Importance of lacquer process, their class/types and their application by Peiying Tee https://padlet.com/tpying93/g2ofvf6vbpd en-us 2016-11-21 05:49:15 UTC 2025-10-04 02:35:27 UTC hello@padlet.com Importance of lacquer process tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/138999980 In the manufacture of cans for the food industry, coatings are obtained by the application of a liquid lacquer, which is subsequently dried at a high temperature to provide better protection against corrosion. The canned product is separated from the metal in presence of protective property of varnish. Besides, the presence of lacquer limit dissolution of tin into the products.

Lacquer is also used to protect the surface of canning container from the action of food products. If the metal is not lacquer, the sweet, sour, salt or protein containing food product cause its corrosion. The action of metal formed lead to changes of colour, appearance and taste of the ready prepared food.  The choices of lacquer to use depend on acidity and corrosive properties of product that will be packed, taste, product migration, appearance and production method.
]]> 2016-11-21 05:54:25 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/138999980 Types of lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140373192 There are several types of lacquers, which are Organosols, Oleoresinous, Vinyl, Phenolic and Epoxyphenol.

]]> 2016-11-29 00:57:34 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140373192 Epoxyphenol lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140401008 ● Epoxy phenolic lacquers is the most common type of lacquers.

● They are produced by a simple blending of epoxy and phenol formaldehyde resin.

●Epoxyphenolic lacquers combine high degrees of flexibility and adhesion with chemical resistance.

● They are normally gold in appearance which used for a wide range of acidic and non-acid foods.

● They are sometimes used in a pigmented form (aluminium powder or zinc carbonate) to mask or absorb sulphide staining

● Suitable for packing fish, meat, vegetable and fruit products. 
]]> 2016-11-29 04:32:10 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140401008 Organosols lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140401129 ● Organosols are dispersions of high molecular weight polyvinyl chloride (PVC) resins in hydrocarbon solvents with the inelusion of a suitable plasticiser, dioctyl phthalate and resin additives.

● Have reasonable chemical resistance and resistance to sulphide staining but they are prone to absorb food colorants.
●Free from taste and flavour, therefore particularly suitable for packing biscuit, powder and some drinks.. ]]> 2016-11-29 04:34:19 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140401129 Phenolic resins lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140402720 ● Product of polymerization of phenols and formaldehyde.
 
● Hard film with relatively low flexibility and limited adhesion to metal.

 ● Have a characteristic golden colour arises as natural result of the curing process.

● Exhibit good sulphur resistance. Thus, they are suitable lacquer for product containing sulphur, such as meat, peas, and beans. ]]> 2016-11-29 05:02:58 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140402720 Oleoresinous lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140409765 ● Product of condensation of phenol-formaldehydrate with Chinese wood oil or mixture of oxidized flax oil and dehydrated castor oil in turpentine.
● Has high physicomechanical properties, water and salt resistance.
● Used in production of canning container from the tin plate, intended for crab and neutral medium fish preserve.]]> 2016-11-29 06:53:36 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140409765 Vinyl lacquer tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140410399 ● Exists a family of vinyl-based lacquers ranging from low viscosity/ low solids solution vinyls through mid-range vinyl alkyds used in decorative coatings up to the higher so lids dispersion organosols and plastisols.

● The essential qualities of vinyl products are adhesion, high flexibility and a complete absence of taste.

● Suitablefor the spray application of the internal top-coat for three-piece beer and softdrinks, cans and for other applications where absence of taint is essential, e.g. dry powders.]]> 2016-11-29 07:03:48 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140410399 References tpying93 https://padlet.com/tpying93/g2ofvf6vbpd/wish/140487415 ·  Barilli, F., Fragni, R., Gelati,S., Montanari,A. (2003). Study on the adhesion of different types of lacquers. Progress in Organic Coatings 46, 91–96.

·  Coles, R. M., McDowell, D., Kirwan, M.J. (2003). Food Packaging Technology. London : CRC Press.

·  Sukhareva, L. O., Legonkova, O.A., Yakovlev,V.S., Zaikov, G.E. (2008). Polymers for Packaging and Containers in Food Industry. Leiden : Koninklijke Brill NV.

·  Turner, T. (1998). Canmaking:The Technology of Metal Protection and Decoration. Wantage: Blackie Academic & Professional.

 

]]> 2016-11-29 13:51:00 UTC https://padlet.com/tpying93/g2ofvf6vbpd/wish/140487415