Transcript Steeling a knife

Knife Sharpening
Sheldon Becker
Southern Qld Institute of TAFE
Poultry Processing
Using knives continuously
relates up to 50% of injuries
(lacerations or muscle strains)
Meat processing
In the red meat industry
up to 68% of injuries
Of which 32% is cuts &
lacerations
Blunt Knives
- are frustrating to use
- can lower the quality of the product
- often the cause of accidents
- can be responsible for Occupational
Overuse Syndrome (OCC) type injuries
Who likes sharpening knives?
Blunt knives can lead to unsafe
practices
Poor running point – Running hand up blade
 Pushing when blunt – Physically pushing and dragging the knife
 Over stretching – Not maintaining balance properly, not keeping up
 Violent or sudden movements – Stabbing or hacking at the product
 Deterioration – Tiredness, hands and arms are can cramp up & get sore
 Emotional and Physical well being – Facing another day with a

blunt knife is not fun, social issues impacting on your work

Incorrect steeling practices – Back steeling, uneven angles, not
checking steeling action, grip on knife, and steel is incorrect

Repetition work – Continuously making additional cuts or doing same
task
How have most people here
learnt how to sharpen a knife?
 Maybe
 Some
from a fellow worker
workplaces have a mentor/ trainer
 Watching
 Taught
others sharpen their knives
themselves through trail and error
Benefits of Knife Sharpening training
Would see a reduction in:
 Knife
related injuries
 Tendonitis
 Carpel Tunnel
 Tennis Elbow
 Musculoskeletal injuries
 Time off work
 Improved production
 Job becomes easier
Training
Who to start with:

staff new to the plant or industry

all staff demonstrating poor technique

staff with high incidents of knife injuries

staff struggling with the job

staff open to change
Key points to lessen knife
injuries

Warm up before starting
– Follow recommended stretching practices.
 Use a good shape blade
– Choose the correct knife for the job.
 Work with a rhythm
– Minimise your blows or cuts and work
more efficiently
 Take breaks
– Do not work through breaks
- Take breaks as required
Identifying the symptoms of
musculoskeletal injuries
 Muscle
discomfort
 Fatigue
 Aches
and pains
 Soreness
 Hot feelings
 Cold feelings
 Muscle tightness
 Numbness tingling
 Muscle weakness
Occupational Overuse
Syndrome (OOS)
 OOS
usually develops over a
period of time.
 Caused or aggravated by :- sustained or constrained postures
- repetitive movements
 One
explanations for OOS is that it is
caused by the muscles being held too tight
for long periods of time
NZ Grip force study
Independent study found



20% of the process workers have a
reasonably good knife
40% had an average knife
40% had a knife that was insufficient for
the task
NZ Grip force study
 Study
also found the tighter the grip on the
knife the less blood flow in the hand and arm.
 The
size of the hand holding the knife is also
a factor on grip force.
The knife length
The length and weight test used to determine grip
force
 Place a 0.5 kg weight 13 cm, 15 cm, 17 cm
distances along the steel or bar.

The grip force has increased as the length of
each knife increases.

Longer blades require a greater grip force than
shorter blades.
Cutting Force





A sharp knife requires 30% less force to cut than an
average knife
A sharp knife also enables a task to be performed 30%
faster, and requires 30% less grip force
A processing room with consistently sharp knives produced
a 1 to 3 % greater yield than the same room with normal
levels of sharpness
By testing a knife we can now tell how much cutting force is
required to cut with that knife
We can now calculate how much cutting force a worker is
using over a days work
Sharpness Tester
Score
Example

A worker boning forequarters all day would use
approx 6400 cutting strokes a day

A sharp knife has a cutting force of 1.1kg per
cutting stroke

1.1kg x 6400 strokes = 7.40 tons of daily force

If we multiply 6400 strokes with a 15kg blunt
knife, we end up with a daily force of 96 ton

This equates to 88.6 tons more cutting force
than a sharp knife
NZ experience
Photo courtesy of Anago Ltd
Equipment use to sharpen
and maintain knives
 Knives and their correct storage equipment
 PPE (cut resistant gloves, safety glasses)
 Grinding wheels (grinders)
 Sharpening stones
 Steels
 Washing & sterilising facilities
Safety Equipment used
when sharpening a knife
Cut resistant
Safety glasses
Choose a knife suitable for
the task.
Skinning Knife
Curved boning knife
Straight boning knife
Slicing knife
Knife Shapes
Convex
Flat
Hollow
Concave
Equipment used to shape/sharpen
knives
Sandstone wheel
Belt Grinders
Grinding the knife
Sharpening the knife
Sharpening or honing stone are used to
establish a sharp edge on a knife.
Methods used to sharpen a
knife
Sharpening stone
Setter
Issues

Evenly grinding of knives to the correct shape
- both sides
- from tip to heel

Evenly sharpening knives (correct edge)
- both sides
- from tip to heel

Evenly & effectively steeling knives
“It all about the correct angles”
Hollow Grinders
Used by authorised personal only
Knife setter
Knife setters
Creating a feather
Stand on handle side of knife
when stoning. Place thumb
and forefinger on stoning rod &
other hand on stoning bar.
Work from tip to heel, then heel to tip
to develop a feather.
Turn knife over & repeat process
Removing feather
Start by placing heel of stone on the
knife tip. Pull the stoning rod
straight back over the cutting edge
overlapping the stone on each stroke.
Turn knife over & repeat
Run the knife through a plastic block
(Feathering Block)
Finishing strokes
Place the heel of the stone on the tip
of the knife and pull stoning rod back
toward the knife handle 6 times.
Turn knife over and repeat process
Steeling a knife

To remove any burrs from the edge

To straighten (centre) the edge
Types of Steels
Holding a knife
Make sure the knife butt
sits in the groove of your
thumb and forefinger
palm
Make sure you tuck
your little finger on the
side of the handle
The knife should be in a
straight line with your arm
Steeling a knife
Hold steel as above with the
thumb tucked behind steel
Check arm, steel and knife are
square and in line.
Knife handle centre of wrist
Storing Knives
Knives must be stored in the pouch when not in use
Testing bite
Bites left
Bites right
Bite Stick Stick
Both sides of the knife are sharp
Testing bite
Bites left
Slides right
Bite Stick Stick
Bite left only knife is turned to the left
Steel left side of knife the bite side.
Testing bite
Slides left
Bites right
Bite Stick Stick
Bite right only knife is turned to the right
Steel right side of knife the bite side
Testing bite
Slides left
Slides right
Bite Stick Stick
Slides both ways, there is no bite, knife will
need to be steeled again or sharpened
Safety Equipment
when using a knife
Cut resistant
Mesh
Safety Aprons
Now That’s A Knife
Acknowledgements
Southern Qld Institute of TAFE would like to
acknowledge contributions by: Big
Bay Skills Training Ltd
 Argus
 Teys
Realcold Limited
Bros Pty Ltd
Question?
Thankyou