The lotion pump head is integrated by different plastic components and accessories.
 
This article focuses on the reason why the head cannot rebound or the rebound is slow after pressing and how to check it.
 
Among the lotion pump head components and accessories, the most important ones are the piston (three-piece set), the spring, and the body (the part of the barrel with the spring).

The piston, relying on the elasticity of the tension spring, continuously performs a stroke effect in the body to draw the material out of the bottle.
 
Any non-cooperation between some will lead to the serious problem pointed out in this article, that the head cannot rebound or the material cannot be discharged after pressing.
 
In order to prevent the occurrence of this kind of situation, in the production process, we firstly check whether the length of the tension spring is standard or not. The difference is a thousand miles away. The length cannot ignore the effect of the piston. If it is short, it will cause the return stroke of the piston. In place, directly after pressing the head down, the rebound will not be able to rebound or the rebound will be slower.
 
Secondly, check whether the thickness of the piston fits the body. During the movement of the piston, any trace of open space will cause weak suction, and the body cannot be discharged by pressing the head. Because plastic has the properties of thermal expansion and contraction, a normal piston is important to ensure the quality of the emulsion pump head.
 
Finally, let’s analyze the body. In view of the elasticity of the plastic, if the injection time is improperly operated, the lack of injection will cut off a thin layer of the body, resulting in uneven inner wall, which cannot be prevented during the piston punching process. Under the gap, the material cannot be discharged.
 
After the analysis of the above 3 components, it can't be pressed, or the appearance that the head can't pop up after pressing can actually be prevented.
 
We need to check carefully and persevere in the test to ensure the normal use of each set of products for our customers.