Metallizing

/Metallizing
Metallizing2019-01-31T12:27:39+02:00
  • metallizing

Metallizing Film

The primary goal of the metallizing process is the increment of impermeability to gas, steam, humidity, and light, and at the same time it is used to provide the preservation of the characteristics of the substrate.

Metallization belongs to the types of process called “P.V.D” ( Physical Vapour Depositation): a variety of vacuum deposition methods used to deposit thin films by the condensation of a vaporized form of the desired film material onto various work piece surfaces.  The product is a very thin and uniform film that merges coherently with the chosen substrate.

The process: the film coil ( whether it is OPP, CAST, LDPE, HDPE, PET, PVC, PS, OPS, NYLON, or paper, paperboard, woven and nonwoven fabric, and biodegradable film) is placed inside the vacuum metallizer, where the metallization takes place in high vacuum conditions, about 10-4 hpascal. The film coil is then rolled and unrolled many times on another axle. During the unrolling, the film passes through a special roller, below which are positioned the evaporators.

 

The evaporators are made with bars of conductive material that, being electrically resistive, is heated until the vapor pressure is high enough to evaporate the metal film. The vapor deposition is therefore deposited onto the surface of the film, during this passage. The amount of aluminum deposited depends mostly from the amount of aluminum evaporated,  and from the velocity of the film during its passage through the evaporators.

Usually the thickness of coating ranges from a minimum of 30 Ångström up to a maximum of 350 Ångström. Since it is so difficult to measure such thin gauges, it is a common practice to measure the deposit indirectly: either it is measured the surface resistance of a squared-shaped sample, or it is analyzed by the optical density that can be defined thanks to the transparency of the metallized film. On our machineries are installed some sophisticated control systems which measure the optical density. They are placed downstream the evaporators: in this way they can measure and record the values during the unrolling of the coil and for all its length.

After the metallizing process, the film coils are immediately “rewound”: they are rolled and unrolled with the help of special machines called rewinders or slitter rewinders. During this process the film can be cut on the edges to eliminate the selvedge, or it can be cut to produce smaller coils. In fact, in order to minimize costs, it is better to metallize coils with the largest width available, that, in our case, is even 2400 mm, and then cut to obtain more coils of desired width.

Technical features of our metallizers

Technical property Units of measurement machine n° 7 machine n° 5 machine n° 4
Max. width mm 2400 1650 1650
Diam. Max. Coil mm 1000 1000 930
Thickness. Min. Film micron 7 7 7
Thickness. Max Film micron 800 800 800
Optical density min O.D. 0,4 0,4 0,4
Optical density max O.D. 3,2 3,2 3,2
Plasma treatment available available available

Technical property of the cutting and rewinding machine

Technical property Units of measurement machine n° 7 machine n° 6 machine n° 2
diam coil max. mm 1000 1000 1000
Diam. Max. Coil yes yes yes
Trimming process 4 2

Materials that metallized

  • OPP (polypropylene)
  • CAST
  • LDPE (Polyethilene low-density)
  • HDPE (Polyethilene high-density )
  • PET (polyester)
  • PVC (pvc)
  • PS (polystyrene)
  • OPPS ( Printet polypropylene)
  • NYLON
  • PAPER
  • PAPERBOARD
  • BIODEGRADABLE FILM
  • WOVEN
  • UNWOVEN FABRIC

Quality: the film division

Quality means customer’s satisfaction: it is our first goal to fulfill our customers’ requests.
The continuous improvement of quality is one of our top priorities and it is a guarantee of performance of our products.
Metalfilm’s thirty-years long experience assures the correct quality evaluation of the different kind of film and of the best process to carry out the metallization.
The ISO 9001 certified company performs quality control if asked by the customer. In absence of specific requests, a standard procedure is carried out, based on our experience that includes the following tests:

Visual inspection of the incoming coils: in order to detect possible defects that might prevent the metallization.
We run some tests on the film surface in order to verify that the metallization can be carried out. The aim of the test is to prove the wettability of the film surface, and it is performed with specific liquids. If there isn’t enough wettability, we can apply a pre-treatment with a plasma system. It is also used to increase the metal adherence of pre-treated corona or open-flame. This equipment is installed on every single one of our metallizers.
During the metallizing process the optical density is constantly controlled. The operator adjusts the machine parameters in order to get the optical density requested by the customer. The metallizators have photometric tools, one every 100mm, that constantly record and report, on a specific chart, the recorded data. The operator checks the chart and, if necessary, intervenes to adjust the machine parameters. The data regarding the optical density of all the coils are collected in order to have a history of every processed product.
After the metallizing process, the film coils are immediately rewound to stabilize, trim or cut the film, in order to produce smaller coils. During this phase a visual inspection is carried out when the film is rewound. Moreover a sample is examined to test the level of coating adherence and to measure the optical density with a laboratory device, to assure the compliance to the values requested by the customer.

Perché sceglierci

  • Metallizziamo // qualsiasi tipo di film
  • Fascia massima // 2400 mm
  • Controllo // on-time
  • Scarti di inizio fine bobine // molto contenuti
  • Le nostre macchine // tra le più all’avanguardia
  • Esperienza // dal 1982
  • Puntualità  // da sempre

Gallery

Metallizing film