Differences Between Internal Springs and External Springs
External pumps (external springs): For sprayers and pump heads, you should know that a spring needs to be placed inside the center of the product. An external pump means the spring in the center of the sprayer/pump head is externally visible, usually placed above the pump core, and directly connected to the sprayer/pump head cap during assembly. The advantage of external pumps is that they do not directly contact the liquid in the bottle, which is both environmentally friendly and hygienic. They can also 100% avoid the possibility of rust from individual springs (though this is extremely rare, as most springs are treated) affecting the quality of the product inside the bottle. In addition, the force of external pumps is relatively stronger than that of internal pumps, so they are more commonly used for pump heads, especially suitable for thick liquids such as lotion concentrates.
External lotion pumps (external springs)
Advantages:
- Good anti-pollution performance: The spring does not directly contact the contents, avoiding contamination of the contents due to spring rust and better ensuring product quality and hygiene.
- Strong pumping force: The spring, located externally, is less restricted by the internal space of the pump body. It can be designed to be larger and more elastic, making it easier to pump high-viscosity liquids such as emulsions containing particles or petals.
Disadvantages: The appearance may be relatively more complex than internal pumps, and the design may not be as concise as internal ones.
Internal pumps (internal springs): In contrast to external pumps, internal pumps have the spring in the center of the sprayer/pump head hidden internally, usually located in the middle of the pump body. The internal spring can directly contact the liquid, and the pressing force is slightly weaker than that of external pumps. They are generally used for products such as health care essential oils, perfumes, and skincare toners, which have a consistency close to water.
Internal lotion pumps (internal springs)
Advantages:
- Compact structure: Components such as the spring are located inside the pump body, resulting in a compact overall structure that takes up little space. It is an ideal choice for packaging designs with limited space or small containers.
- Lower cost: The manufacturing process is relatively simple, with no need for additional external spring installation structures, leading to lower production costs.
- Concise appearance: Without the abruptness of an external spring, the overall appearance is more concise and aesthetically pleasing, blending better with the container and the overall style of the product.
Disadvantages:
- Prone to contamination: The spring directly contacts the contents. If the spring rusts or is made of poor-quality materials, it may contaminate the contents, affecting product quality and usage effect.
- Relatively weaker pumping force: Due to space constraints inside the pump body, the elasticity and pumping force of internal springs are relatively weaker than those of external ones, resulting in less effective pumping for high-viscosity liquids.
The above is an explanation of some sprayer/pump head products. We hope it will be helpful to you!
