Strapping , also known as bundling and appeal , is the process of applying a string to an item to combine, stabilize, hold, strengthen, or tighten. The rope can also be called as . Strapping is most often used in the packaging industry.
Video Strapping
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Ropes are flexible flat materials, most often made of steel or various plastics.
Steel
Steel is the oldest and highest tensile strength. It is available in various widths and thickness as well as variations in steel grade. Steel is used to hold heavy duty where high strength and minimum stretching are desired. The final surface for steel straps includes: paint, paint and wax, bluing or zinc and wax. The wax is used to transmit the voltage better around the bundle and for use with certain types of tensioners. Common applications include steel reels, metal bundles, wire baling, bricks and paver, and the final binding of the rolls. Steel Strapping is sold by weight not long, due to natural expansion and steel contraction in the manufacturing process. A 3/4 x 0.020 Steel Strapping Coil produces about 19.6 feet per pound.
Polypropylene
Polypropylene rope (oriented or tensilized) is an economical material designed for light, medium, palletizing and bundling unitization. These are available in a wide range of thicknesses, and polymer variations (eg, copolymers). Most polypropylene is embossed, some of which are also printed. This product offers higher elongation at rest but tends to have a stretch that can not be fixed with constant stress. What most end-users do not know is that the polypropylene binder will lose about 50% of the applied voltage in an hour, and that the loss of this voltage is accelerated by an increase in ambient temperature, consequently although it is suitable for packaging with stored energy levels which will take each relaxation occurs on the rope, unacceptable stiffness ropes can occur after time if used on 'Solid' products such as brick or concrete. Further the polypropylene binder is susceptible to UV degradation and can be rapidly degraded if left outside the affected elements. Reasonable color choices will slow down the process, such as determining black cords. Similarly, UV inhibitors can be determined.
Polypropylene strapping can be printed, both during production and pre-embossing for the highest quality and precision, or post-production through embossing for reduced quality. Both offer the security and marketing advantages for a tied product.
Polyester
Polyester or nylon that is oriented or knitted is the strongest plastic product of strapping and used as an alternative steel binder in some industries. Polyester provides excellent retention voltages at rigid loads. Its excellent recovery properties help the load absorb collisions without damage to the rope.
There are special types available for custom apps. For example, in a cold climate the ropes bonded with hot liquid glue are used because of weather resistance.
Nylon
Nylon strap has the greatest special strength of the three plastics, but is rarely used because of its high price. In the past nylon ropes were once very popular, but over time polyester has replaced almost all its uses. One application that still uses this type of strap is cold space applications, because it does not creep up as many other types of plastics.
Woven and woven
Woven and webbing straps are available in several constructions, especially those involving polyester and rayon. Some types can be reused. Because this system uses a buckle for joint joints, the straps and webbing can have greater system strength than steel appeal. The braided polyester bond straps also have a higher extension than any other binder system, which gives it ideal memory for ocean and rail shipments. Because polyester ropes are woven and woven lightly and softly, they are also a safer alternative to steel appeal.
Paper
Paper straps are used to bind paper products between industrial processes. This allows the bundle to be put into the process without the need to cut the rope, which can cause the product to fall apart prematurely.
Composite
Composite bonding has a filament embedded in it. In the burden security industry it is often referred to as "synthetic steel". It is highly abrasion resistant and has the highest connection efficiency when used with a buckle. Both advantages are not affected by climate.
Maps Strapping
Strapping use
Examples include:
- Brings together items for handling and shipping: newspapers, pipes, wood, concrete blocks, etc.
- Attach items to pallets, drops, and crates
- Strengthen wooden boxes, crates, and corrugated boxes, like gaylords
- Paste items into flatcars, semi-flatbed trailers,
- Securing the load of brick units, glass packaging, metal parts, etc.
- Closes corrugated boxes and shipping containers
- Securing steel or paper coils
- Store bales of agricultural or textile products
- Load safe items in intermodal containers, box carts, and semi-trailers
Strapping is most commonly used in complete horizontal or vertical bands. Protective end is used to help spread the load at an angle and reduce damage to the load by a tightened string. Strapping can also be used in loops attached to the holding location on rail cars, skid, etc.
Join the
methodOnce the rope is tightened, the rope is often sealed for itself. Steel ropes are sealed with seals and notch, seal and crimp joints, seamless joints, or welding. The seals come in various forms depending on the application; some can be mounted after the rope is tightened, while others must be installed before tensioning. To make seals, seals and ropes mounted on both sides; if a set of notches is created then it is called a single notch together, if two sets of notches are created then it is called double position together. Crimp joints also use seals, but binding creases are used instead of notches. These wrinkles form a great friction force that makes the joints not seep. Seal-less joints are made by forming the interlocking keys to the center of the rope.
The plastic strap is most often put together by fusing the rope together by adding heat to the joint. For lighter gauges, typically 16 mm (0.63 inches) and narrower, heat is introduced with a hot blade system. First, the hot blade moves between the straps. Then a plate appears and compresses the rope and the hot knife on a runway of tens of milliseconds. The plate then falls and the hot knife is removed. After the hot blade is completely clean of the rope, the plates go back up and press the joints so that the melted part of the strap mix and harden.
For thick plastic straps, usually 0.73 mm (0.029 inches) and thicker, friction is used to create heat inside the joint. The process begins with a compressed rope between the plate and the foundation. There is a vibrator built on one of the plates or the foundation, which has a tooth; there is also a tooth on the opposite component that is not moving. Vibrators quickly vibrate, which creates enough heat to melt the interface between the two straps, due to friction. To complete the weld, the vibrator is stopped and the pressure is held until the connection is solidified. Polypropylene and Polyester strapping can also be sealed in a manner similar to the heat generated by sound in the form of ultrasonic waves passing through the material and out of the molecular structure. They are then compressed as in a hot seal. In ultrasonic plastic welding, high frequency (15 kHz to 40 kHz) low vibration amplitude is used to create heat by means of friction between materials to be joined. The interface of two parts is specially designed to concentrate energy for maximum weld strength.
It can also be combined manually by closing the seal or through the buckle.
Connections are the weakest part of the system, therefore the type of merging method used is very important if strength is a problem. The strength of the joint is defined as the force required to break the rope in uniaxial tension. This is then compared with the uniaxial strength of the rope and is recorded as a percent difference (for example, the steel rope sample may have a fracture force of 5,000 pounds (2,300 kg) and the seal may fail at 3,000 pounds (1,400 kg), so the seal is said to have 60% strength). The hot welded blade has a minimum break strength of 55%. The friction weld has a minimum breaking strength of 65%. Well set up a strapping machine or friction welding tool will aim for about 80% of the break strength. Clip/metal seal is surprisingly low with about 100 - 120 kg slip resistance.
For strapping palettes based on ASTM D3953 Standard Specification norms, the number of binding procedures is about 10 times to a minimum.
Tools
There are two main types of equipment available for fastening: hand tools and binding machines. Dispensers are used with both types of equipment to remove the rope. Some strapping machines have built-in dispensers, others (usually on large arch machines) have separate powered dispensers, which can automatically load or associate new reels. The non-powered, separate dispenser has a pulley that releases and activates the brake to stop the inertia of the roll so that the rope is not too excessive to the floor. Usually the dispenser used on the large arch strapping machine has several pulleys to act as a way to store the rope in a way that can be quickly eliminated. Smaller curved engines such as table top engines will provide a rope into the pool box/accumulator instead. In either case this is necessary if the strapping machine will pull the rope faster than the dispenser can pay.
In the hand tools there are manual and automatic tools. Manual tensioner and crimping systems are available for low volume applications. Automatic hand tools are used for higher volume applications. Automatic tools are available using a battery power or compressed air. Both manual and automatic tools are available as a combination tool, which performs tensioning, sealing and cutting, or as separate tensioners, seals, and cutters. The manual sealer for plastic straps always uses seals and compression (jagged seals) or crimp joints (seals behave smoothly). Manual and automatic sealer seals for steel can use seals or seamless joints. Automatic hand tools for plastic straps using friction welding.
Strapping machines, also known as bundlers , are used for higher volume applications or specialized applications. They are available in horizontal and vertical orientations, but vertical orientation is much more common. They are also available in the bottom seal, side seal, and top seal orientation, which determines where the connection lies in the bundle. They are available in semi-automatic and automatic varieties. The automatic versions can also be used parallel to the conveyor system. Photocell is used to detect when the bundle is in the correct location, stop the conveyor, and activate the strapping machine. But most will be found in standalone apps.
See also
- Cable ties
References
Further reading
- Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & amp; Children, 2009, ISBN 978-0-470-08704-6
- Wulftec International
Standard
- ASTM D3953 Standard Specification for Strapping, Flat Steel and Seals
- ASTM D3950 Standard Specification for Strapping, Nonmetallic (and Joining Method)
- ASTM D4675 Standard Guide for Selection and Use of Flat Strapping Materials
- BS EN13891: Strapping Strapping 2003 - Guide of selection and use of strapping struk
- BS EN13394: Packaging 2001 Specification for non-metallic binder
Source of the article : Wikipedia
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