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PVC vacuum plastic
Vacuum forming
Use vacuum to bond the PVC film to the glued fiberboard to achieve the effect of covering various types of decorative parts such as flat surfaces, concave and convex grooves, curved edges, hollow carvings, etc.
The vacuum forming process is simple and the production cost is low. It is widely used in the manufacture of furniture such as paint-free doors, sliding doors, cabinets, etc.
Common problems and reference solutions for vacuum plastic suction application
1. Poor spraying (glue breaking, spray gun clogging, etc.)
Possible reasons:
1) The viscosity of the plastic suction is too high.
2) Dust and other particulate impurities are mixed into the plastic suction, or the skin is formed by itself, causing the spray gun to be blocked
Reference solution:
1) Adjust the plastic suction formula, reduce the amount of thickener, and lower the viscosity of the plastic suction.
2) Re-filter the plastic suction with a 200-mesh filter
2. When spraying, the atomization is too small or too scattered
Good atomization effect can help the plastic suction droplets to be more evenly dispersed, which is helpful for the board surface effect; but sometimes, the atomization effect is too good, and the plastic suction spray area will become very large, which is not conducive to the spraying of fine parts
Possible reasons
1) The spray gun is not adjusted to the appropriate state.
2) The viscosity of the plastic suction is not adjusted to the appropriate range.
3) The rheological state of the plastic suction is not adjusted well.
Reference solution
1) Adjust the spray gun to increase or decrease the atomization effect.
2) Lowering the viscosity of the blister glue can improve the atomization effect; increasing the viscosity of the blister glue can reduce the atomization effect.
3) Without changing the viscosity, the atomization effect can also be improved by selecting different thickeners to adjust the rheological state of the blister glue. Reducing the viscosity under high shear can improve the atomization effect; increasing the viscosity under high shear can reduce the atomization effect.
After spraying, the board surface takes a long time to dry
Possible reasons:
1) The glue film is sprayed too thick, resulting in the surface of the glue layer being filmed, while the internal moisture is difficult to evaporate.
2) Environmental influence (such as low temperature and high humidity).
3) Adding too much water to the blister glue formula system to adjust the solid content, or adding too much wetting and leveling agent may also slow down the drying speed.
Reference plan:
1) Spray evenly and reduce the amount of glue appropriately according to application requirements.
2) Environmental factors are the most uncontrollable, and it is recommended to extend the waiting time appropriately; you can also place the fiberboard in a high temperature and ventilated place to help its moisture evaporate.
3) Check the formula system of the blister glue and adjust it within the application requirements
After the film is dried, there are defects such as orange peel or pitting on the board surface
Possible reasons:
1) The spray gun is not adjusted properly (the atomization effect is not good during spraying).
2) The viscosity of the blister glue is too high and the fluidity is not good.
3) The state of the blister glue system is not well prepared
Reference plan:
1) Adjust the spray gun to adjust the atomization effect to the appropriate state.
2) The blister glue system is adjusted to the appropriate viscosity and rheological state, and supplemented with an appropriate amount of wetting and leveling agent to improve the surface effect.
(If necessary, please contact us, we will recommend a suitable thickener solution for you according to the actual application needs)
3) After the film is dried, gently polish it with fine sandpaper.
After vacuuming, the PVC film in the groove cannot be sucked down or is not firmly attached
Possible reasons:
1) The vacuum degree of the blister machine cannot be reached.
2) When vacuuming, the four sides of the groove are tightly fitted together, so that the air inside the groove cannot be extracted.
Reference plan:
1) Check whether there is a problem with the blister machine.
2) When spraying the blister glue, try not to spray too thickly around the groove.
3) If conditions permit, opening 1~2 holes at the bottom of the groove can effectively solve this problem
After decompression
After decompression, the PVC film in the groove slowly rebounds, and the outline of the decorative parts gradually becomes unclear (on the same day or the next day)
Note: After decompression, if the PVC film is not firmly attached, the later hand-tear strength and heat resistance will be affected
Possible reasons:
1) The blister temperature is not enough, and the film cannot be activated well.
2) The board surface temperature is still very high during decompression, and the initial strength of the blister glue cannot be well established; at this time, the blister glue with poor heat resistance is more likely to rebound
Reference plan:
1) Appropriately increase the temperature of the blister machine or extend the blister time to allow the film to be fully activated (the film layer temperature should be kept above 55°C as much as possible).
2) Especially in hot summer weather, the temperature of the board surface drops very slowly. You can use electric fans to blow directly or wipe with cold water to cool the board surface before removing the pressure.
3) For the blister glue formula, you can choose a resin with better heat resistance and appropriately increase the proportion of resin in the formula system.
After unloading, the edge is not firm or the edge is unsealed (on the same day or the next day)
Reference plan:
1) Tear off the edge and observe that a continuous film can be formed on the side of the fiberboard, but there is no stickiness with the PVC film, then you need to consider the activation problem.
Appropriately increase the temperature of the blister machine or extend the blister time to allow the film to be fully activated (the temperature of the side film layer should also be kept above 55°C as much as possible).
If the temperature cannot be increased, adding 2~3% of tackifying resin to the blister glue formula system can sometimes partially improve the problem.
1) Tear off the edge, the film is on both sides of the fiberboard and the PVC film, but there is no bonding strength, considering the initial strength or heat resistance is not enough.
Cool the board surface by direct fan blowing and wiping with cold water before removing the pressure.
For the formula of blister glue, you can choose a resin with better heat resistance and appropriately increase the proportion of resin in the formula system
The grooves of the fiberboard with blister glue rebound and the edge glue opens during the later storage process
Possible reasons:
On the premise of confirming that the initial blister is intact, it may be caused by high ambient temperature and insufficient heat resistance.
Reference plan:
1) Choose a resin with better heat resistance and appropriately increase the proportion of resin in the formula system.
2) Adding 2~5% curing agent to the blister glue can effectively improve the heat resistance. Note: The curing agent should be prepared and used immediately, and it is recommended to use it when the heat resistance requirement is high.