Mastering Capsule Filter Production: Your Ultimate Guide

Capsule filters are ready-to-use products with disposable filter assemblies suitable for many applications. They can be made into different lengths and pore sizes and can be made with different membrane types and membrane layers. Because the outer housing of the capsule filter is made of polypropylene material, which does not contain adhesives and other chemicals and does not contaminate samples, capsule filters are usually used for precision filtration. In order to enhance the user’s understanding of capsule filters, we will introduce the capsule filter here.

Capsule Filters

Structure of capsule filters:

Capsule filters have an inner cage and outer housing. Pleated media are put inside the inner cage. For small-size capsule filters, there are two halves of outer housing at both ends. For larger capsule filters, there are two halves of housing and a middle housing. On the housings at both ends, there will also be fluids inlet, outlet, and exhaust port. Their structure and arrangement are determined according to actual needs.

Structure of the Capsule Filter

The working principle of capsule filters:

The working principle of the capsule filter: Let the fluid flow into the filter from the inlet direction. After the filtrate fills the filter and all the air is squeezed out, tighten the exhaust port of the capsule filter. After the filtration process is completed, open the outlet at the bottom of the filter and discharge the remaining filtrate. Then we can achieve the purpose of purification and filtration.

During the working process of the capsule filter, a certain pressure difference will occur when the liquid passes through the filter’s inner core. This pressure difference is caused by the difference between the pressure inside the filter housing and the pressure inside the filter’s inner core. As the liquid passes through the pores of the filter media, larger particles are trapped on the filter media, while smaller particles can pass through. In this way, the capsule filter can effectively separate impurities of different particle sizes.

How to produce capsule filters?

1. For small size filters:

Step1: Put pleated media inside the inner cage

Step2: Weld end caps on the inner cage

Step3: Weld the left housing end to the cage

Step4: Weld the right housing on the left housing

2. For larger filters:

Step1: Put pleated media inside the inner cage

Step2: Weld end caps on the inner cage

Step3: Weld the left housing end to the cage

Step4: Weld the middle housing to the left housing

Step5: Weld right housing to the middle housing

Small Size and Large Size Capsule Filters

Application of capsule filters:

According to the different characteristics of the filter objects of the capsule filter, different filter media are used, and the applications are various. The following are several commonly used filters:

  1. PTFE typeuses hydrophobic polytetrafluoroethylene (PTFE) filter membrane, which is suitable for filtration of solvents and corrosive solutions, and vent filtration of air and gas. ​


  1. Air sterilization filter
  2. Filtration of water and chemical reagents
  3. Ink filtration

Capsule Filter For Air sterilization

  1. PP typeuses hydrophilic polypropylene (PP) filter membrane, which is suitable for pre-filtration for reverse osmosis and ultra-filtration, ink filtration, etc. Suitable for filtering aqueous solutions and solvent samples.


Pharmaceutical industry: filtration of liquid medicine, cell debris, biological products, etc.

Chemical industry: filtration of organic solvents, chemical reagents, inks, plating solutions, etc.

Food industry: filtration of drinking water, mineral water, beverages, beer, wine, fruit wine, etc.

Electronics industry: pre-filtration of the reverse osmosis water system, pre-filtration of the deionized water system

Air filtration: filtration of compressed air, nitrogen, carbon dioxide, etc.

Other industries: photosensitive resist, magnetic media, etc.

Food And Beverage Capsule Filter

  1. Nylon typeuses nylon membrane, which is characterized by a fast flow rate and low level of extractable. Glass fiber can be added to filtration media to extend the service life of the nylon membrane and is suitable for filtration of larger samples and difficult-to-filter samples.


Pharmaceutical industry: Sterilize, and remove particles.

Food industry: filtration of drinking water, mineral water, beverages, beer, wine, fruit wine, etc.

Nylon Capsule Filters

In conclusion, capsule filters have a wide range of applications and are especially suitable for precision filtration. If you need to produce capsule filters, we can provide you with the required capsule filter making equipment. Knmtech is a professional filter production line machine manufacturer in China with over 10 years of expertise. Our product lines include pleated filter cartridge machines, melt blown filter cartridge machines, filter bag ultrasonic welders, infrared welding machines, capsule filter machines, filter winding machines, customized filter making machines, etc. Feel free to reach out.


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