How to select welder according to materials of pleated filter cartridges?

Nowadays, pleated filter cartridges are widely used in large-scale pharmaceutical industry, electronics industry, automotive industry, etc. In order to achieve better performance during the filtration process, the filter cartridge should have a high fluid flow rate and good total throughput. Membrane pleating allows a larger area of the filter media to be packed into one element to increase the efficiency of the filter. This is an important reason why this type of filter cartridge is so popular. There are now many types of pleated filter cartridge welding equipment, and filters are also made of various materials. So today, we are going to discuss how we should choose machines in order to produce filters of different materials.

Filter membrane makes an important impact in filtration. In order to meet different needs, the filter membrane materials mainly include the following types:

  1. PES (Polyethersulfone)

Since its excellent mechanical and thermal properties, polyethersulfone has been widely used as a promising material in medical applications and waste-treatment membranes. The membranes always show asymmetric structure and are prepared by a phase inversion method. Because of the membranes’ superior flow rate, high throughput and low protein and drug binding functions, PES membranes can be your best choice for sterile pharmaceutical filtration, infusion therapy and micro analysis, etc.

  1. PP (Polypropylene)

PP membrane is a hydrophobic membrane which is flexible, durable, unbreakable, nontoxic, and uniform in strength. It has excellent chemical resistance, acid and alkali resistance and solvent resistance. It is suitable for both liquid and gas filtration. PP membrane is now widely used in wastewater treatment, oil-water separation, as a separator of batteries, etc.

  1. Nylon 6-6

Nylon membrane is Hydrophilic in nature and biologically inert. It has wide chemical compatibility and is resistant to strong solvents and alcohols. High-quality nylon membranes are suitable for filtering aqueous solutions and most organic solvents.

  1. PVDF (Polyvinylidene fluoride)

PVDF is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. PVDF is favoured as a material due to its high thermal stability, good chemical resistance, high hydrophobicity, and good mechanical strength. High-capacity PVDF membrane is cast in a form that creates high void volumes and high dirt-holding capacity for filtration. It is now widely used for immunoblotting techniques.

  1. Fiberglass

Fiberglass membrane is a waterproof fabric. It is used on depth filters. The high dirt-holding capacity and long life of fibreglass media in prefiltration applications make it ideal in highly loaded product streams.

  1. PTFE (Polytetrafluoroethylene)

Inherently hydrophobic, the PTFE membrane will not absorb moisture from air or gases, making it ideal for venting applications, phase separations and aerosol samplings. Laminated PTFE filters can be used to filter aqueous solutions when prewetted with methanol. They are autoclavable up to 130°C.

Then we will introduce the production steps of the pleated filter. Usually, the production of pleated filter elements goes through several steps: pleats making, length cutting, middle seam welding, end cap welding, length connecting and adapter welding.

Among these steps, middle seam welding, end cap welding and adapter welding have a great relationship with the material. Although the machine used for length cutting is also related to the membrane material, our machine can adapt to the requirements of all the above materials for cutting.

Cutting Machine For Pleated Filter


There are many kinds of middle-seam welding machines. For PP and non-woven filter membranes, this ultrasonic welding machine will be very suitable.

ultrasonic welding for pp filter bag top


For PES, PVDF, PTFE, Nylon, and Fiberglass membranes, we have this type of hot melt machine for your choice.

Filter membrane seam hot melt welding machine1


For the welding of the end cap and adapter, not only the material of the filter membrane but also the material of the cage must be considered. For the PP and PES cage and end cap, the hot plate welder can be a good choice.

Pneumatic Control High Flow Filter Hot Plate Welding Machine

For PFA, PTFE, PVDF, and GF materials, we recommend using an infrared welding machine because these materials have high melting points, and hot plates are not possible. In addition, infrared heating can be more precisely controlled and is suitable for advanced materials and strict requirements.

Filter End Cap Infrared Welding Machine with Two Stations



Since most cages and adapters are made of PP material, we recommend using a hot melt interface machine. If other materials are used, the welding method should be considered based on the melting point of the material, thickness and other factors.


If length connecting is needed, then you need a lengthening machine. Since the machine will only weld the cage together, we will only consider the material of the cage. Generally speaking, the cage material is PP, so we recommend using this hot plate welding machine.


Servo Control Hot Plate Lengthening Machine for Filter Cartridge

In summary, for the welding of pleated filter cartridges, we must consider the materials of the filter membrane and cage to choose the appropriate machine. For PP membrane middle seam welding, we recommend ultrasonic welding machines. For PES, PVDF, PTFE, nylon and GF membrane middle seam welding, a hot melt welding machine will be a good choice. For end cap welding, a hot plate welder is a suitable option for PP and PES material and infrared welding machines can be used for PFA, PTFE, PVDF, and GF welding. For adapter welding, generally, a hot melting machine will be enough. If a length connecting machine is needed, a hot plate welding machine is recommended.

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