strapping training
DESCRIPTION
Strapping Training. Ersoy Tuncay – 2012. GENERAL COMPARISON. RANGE OF USEs OF STRAPPING. Chains, wire rope, Woven polyester, etc. LASH ING. Weight of Application. STEEL Strap. COMPOSITE STRAPPING. PET Strap. PP Strap / Stretch film. Market Volume. Strapping typ e s in General. - PowerPoint PPT PresentationTRANSCRIPT
Strapping Training
Ersoy Tuncay – 2012
GENERAL COMPARISON
TENSILE STRENGTH N/MM2
ELONGATION WORKING RANGE
ELONGATION AT BREAK
PP DYLASTIC 300 6% 26%PP-Machine Grade DYLASTIC T 350 3,5% 18%PET TENAX 400 2% 15 - 20%PET - High Strength TENAX HS 450 2% 13%STEEL STRAP APEX 850 0,2% 13%STEEL STRAP MAGNUS 1050 0,2% 13%COMPOSITE STRAPPING CO-STRAP n/a 4% 12 - 15%
STRAP TYPES
RANGE OF USEs OF STRAPPING
Market Volume
Weight of Application
PPStrap / Stretch film
PET Strap
STEEL Strap
COMPOSITE STRAPPING
Chains, wire rope, Woven polyester, etc. LASHING
Steel strapping: Magnus-strap 1000 - 1070 Newton/mm2
Heavy packs Apex-strap 780 - 900 Newton/mm2
Simple / medium typ applications / cost reductions Plastic strapping:
PET strap PET high strength 16 – 32 mm (6.000 – 18.800 Newton) Normal PET 9 – 16 mm (2.000 – 5.000 Newton)
PP strapping Machine strapping 5 – 16 mm (500 – 4.500 Newton) Manual strapping 11 - 15 mm (2.000 – 3.000 Newton)
Polyester Corded Strapping Manuel Application As strong as Steel Strap and excellent retain tension performance ( 2000 kgf Break
Strength)
Strapping types in General
Sıra No Norm Kodu Açıklama1 EN 13246 Specification of Tensional Steel Strapping2 EN 13247 Specification for tensional steel strapping for lifting, lashing and securing of loads
3 EN 13394 Specification for Non-Metallic tensional strapping4 EN 13891 Tensional strapping — Guide to selection and use of tensional strapping5 ASTM D 3950 Standard Specification for Strapping, Nonmetallic (and Joining Methods)6 ASTM D 3953 Standard Specification for Strapping, Flat Steel and Seals
Ambalaj Çemberi ile İlgili Normlar
STRAPPING NORMS AND STANDARTS
STRAP PROPERTIES– Strength
• Tensile Strength• Break Strength
– Joint Efficiency– Working Range– Retained Tension– Elongation and Recovery– Impact Resistance
Tensile Strength
Tensile strength is characteristic of a type of material and the way it has been processedPP 320 N/mm2PET 400 N/mm2PET 450 N/mm2Apex STEEL 850 N/mm2Magnus STEEL 1050 N/mm2Composite Strapping n/a ( No homogenous Crossection)
Break Strength
Break strength is characteristic of a specific strap. It is the product of cross-sectional area and tensile strength
PET 19mm x 1.27mm x 450N/mm2 = ~ 11,000NMagnus Steel Strap 19mmx0.63mm
= 19mm x 0.63mm x 1.050N/mm2 = ~ 12,500N
The joint strength determines the loop strength!Examples for PET Strapping:
Pneumatic hand tools 45 to 60% (Stick to min for variations in air pressure and flow or PET sheet material.)
Battery Charged Tool 60 to 75% (Depending on strap type sheet single extruded)
Machines80 to 90 % single extruded
Joint Strengts
JOINT EFFICIENCY of POLYESTER CORDED COMPOSITE STRAPS
: 80 – 90 %
Joint Strength of Composite Strapping
Joint Strength of Steel Strapping at Different Joint Types
Retained Tension
Retained tension :• Steel 90 to 95%• PET 65 to 75%• PP 25 to 35%• Composite Strap 80 to 90%
The size of the strap does not affect the RT.
Retained tension is the strap tension that remains over time
Applied tension is the tension that is initially applied to a strap
Tension decay is the tension that is lost over time
WORKING RANGE
Working range of PET and steel strap are about 50% of their break strengths.
Working range of PP is about 35% of its break strength. Working range elongation is the main reason why PET is tougher
than steel.Steel 0.2 -0.3 %PET 2 - 4%PP- Special 6%
Composite Strapping 4 – 6%
Working Range
Impact resistance is measured by work (energy necessary) to break/deform the strap.
Calculation: Working range (%) x Joint strength (N) x Working
range elongation (%) Comparison between Steel Strap 32 x 0,8 applied with a double notch seal, and a PET 19 x1,27mm
PET Strap with battery tool : Apex 31,75 x 0,8 mm BS is 20.000Nx 70% JS = 14.000 N 50% x 14.000 x 0,3 = 2.100 Nmm PET 19,05 x 1,27 BS is 10.000 N x 75% JS = 7.500 N 50% x 7.500 x 4 = 15.000 Nmm
So the PET Strap and also COMPOSITE STRAPs in this case is half the strength but 7 ( Seven) times tougher!!!!
Impact resistance
3,000
2,500
1,000
500
1,500
2,000
021 6543 7 8
ELONGATION
Poun
ds
LOAD - ELONGATION CURVE
Steel Strap
Composite / PET Strap
Work to break Steel400 units WORK = 1/2x0.3x2000 300 units
Work to break Composite / PET Strap WORK = 1/2x1000x42000 units
3,000 / 13345
2,500 / 11,120
2,000 / 8,896
1.500 / 6,672
1,000 / 4,448
500 / 2,224
POU
ND
S / N
EWTO
NS
Steel Strap Break Strength (BS) = 11,120 Newtons: PET Strap BS = 5,560 Newtons
Choosing Your Strap
Function or purpose of the strapPackage characteristicsShipping or handling considerations
Strapping may perform the following functions: package reinforcement, carton closure, securement, unitization, baling, bundling, bracing, paletization, compression retention and pilferage reduction.
Package characteristics that influence strap selection are: weight, stability, rigidity, integrity and sharpness of the edges (sharp edges may demand heavier strapping or corner protection).
Shipping considerations that affect the choice of strapping include: how far the package is shipped; how it’s handled by both the shipper and receiver; and where and how it’s stored.
Factors affecting strap choice
Shape: Rectangular Normal hand-tools / Machines Round Push type tools / (Machines)
Weight: How much mass has to be held together?
Weight Straps Package stability:
Is the product stabile by itself, is the stacking stabile? Strapping to hold pack on pallet, or to hold pack together? What happens when a strap breaks?
Costs Safety
Product edges: Does strap damage product? Corner-protection Does product damage strap? Need to distribute more tension?
EQUIPMENT BY PACKAGE TYPES
You may ask yourself the following questions: How is the pack lifted / handled?
Forklift, magnetic overhead crane, roller-conveyor, etc. How long is the pack in storage?
Shrinking, corrosion. Conditions of storage?
Moisture, dust, sunlight, heat, ice, etc. Way of storage?
Stacked, in racks Way of transport?
Truck, train (shunting), ship, airfreight. Distance of transport?
Domestic or Export, the more transport actions, the higher the risk .
Transport (Intern/Extern)
How does the end customer handle the package? Forklift truck, roller conveyor, magnetic crane, etc.
How / when does he take the packaging apart? Any hazards, complications?
Is there intermediate storage? Many more handlings, very long storage times.
Does the pack get resold? Needs to be broken down to smaller units.
Try to think further …..
At the end customer
Types of Steel Strapping
Apexis a cold-rolled, low carbon steel strapping. It isused for light and medium duty loads that needhigh strength and high retained tension but are not subject to impacts or shock.Magnussteel strapping is made from higher-carbon, cold-rolled, heat treated steel. It is used on heavy/very heavy loads that require high strength and are subject to impacts andshock during transit and handling.USLMsteel strapping is made from higher-carbon, cold-rolled, heat treated steel. It is used on very heavy/extreme loads.
Chemical Analysis of Steel Strap Types
APEX MAGNUS USLMC [%] 0,13 - 0,17 0,29 - 0,33 0,44 - 0,46
Mn [%] 0,45 - 0,70 1,25 - 1,45 0,70 - 0,90
Why waffled strap
Advantages: A thicker strap with a lower Gram / Meter (Cheaper) Stiffer, good feeding through chutes
Disadvantages at heavy waffling : Longer weldtime, or weaker weld. Less meterage per Kg. Tension-wheel grips in “air” A smaller smooth strap can replace a wider waffled strap.
TRUCK TRANSPORTATION
RAILWAY TRANSPORTATION
SEA TRANSPORTATION
Minimum Number of Straps =(Load Weight x G Force x 1,5 )/System Strength
1,5 : Safety FactorSafety Factor can be varied according the transportation mode and also type of the product.
System Strength of Composite Strapping = 1,6 x Nominal Break Strength
NUMBER of STRAPS REQUIRED CALCULATION
Palet Weight : 3000 kg Strap Used : CS32ESTR Composite Strap Break Strength of the Strap : 1600 kg System Strength of the Strap : 2560 kg
Safety factor : 1,5
Minimum # of Straps should be on the Pallet = 3000 x 1,5 / 2560
= 1,76 Two ( 2 ) Straps
Çember Miktarı Hesaplama Örneği :
Advantages DisadvantagesHigh Corner Strentgth Low ElasticityHigh Breaking Strength Low Elongation RecoveryTensionable with hand, pneumatic or fully automatic machines
Low Shock Absorbency ( Impact )
High Static System Strength if closed properly
Low3 Dynamic System Strength
Can be tensioned manually or sealed with battery tensioner
Dangerous to users , Damage to products
Also fully automatic possible Expensive than PET / Composite strapping
Steel Strapping vs
PET / Composite StrappingSteel Strapping has :
Thank You
Ersoy Tuncay / 2012