Wallpaper Manufacturing Process

The Manufacturing
Process
Making the paper

    1 Ground wood sheets of paper are produced by using an entire tree, removing the bark, and pressing the tree against a revolving tread, which grinds the wood into slurry. The slurry is used to make a ground wood sheet—a relatively inexpensive wall-paper backing.

    Wood pulp sheets are made by debarking a tree and chipping the tree into a slurry. The mixture is run through a pulp mill where chlorine dioxide and oxygen are added to separate the lignin (which cements the woody cell walls together) from the rest of the wood pulp and bleaches the pulp. Wood pulp sheets with fibers can have synthetic fibers added to give the paper additional texture.

    A roll of paper from the paper mill is 65 in (1.65 m) wide, possibly as long as 22,000 ft (6,706 m), and weighs approximately one ton. Once sold to a printer, each paper roll is cut into six sub-rolls which are 21 in (53 cm) wide by 10,000 ft (3,048 m) long.

Coating

    2 Before the pattern is printed, the backing must be coated with a ground color. Ground wood sheets are coated with colored vinyl (PVC), which varies in thickness depending on the durability and strippability of paper under production. Vinyl may also be laminated to backings for exceptional serviceability.

    Wood pulp sheets are coated with one or all of the following: kaolin clay for drapability, titanium dioxide for opacity, and latex for ease in handling and color.

Printing

There are four possible types of printing techniques.

    3 Surface printing. Metal rollers impregnated with a raised rubber pattern are mounted on a single machine. Ink is applied to the surface roller, and the ink lays in the hills or rubber pattern sitting above the surface of the roller. The ink is then pressed onto the paper.
    4 Gravure printing. Each color of the pattern is printed with a single roller. Copper cylinders are laser-etched then chrome-plated for durability. Large gravure-printing machines hold a maximum of 12 cylinders that together create the whole pattern. The paper roll moves to one cylinder, a back roller picks up color and pushes it against an engraved roller. A steel doctor blade pushes against the engraved cylinder, forcing ink into the etched detail. A rubber roller then presses paper against the cylinder, enabling it to pick up the ink in the valleys of the engraving. Finally, rollers carry the paper away from the cylinder into a dryer, where the ink is set. Once the ink is dry, the process begins again with the next cylinder.

    5 Silk screen printing. Stencils for each color present in the pattern are created from silk mesh screen, using a photographic process. First, a photographic negative is made of the pattern. Then, a silk screen approximately 36 in (91 cm) long is stretched taut over a magnesium or wood frame. The screen is coated with a light sensitive emulsion, and the negative is placed on top of the screen. Once hit with bright light, the emulsion hardens in the areas not covered by the negative, forming a stencil.

    Paper is set upon a long table, a screen stencil is placed on top, and ink is applied by a scraper or squeegee. Color is deposited on the paper where the screen permits the ink to pass through to the paper. The stencil is picked up, moved down the paper, and inked again along the entire length of the paper roll.

    Before the next color is applied, the ink is thoroughly dried. Each screen is carefully put down with blocks, guides, etc. so that the pattern is aligned and repeats without breaks. Hand printing produces patterns with thick, evenly applied color. Theoretically, the number of colors used in the screening process is limitless; however, the high cost of hand printing necessarily limits the number of colors companies can include in the pattern.
    6 Rotary printing. This type of printing process combines the mechanics of gravure printing with the precision of photographically produced stencils. Mesh stencils are wrapped around hollow tubes mounted within a machine. Ink continuously flows through the film-wrapped tubes and onto paper, imparting a tremendous amount of color (a maximum of 12 colors). This technique resembles the more expensive silk-screening, but it can print much more quickly—approximately 80 yd (73.12 m) of wallpaper per minute.

Prepasting

    7 Printed wallpaper is rolled with a wet cornstarch or wheat starch-based coating and then dried.

Packaging

    8 Residential-use wallpapers are cut down from 3,000 yd (2,742 m) rolls to 15 yd (13.71 m) rolls. Commercial-use rolls are generally packaged in 30, 45, and 60 yd (27, 41, and 55 m) rolls. A printed label, run number, and hanging instructions are placed against each roll and shrink wrapped together. Rolls are stored in a warehouse until final shipment.

All About Ganesha

Ganesha also spelled Ganesa, also known as Ganapati and Vinayaka is a widely worshipped deity in the Hindu pantheon.His image is found throughout India and Nepal.Hindu sects worship him regardless of affiliations.Devotion to Ganesha is widely diffused and extends to Jains, Buddhists, and beyond India.

Although he is known by many attributes, Ganesha's elephant head makes him easy to identify.Ganesha is widely revered as the remover of obstacles,the patron of arts and sciences and the deva of intellect and wisdom.As the god of beginnings, he is honoured at the start of rituals and ceremonies. Ganesha is also invoked as patron of letters and learning during writing sessions.Several texts relate mythological anecdotes associated with his birth and exploits and explain his distinct iconography.

Ganesha emerged as a distinct deity in the 4th and 5th centuries CE, during the Gupta Period, although he inherited traits from Vedic and pre-Vedic precursors.He was formally included among the five primary deities of Smartism (a Hindu denomination) in the 9th century. A sect of devotees called the Ganapatya arose, who identified Ganesha as the supreme deity.The principal scriptures dedicated to Ganesha are the Ganesha Purana, the Mudgala Purana, and the Ganapati Atharvashirsa.

Wallpapers Types and Sizes

In terms of methods of creation, wallpaper types include painted wallpaper, hand-printed woodblock wallpaper, hand-printed stencil wallpaper, machine-printed wallpaper, and flock wallpaper.

Modern wallcoverings are diverse, and what is described as wallpaper may no longer actually be made from paper. Two of the most common factory trimmed sizes of wallpaper are referred to as "American" and "European" rolled goods. American rolled goods are 27 inches by 27 feet (8.2 m) in length. European rolled goods are 21.5 inches wide by 33 feet (10 m) in length. Approx. 60 square feet (5.6 m2). Most wallpaper borders are sold by linear foot and with a wide range of widths therefore square footage is not applicable. Although some may require trimming.

The most common wall covering for residential use and generally the most economical is prepasted vinyl coated paper, commonly called "strippable" which can be misleading. Cloth backed vinyl is fairly common and durable. Lighter vinyls are easier to handle and hang. Paper backed vinyls are generally more expensive, significantly more difficult to hang, and can be found in wider untrimmed widths. Foil wallpaper generally has paper backing and can (exceptionally) be up to 36 inches wide, and be very difficult to handle and hang. Textile wallpapers include silks, linens, grass cloths, strings, rattan, and actual impressed leaves. There are acoustical wall carpets to reduce sound. Customized wallcoverings are available at high prices and most often have minimum roll orders.

Solid vinyl with a cloth backing is the most common commercial wallcovering and comes from the factory as untrimmed at 54 inches approximately, to be overlapped and double cut by the installer. This same type can be pre-trimmed at the factory to 27 inches approximately.

Furthermore, wallpaper comes in the form of borders, typically mounted horizontally, and commonly near ceiling level of homes. Borders come in varying widths and patterns.