The influence of bottle mouth design and material on the selection of lotion pumps
Standard example: Plastic Bottle Finish SP - 410
(List of common lotion pump size specifications)
Sealing test items in inspection and quality control, fill the bottle with colored water (or material body) according to product specifications, use the corresponding torque according to different calibers to match the pump head with the bottle, press the head in a locked state, place it horizontally, and vacuum test -0.03 ~ -0.06MPa/5min (different customers have different requirements). After the test, there is no leakage at the matching point between the bottle and the screw thread, the matching point between the body and the lock cover, and the pressing head. At the same time, it is required that the screw thread and the bottle mouth match smoothly without slipping, blocking, or skewing.
The bottle mouth is injection molded, the process is more stable, the mouth size and thread accuracy are higher, and it can meet higher sealing needs. For the bottle mouth structure of the product, the following aspects are generally considered:
First, the shape. Generally, the bottle mouth shape is designed to be round. The round shape is more conducive to ensuring the size accuracy of the bottle mouth, and better matches the lid for sealing and the distribution of the bottle body wall thickness during blow molding.
The second is the bottle mouth structure, which is generally divided into a threaded structure and a buckle structure. The threaded structure is more conducive to the sealing effect of the bottle and the lid. It is often used in pharmaceutical packaging, liquid beverages, and cosmetic bottle packaging. It is combined with various threaded caps, safety caps, nozzles, and pump heads, etc., and has high sealing reliability. The size and form of the thread can be flexibly selected according to product needs. The buckle structure is often used for solid or paste packaging, and can also be used for liquid packaging. The advantage is that it is easy to use and suitable for high-speed filling. However, when used as liquid packaging, attention should be paid to the design of the lid material, sealing structure, and interference, and process control should be done to ensure its sealing.
The third is the size of the bottle mouth. For PET, the bottle mouth size is relatively flexible, but for PP materials that are more suitable for molding wide-mouth bottles, the bottle mouth should not be too small, otherwise it will have a greater impact on the molding and wall thickness distribution of the product. Generally speaking, the ratio of the bottle body diameter to the bottle mouth diameter is less than 2 times.
02 Selection according to the characteristics of the viscosity/fluidityUsually, the liquid can be poured into the beaker and judged according to the liquid surface condition:
(Diagram of bottle mouth size marking code)
A. The liquid surface can reach horizontal in an instant, and there is no trace on the liquid surface. All emulsion pumps and derivative pumps can be used. You only need to consider the characteristics of the liquid formula to choose the appropriate one.
B. The liquid surface can reach horizontal quickly, but there are slight traces of stacking on the liquid surface. The spray pump needs to verify its spray effect. Other emulsion pumps and derivative pumps can be used.
C. The liquid surface can reach horizontal in 1-2 seconds, and there are obvious traces of stacking on the liquid surface. It is necessary to use an emulsion pump with large suction and spring elasticity. High-viscosity pumps are preferred, followed by vacuum cans/bottles.
D. The liquid surface has obvious traces of stacking and cannot reach a horizontal state in a short time. High-viscosity pumps also need to be verified. Vacuum cans/bottles are preferred for packaging, or lid packaging is selected.
E. Invert the beaker containing the liquid. The liquid cannot be poured out in a short time. Only vacuum cans, or other packaging forms such as lids, hoses, cans, etc. can be used.
For example: if the recommended usage is 1.0 ml/time, you can choose a lotion pump with a pumping volume of 1.0 ml/time, or you can choose a lotion pump with a pumping volume of 0.5 ml/time.
05 Select according to the final packaging form
After confirming the packaging capacity, select the lotion pump specifications based on the size of the packaging capacity and the expected number of uses. Generally, the number of uses of a package is 100-300 times.
Example 1: A 100ml bottle has been confirmed, and the lotion pump can be selected with a 1.0ml/time lotion pump, which can be used about 100 times, or a 0.5ml/time lotion pump can be selected, which can be used about 200 times.
Example 2: A 500ml bottle has been confirmed, and the lotion pump can be selected with a 2.0ml/time lotion pump, which can be used about 250 times, or a 3.5ml/time lotion pump can be selected, which can be used about 140 times.
