Presentation on theme: "Knife Sharpening Sheldon Becker Southern Qld Institute of TAFE."— Presentation transcript:
1 Knife SharpeningSheldon BeckerSouthern Qld Institute of TAFE
2 Poultry Processing Using knives continuously relates up to 50% of injuries(lacerations or muscle strains)
3 Meat processing In the red meat industry up to 68% of injuries Of which 32% is cuts &lacerations
4 Blunt Knives Who likes sharpening 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 injuriesWho likes sharpening knives?
5 Blunt knives can lead to unsafe practices Poor running point – Running hand up bladePushing when blunt – Physically pushing and dragging the knifeOver stretching – Not maintaining balance properly, not keeping upViolent or sudden movements – Stabbing or hacking at the productDeterioration – Tiredness, hands and arms are can cramp up & get soreEmotional and Physical well being – Facing another day with a blunt knife is not fun, social issues impacting on your workIncorrect steeling practices – Back steeling, uneven angles, not checking steeling action, grip on knife, and steel is incorrectRepetition work – Continuously making additional cuts or doing same task
6 How have most people here learnt how to sharpen a knife? Maybe from a fellow workerSome workplaces have a mentor/ trainerWatching others sharpen their knivesTaught themselves through trail and error
7 Benefits of Knife Sharpening training Would see a reduction in:Knife related injuriesTendonitisCarpel TunnelTennis ElbowMusculoskeletal injuriesTime off workImproved productionJob becomes easier
8 Training Who to start with: staff new to the plant or industry all staff demonstrating poor techniquestaff with high incidents of knife injuriesstaff struggling with the jobstaff open to change
9 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 efficientlyTake breaks– Do not work through breaks- Take breaks as required
10 Identifying the symptoms of musculoskeletal injuries Muscle discomfortFatigueAches and painsSorenessHot feelingsCold feelingsMuscle tightnessNumbness tinglingMuscle weakness
11 Occupational Overuse Syndrome (OOS) OOS usually develops over aperiod of time.Caused or aggravated by :-- sustained or constrained postures - repetitive movementsOne explanations for OOS is that it is caused by the muscles being held too tight for long periods of time
12 NZ Grip force study Independent study found 20% of the process workers have a reasonably good knife40% had an average knife40% had a knife that was insufficient for the task
13 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.
14 The knife lengthThe length and weight test used to determine grip forcePlace 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.
15 Cutting ForceA sharp knife requires 30% less force to cut than an average knifeA sharp knife also enables a task to be performed 30% faster, and requires 30% less grip forceA processing room with consistently sharp knives produced a 1 to 3 % greater yield than the same room with normal levels of sharpnessBy testing a knife we can now tell how much cutting force is required to cut with that knifeWe can now calculate how much cutting force a worker is using over a days work
18 ExampleA worker boning forequarters all day would use approx 6400 cutting strokes a dayA sharp knife has a cutting force of 1.1kg per cutting stroke1.1kg x 6400 strokes = 7.40 tons of daily forceIf we multiply 6400 strokes with a 15kg blunt knife, we end up with a daily force of 96 tonThis equates to 88.6 tons more cutting force than a sharp knife
20 Equipment use to sharpen and maintain knives Knives and their correct storage equipmentPPE (cut resistant gloves, safety glasses)Grinding wheels (grinders)Sharpening stonesSteelsWashing & sterilising facilities
21 when sharpening a knife Safety Equipment usedwhen sharpening a knifeCut resistantSafety glasses
22 Choose a knife suitable for the task. Skinning KnifeCurved boning knifeStraight boning knifeSlicing knife
32 Creating a feather Stand on handle side of knife when stoning. Place thumband forefinger on stoning rod &other hand on stoning bar.Work from tip to heel, then heel to tipto develop a feather.Turn knife over & repeat process
33 Removing feather Start by placing heel of stone on the knife tip. Pull the stoning rodstraight back over the cutting edgeoverlapping the stone on each stroke.Turn knife over & repeatRun the knife through a plastic block(Feathering Block)
34 Finishing strokes Place the heel of the stone on the tip of the knife and pull stoning rod backtoward the knife handle 6 times.Turn knife over and repeat process
35 Steeling a knife To remove any burrs from the edge To straighten (centre) the edge
37 Holding a knife Make sure the knife butt sits in the groove of yourthumb and forefinger palmMake sure you tuck your little finger on the side of the handleThe knife should be in astraight line with your arm
38 Steeling a knife Check arm, steel and knife are square and in line. Knife handle centre of wristHold steel as above with the thumb tucked behind steel
39 Storing KnivesKnives must be stored in the pouch when not in use
40 Testing bite Bites left Bites right Bite Stick Stick Both sides of the knife are sharp
41 Testing bite Bites left Slides right Bite Stick Stick Bite left only knife is turned to the leftSteel left side of knife the bite side.
42 Testing bite Slides left Bites right Bite Stick Stick Bite right only knife is turned to the rightSteel right side of knife the bite side
43 Testing bite Slides right Slides left Bite Stick Stick Slides both ways, there is no bite, knife willneed to be steeled again or sharpened
44 Safety Equipment when using a knife Cut resistantMesh