Membrane vacuum adhesive and its application method
This product is specially designed for coating wood products in vacuum presses. All its properties are optimized and selected for this operation. One of the main features of this type of adhesive is its adhesion strength. This product is ideal for ABS, PVC or PET coatings on MDF, wood panels and a variety of products. As mentioned, this product is a single component and does not contain any organic solvents which preventing any shrinkage or opaque. This defect is clearly visible in non-standard adhesives available in the market, and by mistake, sometimes it is attributed to vacuum press machines. A non-standard vacuum adhesive will include organic solvent materials that can easily be negatively impacted with reducing the quality and clarity of the coating. This product is easily sprayed on the workpiece by a 1.8 mm to 2 mm adhesive nozzle and subjected to vacuum pressure in the machine at a temperature of at least 60 ̊C for 20 to 40 seconds. The color of this adhesive is white, fluorescence and will have a medium viscosity.
Membrane and vacuum presses are used to produce vinyl wrapped doors, which are an alternative to real wood or painted doors. A moulded and sometimes routed MDF core is sprayed with a polyurethane dispersion adhesive and allowed to dry. The panel, with dried adhesive is then covered with a PVC foil and placed in a membrane or vacuum press which heats the foil, applies vacuum for decompression, applies pressure and reactivates the glue line. The result is a door panel that is produced much faster than a lacquered solid wood or painted door, with a vinyl covering that is easy to clean and durable. As this type of production has become more popular over the years, foils are now extremely authentic with realistic wood effects and matt and high gloss finishes emulating a typical painted product. These foils have in turn put more demands on the membrane press adhesives to create the perfect finish.
Membrane Vacuum Adhesive
Excellent thermal resistance
Suitable activation temperature
Capable for storage and after applied on the work piece can be used for a long time
The work piece can be sanded after spreading the adhesive
Great technical information
Suitable for thin foil and high gloss pieces
Since a layer of adhesive should be applied among the PVC and the work piece, the adhesive should have a viscosity in the range of 2000-2800 cps to perfectly coat the surface of the work piece and on the other hand, it can be easily sprayed onto the work piece. The viscosity of this product is 2500 cps which is the highest viscosity in compared with other available adhesives.
The ability to withstand direct and indirect heat applied to the adhesive is one of its main factors.
The temperature that the polymerization and chain extension reactions are began in is defined as the activation temperature. The low activation temperature is considered as one of the adhesive superiority.
Here are some highlights of the low activation temperature advantages:
- Decline of the glue consumption by 10% for every 10 degrees of activation temperature reduction
- Increment of the production efficiency (more trays can be setup (
- Reduction of the production costs (reduction of the energy consumption, thinner coatings can be used without quality loss, etc…
- As the temperature rises, the opaque finish becomes shiny and the glass finish becomes opaque.
- Ability to work with non-MDF substrates, such as resin and polymers which are used in capitals of columns, which are decomposed at temperatures of 50-55 ͦ
Appropriate technical information
Since it takes a long time for the adhesive to dry after spraying and, on the other hand, it should not be too long, the adhesive standby time according to CE standard should be 24 hours and the longer this time can be the adhesive advantage for the costumers. Because it gives the consumer more time to work with the work piece.
In general, the proper and standard technical specifications of any ideal membrane adhesive should be in accordance to give the consumers maximum and best efficiency:
- The adhesive has the ability to be sprayed through the nozzle with the diameter of 1.8 to 2 mm
- The pressure of spraying should be 4-6 bar
- The thickness of the adhesive layer should be between 0.01-0.02 cm
- Adhesive consumption volume for smooth surfaces with for the MDF is 60 g/m2 and for 3D surfaces, convex surfaces and edges is 80-100 g/m3
Since this membrane adhesive is highly specialized, it is important to be aware of the homogeneity, proper spraying pressure and very low spraying thickness on the surfaces. The highest importance in choosing the right code is the work piece material.