In the spraying operation, sprayer nozzle leakage is a common but troublesome problem. It not only leads to a large amount of paint waste and increases production costs, but also seriously affects the quality and efficiency of spraying, causing defects such as sagging and mottled on the sprayed surface, ultimately affecting the appearance and quality of the product. So, what is the reason for sprayer nozzle leakage? Below we will conduct an in-depth analysis from multiple aspects and provide corresponding coping strategies.

Nozzle problems: wear and damage are the main causes

Nozzle front end gap

The front end of the nozzle is the key part of the paint spraying. During long-term use, due to the impact of high-pressure paint and the friction with the spraying surface, the front end of the nozzle is prone to gaps. Once a gap appears at the front end, the arc shape of the nozzle will be destroyed, resulting in uneven spraying of the paint, resulting in leakage. Imagine that the originally round front end of the nozzle becomes uneven due to wear, and the paint will leak out uncontrollably when passing through these gaps.

Nozzle internal blockage

The paint may contain some impurities, such as particles and fibers, which may enter the nozzle during the flow of the paint, gradually accumulate and block the nozzle channel. When the nozzle is blocked, the paint cannot pass normally, and will accumulate at the blockage, and then leak out from other parts of the nozzle. For example, when spraying some paint containing fillers, filler particles can easily accumulate at the nozzle, causing blockage.

Nozzle material is not corrosion-resistant

Different coatings have different chemical properties, and some coatings may contain corrosive ingredients. If the nozzle material is not corrosion-resistant, the nozzle surface will be corroded during long-term contact with the coating, resulting in pits, cracks, etc., which will cause leakage. For example, some strong acid or alkaline coatings may cause serious corrosion to ordinary metal nozzles.

Sealing component problem: sealing failure leads to leakage

Crescent pad is worn or damaged

The crescent pad is an important sealing component at the connection between the nozzle and the spray gun. It seals the paint and prevents leakage. However, during the spraying process, the crescent pad will be squeezed and rubbed by the high-pressure paint, and it is easy to wear or damage. Once there is a problem with the crescent pad, it will not be able to effectively seal the paint, causing the paint to leak out from the connection between the nozzle and the spray gun. Just like a crack in a sealing ring, the paint will seep out along the crack.

The sealing ring is aging or cracked

In addition to the crescent pad, other sealing rings may be used at the spray nozzle to ensure sealing. During long-term use, the sealing ring will be affected by factors such as paint erosion, temperature changes and mechanical wear, and gradually age or crack. When the sealing ring loses its elasticity or cracks, it cannot fit tightly on the contact surface of the nozzle and the spray gun, resulting in leakage. For example, some paints containing chemical ingredients may corrode the material of the sealing ring and accelerate its aging process.

The sealing surface is uneven

The sealing surface between the nozzle and the spray gun needs to be flat to achieve a good sealing effect. If the sealing surface becomes uneven due to long-term use or improper installation, such as scratches, bulges or depressions, it will lead to poor sealing and paint leakage from the gaps in the sealing surface. It is like two uneven surfaces pressed together and cannot be completely sealed.

Spray gun adjustment problem: Improper pressure and flow cause leakage

Excessive pressure

The pressure regulation of the spray gun is crucial to the spraying effect and preventing leakage. If the pressure of the spray gun is set too high, the flow rate of the paint at the nozzle will be too fast and the impact force will increase, which may cause the nozzle to be unable to withstand the excessive pressure and deform or damage, causing leakage. At the same time, too high pressure may also cause turbulence of the paint at the nozzle, destroying the normal flow state of the paint and causing leakage.

Excessive traffic

In addition to pressure, the flow rate adjustment of the spray gun will also affect the sealing of the nozzle. If the flow rate is set too high, the amount of paint passing through the nozzle per unit time will increase, and the nozzle may not be able to spray the paint evenly in time, causing the paint to accumulate and leak at the nozzle. For example, when spraying a large area, if the operator adjusts the flow rate too high in order to pursue speed, it is easy to cause leakage.

Improper adjustment leads to loose seal

During the spraying process, if the operator frequently adjusts the pressure and flow of the spray gun without properly fixing the connecting parts between the nozzle and the spray gun, the seal may become loose, causing the paint to leak. For example, when adjusting the pressure, if the screws between the nozzle and the spray gun are not tightened, the seal may be loose.

Paint problem: viscosity and impurities affect nozzle sealing

Paint viscosity is too high

The viscosity of the paint is one of the important factors that affect the spraying effect. If the viscosity of the paint is too high, the fluidity will be poor and it will encounter greater resistance when passing through the nozzle. In order to spray the paint smoothly, the spray gun needs to apply greater pressure, which may cause the nozzle to be subjected to excessive pressure and leak. At the same time, high-viscosity paint may also cause blockage at the nozzle, further exacerbating the leakage problem.

Too many impurities in the paint

As mentioned above, impurities in the paint can clog the nozzle and cause leakage. In addition, impurities may accumulate in the sealing area between the nozzle and the spray gun, affecting the sealing effect. For example, some large impurities may get stuck between the sealing ring or crescent pad and the contact surface between the nozzle and the spray gun, destroying the sealing and causing paint leakage.

Response strategy: Accurately solve the problem of leakage

Solution to nozzle problem

For the problem of the gap at the front end of the nozzle, you need to replace the new nozzle in time. When replacing the nozzle, you should choose a product with reliable quality and matching the sprayer model. If the leakage is caused by the blockage inside the nozzle, you can try to use a special nozzle cleaning agent to clean it to dissolve or flush out the impurities blocked in the nozzle. If the problem still cannot be solved after cleaning, you need to replace the nozzle. If the nozzle material is not corrosion-resistant, you can choose a nozzle made of a suitable corrosion-resistant material according to the properties of the coating, such as stainless steel, ceramic, etc.

Solution to sealing component problems

When the crescent pad is found to be worn or damaged, it should be replaced with a new one immediately. When replacing the crescent pad, make sure it is installed correctly and fits tightly with the contact surface of the nozzle and the spray gun. For the problem of aging or cracking of the sealing ring, it is also necessary to replace the new sealing ring in time. When installing the sealing ring, you can first apply a proper amount of lubricant on the surface of the sealing ring to ensure that it can be installed smoothly and reduce wear. If the sealing surface is uneven, you can use sandpaper or other grinding tools to grind the sealing surface to make it flat. During the grinding process, pay attention to the uniform force to avoid excessive grinding that makes the sealing surface too thin.

Solution to the spray gun adjustment problem

The operator should reasonably adjust the pressure and flow rate of the spray gun according to the properties of the paint and the spraying requirements. Generally speaking, the best parameters that can ensure the spraying quality and avoid leakage can be found by gradually increasing the pressure and flow rate. During the adjustment process, pay attention to observe the spraying effect of the nozzle and whether there is leakage. At the same time, when adjusting the spray gun, make sure that the connecting parts are tightened to avoid leakage due to loose seals.

Solution to coating problems

If the viscosity of the paint is too high, you can use an appropriate amount of thinner to dilute the paint according to the paint manufacturer’s recommendations to reduce its viscosity. During the dilution process, stir evenly to ensure that the performance of the paint is not affected. For the problem of too many impurities in the paint, you can use a filter device to filter the paint before the paint enters the sprayer to remove the impurities. The filter device should be cleaned and the filter element replaced regularly to ensure its filtering effect.

The problem of nozzle leakage in sprayers is caused by a variety of factors. When encountering nozzle leakage, the operator should carefully investigate the cause and take appropriate countermeasures from the aspects of the nozzle itself, sealing components , spray gun adjustment and coating. Only by solving the nozzle leakage problem in time can the smooth progress of the spraying operation be guaranteed, the spraying quality and efficiency can be improved, and the production cost can be reduced.