What Are Conveyors?
Conveyors are a type of material handling equipment which assists in moving products, packages, foods or equipment from one place inside a facility to another, or through various stages of automated manufacturing or finishing. Because conveyors move such a broad range of items, different conveyor configurations are available to meet the material handling needs of manufacturers and distributors everywhere. Belt conveyors are the most common, followed by chain conveyors, roller conveyors, spiral conveyors, overhead conveyors, vertical conveyors and conveyor systems内蒙古快3-首页, which may use combinations of many different conveyor types.
Conveyors are usually motorized, but some conveyor types, such as ball transfer and chute, are gravity conveyors. Pneumatic conveyors also assist in transporting materials, but these tubular air-powered conveyors specialize in bulk powder solid transportation, a different type of conveying. Manufacturers and package handlers in almost every industry make use of various types of conveyors or conveyor systems, especially food conveyors and industrial conveyors, to transport parts, products and packages through various processing systems. In a setting, such as a manufacturing business, conveyors may be set up between work stations.
内蒙古快3-首页The most typical conveyor is the belt conveyor, which consists of a wide polymer or rubber belt wrapped around rollers which turn in the same direction, giving the belt and all objects on the belt linear movement. This same construction is used with chain conveyors, except that chains are wrapped around the wheels instead of a belt; chain conveyors may move products along one chain or multiple parallel chains. These are the most common conveyor types, being used for general product movement in food processing, packaging and parts manufacturing industries to transport items or to move unfinished products through various stages of processing. Chain conveyors utilizes parallel horizontal chains to move materials through a conveyor system and from one place inside a facility to another, or through various stages of automated manufacturing or finishing. Chain conveyors are commonly used to move parts such as powdered metal parts through ovens for sintering or drying, or to move unfinished metal parts through parts washing processes.
Roller conveyors are commonly used in these industries as well, using individual rollers placed parallel to one another to provide movement. Vertical conveyors are configured with platforms, buckets, grippers or magnets around moving belts or chains, which lift items from one level to another; although not as common, vertical conveyors can be crucial in facilities where it is necessary to safely transport food items or parts vertically. Parts manufacturers frequently use overhead conveyors to transport parts and products across a facility and/or through processing systems such as spray paint booths, dryers or ovens. Conveyor systems combine many or all of these conveyor types to transport products across a facility or to move unfinished products through automated assembly lines or finishing processes. While most conveyors are powered by electric or pneumatic motors and drive systems, some conveyors are propelled by gravity; roller conveyors are often moved by the inertia of products or packages rolling over them, a design typically used in downward spiral conveyors.
内蒙古快3-首页Conveyor and conveyor system manufacturers are creating innovative solutions to new manufacturing challenges every day. All conveyors may twist, turn and travel vertically up and down floors to transfer items. As a result, modern conveyor systems are equipped not only to move parts across horizontal and vertical distances, but also to curve, divert, lift and sort products and packages as part of complete automated systems. These types of advanced conveying processes are done by brushes, magnets, automated levers, rails and even simple gravity. Packaging industries have designed conveyor systems pre-programmed to sort specific boxes into separate chutes, and automated food processing conveyors can handle and sort the most delicate fruits and vegetables using sensors and robotic handlers. When integrated with robotic processing, conveyors and conveyor systems become powerful processing tools.
The History of Conveyors
内蒙古快3-首页The modern conveyor belt dates back to 1892, when inventor Thomas Robins created a rotating system of belts to aid in the extraction of ores and coal in the mining industry. Since then, there have been many revisions and new takes on the idea of a heavy-duty conveyor system. New implementations include the chain conveyor, overhead conveyor, roller conveyor, and the updated conveyor belt, using modern, corrosion resistant materials such as stainless steel.
Conveyors – Metzgar Conveyors
Conveyors – Metzgar Conveyors
Conveyors – Metzgar Conveyors
Conveyors – Metzgar Conveyors
How Conveyor Belts Work
Depending on the type of conveyor system being used, there are different ways they are intended to function. Some conveyors use gravity, others allow the worker to give the object a solid push to get it moving down the conveyor, but many are operated mechanically for automatic transport.
Gravity roller conveyors are essentially a line of freely moving conveyor rollers, often placed at a slight downward angle, giving rigid items, such as boxes, a direct, energy-free route from one section to another.
Overhead conveyors can be either mechanically or manually operated. The idea behind an overhead conveyor is that it saves ground space by employing a series of tracks attached to the ceiling of the warehouse or factory. A free-hanging chain, pulley, hook, or any other transportation vessel in attached and performs the same action as any other conveyor, only from above rather than on the floor.
内蒙古快3-首页Belt conveyors and chain conveyors are almost always mechanically operating. These systems perform their function with the aid of a mechanical system called a V-Belt Drive. The V-Belt Drive is the turning part that pulls the conveyor. The type of conveyor surface, as with any machinery, is determined by the items being moved. Chain conveyors are a metal, mesh-like surface, reminiscent of a chain link fence. The belt conveyor, as it implies, is a soft, flexible belt, often times made of rubber.
How These Are Implemented
内蒙古快3-首页Deciding on which conveyor system is most appropriate is not always a straightforward process. It is often the best course of action to consider the details of an operation, such as where this system is to be located, how often it is going to be used, where the items need to be moved to, any obstacles in the way, how often, depending on wear and tear, you might need conveyor maintenance, and, most importantly, what you are going to be moving with your conveyor system.
The main benefit of the iconic conveyor belt is its simplicity. It is a flat, smooth surface that pulls items from any point on the belt, to its end, or the next belt lined up to it. This is an ideal system for most small to medium sized products, especially boxes and bulk materials. If you take into account weight and size of your products, the belt conveyor can be a versatile system for several types of operations.
Just make sure to take into account the effect the product could have on the belt. Is it sharp? Is it perhaps sticky or coated in an oil? If so, perhaps another system may be better suited for this product.
内蒙古快3-首页Chain conveyors are often seen in food production. For example, a chain conveyor using non-stick stainless steel can be used in the production of donuts, gently moving the dough and finished products through the several stages of cooking and flavoring, with less risk of the food items sticking to the conveyors. These also allow for easier cleaning due to their open and flexible pattern.
A roller conveyor system is a primary candidate for warehouses or shipping. Boxes of all sizes are seamlessly moved with far less stress on workers than if they were to pick them up and walk them to their secondary location. With a gravity based rolling system, a worker only has to place the box, or any object being produced for that matter, onto the roller system and give it a push. The low-friction roller system allows the box to fly across the factory as if it weighed next to nothing. Even more effortless is the motorized roller system. The motorized roller conveyor performs the same task, except it uses a mechanical system, such as a V-Belt Drive内蒙古快3-首页, to rotate the rollers at a consistent pace.
Overhead conveyors are among the most open-ended systems available. If your warehouse or workshop has a ceiling or series of beams with good structural integrity, the movement of anything from a small part to something as heavy, or even heavier, than an engine block, becomes much easier. Rather than having to lift a part up onto a ground conveyor, these overhead conveyor systems open up the use of pulleys, levers, and other practical methods to lifting and positioning products. Once the part has been secured onto the hook, chain, platform, or any other method being utilized, the part is then either pushed or mechanically pulled by the rail system on the ceiling.
The overhead conveyors also have the added benefit of opening up ground space and providing the product with a direct path from one end of a workshop or warehouse to the other without the obstacles of workspace being taken up on the ground. The advantages of overhead systems is the combination of efficiency and ease of use. Even a multi-story operation can optimize their productivity by eliminating the bulk and hassle of a conveyor belt going from a second floor to a first floor by just using the simple, low maintenance overhead system. Simply keep the tracks cleaned, well lubricated, and regularly inspected is all it takes to keep your system safe and running smoothly for a long time.
The Incorporation of Conveyors
Conveyor manufacturers often have expert technicians who are well qualified to install a wide range of conveyor systems, but it doesn't hurt to know the basics of how such a system is implemented. They all follow a similar process, despite their functional differences. Ground conveyors (not including overhead conveyor systems) are installed after designating an area to them. An operation's layout may be altered or centered around the conveyors depending on floor or space restrictions, or simply for ease of access. The height of the system is optimized for the type of work stations it may be attached to. The direction, of course, is based on where you want the finished product to end up, and is meant to be designed in relation to the flow of the workshop or warehouse. The conveyors must be optimized to properly material handle the products assigned to it.
The system is set up with its base fixed and direction determined. The tracks are set up, holding the gears, pulleys, cogs, belts, chains, and any other parts serving the conveyor system's primary function. Then, assuming the model is mechanical, the motor, belt drive, power system, and weight distribution systems (again, depending on the type of conveyor) is set up and checked to ensure proper functionality.
内蒙古快3-首页If the system is gravity based, like with a free-spinning roller conveyor, the rollers are placed within the grooves and predetermined slots on the conveyor tracks and locked into place, while still allowing the rollers to spin freely.
内蒙古快3-首页With the overhead conveyors, the process is not much different. First, the path of the rails is determined based on the structure itself. The one downside of an overhead conveyor, compared to ground conveyors, is that they can only be placed where the structure will allow it to safely hang. The restrictions become even more intensive as the object gets heavier. With a ground system, weight is not as much an issue if the conveyor can tolerate it. With the overhead rails in place, the next step is attaching the chains, belts, pulleys, free-hanging vessels or chains, and the motor in the case of a mechanically operated overhead conveyor.
Then, the only thing left to do is test out the new system. Place products as you would normally, giving the system a trial run. Most conveyors can be lined up, connected, change direction, and bring things to higher or lower ground. These aspects are sometimes not available with less flexible systems内蒙古快3-首页, but inquiring about your specific needs with the conveyor manufacturer or installer is always recommended. The main purpose of conveyor belts is to improve your efficiency, so specific aspects should be a priority when ordering one.
Safety Regarding Conveyors
内蒙古快3-首页Safety is a given in any professional operation. Every aspect must be taken into consideration when using conveyor equipment. Will this set up pose any sort of risk to you or your workers? Can the system, if not properly used, damage products? Are there any indirect risks created as a result of implementing a conveyor system? These questions must be addressed and investigated if the answer is 'yes' to any of them. Overhead conveyors can be a hazard if improperly placed, possibly hitting objects or workers. Or, if an item is not properly secured, it could fall, opening a new variety of potential risks. Even traditional ground conveyors can block paths, catch loose objects, such as shirts, neck ties, hair, or cause someone's finger to get caught.
内蒙古快3-首页Safety training is necessary for the health and well-being of your workers, yourself, and the company as a whole. As an employer, you could be liable for dangerous conditions. The installation of these conveyor systems must be supervised and inspected by a professional to avoid risks or hazards that you may not even have considered. These experts are trained to mitigate safety issues and understand dangers or potential problems that, to the untrained eye, may not seem problematic at all.
How To Keep Your Conveyor System Well Maintained
A conveyor system is an industrial handling equipment that transfers heavy industrial goods from one place to another. These machines offer a great convenience to a manufacturing business by unloading the burden of their workers. With these machines, moving heavy and bulky materials to other places or levels becomes easy.
内蒙古快3-首页Conveyors are used for quick and safe handling of materials within the perimeter of the plant. This plant and facility equipment is available in a wide variety of design and capacity options to suit a variety of industrial requirements. Wheel and chain conveyors are two of the most common types. Traditional conveyors are run by hand (by laborers), while the modern machines are mostly fueled by electricity.
The importance of conveyors cannot be overlooked in industrial processes. For safe, reliable, and timely conveyance of materials, conveyor systems need to be kept well maintained. On time maintenance ensures unbarred and enduring performance.
Here are a few tips for easy maintenance of conveyor systems –
Regular Inspection – You should have machine experts in your team to take a closer look at the irregularities in your plant’s conveyor system. You should ask them to create an inspection routine. There should be a checklist that should include all the standard and essential points regarding the performance of the machine. These factors should be checked on a regular basis in order to avoid the intensification of any insignificant problem.
The idea is to make sure that your machine is working properly and is not experiencing any hindrance in its operation. The routine checkup will lower the chances of unexpected downtimes, which can cost you thousands of dollars.
Training of personnel – The second most important step to increase the efficiency of your conveyor system is to train your staff about handling and maintenance for the machine. If your staff is updated with these pieces of information and sets of procedures, you would be able to address the problems the moment they occur in the conveyor system.
Customized conveyor systems内蒙古快3-首页 – At times, because of incompatibility, conveyor systems fail to meet your application requirements. Sometimes, low capacity conveyors are used for moving heavy materials. Such practices may result in machine damage. You should consider having a customized conveyor system at your facility. By choosing to customize your machine according to your specific application requirements, you will put an end to all such possibilities.
Have backups ready – Ask your expert mechanics to have essential conveyor parts ready as backup in their store. In case, there is a need for quick repair or replacement, such backups will stand as a great help. Furthermore, you should make provisions for sufficient power backup systems in place, since modern-day conveyors work on electricity.
Proper cleaning内蒙古快3-首页 – Last but not the least, your facility should have arrangements for adequate cleaning. There should be an active dust management system to control the spread of dust and other particulates inside your plant. It will help you keep dust and other possible contaminants away from your conveyor system. Just like the maintenance of conveyor system, you should have a daily checklist of cleaning routines for your site.
How To Select Conveyor System for Your Process
A conveyor system is a machine, used by industries to move pieces of heavy equipment from one place to another at their manufacturing plant or warehouse. For the safe handling of machines and products, it is important to choose the right type of conveyor system.
Understand the different types and capacities of conveyor systems
On the basis of your application requirements – such as, size, capacity, length, speed, control, product, etc. – this plant and facility equipment can be categorized into many types. There are also available customization options.
Based on their mechanism, different types of conveyor systems are: chute conveyor, chain conveyor, roller conveyor, flat belt conveyor, magnetic conveyor, and wheel conveyor. Conveyors come in a diversity of sizes and capacities. You can get your machine’s capacity and conveyor belt size designed to your specification. When selecting a conveyor, your focus should be on your requirements. You can ask your supplier to design and provide you with a machine that fulfills your needs.
Ease in operation
内蒙古快3-首页You should pick a system that does not have a complex control panel. It is imperative because your workers will be operating the machine, not the engineers who have designed it. Therefore, you should select a conveyor that has a simple operating system.
内蒙古快3-首页When scanning through the quotations from various conveyor suppliers, you should give preference to a supplier, who has the latest machines in their inventory. This way, you will get hold of the most advanced technology for your process.
Safe to use
Using a machine that does not fit into your specifications and space could raise safety concerns. You should invest in a conveyor system that supports the safety of users and the products that it has to move.
Reliable and low on maintenance
内蒙古快3-首页To save on your repair and maintenance outlays, you should buy a conveyor system offered by a reliable supplier. In addition to this, you should also make sure that the machine has dependable and tried and tested design, while being low on maintenance. These factors help you save a lot on frequent, unwanted repair and maintenance requirements.
Conveyor systems run on electricity. You should double check from your supplier about the energy efficiency rating of the machine you are interested in.
Modularity is a significant factor to look for. Ensure that your conveyor system has thoroughly engineered sections and modules that give you the freedom to make future additions.
Know your product well
Before you finalize the deal, it would be ideal to check through the brochure of your product. The idea is to know every single detail about the machine that you are going to purchase. You should learn about its features, specifications, and operations. Apart from this, you should also know your system’s requirements.
Having these details and your application requirements in your consideration, will help you in selecting the right conveyor system for your process.
Different Types of Conveyor Systems and Their Use
Conveyor systems are advanced material handling technology that involves the transportation, safe management and storage of a wide range of materials. These advancements are used across industries by manufacturing, transportation, packaging, and warehousing businesses. Every business is not the same size. They do not operate on the same level. Therefore, it needs to be made sure that the right type, size, and capacity of conveyor system is used by the plant.
内蒙古快3-首页For the selection of an appropriate conveyor system, factors to keep in consideration are – product size, product weight, quantity, frequency of conveyance, plant environment, and power options.
内蒙古快3-首页There are different types of conveyor systems available to suit varying application requirements. Here, the following offers a brief summary about various types of conveyors–
These machines are used by packaging businesses. They use it for loading/unloading packages into/from the vehicle and sorting the packages or products at the their facility. Gravity conveyors are cheaper than other types of conveyors, due to their minimal and simple machine parts. Also, gravity conveyors do not have advanced control options, as there is no provision for power input. Simply, these are non-powered conveyors that are used for limited applications.
内蒙古快3-首页Belt conveyors are used for transporting materials from one place to another. These conveyors are used for handling packages and materials. Many businesses use them for moving medium to small size packages and materials. Belt conveyors are used in elevators. The platform in a belt conveyor is moved by a moving and controllable “belt”.
Roller conveyors have rollers to move the materials and parts placed on them. It is considered the best utility for moving lightweight products and packages. The rollers can handle small to medium size and weight materials.
内蒙古快3-首页In addition, there is also minimum pressure conveyor systems available – that is also a type of roller conveyor. Minimum pressure systems are a solution for medium size products in a facility that has short sections and limited space.
Additionally, roller pallet conveyors are taken in use for dragging or moving extremely heavy loads. They are also a type of roller conveyors.
Drag Chain Pallet Conveyors
These systems have a robust chain to drag, move or handle heavyweight products, parts and materials. Apart from heavy loads, these conveyors are considered ideal for extreme high and low temperature and high-pressure environments. These machines can also be used for moving special pallet configurations.
Overhead conveyor is a material handling technology for food packaging, trash removal, assembly line, and paint businesses. These machines work on the oldest principles of material handling technique. However, due to their reliability and consistency, they are used in the present time as well. Additionally, they do not also require frequent maintenance. That’s why, overhead conveyors are still an ideal choice for a large number of businesses.
内蒙古快3-首页Technically known as magnetic slide conveyors, these machines are utilized for moving small packages. In addition to that, you can also use them for removing small metal parts and chips from a machinery or an amassing of materials.
Who to Buy From
内蒙古快3-首页When picking a manufacturer or conveyor company to buy your new system, take into consideration the prices, the reputation of the company, their willingness to serve your needs, and the services they offer. By checking reviews, you can have an idea of other individuals' experiences with the company you are considering purchasing from. Call the manufacturer, explain to them what you are looking to purchase, or ask them what would best suit your needs. By just investigating and understand how these companies operate, you save yourself the risk of being unhappy with your conveyors, while also obtaining some insight on how to best implement them into your daily operations.
Conveyor System Types
- Accumulating Conveyors allow for the collection of materials at a given point on the conveyor line, and are common in grouping and sorting operations.
- Automated Conveyor Systems perform conveying functions automatically, instead of through manual operation, saving time and reducing labor costs.
- Ball Transfer Conveyors are a type of material handling system that facilitates omni-directional manual transportation.
- Belt Conveyors use a belt to transport materials through the conveying system. Belt conveyors are common in moving light to medium material loads.
- Chain Conveyors use parallel horizontal chains to move materials through a conveyor system. Chain conveyors are useful when moving bulky materials, but they sometimes produce an inconsistent flow, need to be lubricated and can be loud.
- Chain Roller Conveyors are conveyors that have tread rollers attached to the sprockets, and are driven by a chain.
- Conveyor Systems are a type of material handling equipment which assists in moving products from one place inside a facility to another and may involve one type of conveyor or a combination of many different conveyor types.
- Decline Conveyors are conveyors that move at a downward angle.
- Food Conveyors are material transferring systems that are specifically designed for use in the food processing and beverage industries to handle both raw and cooked food items that are mass produced.
- Gravity Conveyors are conveyors in which objects are manually advanced by gravity, used in applications that require ease of rotation, transportation and accumulation of cartons, boxes and bags.
- Incline Conveyors are conveyors that move at an upward angle.
- Industrial Conveyors are material handling systems that are fixed and permanent and transport packages, boxes, food, raw materials, products, parts and equipment from one facility location to another or through various stages of automated manufacturing or finishing.
- Material Handling Conveyors are industrial equipment that are fixed and permanent systems that move and transfer packages, boxes, food, raw materials, products, parts and equipment from one facility location to another or through various stages of an assembly line.
- Overhead Conveyors provide continuous movement of materials overhead, as opposed to standard floor conveying systems. Overhead conveyors save space and are common for moving materials around an industrial facility.
- Pallet Conveyors consist of portable platforms called pallets that move parts to different locations between industrial operations.
- Reversible Conveyors are conveyors capable of moving in both directions.
- Roller Conveyors use round rotating parts called rollers to transport material through the conveying system. Roller conveyors are common in accumulating materials and in converging conveyor systems, in which separate conveyor lines join to form a single conveying line.
- Slat Conveyors are conveyors that use steel or wooden slats mounted on roller chains to transport products.
- Spiral Conveyors can use belts or slats to vertically move packages, boxes, food products and other individual items or parcels, or they can be an enclosed screw which transports loose bulk particles vertically.
- Vertical Conveyors move materials up or down instead of traditional horizontal movement, and are common in applications with limited available space. Reciprocal vertical conveyors move materials up or down and return to the initial starting point; continuous vertical conveyors move materials to different levels without returning to the initial point.
Conveyor System Terms
Axle – A non-rotating shaft that wheels and rollers are mounted on in a conveyor system.
Bag Flattener – An assembly that holds one conveyor upside-down over another to squeeze or flatten the product.
Bearing – A mechanism on which a conveyor shaft rotates that prevents the rubbing together of the bed and the shaft.
Bed – Conveyor component on which the materials to be conveyed are placed.
Belt – Elastic band wrapped around the conveyor pulley that transmits the motion necessary for the movement of materials between two points.
Belt Scraper – Brush that removes excess material stuck to the conveyor belt.
Belt Speed – Measurement indicating the amount of conveyor belt moving in a specified period of time.
Brake Motor – A device on the motor shaft that is engaged when the electric current fails.
Brake Rollers – Roller conveyor brakes that control the movement of conveyed materials through pneumatic or mechanical power.
Casters – Wheels that make the conveyor portable.
Ceiling Hangers – Rods that hang from the ceiling and support the conveyors to free up floor space.
Center Drive – A drive assembly mounted on the conveyor, usually underneath and in the center, used for reverses and incline applications.
Cleat – Mechanism fastened to a conveyor to help control the movement of materials.
Cleated Belt – A belt with raised sections that helps stabilize the flow of material on belts operating on inclines. These can be part of the belt or fastened on.
Clutch-Brake Drive – A drive that is used to stop the conveyor belt immediately without cutting off the supply of power.
Clutch Drive – A drive used to disengage the motor from the reducer without stopping it or cutting off the power.
Converging – A section where two conveyors meet and merge into one.
Cross Bracing – Rods that are placed diagonally over the conveyor in order to help in squaring frames, useful for tracking.
Drive – A motor and other parts that collectively produce the power necessary for conveyor movement.
Drive Pulley – Pulley responsible for conveyor belt movement. This is attached to the conveyor drive shaft.
Feeder – A conveyor that is designed to control the rate of delivery of objects.
Flow – A term for the direction of travel on a conveyor.
Frame – A structural conveyor system component that provides the main support for the network of machinery that makes up the conveyor system.
Horsepower – A measure of the time rate of doing work.
Infeed End – The part of the conveyor that is nearest the loading zone.
Intermediate Bed – The part of the conveyor that is in the middle and does not contain the tail or drive assemblies.
Lacing – What is used to attach segments of belts together.
Magnetic Starter – An electrical device that controls the motor and provides overload protection.
Motor – A machine that is used to transfer electrical energy into mechanical energy.
Nose Roller – Small roller on a power belt curve conveyor that reduces the gap at the transfer points.
Overhead Drive – A drive assembly that is mounted over the conveyor belt and allows clearance for the product.
Plow – A device that is placed across the path of a conveyor at a certain angle and is used to discharge or deflect objects.
Pop-Out Roller – A roller used to aid in transfer, set in a wide groove to allow it to eject if an object comes between it and the belt.
Powered Feeder – A part of a belt conveyor that is used to move products horizontally onto an incline conveyor.
Pressure Roller – In a belt driven live roller conveyor, a roller used for holding the driving belt in contact with the load carrying rollers.
Pulley – Wheel mechanism that controls the movement, speed and direction of materials. These contain a bore or a groove to which the conveyor is attached.
Pusher – A device that is used for diverting a product from one conveyor line to another line or chute.
Roller – A round part that revolves around the outer surface of a conveyor. These can be straight, tapered or crowned, and serve as the rolling support for the load being conveyed.
Roller Bed – An assembly of rollers over which products move on a roller conveyor.
Shaft – Bar responsible for the transmission of force to the support of materials on the conveyor.
Slider Bed – The surface on which the belt conveyor slides.
Slug Mode – A mode that allows all packages to be released simultaneously.
Throughput – Amount of material conveyed in a specific amount of time.
Tracking – The act of steering the belt to maintain the desired path.
Transfer – A device that is used to move products at right angles to adjacent or parallel conveyor lines.
Turnbuckle – Link that has a screw thread at both ends, and is used for tightening the rod, normally in cross-bracing.
Turning Wheel – A wheel that helps ensure proper package orientation.
Conveyor Informational Video