Water-borne fluorocarbon coatings is a kind of coatings with water as solvent or dispersing medium. General industrial coating field, including anti-corrosion coating field, still use a large number of solvent based coatings, but with the increasing strengthening of environmental protection laws and people's awareness of environmental protection, water-based coatings instead of solvent based coatings is an inevitable trend.
Water - based fluorocarbon coatings with water - based fluorocarbon resin as the main film - forming material, the main characteristics of the resin contains a large number of F-C bonds. The f-c bond has the highest bond energy of all bonds, at 485 kilojoules per mole. Because the c-f bond energy is larger than the c-h bond energy, the shielding effect of the electron cloud of fluorine atom on the c-c bond is called strong hydrogen atom. Meanwhile, because the covalent radius of fluorine atom is very small, it is difficult to insert the reaction reagent, effectively protecting the c-c bond and making the c-f bond difficult to be destroyed by heat, light and chemical effects.
Therefore, fluororesin has many excellent properties: low intermolecular cohesion, low surface free energy, difficult to be liquid or solid infiltration or adhesion; Small friction coefficient, excellent weather resistance, corrosion resistance, water and oil resistance. Water-borne fluorocarbon resin has become an important development direction of coatings industry.
(1) the thickness of the paint film is mainly determined by the lifting rate of the object and the viscosity of the paint. After controlling the viscosity of paint according to the above requirements, according to the larger limit of paint film about 30um, according to different equipment, determine the appropriate rate of lifting. Lift the painted object evenly at this rate. Fast lifting rate, thin film; The lifting rate is slow, the film is thick and uneven.
(2) the dip coating operation sometimes results in the thickness difference between the upper and lower paint film, especially in the lower edge of the coated product. To improve the decoration of the coating, use a brush to manually remove excess accumulated paint droplets when dipping in small batches. Centrifugal force or electrostatic force can also be used to remove these paint droplets.
(3) the dip time of wooden parts should not be too long, lest the wood inhales excessive paint, causing slow drying and waste.
(4) after large objects are soaked and coated, the solvent should be basically volatilized before being sent to the drying room. Inspection to thick coating parts of the paint does not stick to the hand, no finger print shall prevail.
(5) constantly pay attention to the determination of coating viscosity, each shift should be measured 1-2 times viscosity, if the viscosity increases more than 10% of the original viscosity, should be timely add solvent. When adding solvent, stop dipping operation. After mixing, measure the viscosity, and then continue.
(6) attention should be paid to the mounting of painted objects. Design the hanging tool and mounting way by dip in advance to ensure that the workpiece is in a better position. The larger plane of the coating should be close to the vertical, and the other plane should be at an Angle of 10°-40° to the horizontal, so that the remaining paint can flow out smoothly, and the phenomenon of coating or "air bag" should be avoided as far as possible.
(7) in order to prevent the diffusion of solvent in the workshop and dust fall into the paint tank, the dip tank should be protected. Outside the time of operation, small dip lacquer chamfer should build, big dip lacquer chamfer needs to discharge coating clean, clean with solvent at the same time.
(8) strengthen ventilation equipment to prevent the harm of solvent vapor; Pay attention to fire control arrangement and regular inspection.