Factors affecting paint loss and paint loss control methods.

Paint loss, that is, paint "waste". In the coating process there will be a theoretical paint dosage, that is, no loss at all, all paint is coated on the surface of the work piece and thickness is just the thickness required by the design, then the paint theory coating rate (units: m2/L) is calculated as: volume solids (%) ×%) ×10÷ dry film thickness (sm)
÷ Of course, this is not possible, so there is paint loss, such as: paint barrels are not used up, spray paint is not sprayed on the work piece, thickness is greater than the design, filling the surface of the work parts pits (such as sand roughness), construction tools wasted, thickness than the design thickness part, splashing and so on are the cause of loss.
Paint loss coefficient: Usually the loss coefficient in industrial paint coating refers to the ratio between the actual amount of paint used and the amount of paint used in theory, that is, the ratio between the actual coating rate and the theoretical coating rate, which is usually between 1.3 and 2.0 .
, the main factors affecting paint loss
1. Structure type: The
of different surfaces to be applied will directly affect the loss of paint during construction. In general, the paint loss on complex structure is quite large compared with the paint loss on simple structure. When the size of the structure is small, the loss will be higher than the construction of the structure of the large structure
2. Coating method:
paint coating with brushing, roller coating, traditional air spraying and high-pressure airless spraying and so on. And industrial paint for large areas of construction of high solid parts of the paint, generally requires the use of high-pressure airless spraying, this coating method can form a high-quality coating film, coating efficiency is also very high, although its construction loss is lower than the traditional air spray, but far greater than brushing and roller coating.
3. Rough surface to be coated: The
surface to be coated, the greater the paint loss of its construction. In order to achieve good adhesion and optimum performance of coatings, industrial paints require sand blasting or polishing of the coating surface, which must be taken into account. For multi-coated construction, the smooth condition of each layer of paint surface, as well as the sandpaper grinding effect of the surface after construction, will directly determine the subsequent paint construction loss.
4. Coating minimum film thickness:
Usually the minimum value or range of total dry film thickness has been specified in the construction, and the loss that the operator inevitably produces in order to reach the specified minimum film thickness, which is also known as the distribution loss of the coating.
5. Application equipment selection:
different choice of coating equipment, but also greatly affected the loss of paint. For example, for the use of high-pressure airless spray method to coat small-size components, the use of smaller spray nozzles when its loss will be lower, and often construction units or builders to meet the requirements of tight construction progress, to achieve a higher spray efficiency, the use of larger spray nozzles, thereby improving the loss of paint. Moreover, different brands of airless spray equipment, spraying may form different spray atomization effect, loss of course is also different.
6. Environmental factors:
environment around the construction also affect the paint loss to varying degrees. The construction of windy outdoor places is obviously higher than that of well-ventilated and relatively closed workshops.
7. Construction process and construction process management:
different construction processes and construction management, will also significantly cause different paint losses. For example, the placement of the components to be coated may directly determine the operator's different spray posture and angle, paint loss is also different. The rational design of the construction process is also conducive to the reasonable control of paint loss.
8. Inevitably paint waste:
it should be mentioned that paint waste is also inevitable, because paint can be spilled and some paint remains in the exhausted tank. For two-component coatings, mixed coatings can be wasted over the life of the coating.
9. Builder's operating level:
different construction operators, due to their individual operating level, in a large number of construction, may produce completely different construction losses.
, the main control method of unreasonable loss is
. 1. Coating environment requirements
1.1 Wind: as far as possible to ensure that coating construction in the indoor, windy weather should stop spraying construction, thereby reducing paint fog caused unnecessary paint waste.
1.2 Lighting: The coating construction environment should be fully illuminated and the illumination should be greater than 500Lux.
1.3 temperature, humidity, dew point, component surface cleanliness, etc. should comply with specifications to avoid unnecessary paint waste due to rework and repair of poor quality coatings.
1.4 Construction site: construction site should be able to meet the different specifications of the components for mass coating construction requirements, to avoid multiple small numbers of components of the coating construction and increase the loss of paint.
1.5 Construction bracket for coating construction: the construction bracket used for the placement of components during coating construction should be highly suitable, too high or too low paint support will cause spray construction more difficult, resulting in increased paint loss.
1.6 Placement of components: For smaller components, the same form factor components should be kept together and ensure the appropriate distance between the components, so as to avoid paint placement is uneven and cause spraying difficulties and waste of paint.
2, roughness
the roughness of the base surface is an important factor in determining the size of the loss of the primer, the greater the roughness, the greater the loss of paint, so the blasting process should control the roughness of the base surface in the primer requirements of the reasonable roughness range.
3, construction equipment and tools
3.1 Spraying construction equipment should maintain good working conditions, to avoid repeated repair equipment during the spraying process caused paint over service life and other paint waste.
3.2 Nozzle size should be selected according to the paint variety and the size and surface condition of the components, so as to avoid all paint components of different sizes using the same nozzle resulting in more paint loss. In addition, the nozzle should be replaced in time after a certain period of time.
3.3 the size and type of brush and roller used for brushing and rolling should be selected depending on the size of the component. Waste paint brushes and rollers should be replaced in time to avoid uneven paint coating thickness due to the inappropriate construction tools, thereby increasing paint loss.
3.4 If conditions permit, try to use special spray equipment for each paint to avoid paint waste due to spraying different types of repeated cleaning equipment.
4, construction method
4.1 should be based on the shape and size of the components to choose a reasonable construction method, for smaller components should try to use brush and roll coating to reduce the loss of paint.
4.2 For edges, corners and hard-to-spray components, brush construction should be used to avoid forced spraying resulting in wasted paint and poor quality coatings.
4.3 roll and brush paint will be significantly reduced compared to spraying.
5, construction skills and construction management
5.1 good coating construction technology will reduce the loss of paint, spray construction, spray gun angle, moving speed, spray overlap area size and spraying methods will have an impact on the loss of paint, so the construction team with good construction technology on the loss of paint control is essential.
5.2 How much paint should be used to make how much, to avoid paint waste caused by mixing paint beyond the mixing life.
5.3 Every time the construction, to do the container residual paint as far as possible, to avoid more paint residue and cause waste of paint.
5.4 The construction party shall have a person and organization to recommend management and control of paint loss in paint construction.
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