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The process of application of a film of plastic on the surface of an item is known as lamination. When an item is given a plastic coating, it becomes tear-proof and waterproof since the laminating film encapsulates the item completely, by being bonded to both its sides.

Items that are Laminated

There are many things that benefit from this process. For example, different types of paper documents are laminated in order to protect them from smudges, fingerprints, water damage, etc. Sometimes, lamination is done in order to enhance the item's contrast and color. Lamination can also benefit items like menus, identification cards, instruction printed on paper, or any other thing that is handled frequently. It also helps in keeping materials as good as new for many years, increasing their durability as well as color preservation. In fact, laminated paper can be gifted, without requiring any additional frames or support.

The Process

The lamination process is quite simple, although its development was not easy. Laminating machines are products of decades of perfection and refinement, which have resulted in producing two of the most common types of lamination processes; one using a pouch machine and one that uses a roll machine.

Pouch Machines: They are meant for home and office use, and are quite inexpensive and effective. Also known as pouch laminators, these machines use a lamination pouch that is generally affixed on one side. A heat-activated film lines the inside of this pouch, which adheres to the item being laminated, as it is run through the machine. The board's substrate side consists of a heat-activated adhesive, which helps in bonding the print onto the substrate. This can be any type of board, or could even be another sheet. The pouch that contains the substrate, laminate, and print, is put through heated rollers with pressure applied to it, which ensures that each adhesive layer bonds in a perfect manner.

The pouches are available in various thicknesses, and are measured in micrometers. The standard ones used in office or home machines are 80 to 250 micrometers thick. These sizes also depend on the various machine types. The thicker the size, the more expensive it is. Certain varieties like the butterfly pouch are used to make ID cards. They are also available with embedded magnetic stripes.

Roll Machines: They can be used to preserve and protect a wide variety of documents between the film sheets. These machines are available in a wide range, from those specially designed for schools, to heavy-duty machines used in industrial settings, or for commercial purposes. The commercial types are available in many kinds of format sizes, to meet the requirements of in-house graphic departments, business service centers, print shops, copy shops, etc. Such devices that are meant for schools, can provide a cost-effective way of preserving teaching material and the work of students. Designed for flexibility, quality, and convenience, these machines have various features like adjustable heat control, variable speed control, adjustable tension, and automatic shutdown. There are two types of roll laminating machines - hot rollers and cold rollers.

Hot Roll Lamination: In this type, melted glue is applied to the laminating film with the help of hot rollers. This helps to stick the film onto the material to be laminated, in a faster manner, and at the same time, ensures a good-quality lamination. This method is cheaper than the cold roll technique, and is used mostly to protect papers that have printed content, as well as those that are in the form of pictures or photographs. The glue used is in a solid form at room temperature, and hence, after it solidifies, the laminated material is hardly affected by any other factors. In this method, two rolls are used for the process; one is at the top, and the second one is fixed at the bottom. Metal bars called 'mandrels' are a part of these rollers. They help in assembling the film and its application on the object to be protected.

Cold Roll Lamination: In this technique, small rollers are used to laminate an object with the help of a plastic film. A liquid adhesive along with a glossy finish is used, contrary to the glue that is utilized in the hot roller method. The required machinery varies in size, from a couple of rollers, to large devices used in industries. After removal of the glossy finish, the adhesive sticks firmly to the object along with the film. By using this method, objects that can be affected by heat can be protected, as the adhesive used does not react to heat. Apart from laminating printed papers and documents, cold roll lamination can also be used to protect glass and steel objects. Large hoardings and sign boards outside major commercial establishments are also laminated by using this technique.

Apart from the above-described techniques, other methods like wax lamination, wet lamination, dry lamination, and solventless lamination are also used.
  • The first method uses a type of wax in molten state along with an aluminum foil. It is utilized for lamination of various bakery products.
  • In wet lamination, the adhesive used is in a liquid state, and this allows for better bonding of the film along with the object.
  • Dry lamination uses a laminate, which is first dissolved in water, and then dried using an oven. This ensures a smooth process, especially with the help of hot rollers.
  • Solventless lamination utilizes types of adhesives which do not require to be dissolved in solvents, and consist of substances that react with each other during the process of lamination.
Among the various supplies required for lamination, one of the most important ones is the films. They are available in varieties like 'de-lustered' and 'clear'. The former has a non-glare matte finish, which is highly suitable for reading material. The latter is very popular, as it provides a sheen-like finish, and helps to enhance the colors of the items being laminated.

Something You May Like to Know

Wood Veneer: Though primarily used for decorative purposes, wood veneers are often compared to plastic laminates. The concept is similar to lamination in that veneer is a coating of a thin layer of superior wood on a base of inferior wood. The process is used for paneling doors, cabinets, and floor. Compared to plastic, wood veneers are an eco-friendly option and also more durable. But laminating using wood and that using plastic have different purposes.

Laminated Glass: In a laboratory accident in 1903, a glass flask dropped but surprisingly, did not break to pieces. Chemist Edouard Benedictus knew that the flask was coated with plastic cellulose nitrate, which led him to make a glass plastic composite that could be used to prevent glass breakage. Today's laminated glass is made using two glass layers that are bonded with an interlayer of plastic. It is widely used in automobile windshields and hurricane-resistant constructions.

Recent improvements in the lamination process include higher-speed machines and laminating systems that use sheet cleaners, thus improving the output. The use of metalized and holographic laminating films are among the other developments in this field.