{"id":9557,"date":"2017-01-30T18:22:22","date_gmt":"2017-01-30T16:22:22","guid":{"rendered":"https:\/\/revistadinlemn.ro\/?p=9557"},"modified":"2024-04-29T09:01:16","modified_gmt":"2024-04-29T06:01:16","slug":"why-and-when-we-need-polyurethane-varnishes","status":"publish","type":"post","link":"https:\/\/revistadinlemn.ro\/en\/2017\/01\/30\/de-ce-si-cand-avem-nevoie-de-lacuri-poliuretanice\/","title":{"rendered":"Why and when we need polyurethane varnishes"},"content":{"rendered":"

Polyurethane varnishes have long been used in the furniture industry, in many places replacing the use of nitrocellulose varnish, one of the oldest and best-known varnishes used for wood finishing. Nitrocellulose varnish has always been a simple varnish to use and preferred in production because, if defects appeared, it could be easily removed with thinner and drying was a reversible process. This quality, however, becomes a defect when the film is subjected to aggression. The need for more resistant varnishes arose, and the polyurethane varnishes were the perfect answer.<\/p>\n

\"polyurethane
photo source: triftyfun.com<\/figcaption><\/figure>\n

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In general, polyurethane varnishes are produced in 2 components, the varnish and the hardener (catalyst), which react with each other resulting in the varnish film, a product with superior qualities to those from which it came. The parts are mixed in a certain proportion. The reaction is not instantaneous; the mixture remains in a liquid state for a period of time, called the pot-life, after which it hardens irreversibly.<\/p>\n

Polyurethane varnishes are not always 2-component, but the principle remains the same. Only that the 2 components are already mixed, but only react in the presence of a stimulus. Usually this stimulus is oxygen in the air or light radiation.<\/p>\n

But I don't want to give you a chemistry lesson because I know that's not the best way to convince you to stick with me. \ud83d\ude42 The question is why do we need these varnishes whose use is not as simple as nitro varnishes? They are needed when furniture or finished wood products have higher strength requirements or are used in more aggressive environments. Don't think of special requirements or acid vapor environments. No, the answer is much simpler. Do you want a table on which you can directly place your wet cup of scalding hot coffee without the need for a tablecloth or a cardboard 'biscuit'? Then finish the table with polyurethane varnish and the cup will certainly leave no white marks.<\/p>\n

\"polyurethane
photo source: cleanipedia.com<\/figcaption><\/figure>\n

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Polyurethane varnish should also be used when you want your furniture to be more resistant to scratching or knocks.<\/p>\n

\"polyurethane
photo source: oakfurnitureuk.co<\/figcaption><\/figure>\n

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If we're talking about a harsh environment, it could be the kitchen for a nitro lacquer. Simply run water frequently down the sink mask. Over time the varnish will start to break down.<\/p>\n

\"polyurethane
wzchutian.com<\/figcaption><\/figure>\n

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Finished with polyurethane varnish, the mask will be much more resistant to moisture and will save you a lot of trouble.<\/p>\n

Using polyurethane lacquers produces much more resistant films. They are resistant to scratching, solvents, hot and cold liquids, wine, coffee and other colored liquids, and knocks. They are therefore recommended for finishing table tops, bathroom and kitchen furniture floors<\/a>.<\/p>\n

\"polyurethane
photo source: rhucs.com<\/figcaption><\/figure>\n

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They are also a very good choice because no special installations are required to finish with them. They can be used with a simple can spray, like any other varnish. The important thing is that, after each use, the spray gun must be washed thoroughly with thinner to remove all traces of varnish. Otherwise, the varnish hardens inside and the spray gun will have to be replaced because, as mentioned above, the reaction is irreversible and the varnish no longer dissolves in the solvent.<\/p>\n

Polyurethane varnish is a much harder varnish. However, this hardness often comes with a loss of elasticity. Therefore, when using polyurethane varnishes, especially if you are finishing solid wood, you must be careful with the amount of varnish applied and the number of coats. Unlike MDF or veneered chipboard, solid wood has dimensional variations due to variations in atmospheric humidity. When the wood moves, the top layer of plywood is under stress and if the elasticity is very low, it can crack. And if the layers of varnish are more or thicker than the manufacturer has recommended in the data sheet, the elasticity decreases further and the risk of cracking increases.<\/p>\n

The polyurethane finishing system is now widely used. As well as being hard-wearing, polyurethane lacquers are also beautiful and have a nice touch. It's a system I recommend when it comes to table tops or furniture used in an environment with a lot of moisture or possible mechanical aggression. That is, of course, unless more sophisticated systems are used (such as UV drying, for example).<\/p>\n

\"polyurethane
photo source: messiya.com<\/figcaption><\/figure>\n

 <\/p>","protected":false},"excerpt":{"rendered":"

Lacurile poliuretanice se folosesc de mult\u0103 vreme \u00een industria mobilei, ele \u00eenlocuind \u00een multe locuri folosirea lacului nitrocelulozic, unul dintre cele mai vechi \u0219i mai cunoscute lacuri folosite pentru finisarea lemnului. Lacul nitrocelulozic a fost \u00eentotdeauna un lac simplu de folosit \u0219i preferat \u00een produc\u021bie pentru c\u0103, dac\u0103 ap\u0103reau defecte, el putea fi \u00eendep\u0103rtat cu […]<\/p>\n","protected":false},"author":5,"featured_media":9564,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"2175","_seopress_titles_title":"","_seopress_titles_desc":"Dac\u0103 cerin\u021bele sunt s\u0103 ob\u021bine\u021bi o suprafa\u021b\u0103 finisat\u0103 cu rezisten\u021b\u0103 crescut\u0103 la p\u0103t\u0103ri \u0219i agresiuni mecanice atunci trebuie s\u0103 folosi\u021bi lacuri poliuretanice.","_seopress_robots_index":"","footnotes":""},"categories":[2175],"tags":[1261,1262,1265,1264,1263],"class_list":["post-9557","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-finisaje","tag-lacuri-poliuretanice","tag-lacuri-rezistente","tag-lacuri-rezistente-la-patari","tag-lacuri-rezistente-la-umezeala","tag-lacuri-rezistente-la-zgariere"],"_links":{"self":[{"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/posts\/9557","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/comments?post=9557"}],"version-history":[{"count":8,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/posts\/9557\/revisions"}],"predecessor-version":[{"id":38525,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/posts\/9557\/revisions\/38525"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/media\/9564"}],"wp:attachment":[{"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/media?parent=9557"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/categories?post=9557"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistadinlemn.ro\/en\/wp-json\/wp\/v2\/tags?post=9557"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}