The term lacquer is used for a number of hard and potentially glossy finishes applied to materials such as wood. It falls into a number of very different groups.
The term lacquer is derived from the Sanskrit word l? Ksh? (??????) represents the 100,000 numbers, used for lac insects (due to their large quantities) and the secretion of red, lacquer-rich resins, which produce those used as wood finishes in ancient India and surrounding areas.
Asian varnish, which can be called "true lacquer", is a sap-coated, dyed and dried object of Toxicodendron vernicifluum or related tree, which is applied in several layers to a base that is usually wood. It dries to a very hard and smooth surface layer that is durable, waterproof, and appealing to feel and see. Asian varities are sometimes painted with pictures, decorated with leather and other materials, or carved, and sprinkled with gold and given other decorative treatments.
In modern techniques, lac means a variety of clear or colored wooden layers that are dry by solvent evaporation or a preservation process that produces a hard and durable finish. The end result can be a sheen level from ultra matte to high gloss, and can be polished further as needed. It is also used for "cat lacquer", which is a paint that usually dries better on hard and smooth surfaces.
In the case of modern products for finished coatings, lac based finishes tend to be called shellacs, while lacquer often refers to other polymers dissolved in volatile organic compounds (VOCs), such as nitrocellulose, and then acrylic compounds dissolved in lacquer thinner , mixtures of some solvents which normally contain butyl acetate and xylene or toluene. Lacquer is more durable than lacquers.
Video Lacquer
Etymology
The English lacquer is from the ancient French word lacre "a kind of sealing wax", from the Portuguese lacre , itself a Medieval Latin variant that can not explained. lacca "resin substance" from Arabic lakk , from Persian lak , from Hindi lakh (Prakrit < i> lakkha ). This finally comes from Sanskrit l? Ksh? (??????), which is used both for Lac insects and the resulting red resin secretion used as the finished wood. Lac Resins were once imported in considerable quantities to Europe from India along with the eastern forests.
Maps Lacquer
Sheen Measurement
Lacquer sheen is a measure of luster for the given shellac. Different manufacturers have their own names and standards for their sheen. The most common names of the most shiny to the most sparkling are: flat, matte, eggshell, satin, semi-gloss, and gloss (high).
lacquer based on Lakac
In India lac insects, or Lakac used since ancient times. Shellac is a secretion of lac bug ( Tachardia lacca Kerr. Or Laccifer lacca ). It is used for the production of red dyes and pigments (red lakes), and for the production of various levels of lacquers, used in surface coating.
Urushiol-based louquers
The Urushiol-based Lak differs from most others, becomes slow dry, and governed by oxidation and polymerization, not by evaporation alone. To be well regulated it requires a humid and warm environment. Phenols oxidize and polymerize under the action of the laccase enzyme, producing a substrate which, after proper evaporation of its water content, is difficult. It produces a very tough and durable finish that is beautiful and highly resistant to damage by water, acid, alkali or abrasion. The active ingredient of the resin is urushiol, a mixture of various suspended phenols in water, plus some proteins. Resins originate from native trees to East Asia, such as varnish trees Toxicodendron vernicifluum , and wax trees Toxicodendron succedaneum . Fresh resin from T. vernicifluum tree causes urushiol-induced contact dermatitis and is much needed in its use. The Chinese treat allergic reactions with crushed shells, which should prevent varnish from draining properly. Lacquer skills have grown tremendously in Asia, and many highly decorated pieces are produced.
During the Shang Dynasty (1600-1046 BC), the advanced technique used in lacquer process was first developed and became a highly artistic craft, although prehistoric lacquer has been unearthed in China since Neolithic times and objects with lacquer in Japan from period J 'end. The earliest surviving lacquer object, a red wooden bowl, is found in the Hemudu cultural location (5000-4500 BC) in China. In the Han Dynasty (206 BC - 220 AD), many varnish production centers became established. Knowledge of Chinese method of varnish process spread from China during Han Dynasty, Tang and Song. Finally introduced to Korea, Japan, Southeast and South Asia.
Trade of lacquer objects travels through various routes to the Middle East. Varnish applications known in China include coffins, musical instruments, furniture, and various household items. Lacquer mixed with cinnabar powder is used to produce traditional red varnish from China.
The trees should be at least ten years before cutting to remove the resin sap. This is defined by a process called "aqua-polymerization", absorbing oxygen to regulate; putting in a humid environment allows to absorb more oxygen from water evaporation.
Leachate trees in Thailand, Vietnam, Burma and Taiwan, called Thitsi, are slightly different; they do not contain urushiol, but a similar substance called "laccol" or "thitsiol". The end result is similar but softer than the Chinese or Japanese varnishes. Burmese lacquer is slower, and is painted by artisans' hands without using brushes.
Raw lacquer can be "stained" by the addition of small amounts of iron oxide, giving red or black depending on the oxide. There is some evidence that its use is even older than 8,000 years from archaeological excavations in China. Then, pigments are added to make the color. It is used not only as a final product, but is mixed with fired soil and unused clay for molds with layers of hemp cloth, can produce objects without the need for other nuclei such as wood. This process is called "kanshitsu" in Japan. Sophisticated decorative techniques using additives such as gold and silver powder and shale ("makie") are refined to a very high standard in Japan as well after being introduced from China. In the varnish of the Chinese musical instrument, guqin, varnish is mixed with deer horn powder (or ceramic powder) to give it more strength so it can stand to touch.
There are a number of forms of urushiol. They vary based on the length of the R chain, which depends on the plant species that produce urushiol. Urushiol may also vary in the degree of saturation in the carbon chain. Urushiol can be described as follows: R = (CH 2 ) 14 CH 3 or
R = (CH 2 ) 7 CH = CH (CH 2 ) 5 CH 3 or
R = (CH 2 ) 7 CH = CHCH 2 CH = CH (CH 2 ) 2 CH 3 or
R = (CH 2 ) 7 CH = CHCH 2 CH = CHCH = CHCH 3 or
R = (CH 2 ) 7 CH = CHCH 2 CH = CHCH 2 CH = CH 2
Type lacquer
These types of lacquers vary from one place to another but can be divided into categories that are not processed and processed.
The basic unprocessed lacquer is called raw lacquer (??: ki-urushi in Japanese, shengqi in Chinese). It's straight from the tree itself with some filtered filth. Raw lacquer contains about 25% water content and appears in light brown. It comes in a standard class made of Chinese varnish, which is commonly used for soil layers by mixing with powder, and a high-quality class made of Japanese varnish called kijomi-urushi (????) which used for the final finishing layer.
The processed form (in which the lacquer is stirred continuously until much water content has evaporated) is called guangqi (??) in Chinese but comes with many different Japanese names depending on the variation, for example, kijiro () is a standard transparent lacquer sometimes used with pigment and roiro-urushi (????) is the same but pre-mixed with iron hydroxide to produce black lacquer. Nashiji-urushi (????) is a transparent varnish but is mixed with gamboge to create a yellow varnish and is primarily used for gold-sown techniques. This is generally used for the middle layer. This type of Japanese locker is generally used for upper layers and begins with the word jo - (?) Which means 'top (layer)'.
The processed cook can be added oil to make it shiny, for example, shuai-urushi (???) mixed with linseed oil. Other specialist skis include thick ikkake-urushi (??) and are used primarily for applying gold or silver leaves.
Nitrocellulose Leech
Nitrocellulose-based solvent-based coatings, resins obtained from cotton nitration and other cellulose materials, debuted in the 19th century along with other nitrocellulose commercial applications. They are used, for example, on brass items such as musical instruments. The drier and more durable dried versions of lacquers were developed in the early 1920s and soon replaced the much slower use of paints and slipper lacquer that preceded them; they are widely used in the automotive industry and others over the next 30 years until further chemical advancement replaces it. Prior to their introduction, mass-produced automotive finishes were limited in color, easily damaged, and took ages to dry, with Japan's black being the fastest drying and thus the most economical to use. In 1923, the Oakland General Motors brand car was the first to introduce one of the new fast dry, nitrocellulose bell, manufactured by DuPont under their Duco trade name. In 1924, other GMs followed suit, and in 1925 nitrocellulose lacquers completely disrupted the business of traditional paints for cars, appliances, furniture, musical instruments, coffins, and other products.
Nitrocellulose lacquers are also used to make fireworks waterproof fuses. Nitrocellulose and other resins and plasticizers are dissolved in a solvent, and each varnish layer dissolves several layers beforehand. These lacquers are a major overhaul of cars and furniture finished before, both in ease of application and color retention. The preferred method for applying dry-fast lacquer is by spraying, and the development of nitrocellulose symbols leads to extensive use of spray guns. Nitrocellulose lacquers produce a tough but flexible, durable finish that can be polished to high sheen. The disadvantages of this shellac includes the dangerous properties of solvents, which are flammable and toxic, and the nitrocellulose danger in the manufacturing process. The classification of soluble nitrocellulose is closely related to the higher forms of nitration used to make explosives. They become relatively non-toxic after about a month since, at this point, lacquers have evaporated most of the solvents used in their production.
Acrylic drawer
Lacquer uses acrylic resins, synthetic polymers, developed in the 1950s. Colorless acrylic resin, transparent thermoplastic, obtained by polymerization of derivatives of acrylic acid. Acrylic is also used in enamel paints, which have the advantage of not having to be scrubbed to get the luster. Enamel, however, is slow drying. The advantage of acrylic lacquer is its very fast drying time. The use of lac on the finishing of the car is stopped when a stronger, more durable, longer lasting, weatherproof and chemical resistant polyurethane coating is developed. These systems typically consist of primers, color coats and clear top layers, commonly known as clear coatings.
water-based lacquer
Due to the health risks and environmental considerations involved in the use of solvent-based lacquers, much of the work has gone into the development of water-based lacquers. Such varnishes are much less toxic and more environmentally friendly, and in many cases, produce acceptable results. Although laker-based water fumes are much less harmful, and have no burning problems than solvent-based lacquers, the product is still dry quite quickly. Although the smell is weaker, water-based varnish can still produce airborne particulates that can enter the lungs, so proper protective clothing should still be worn. More and more water-based lacquers replace solvent-colored and colored lacquer under the hood and interior applications in automobiles and other similar industry applications. Water-based lacquers are widely used in finishing wood furniture as well.
One disadvantage of water-based lacquer is that it has a tendency to be highly reactive to other fresh touches such as dry fast primers (excluding water-borne primer lacquer), caulking and even some paint that has a paint/primer aspect. Tannin bleed-through can also be a problem, depending on the brand of varnish used. Once that happens, there is no easy improvement because the varnish is highly reactive to other products. The best way is when planning to spray white lacquer on raw wood to the source and find the primer that will seal the tannin. Some painters will use a clear seal, but some light and fast drying coatings should be applied to ensure a good seal. It is then recommended to wait until the next day to start spraying the color so that it obviously has time to harden and keep the white from pulling tannins through the clear. Also, depending on the state/province where the product was purchased and how familiar the supplier is with the country, it may be difficult to get answers from the representatives, as many are unfamiliar with potential reaction problems and how to fix them if they arise.
Water-based Lacquer used for wood finishing is also not assessed for exterior wear unless otherwise specified.
Japanning
Just as china is the common name for porcelain,
See also
References
Further reading
Source of the article : Wikipedia
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