When it comes to dispensing pumps, you normally have two variances of mechanisms to choose from. These include:
Design #1 – Spring in the ACTUATOR
Design #2 – Spring in the CHAMBER
These two options can seem a little confusing at first, Especially if you’re new to the world of packaging.
#1 Spring in the actuator
A spring in the actuator of the dispensing pump enables liquid to pass through the pump mechanism without touching the spring. Some products can be quite aggressive or abrasive to the metal spring. This can sometimes erode the spring and cause a break, discolour the liquid contents or cause an ugly rust effect inside the dispensing pump. This can be seen if using a transparent colour finish.
Liquid content high in salt or acid would best suit this type of design.
#2 Spring in the chamber
This dispensing pump design allows the liquid to touch the metal while being dispensed. This is fine for liquids that won’t erode standard grade 304* metal. Manufacturers can use a better grade metal spring such as 316, however, the MOQ (Minimum Order Quantity) would have to be high for the product to be viable.
* The two most common stainless steel grades are 304 and 316. The key difference is the addition of molybdenum, an alloy which drastically enhances corrosion resistance, especially for more saline or chloride-exposed environments. 316 stainless steel contains molybdenum, but 304 doesn’t. [Source]
Dispensing Pump Highlights
Both designs can have the same price points in the manufacturing process. When comparing a spring (304 grade) to a nonspring chamber design. The dose can also be the same for each dispensing pump. Another factor to take into consideration would be the viscosity of the liquid. However, both pump designs can handle different thickness product lines.
If you would like further information on what dispensing pump would best suit your product. Please give one of our account managers a call today for a friendly discussion.