
7.6050
0.0035
7.6050
7.6028
0.0022
7.6028
7.6011
0.0017
7.6011
7.5984
0.0027
7.5984
7.5948
0.0036
7.5948
7.5926
0.0022
ANALYSIS
: Readings
SAMPLE 2 ANGLE = 45°
INITIAL WEIGHT(g)
FINAL WEIGHT(g)
MASS LOSS(g)
7.7282
7.7266
0.0016
7.7266
7.7213
0.0053
7.7213
7.6987
0.0226
7.6987
7.6969
0.0018
7.6969
7.6955
0.0014
7.6955
7.6940
0.0015
7.6940
7.6923
0.0017
7.6923
7.6908
0.0015
7.6908
7.6895
0.0012
7.6895
7.6883
0.0012
Challenges
1.
1. OPERATOR SAFETY
2. SURFACE CONTAMINATION
Grit blasting involves high-velocity abrasive particles,
which can be hazardous if not properly handled.
Operators need to use appropriate personal protective
equipment (PPE) such as protective clothing, gloves,
goggles, and respirators to safeguard against the
impact, inhalation, and exposure to abrasive materials.
Grit blasting can introduce contaminants into the
blasted surface. This can occur if the abrasive material
itself is contaminated or if the blasting environment
contains contaminants. Controlling the cleanliness of
the abrasive material and ensuring a clean blasting
environment are important to prevent recontamination
of the surface.
3. ACCESSIBILITY AND COMPLEX SHAPES
4. ABRASIVE MATERIAL RECYCLING AND DISPOSAL
Grit blasting may encounter challenges when working
on complex or intricate surfaces with restricted access.
It can be difficult to reach recessed areas, corners, or
curved surfaces effectively. Specialized equipment,
techniques, or manual interventions may be required to
address these challenges and ensure uniform surface
preparation.
Depending on the type of abrasive material used, there
may be challenges associated with its recycling or
proper disposal. Some abrasive materials contain
hazardous components, requiring careful handling,
containment, and disposal in compliance with
environmental regulations.
Improvements
1.
1. ADVANCED ABRASIVE MATERIALS
2. ECO-FRIENDLY PRACTICES
The development of new abrasive materials with
improved characteristics has contributed to better
performance in grit blasting. These materials include
synthetic abrasives like aluminum oxide, silicon carbide,
and garnet, which offer higher cutting efficiency, longer
life, and reduced dust generation compared to
traditional abrasives like sand.
Efforts have been made to develop and promote ecofriendly practices in grit blasting. This includes the use
of environmentally friendly abrasive materials, such as
recycled glass beads or garnet, and the implementation
of water-based blasting methods that minimize dust
generation and waste.
3. PROCESS MONITORING AND QUALITY ASSURANCE
4. PRECISION EQUIPMENT AND NOZZLE DESIGNS
Advances in technology have facilitated real-time
process monitoring and quality assurance in grit
blasting. Non-destructive testing (NDT) techniques,
such as surface profilometry, digital imaging, and
ultrasonic inspection, allow for accurate assessment of
surface cleanliness, profile, and coating adhesion,
ensuring adherence to required specifications.
Modern grit blasting equipment incorporates advanced
nozzle designs and controls for precise and efficient
blasting. Adjustable nozzles, automated blasting
systems, and robotic equipment provide better control
over parameters such as blasting angle, distance, and
coverage, leading to improved surface preparation
results.
Grit blasting is employed in
various industries, including
automotive, aerospace,
construction, metal fabrication,
shipbuilding, and restoration. It
is an effective method for
preparing surfaces for further
treatments, improving adhesion,
and achieving the desired finish.
However, it requires proper
safety measures and protective
equipment due to the potential
hazards associated with highpressure blasting and exposure
to abrasive materials.