Metallized Polyester Films

Product Range and Characteristics of metallized PolyesterDue to high expertise in coating and metalizing we offer tailor made solutions for virtually any kind of application for packaging or industrial use. These applications range from basic structures to the most demanding ones.

TPL offers one of the most extended range of high quality metallized films on the market. Our range includes, among others, films with supreme metal adhesion, outstanding barrier properties or high resistance to chemicals. For special visual effects matt, gold and white metallized films offer differentia-tion possibilities.

Moisture and oxygen barriers of metallized films are needed in packaging to preserve food products. The oxygen barrier prevents loss of flavour and extends the shelf life. The moisture barrier is important on one side to keep products dry and crispy. On the other side it avoids that humid products dry out.

Illustration 1: OTR of met PET Illustration 2: WVTR of met PET

As illustrated in table 1 and 2 you can see some examples picked up among our extensive range of met-allized polyester films, which offer our customers the possibility to choose the material which is perfectly adapted to their individual needs.

Metallized PET Films

With high barrier metallized films and a high optical density, the metal adhesion used to deteriorate. Therefore customers faced a trade-off between barrier and bond strength requirements. We are offering a solution to this problem. MT5000 combines very high bond strength with a supreme barrier to oxygen and water vapour (OTR 0.5 cc/m2/day / WVTR 0.3 cc/m2/day). At the same time it offers a bond strength of 600 gm/25mm (Polyplex Method).

Another very important topic in metallized poly-ester films is the metal adhesion in order to secure good bond strength, illustrated in table 3. Polyplex developed some metallized films with very high adhesion. The result is HB1000, providing an extraordinary high bond strength.

Illustration 3: Bond strength of met PET

A further characteristic of interest for our high performance metallized films is the temperature applica-tion range of the material. Most of the metallized films are recommended to be used in ambient condi-tions and are not feasible for pasteurization. TPL specialities HB1000 and MT5000 are especially designed to resist high temperatures and can be used at 110° C during 20 min.

110°C

Illustration 7: Aluminium wires and crucibles

Metallized PET Films

Polyester films are metallized via a vacuum metallization process. During this process metal is heated to its melting point in a vacuum chamber and it condenses on to a PET web.

During the metallization process itself aluminium wires (illustrated in picture 6 and 7) are heated to their melting point. The web, which moves at a high speed above evaporators, receives both radiated heat from evaporators and latent heat from the condensing aluminium. Therefore, it is important that the substrate is tensioned between rollers as it passes through the coating area as well as cooled by the chill roll. The required optical density is achieved by controlling the speed of the web moving over the crucibles. The evaporated aluminium condenses on to the base film, which is moving over a cooling roll. Then the metallized film is re-wound, the chamber is opened and the reel is taken out.

The metallization process is a batch process. In a first step the reel with the base film is placed on to the un-winder station. The trolley (illustration 5), which is carrying the reel, is moved into the metal-lization chamber and a vacuum is created to reduce the boiling point of the aluminium and providing homogeneous aluminium deposition.

For a better adhesion of the metal onto the film, the surface of the PET film has to be cleaned by a plasma treatment. This process can be improved by using various different gases, which is the key to produce excellent metallized PET films.

Due to the batch production process it is essential to have high machine utilization in terms of width and length, for a cost efficient production. Polyplex Turkey has 4 metalizers with a capacity of 15’000t per year. The experience in metalizing polyester films and the focus on continuous improvements makes Polyplex the perfect partner for your metallized films. Furthermore Polyplex has a large know how and is using highly advanced technology for their production of base films to achieve high performance met-allized films.

Production of PET met

Illustration 4: Metallization Process

Illustration 5: Trolley of metalizer Illustration 6: Vacuum chamber

Metallized PET Films

Polyplex has implemented a strict quality management system to ensure an ongoing high quality level of their products. For metallized products the quality control consist of four parts, as illustrated below. First of all the general film properties are being assured by controlling the optical, mechanical and ther-mal properties, the thickness and various surface properties. Additionally the coating quality is continu-ously monitored. A special focus is given to the control of the metallization where, besides the visual inspection, the optical density, the resulting OTR and WVTR as well as the metal bond strength are supervised. Last, but not less important, the slitting process is examined. Reels are being checked for visual physical defects and appropriate winding and labelling are assured.

Due to our strong cooperation with our suppliers we are able to control the complete production chain from the polymerisation of the PET resins, over the polyester extrusion and metallization until the slitting and the distribution of the reels to our customers. This integration of the supply chain processes enables us to ensure a full traceability of our metallized films and have entire control over quality. The material can be traced by batch, reel or even order number.

Quality System (Traceability)

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