Factors Influencing The Quality of Vacuum Membrane Cabinet Doors
Select high qualified laminate and adhesive
Gluing in a dust-free environment
Fallow the instruction of using the adhesive
Using the MDF boards with high quality and density
Using sharp and winning tools
Factors Influencing the Quality of the MDF Boards
MDF with homogeneous particles and high compression
Excellent quality fiber and sandpaper
High quality hydrophobic foam wax
MDF with low excess material
MDF deep-drawing grade (characterization)
|Moisture content (EN 322)||6±2%|
|Tensile strength across the panel (EN319)||≥0.75 N/mm2|
|Peel resistance (EN 311)||≥1.2 N/mm2|
|Hydrophobic agent||≥2% solids on absolutely dry wood fiber (high-molecular FT wax)|
|Extract contents||≤1% (without hydrophobic agent) on absolutely dry wood fiber (extraction in n-hexanes, 24hours according to Soxhelt method)|
PVC coating storage conditions:
- Ideal storage temperature of 5-30 °C
- Moisture content of approximately 50%
- Maintenance without extra compression
- Shelf life of up to 18 months
Poly urethane adhesive storage conditions:
- Ideal storage temperature 15-25 °C
- Transportation temperature 10-35 °C
- Maximum storage time is 6 months.
- Be sure to check the adhesive temperature during winter transportation
Storage conditions of MDF boards
- Storage temperature is about 20 °C and maximum 2% humidity
- Do not store in the open space at all
- Do not be exposed to direct sunlight, cold or humidity
- Keep on a flat surface to prevent any MDF waves and bends.
All materials must be checked prior to use to comply with the above conditions. Check that materials are kept to the stated standard (temperature and humidity). Check the ambient air to be ideal for work (Temperature at least 20 °C and maximum humidity of 65%).
- Ocular Survey of quality of the veneer
- Check the thickness of the coating, which is good between 0.3-0.4
- The coating must be at ambient temperature before using a non-heating coating
- Suitable for machining
- MDF sheets are neither freshly pressed nor too hot.
- All tools are well sharpened.
- Configure it correctly on the CNC machine
- Do not splash any oils or excessive materials
- Keep the doors on a flat surface
- Keep at proper ambient temperature and dry place
- Move the machined parts to the adhesion room without any dust
- Ocular inspection of the container before use to ensure that the purchased adhesive is returned in the event of heterogeneity, stiffness or loosening.
- Shake the dish thoroughly before using.
- The adhesive should be properly and uniformly sprayed on all MDF surfaces.
- Ocular check for spraying heterogeneity is a must.
- Be sure to add a crosslinker or a suitable adhesive activator.
Required information about the adhesive tool
- All adhesive spray tools in contact with the splash adhesive must be made of stainless steel, Teflon and polyamide or plastic materials.
- The nozzle diameter of the adhesive is between 1.5-2.2 mm.
- Pressure of material 1-3 bar.
- Spray pressure 3-7 bar
Note: If you are using two component adhesives, the adhesive spray must be facilitated with a mixer.
After the gluing process is completed, use water to clean all the sticking parts
Temperature and adhesion in the adhesive process on MDF membrane cabinet parts
- The surface of the MDF parts should be cleaned and free of any dirt and particles.
- The smallest excess particles will become apparent after vacuuming the membranes.
- The adhesives should be sprayed at room temperature more than 18 °C.
- The machined edges and points absorb the adhesives more, so double glue these areas. The first time is to close the pores. Wait for 1 minute. Second time, spray adhesive on machining points and the edges.
- The amount of adhesive used depends on the quality of MDF.
How to dry adhesive during gluing process on MDF membrane cabinet door parts
- The drying process must be in a dust-free environment.
- The adhered parts are ready to be coated at room temperature (20 °C – 5% humidity) after 30 minutes.
- It is possible to reduce the drying time with hot air ducts.
- The temperature inside the hot air duct should not exceed 35 °
- In this channel the air flowrate is essential, not exactly the temperature.
- After the hot air channel, be sure to do the following procedure immediately.
- Avoid waiting too long for the veneer operation.
Membrane laminating operations on glued parts
Following are the features specific to the various laminate systems.
Special Features for Use in Membrane Veneer:
- Membranes are used as a medium for heat transfer
- This coating is formed by vacuum force from below and pressure from above.
- After forming the coating, the MDF cools and separates from the membranes.
Specifications for use in vacuum coating
- In standard coatings, heat is transferred directly from the hot plate to the veneer
- In vacuum operation, the coating is formed by vacuum suction.
- If the Vacuum suction power is strong enough, it can be replaced by membrane
Preparation of veneer
The following parameters must be considered before the coating operation:
- Type of veneer
- Coating thickness
- Color and Surface Type (Standard or High gloss)
- Adjust the pressure and temperature parameters taking into account the type of coating, the type of adhesive and the type of machining.
- Pre-heat the laminate before closing the press chamber.
- Heat should apply to all parts of the coating.
- Depending on the radiant heat, the surface temperature of the workpiece may also rise.
- Preheating of the veneer can also be achieved by heat radiation.
- Membrane temperature and preheating time affect the flexibility of the laminate.
- The preheating time must be precisely adjusted to meet the activation temperature of the adhesive as recommended by the manufacturer.
- The minimum activation temperature varies depending on the type of adhesive, and is approximately between 55-80 °C.
- The veneer is formed by vacuum from the bottom and pressure from the top.
- The formation of 3D depends on temperature, vacuum time, applied pressure and pressing time.
- The settings of these parameters depend on the coating, the adhesive as well as the design of the components.
- The pressing time must be adjusted so that at the end of the pressing time, the piece temperature of the adhesive line is well below the softening point of the laminate. Usually the adhesive temperature should be lower about 10-50°C than the laminate softening point.
Cutting and trimming of the pieces
- The excess laminates should be cut (manually or automatically) after sufficient cooling to avoid shrinkage. The cooling time depends on the adhesive and coating properties. That must be determined by the operator.
- A sharp tool should be used to prevent tearing up the laminate
- The adhesion of the coating should be randomly recorded by peeling test.
Prepared parts should be stored at room temperature for 6 days and then shipped for shipment.