Forview Engineering & Technology Pvt. Ltd.

Parel, Mumbai, Maharashtra

A checkweigher is an automatic machine for checking the weight of packaged commodities online in dynamic condition. It is normally found at the offgoing end of a production process and is used to ensure that the weight of a pack of the commodity is within specified limits. Any packs that are outside the tolerance are taken out of line automatically.

A checkweigher is a system that weighs items as they pass through a production line, classifies the items by preset weight zones, and ejects or sorts the items based on their classification. Checkweighers weigh 100% of the items on a production line.

Typically, an infeed section, scale section, discharge section, rejecter or line divider, and computerized control comprise the physical checkweighing system. Checkweighers and their components vary greatly according to how they are used, the items being weighed, and the environment surrounding them. A checkweigher can weigh in excess of maximum items per minute (depending on product size and accuracy requirements).Checkweighers often incorporate additional checking devices such as metal detectors and X-ray machines to enable other attributes of the pack to be checked and acted upon accordingly.

“Simply stated, a checkweigher weighs, classifies, and segregates items by weight.”

 

For high-speed precision scales, a load cell using electromagnetic force restoration(EMFR) is appropriate. This kind of system charges an inductive coil, effectively floating the weigh bed in an electromagnetic field. When the weight is added, the movement of a ferrous material through that coil causes a loss of ElectroMagnetic Force. A precision circuit charges the coil back to its original charge. The amount added to the coil is precisely measured. The voltage produced is filtered and sampled into digital data. That voltage is then passed through a Digital Signal Processor (DSP) filter and ring-buffer to further reduce ambient and digital noise and delivered to a computerized controller.It is usual for a built-in computer to take many weight readings from the transducer over the time that the package is on the weigh bed to ensure an accurate weight reading.Calibration is critical. A lab scale, which usually is in an isolated chamber pressurized with dry nitrogen(pressurized at sea level) can weigh an object within plus or minus 100th of a gram, but ambient air pressure is a factor. This is straightforward when there is no motion, but in motion there is a factor that is not obvious-noise from the motion of a weigh belt, vibration, air-conditioning or refrigeration which can cause drafts. Torque on a load cell causes erratic readings.A dynamic, in-motion checkweigher takes samples, and analyzes them to form an accurate weight over a given time period. In most cases, there is a trigger from an optical(or ultrasonic) device to signal the passing of a package. Once the trigger fires, there is a delay set to allow the package to move to the "sweet spot" (center) of the weigh bed to sample the weight. The weight is sampled for a given duration. If either of these times are wrong, the weight will be wrong. There seems to be no scientific method to predict these timings. Some systems have a "graphing" feature to do this, but it is generally more of an empirical method that works best.

• A reject conveyor to enable the out-of-tolerance packages to be removed from the normal flow while still moving at the conveyor velocity. The reject mechanism can be one of several types. Among these are a simple pneumatic pusher to push the reject pack sideways from the belt, a diverting arm to sweep the pack sideways and a reject belt that lowers or lifts to divert the pack vertically. A typical checkweigher usually has a bin to collect the out-of-tolerance packs.

Tolerance methods

 

There are several tolerance methods:

• The traditional "minimum weight" system where weights below a specified weight are rejected. Normally the minimum weight is the weight that is printed on the pack or a weight level that exceeds that to allow for weight losses after production such as evaporation of commodities that have a moisture content. The larger wholesale companies have mandated that any product shipped to them have accurate weight checks such that a customer can be confident that they are getting the amount of product for which they paid. These wholesalers charge large fees for inaccurately filled packages.

Application considerations

Speed and accuracy that can be achieved by a checkweigher is influenced by the following:

• Pack length
• Pack weight
• Line speed required
• Pack content (solid or liquid)
• Motor technology
• Stabilization time of the weight transducer
• Airflow causing readings in error
• Vibrations from machinery causing unnecessary rejects
• Sensitivity to temperature, as the load cells can be temperature sensitive
• Quality control tape
• Band with the principles of quality control weight
• Weighing tape quality control principles
• Automatic weighing tape
• Weight control tape
• Food weight control tape
• Drug for weight control tape
• Detergent industry for the quality control tape
• Weight control tape for chemical industry
• Weight control tape for the pasta industry
• Flour weight control tape for the industry

Applications

In-motion scales are dynamic machines that can be designed to perform thousands of tasks. Some are used as simple caseweighers at the end of the conveyor line to ensure the overall finished package product is within its target weight.An in motion conveyor checkweigher can be used to detect missing pieces of a kit, such as a cell phone package that is missing the manual, or other collateral. Checkweighers are typically used on the incoming conveyor chain, and the output pre-packaging conveyor chain in a poultry processing plant. The bird is weighed when it comes onto the conveyor, then after processing and washing at the end, the network computer can determine whether or not the bird absorbed too much water, which as it is further processed, will be drained, making the bird under its target weight.A high speed conveyor scale can be used to change the pacing, or pitch of the products on the line by speeding, or slowing the product speed to change the distance between packs before reaching a different speed going into a conveyor machine that is boxing multiple packs into a box.

 

Typical Uses of a Checkweighers

• Check for under and/or overweight filled packages
• Insure compliance with net contents laws for pre­packaged goods
• Check for missing components in a package including labels, instructions, lids, coupons, or products
• Verify count by weight by checking for a missing carton, bottle, bag, or can in a case
• Check package mixes against weight limits to keep the solid to liquid ratio within established standards
• Reduce product giveaway by using checkweigher totals to determine filler adjustments
• Classify products into weight grades
• Insure product compliance with customer, association, or agency specifications
• Weigh before and after a process to check process performance
• Fulfill USDA or FDA reporting standards
• Measure and report production line efficiency

 

Box-sealing tape, parcel tape or packing tape is a pressure-sensitive tape used for closing or sealing corrugated fiberboard boxes. It consists of a pressure-sensitive adhesive coated onto a backing material which is usually a polypropylene or polyester film which is oriented to have strength in both the long (machine) direction and the cross direction.

Carton sealing machine, Carton sealer, and Carton taping machine: Auto carton sealer is suitable for carton packing, which can be used for single use or production line. It adopts adhesive tape to seal carton, economy and fast, easy adjust. It can finish the sealing both top and bottom. Also you can adjust the height and width for different cartons. It widely used in home appliance, textile, food, general merchandise, medicine, chemical and so on.

Box-sealing tape, parcel tapeorpacking tapeis apressure-sensitive tapeused for closing or sealingcorrugated fiberboardboxes. It consists of apressure-sensitive adhesivecoated onto a backing material which is usually apolypropyleneorpolyesterfilm which is oriented to have strength in both the long (machine) direction and the cross direction.

Most often, the tape is 48mm (approx 2 inches) wide but it is also used in 72mm (approx 3-inch) widths.A variety of backing strengths and calipers as well asadhesiveformulations are available. It is often transparent or tan (beige, buff, brown). Other colors and printing are sometimes available.

Use

The tape is most often used as a closure for regular slotted containers (RSCs). A "single strip" or "center seam" closure is applied over the center seams of a box extending 5075mm (23 inches) onto the end panels.

The tape can be used as a "six-strip" closure or "H-seal" by applying cross strips on the ends of the box. This is used when a relatively weak tape is used or when extra box reinforcement is needed. This method also seals the box to help keep contaminants out.This tape has also been used by artists , as a way to create molds of objects, as the strength of the tape allows for a strong shell for the mold when completed.

thecaseweigher-caware preferable to use in all industries such as food, pharma and all industries those require dynamic weighing system. Quick weight calculation. Continuous, dynamic weighing. And synchronization with existing conveyor systems. Numerous connection facilities for external control (plc) and computer systems. With pneumatics pusher for rejection and end solution for rejection conveyor.

the caseweigher is a kit consisting of a motor with gear box for operating conveyor system. Load cells are mounted for capturing weight and control panel with plc system.

the weighing terminal displays the weight information and allows the weighing history to be transmitted to an external device via network interface.

acaseweigheris an automatic machine for checking theweightof packaged commodities online in dynamic condition. It is normally found at the offgoing end of aproduction process and is used to ensure that the weight of a pack of the commodity is within specified limits. Any packs that are outside the tolerance are taken out of line automatically.

a caseweigher is a system that weighs items as they pass through a production line, classifies the items by preset weight zones, and ejects or sorts the items based on their classification. Caseweighers weigh 100% of the items on a production line.

typically, an infeed section, scale section, discharge section, rejecter or line divider, and computerized control comprise the physical checkweighing system. Caseweighers and their components vary greatly according to how they are used, the items being weighed, and the environment surrounding them.

Aconveyor systemis a common piece of mechanical handling equipment that moves materials from one location to another. Conveyors are especially useful in applications involving the transportation of heavy or bulky materials. Conveyor systems allow quick and efficient transportation for a wide variety of materials, which make them very popular in thematerial handlingandpackagingindustries. Many kinds of conveying systems are available, and are used according to the various needs of different industries. There are chain conveyors (floor and overhead)as well. Chain conveyors consist of enclosed tracks, I-Beam, towline, power & free, and hand pushed trolleys.

Industries that use conveyor systems

Conveyor systems are used widespread across a range of industries due to the numerous benefits they provide.

• Conveyors are able to safely transport materials from one level to another, which when done by human labor would be strenuous and expensive.
• They can be installed almost anywhere, and are much safer than using a forklift or other machine to move materials.
• They can move loads of all shapes, sizes and weights. Also, many have advanced safety features that help prevent accidents.
• There are a variety of options available for running conveying systems, including thehydraulic, mechanical and fully automated systems, which are equipped to fit individual needs.

Conveyor systems are commonly used in many industries, including theautomotive, agricultural, computer, electronic, food processing, [4]aerospace, pharmaceutical, chemical, bottlingand canning, print finishing andpackaging. Although a wide variety of materials can be conveyed, some of the most common include food items such as beans and nuts, bottles and cans, automotive components, scrap metal, pills and powders, wood and furniture and grain and animal feed. Many factors are important in the accurate selection of a conveyor system. It is important to know how the conveyor system will be used beforehand. Some individual areas that are helpful to consider are the required conveyor operations, such as transportation, accumulation and sorting, the material sizes, weights and shapes and where the loading and pickup points need to be.

Care and maintenance of conveyor systems

A conveyor system is often the lifeline to a companys ability to effectively move its product in a timely fashion. The steps that a company can take to ensure that it performs at peak capacity, include regular inspections, close monitoring of motors and reducers, keeping key parts in stock, and proper training of personnel.Increasing the service life of your conveyor system involves: choosing the right conveyor type, the right system design and paying attention to regular maintenance practices.A conveyor system that is designed properly will last a long time with proper maintenance. Here are six of the biggest problems to watch for in overhead type conveyor systems including I-beam monorails, enclosed track conveyors and power and free conveyors.
Poor take-up adjustment:This is a simple adjustment on most systems yet it is often overlooked. The chain take-up device ensures that the chain is pulled tight as it leaves the drive unit. As wear occurs and the chain lengthens, the take-up extends under the force of its springs. As they extend, the spring force becomes less and the take-up has less effect. Simply compress the take-up springs and your problem goes away. Failure to do this can result in chain surging, jamming, and extreme wear on the track and chain. Take-up adjustment is also important for any conveyor using belts as a means to power rollers, or belts themselves being the mover. With poor-take up on belt-driven rollers, the belt may twist into the drive unit and cause damage, or at the least a noticeable decrease or complete loss of performance may occur. In the case of belt conveyors, a poor take-up may cause drive unit damage or may let the belt slip off of the side of the chassis.
Lack of lubrication:Chain bearings require lubrication in order to reduce friction. The chain pull that the drive experiences can double if the bearings are not lubricated. This can cause the system to overload by either its mechanical or electrical overload protection. On conveyors that go through hot ovens, lubricators can be left on constantly or set to turn on every few cycles.
Contamination:Paint, powder, acid or alkaline fluids, abrasives, glass bead, steel shot, etc. can all lead to rapid deterioration of track and chain. Ask any bearing company about the leading cause of bearing failure and they will point to contamination. Once a foreign substance lands on the raceway of a bearing or on the track, pitting of the surface will occur, and once the surface is compromised, wear will accelerate. Building shrouds around your conveyors can help prevent the ingress of contaminants. Or, pressurize the contained area using a simple fan and duct arrangement. Contamination can also apply to belts (causing slippage, or in the case of some materials premature wear), and of the motors themselves. Since the motors can generate a considerable amount of heat, keeping the surface clean is an almost-free maintenance procedure that can keep heat from getting trapped by dust and grime, which may lead to motor burnout.
Product Handling:In conveyor systems that may be suited for a wide variety of products, such as those in distribution centers, it is important that each new product be deemed acceptable for conveying before being run through the materials handling equipment. Boxes that are too small, too large, too heavy, too light, or too awkwardly shaped may not convey, or may cause many problems including jams, excess wear on conveying equipment, motor overloads, belt breakage, or other damage, and may also consume extra man-hours in terms of picking up cases that slipped between rollers, or damaged product that was not meant for materials handling. If a product such as this manages to make it through most of the system, the sortation system will most likely be the affected, causing jams and failing to properly place items where they are assigned. It should also be noted that any and all cartons handled on any conveyor should be in good shape or spills, jams, downtime, and possible accidents and injuries may result.
Drive Train:Notwithstanding the above, involving take-up adjustment, other parts of the drive train should be kept in proper shape. Broken O-rings on a Lineshaft, pneumatic parts in disrepair, and motor reducers should also be inspected. Loss of power to even one or a few rollers on a conveyor can mean the difference between effective and timely delivery, and repetitive nuances that can continually cost downtime.
Bad Belt Tracking or Timing:In a system that uses precisely controlled belts, such as a sorter system, regular inspections should be made that all belts are traveling at the proper speeds at all times. While usually a computer controls this with Pulse Position Indicators, any belt not controlled must be monitored to ensure accuracy and reduce the likelihood of problems. Timing is also important for any equipment that is instructed to precisely meter out items, such as a merge where one box pulls from all lines at one time. If one were to be mistimed, product would collide and disrupt operation. Timing is also important wherever a conveyor must "keep track" of where a box is, or improper operation will result.Since a conveyor system is a critical link in a companys ability to move its products in a timely fashion, any disruption of its operation can be costly. Most downtime can be avoided by taking steps to ensure a system operates at peak performance, including regular inspections, close monitoring of motors and reducers, keeping key parts in stock, and proper training of personnel.

Types of conveyor systems

• Gravity roller conveyor
• Gravity skatewheel conveyor
• Belt conveyor
• Wire mesh conveyors
• Plastic belt conveyors
• Bucket conveyors
• Flexible conveyors
• Vertical conveyors
• Spiral conveyors
• Vibrating conveyors
• Pneumatic conveyors
• Electric Track Vehicle Systems
• Belt driven live roller conveyors
• Lineshaft roller conveyor
• Chain conveyor
• Screw conveyoraka Auger conveyor
• Chain driven live roller conveyor
• Overhead conveyors
• Dust proof conveyors
• Pharmaceutical conveyors
• Automotive conveyors

Belt conveyor systems

Conveyors are durable and reliable components used in automateddistributionand warehousing.In combination with computer controlled pallet handling equipment this allows for more efficien tretail, wholesale, andmanufacturingdistribution. It is considered a labor saving system that allows large volumes to move rapidly through a process, allowing companies toshipor receive higher volumes with smaller storage space and with less laborexpense.Rubber conveyor belts are commonly used to convey items with irregular bottom surfaces, small items that would fall in between rollers (e.g. asushi conveyor bar), or bags of product that would sag between rollers. Belt conveyors are generally fairly similar in construction consisting of a metal frame with rollers at either end of a flat metal bed. The belt is looped around each of the rollers and when one of the rollers is powered (by anelectrical motor) the belting slides across the solid metal frame bed, moving the product. In heavy use applications the beds which the belting is pulled over are replaced with rollers. The rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting. Belt conveyors can now be manufactured with curved sections which use tapered rollers and curved belting to convey products around a corner. Theseconveyor systemsare commonly used in postal sorting offices and airport baggage handling systems. A sandwich belt conveyor uses two conveyor belts, face-to-face, to firmly contain the item being carried, making steep incline and even vertical-lift runs achievable.Belt conveyors are the most commonly used powered conveyors because they are the most versatile and the least expensive. Product is conveyed directly on the belt so both regular and irregular shaped objects, large or small, light and heavy, can be transported successfully. These conveyors should use only the highest quality premium belting products, which reduces belt stretch and results in less maintenance for tension adjustments. Belt conveyors can be used to transport product in a straight line or through changes in elevation or direction. In certain applications they can also be used for static accumulation or cartons.

Pneumatic conveyor systems

Every pneumatic system, makes use of pipes or ducts called transportation lines that carry mixture of materials and a stream of air. These materials are such as dry pulverized or free flowing or light powdery materials like cement, fly ashetc. These materials can be transported conveniently to various destinations by means of a stream of high velocity air through pipe lines. Products are moved through various tubes viaair pressure, allowing for extra vertical versatility. Pneumatic conveyors are either carrier systems or dilute-phase systems; carrier systems simply push items from one entry point to one exit point, such as the money-exchanging tubes used at a bankdrive-throughwindow. Dilute-phase systems use push-pull pressure to guide materials through various entry and/or exit points. It is important to note that either air compressors, vacuums, or blowers can be used to generate the air. This will all depend on what the engineers think will be the most efficient and economical way of developing the system.Three basic systems that are used to generate high velocity air stream:

1. Suction or vacuum systems, utilizing a vacuum created in the pipeline to draw the material with the surrounding air.The system operated at a low pressure, which is practically 0.40.5atm below atmosphere, and is utilized mainly in conveying light free flowing materials.
2. Pressure-type systems, in which apositive pressureis used to push material from one point to the next. The system is ideal for conveying material from one loading point to a number of unloading points. It operates at a pressure of 6atm and upwards.
3. Combination systems, in which a suction system is used to convey material from a number of loading points and a pressure system is employed to deliver it to a number of unloading points.

Vibrating conveyor systems

A Vibrating Conveyor is a machine with a solid conveying surface which is turned up on the side to form a trough. They are used extensively in food grade applications where sanitation, washdown, and low maintenance are essential. Vibrating conveyors are also suitable for harsh, very hot, dirty, or corrosive environments. They can be used to convey newly cast metal parts which may reach upwards of1, 500 F(820C). Due to the fixed nature of the conveying pans vibrating conveyors can also perform tasks such as sorting, screening, classifying and orienting parts. Vibrating conveyors have been built to convey material at angles exceeding 45 from horizontal using special pan shapes. Flat pans will convey most materials at a 5 Incline from horizontal line.

Flexible conveyor systems

The flexible conveyor is based on a conveyor beam inaluminiumorstainless steel, with low friction slide rails guiding a plastic multi-flexing chain. Products to be conveyed travel directly on the conveyor, or on pallets/carriers. These conveyors can be worked around obstacles and keep production lines flowing. They are made at varying levels and can work in multiple environments. They are used in food packaging, case packing, and pharmaceutical industries but also in retail stores such asMalls

Vertical conveyor systems and spiral conveyors

Vertical conveyor- also commonly referred to as freight lifts and material lifts - are conveyor systems used to raise or lower materials to different levels of a facility during the handling process. Examples of these conveyors applied in the industrial assembly process include transporting materials to different floors. While similar in look to freight elevators, vertical conveyors are not equipped to transport people, only materials.Vertical lift conveyors contain two adjacent, parallel conveyors for simultaneous upward movement of adjacent surfaces of the parallel conveyors. One of the conveyors normally has spaced apart flites for transporting bulk food items. The dual conveyors rotate in opposite directions, but are operated from one gear box to insure equal belt speed. One of the conveyors is pivotally hinged to the other conveyor for swinging the pivotally attached conveyor away from the remaining conveyor for access to the facing surfaces of the parallel conveyors.Vertical lift conveyors can be manually or automatically loaded and controlled. Almost all vertical conveyors can be systematically integrated with horizontal conveyors, since both of these conveyor systems work in tandem to create a cohesive material handling assembly line.In similarity to vertical conveyors, spiral conveyors raise and lower materials to different levels of a facility. In contrast, spiral conveyors are able to transport material loads in a continuous flow. Industries that require a higher output of materials - food and beverage, retail case packaging, pharmaceuticals - typically incorporate these conveyors into their systems over standard vertical conveyors due to their ability to facilitate high throughput. Most spiral conveyors also have a lower angle of incline or decline (11 degrees or less) to prevent sliding and tumbling during operation.

Vertical conveyor with forks

Just like spiral conveyors also avertical conveyorthat use forks are able to transport material loads in a continuous flow. With these forks the load can be taken from one horizontal conveyor and put down on another horizontal conveyor on a different level. By adding more forks more products can be lifted at the same time. Conventional vertical conveyors have the restriction that the input and output of material loads must have the same direction. By using forks many combinations of different input- and outputlevels in different directions are possible. A vertical conveyor with forks can even be used as a vertical sorter. Compared to a spiral conveyor a vertical conveyor - with or without forks - takes up less space.

Heavy duty roller conveyors

Heavy Duty roller conveyors are used for moving items that are at least 500lbs. This type of conveyor makes the handling of such heavy equipment/products easier and more time effective. Many of the heavy duty roller conveyors can move as fast as 75 feet/minute.Other types of heavy duty roller conveyors are gravity roller conveyor, chain driven live roller conveyor, pallet accumulation conveyor, multi-strand chain conveyor, and chain & roller transfers.Gravity roller conveyors are extremely easy to use and are used in many different types of industries such as automotive and retail.Chain driven live roller conveyors are used for single or bi-directional material handling. Large heavy loads are moved by chain driven live roller conveyors.Pallet accumulation conveyors are powered through a mechanical clutch. This is used instead of individually powered and controlled sections of conveyors.Multi-strand chain conveyors are used for double pitch roller chains. Products that can not be moved on traditional roller conveyors can be moved by a multi-strand chain conveyor.

Chain & roller conveyors are short runs of two or more strands of double pitch chain conveyor built into a chain driven line roller conveyor. These pop up under the load and move the load off of the conveyor.

The90 Degree feeding shrink wrap machineis more cost effective and less time consuming for packing of products but in comparison to space constrain it will take little bit more place.

In consideration to technical aspects a90 Degree feeding shrink wrap machineconsumes less power and less air pressure as there will less operating pneumatic cylinders

1. The products which are planning to shrink-wrap will travel in a single line 90 degree to pneumatic pusher which pushes the products onto sealing units (web sealer)
2. A pneumatic pusher collates the boxes / containers into the pre-selected pack formation, once the required gets formed the product holder holds the matrix and the sensor will give the signal to seal bar to cut and seal the paper.
3. Once the welding bar ascends, the pusher advances to transfer the new collation into the welding position, at the same time displacing the previously wrapped collation onto continuously moving wire mesh shrink tunnel conveyor.
4. The wrapped collation soon enters the shrink tunnel chamber where re-circulated hot air causes the wrap to shrink and tightly conform to the contours of the contents.
5. Once the pack is out of the hot chamber , forced air cooling is used to tighten sleeve wrap to achieve a strong, secure pack ready for stacking on pallet or a placing on a shipping carton.

Auto Palletizer is usually combined with carton packaging machine, which can put the cartons filled with container on the tray (moodiness) in a fixed order and stack them automatically. The multilayer of palletizing enables the fork moves them into storehouse. This equipment adopts PLC touch screen and intelligent managing which is not only simple and easy to master, but also reducing the labor.Automatic palletizers arrange boxes and bags in tiers on pallets. There are several types of automatic palletizing machines including low table, high table and robotic. In most applications each tier is loaded ninety degrees to the previous tier in order to better stabilize the load.

1. In aStraight feeding Shrink Wrap MachineThe products which are planning to shrinkwrap will travel in a single line , inline to sealing unit and the products will collate on collation plate and pneumatic pusher which pushes the products onto sealing units (web sealer) but such option is possible only for the single column and with multiple row option i.e 1x1, 1x2, 1x3, .1xn
2. If you have multiple columns and rows then need an vertical pusher i.e for the matrixes 4x4, 3x4, 5x4 nxn. Accordingly the machine size and pusher size infect all change parts will very and the packing time also
3. In a single column and multiple row options a pneumatic pusher collates the boxes / containers into the pre-selected pack formation plate, which upon completion is transferred forwarded into the welding position.
4. In and multiple row and column option there will two or multiple pusher to collate and form the matrix
5. Once the required matrix gets formed by respective pushers as per set product size the pusher advances to push the formed matrix to sealing unit , once the matrix reaches the forming unit or forming plate the sensor gives the signal to welding bar accordingly it descents to complete the wrap, and the pusher returns to prepare the next collation of product.
6. As the welding bar ascends, the pusher advances to transfer the new collation into the welding position, at the same time displacing the previously wrapped collation onto continuously moving shrink tunnel conveyor.
7. The wrapped collation soon enters the shrink tunnel chamber where re-circulated hot air causes the wrap to shrink and tightly conform to the contours of the contents.
8. Once the pack is out of the hot chamber, forced air cooling is used to tighten sleeve wrap to achieve a strong, secure pack ready for stacking on pallet or a placing on a shipping carton.