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Metallised Polymer Composites: A New Class of Materials with Enhanced Mechanical and Electrical Prop



Metallised films have a reflective silvery surface similar to aluminium foil and are highly flammable. The coating also reduces the permeability of the film to light, water and oxygen. The properties of the film remain, such as higher toughness, the ability to be heat sealed, and a lower density at a lower cost than an aluminium foil. This gives metallised films some advantages over aluminium foil and aluminium foil laminates. It was thought that metallised films would become a replacement for aluminium foil laminates, but current films still cannot match the barrier properties of foil. Some very high barrier metallised films are available using EVOH, but are not yet cost effective against foil laminates.[3]


Metallised films were first used for decorative purposes as Christmas tinsel,[1] and continue to be used for items such as wrappers, ribbons, and glitter. Metallic helium-filled novelty balloons given as gifts are made of metallised BoPET and often called Mylar balloons commercially.




metallised



Both metallised PET and PP have replaced foil laminates for products such as snack foods, coffee and candy, which do not require the superior barrier of aluminium foil. Metallised nylon and polyethylene are used in the meat export market. The controlled permeation extends shelf life.


Many food items are also packaged using metallised films for appearance only, as these produce a package with greater sparkle when compared to competing products that use printed paper or polymer films.


KGS Metallised Fabrics are high precision electrolytically metallised mesh fabrics made from high modulus monofilament polyester fibers. KGS Metallised Fabrics are offered in a wide range of mesh counts and provide significant advantages over traditional monofilament polyester. Beside this a wide range of other base materials are offered, such as non-woven fleece, copper wire etc. The main applications for these fabrics are demanding screen printing jobs, electromagnetic shielding (EMI/RFI) and multi colour flocking.


In order to protect the environment and/or electronic devices from electromagnetic or radio-frequency interference (EMI/RFI), KGS has developed a specialized range of electrolytically metallised textile products.


High precision screen printing applications require the best fabric. KGS offers a wide range of electrolytically metallised mesh fabrics to allow for the best screen printing results under demanding conditions.


KGS metallised mesh fabrics are the ideal mesh for multi colour flocking, because of its properties, which gives advantages such as being conductive, no clogging of screen, higher damage tolerance, excellent dimensional stability etc.


Euroscreen Metallised Transparent is a transparent fabric with a metallised back that is designed to exceed the stringent standards in light, glare reduction and insulation from harmful UV rays. With superior heat and reflection properties it assists in maintaining an energy efficient environment. Giving you protection without blocking your view.


Using a coating of molybdenum based paints followed by nickel plating, an interface can be provided that enables ceramic/metal assemblies to be formed by brazing providing joints that are hermetically sealed. A layer of molybdenum-manganese is deposited with a typical thickness of 10 to 30 µm after sintering. The metallisation sintering process is carefully controlled to achieve a balanced mixture of Molybdenum particles surrounded by a matrix of glass to ensure high bond strength between the metallised layer and the ceramic base.


In some cases it is necessary to apply a thin metallised layer to ceramic surfaces for discharging or electrical field generation. A range of coatings are available including aluminium, gold and titanium at typically 1-2 microns thick. Virtually any patterns can be applied and layers are even and consistent. Multi layers of differing materials can be applied such as nickel chrome and nickel gold. This process does allow subsequent electroplating should there be a requirement. Physical vapour deposition, or PVD, is used to apply thin metallisation or coating to fully dense ceramics.


We also offer another specialist PET film product which is aluminium metallised underneath the silicone layer. The aluminium creates an effective barrier to light, air and humidity and also prevents the build up of any electrostatic charge of the film.


Streamline Avionics (formerly Elpac Capacitors) has a series of general purpose metallised polyester film capacitors for filtering, coupling or bypassing in high or low impedance circuits within ac or dc applications.


Idvac Ltd., a UK vacuum research and development specialist, has developed a bright white, non-pigmented metallised film that does not contain titanium dioxide and can be used for applications including barrier packaging and labelling.


Idvac claims that no pigments are used in the production of the final bright white metallised finish on the front and back surfaces of the film. The film reportedly offers UV reflection of about 40-65% at 300nm from the metallised side, which can be adjusted to lower or higher levels. Additionally, visible light reflection in a wavelength range of 400-800nm from the metallised side is around 94%, the company says.


Flexible films such as PET, BOPP, and polycarbonate (PC) can be coated with this new white metallised finish, according to the company. The white film can reportedly also be hot stamped for some applications to give a white, bright finish.


When applied to BOPP film, the company notes that the white metallised coating exhibits good oxygen and water barriers. The white metallised surface is also electronically conductive from the metallised side, according to Idvac.


Idvac concludes that the metallised film can be used in applications such as the hot stamping of security or non-security products like labels and as normal and barrier packaging, including for food and pharmaceutical products.


Pristine and metallised PA66 spherulites were observed with a scanning electron microscope (model XL 30 ESEM FEG, Philips, Guildford, England, UK). PA66/Au NP microspheres were not coated to avoid the overlapping with the metal-conducting layer. EDX analysis was carried out on the sample at a working distance of 10 mm, using the INCA software (Oxford Instruments, Abingdon, UK). To assess the particle size and size distribution, the specimen was observed via a transmission electron microscope at 100 keV (Tecnai BioTWIN, FEI Ltd., Hillsboro, OR, USA). The TEM micrographs obtained were analysed with the program Gwyddion using the grain analysis function. UV-Vis spectra were recorded using a Varian Cary 50 photospectrometer (Varian Medical Systems UK Ltd., Crawley, UK) with the monochromator slit width of 10 nm. To determine the type of interaction between Au NPs and PA66, ATR-FTIR (Tensor 27, Bruker Optics, Rheinstetten, Germany) measurements were conducted at ambient temperature in the spectral range from 4,000 to 550 cm-1 on the PA66/Au NP hybrid material powder recovered.


PA66 spherulites coated with Au NPs as a catalyst were demonstrated by investigating the reduction of MB to leuco MB (LMB) (Figure 7) as a function of time by UV-Vis spectrometry in the wavelength range between 400 and 800 nm (Figure 8) at room temperature. To understand the effect of the hybrid material on the reduction rate of MB, further investigations need to be conducted regarding the amount of the metallised PA66 microspheres and the temperature.


The catalytic ability of the coated PA66 spherulites depends on the size of Au NPs produced. Indeed, gold in bulk state is chemically inert since the redox potential of this noble metal is positive [15]. It has been reported by Haruta et al. that gold is becoming catalytically active for many chemicals at a nanoscale level (diameter below 10 nm) due to the reduction of its redox potential to a negative value [19, 28, 29]. Thus, to act as an effective catalyst, the redox potential of Au NPs needs to be found between the redox potential of the donor and the acceptor system [17, 30]. In this case, noble metal nanoparticles are considered as an electron relay in the redox reaction to transfer the electron from the donor (B2H4/BH4-) to the acceptor system (LMB/MB) since Au NPs act as both donor and acceptor of electrons [17] (Figure 9). Experimental results demonstrate that PA66 metallised with Au NPs accelerates the reduction of MB because Au NPs act as an electron relay in the MB reduction reaction. Based on this observation, it is possible to deduce that the redox potential of the Au NPs produced in this investigation is located between the redox potential of MB (E(MB/LMB) = -1.33 V) and that of sodium borohydride (E(B2H4/BH4-) = -0.21 V) [30] (Figure 9).


Metallised films are created to reduce the permeability of the film to light, water and oxygen whilst creating a highly reflective, mirror-like finish. During the metallising process, the properties of the film are unaffected. Comparing to aluminium foil, metallised film is a more robust product, possesses the ability to be heat sealed and is lower density. All whilst being available at a much lower cost. The characteristics of metallised PET film makes the material an exceptional packaging film for a vast array of food items. Applications include snack foods, coffee and microwave meals.


Camlite is a controlled optical density metallised film. Originally developed for packaging light sensitive electronic components. Camlite is an example of a multipurpose product with at least two applications. Whilst giving the functional advantage of controlled light transmission, Camlite is a metallised film which has anti-static properties and gives a stylish aesthetic quality to promotional packaging application in the form of tinted transparent envelopes e.g. for sales literature and magazines.


Camtherm is metallised films and laminates for thermal insulation. Camtherm can be supplied as a laminate or single web structure and has been designed for a range of insulation applications. It can be produced in a variety of material substrates. All of which demonstrate exceptional barrier to oxygen and moisture as well as excellent emissivity values. 2ff7e9595c


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