Varnish drying on wood

MOS ® The most modern and the fastest system for the varnish drying in the wood sector.

Since its official presentation in 2002, most of the world producers of wood varnish and a number of final users had tested the MOS ® system (Selected microwaves1). From the very first industrial creations in Giardina Officine Aeromeccaniche S.p.A up to date, the MOS ® system has been in use in numerous leading companies dealing with furniture production and wood turning.

Features
The MOS ® system is specially designed for the water-based varnish treatment (spray or curtain-coater application) but can also be used for any kind of liquid varnish. The varnish film absorbs the radiation and the liquid part contained in the varnish is evaporated consequently. The length (usually 30-90 sec.) and the strength of the exposure depend on the varnish density as well as on the quantity of water to be removed. Few seconds are sufficient for the support to obtain a cold but not yet dust dry surface, covered by varnish containing almost 100% of dry residue and no liquid component (vehicle). It is necessary to eliminate the vehicle, representing the most dangerous factor for drying itself, in order to be able to proceed with drying. Thanks to such an innovative system, the humidity does not need to be controlled with expensive conditioning equipments. The treated piece of material is exposed to a high-speed air (10-20m/sec.) and an appropriate temperature (40-60º), thus the drying process is completed in 2 to 4 minutes for the mono/bi-component varnishes. Supports impregnated with water-based UV varnish, without vehicle and any cosolvents, can be directly processed in ultraviolet radiation curing tunnels. On the contrary, hot-air or infrared radiation treatment should precede the ultraviolet radiation phase in the case that solvents are present in the varnish. Since the MOS ® system dries the water-based varnish without modifying the temperature and features of the wooden support, it is not necessary to sand down the pieces after the coating.

Safety and certification
The MOS ® machinery was commercialized after having obtained the EC certification as well as the certification of the emission values during the maximum output production process in a continuous cycle. Thanks to particular technical solutions both in shielding and construction materials of the resonant cavity and in reflection and progressive attenuation systems, the MOS ® system allows to maintain the emission level on 6V/m that is considerably under the maximum limit fixed on 61V/m in line with the internationally recognized standards. Precise harmonized regulations delimit the maximum authorized level in the electromagnetic field to one tenth of radiation, for which the first thermal interaction between radiation and biological tissue of the workers professionally exposed is observed.

Varnish drying on glass and plastic

With the aim of reducing the time and costs of the process, the prototype machines have provided excellent results in the plastic varnishing. Moreover, the type of plastic material involved in the process does not alter the plant configuration, allowing the processing of various items such as electrical plates, bumpers, uppers and all kinds of accessories.

Compact solutions for varnish drying on glass supports, such as tops, sinks, shelves and other products, are still being studied.

Varnish drying on metal

The use of heating technology on ferrous materials enables the innovative use of water-based varnishes rather than traditional solvent-based, greatly saving the processing time and drastically reducing the environmental impact due to the elimination of the use of solvents.

The three components of the system (air, microwave, infrared) work on different aspects of the varnish drying process: the microwaves evacuate all the water from the film of the varnish, the air flow removes it and the infrared radiation heats the material to a temperature sufficient for resin cross-linking.

This combined action helps to obtain pieces of material, also of considerable dimensions and complex geometries (mechanical components production, light and heavy carpentry), in production cycles of approximately twenty minutes, dried and ready to use straight from the curing tunnel.

Varnish drying: Graphics

Microglass has gradually reached different experiences in the domain of graphics, both with infrared and UV technology, in the polymerization of varnish and photosensitive inks and in the digital and transfer printing or sublimatic serigraphy.

The infrared technology Microred was successfully implemented in the digital printing area, on plotter or printers for textile (polyester, Lycra, jersey, voile, etc.), rigid materials, paper and plastic (in rolls or sheets), for ink drying by means of direct irradiation or indirect heating by calenders or cylinders.

By implementing the Microred technology, Microglass has brought about a real innovation in the domain of sublimatic printing. Special inks are heated up in the thermal matrix printer designed for sublimation, which are directly transformed from gaseous condition into solid (powder pigments) and, as a result of a pressure, they penetrate and stay permanently in the surface of the object. Such a process gives a definitive stability to the printed image because it is not superimposed but engraved inside the object. The sublimatic printing represents the best system of printing on objects, in terms of quality, duration and resistance of the image against scratching, washing and fading.

After the transfer of sublimatic inks on paper or film, it is possible to print an image on any kind of material, like textiles (cotton, Lycra, microfibre, etc.), plastic goods or high-temperature plastic objects, pottery, iron, aluminum, plastic reinforced with fiberglass, glass, wood, MDF, carbon, etc.

Fields of application are very disparate:

• Sports/non-sports clothing
• Various equipment (skis, snowboards, skateboards, canoes, sails, windsurfs, water bottles, buttons, key rings, buckles and various goods)
• Ceramics (plates, cups, glasses, crockery) and glass (glasses and jugs, dishes, mats, bottles)
• Items for interior decoration (tiles, floor, doors, windows, shutters, wooden or metallic furniture, friezes, suspended ceilings, walls)
• Signboards of any kind (totems, panels, directional marks, display units)

Nevertheless, difficulties in producing thermal press applied on a single category of objects have so far limited the diffusion and the application of the printing for sublimation. The experience of Microglass gives birth to MicroSER which provides a complete versatility of forms, dimensions and materials for creation of high-quality sublimatic printing.