Two different systems can be used to create metallized paper:
Goto Herofu to know more.
This process involves a gluing process on the paper, normally a non-coated one, to a sheet of aluminiun with a thickness between 9 and 12 micron. This system is used increasingly less owing to the high consumption of aluminium.
This system, which we are going to look at in depth, is the most used and it consists of heating aluminium or another material in a vacuum chamber, vaporizing or sublimating it, and depositing a thin layer on the surface of the a coated substrate. In this case, the main advantage is that 300 times less aluminium is used than in the previous case.
In both cases this type of substrate offers a solution to achieve the distinctive, metallic finish on packaging with only a fraction of the aluminium content of traditional foils. Let's see some more details about the vacuum production process.
As mentioned before the best way to produced a metallized paper it's through a vacuum metallization.
The process of producing the metallized paper by the direct high vacuum method consists of three independent processes, which are the following:
A thin layer of varnish is applied to the coated substrate in order to prepare the surface for subsequent metallization. The paper is pre-coated with lacquers that are applied to smooth out the surface of the paper to act as a barrier between the paper and the metallized layer and to improve the adhesion of the vaporized metal. The varnish is applied in the varnisher through a process similar to gravure printing. Once the varnish has been applied, the paper passes through the hot air drying unitin order to remove the solvents of the varnish and therefore dry the paper until it has a moisture level of between 2 and 3%. Next, and within the same varnisher, the paper passes through a set of refrigerated rollers which prevent the paper from sticking in the winder.
This phase is probably the most critical point during the production process. Once the reeks of paper have undergone the varnishing process they are sent to the metallization area, where they are introduced one by one in order for the layer of aluminium to be applied to the paper. The pre-coated paper is then metallized directly. The varnished paper is placed in a "metallization chamber" where the layer of aluminium is applied through a vaporizing or sublimating process.
All metallized papers are then top coated and re-moisturized as a final process. Once the reel is placed in the lacquering machine, the metallized paper passes through corona treating that facilitates the anchorage of the lacquer on the aluminium. This corona treating acts by increasing the surface tension of the metallized surface. Once the corona process has taken place the lacquer is applied using a system of gravure, as in the varnisher, and is subsequently dried using hot air tunnels.
When the product is coloured, it is the lacquer itself that is coloured with the final colour of the product. The classic colour is gold, but from a technical point of view other colorants could be used if this were necessary. Once dry, the metallized paper passes through cooling rollers, and the water and the dorsal treatment are subsequently applied. This is to ensure that the paper has the final moisture necessary for the finished product and to maintain flatness when it is transformed into sheets or labels.
For more Metalized Paperinformation, please contact us. We will provide professional answers.
The coating protects the aluminium from damage and serves as a print receptive primer for multiple printing applications. A thin layer of lacquer is applied to give the final characteristics of the paper such as printing features, colour such as for gold susbtrates or matte / gloss finishings.
In some applications, metallized paper is intended to replace metallized film, as of eco-friendly and cost effective considerations. In order to assist the customers to get the best of what metallized paper is able to offer, we are going to give a further analysis on the structure of metallized paper, hope it is helpful for the customers to get the ideal packages.
Below graphic shows the detailed structure for metallized paper, with each layer from inner to outer is as below.
Raw paper is usually made from plant fiber, with different lengths of fibers mixed in the paper pulp, so when it is dried into paper substrate, the surface is coarse with dents and humps, that will cause worse presentation for artwork print than a smoothe surface. So to get a smoothe surface with good wetting tension, usually clay coating is applied.
Clay coating can be applied onto single or both sides of the raw paper, that is usually decided by the end application, as you can check the graphic as below, clay coating is going to achieve a more smoothe surface for further printing and coating operation.
Pre-metallization coating layer works like anchor agent that improve the bonding strength between aluminum metallized layer and paper substrate, that is usually achieved before metallization process.
The thickness of aluminum metallized layer is only 30-50 nanometer, that is only 0.04~0.07% of the paper substrate thickness, so usually the thickness of aluminum metallized layer can be neglected when evaluating the thickness for metallized paper. However, this aluminum metallized layer really plays a big role in the printing and packaging applications.
Another layer of top varnish is applied over the aluminum metallized layer, usually working as a protetion layer. As when the metallized paper is intended for print beer labels, usually the print is applied on the surface of aluminum metallized layer, however, aluminum layer would be damaged by the water in the water-type inks. That&#;s why the varnish layer is needed.
Ok, that&#;s all I have to say regarding the structure of metallized paper, and I am going to introduce more on the applications of metallized paper. You are welcome to reach us if you have any questions.
The company is the world’s best Petg Shrink Film supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.