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String-wound filter cartridges

Putsch® has been manufacturing string-wound filter cartridges for many decades. The cartridges are manufactured at the German head plant in Hagen, following the highest quality requirements.

In addition to the fast delivery service, Putsch® can also offer its customers flexibility with regard to special requests.

The string-wound filter cartridges are often used in the food industry, but also for electroplating baths, chemical and water. The application options are manifold.


General information/manufacturer Putsch®

At the Hagen head plant, in central Germany and in the heart of Europe, string-winding technology and with it the production of effective filter media has developed over several decades. Today, Putsch® is a leading manufacturer for string-wound filter cartridges with special filter yarn, producing the best possible filtration effect based on the special filter matrix and the fiber selection.
Each winding machine is the result of in-house development, and each string-wound filter cartridge is a unique product. The longstanding, experienced employees operate the winding machines and monitor the manufacturing process for each filter cartridge. Despite the large number of types and the many orders, the employees are able to meet even short term customer requests and keep delivery times as short as possible if a specific type is not in stock.

Best quality, a high level of flexibility and fast delivery are the guiding principles of Putsch® – we have already convinced many customers with this and want to win over many new customers in the future!

Filter media

The yarn is the filter medium in wound filter cartridges. It determines the filter action and the volume of absorbed contamination. Putsch® has the largest selection of filter yarns, which are sourced only from longstanding suppliers and are defined based on textile characteristics.

Taking into account chemical and thermal specifications or specific regulations, a variety of yarn types are used depending on the area of application:

– Polypropylene – carded yarn (standard)
– Rotor yarn
– Flyer wick yarn
– High-pressure washed yarn
– Cotton 
– Glass fiber
– Viscose
– Nylon® 
– Polyester 
– Fibrillated polypropylene yarn, i.e. thermally bonded polypropylene yarn

For filtration applications below 90 °C, polypropylene filter yarn is most common, as it has a particularly high economic efficiency, a very high chemical resistance and can easily be disposed of. Due to different spinning processes, however, even polypropylene filter yarn can have significant quality differences, because the spinning process affects the filtration properties. Our customers rate Putsch® carded yarn as the best filter yarn with the highest filter action and longest useful life.

Winding technology

The filter yarn is basically the raw material for the string-wound filter cartridges and determines the filtration properties to a great degree. A suitable winding technology increases the filter action and its useful life. The Putsch® employees at the winding machines produce a particularly precise and even winding pattern, creating an optimum depth filtration action. This filtration action and the homogeneous filter matrix determine the effectiveness and useful life of the filter cartridges.

The string-wound filter cartridges have a constant good action and deliver a constant filtration result – even after particularly long periods of use. 

Decades of experience in winding technology have allowed Putsch® as a manufacturer of string-wound filter cartridges to produce a graduated filter matrix during the winding process. As a result, larger particles from the liquid accumulate in the outer wound layers, while smaller particles are only held back at a certain depth. This increases the useful life of the filter clearly and reduces operating costs, whereas with a simple, non-graduated winding matrix, the inflow side of the filter cartridge would become blocked after a short time.

Support cores

The high quality filter yarn is wound onto support cores made of polypropylene or stainless steel.

The suitable material is selected depending on temperature, differential pressure or chemicals. The filtered liquid should pass through the support core unhindered, without affecting its mechanical stability – ideally without pressure loss!

In Putsch® filter cartridges, the perforation of the support cores is ideally adapted to the flow rate of the filtered liquid. This is an advantage over many competitors.

Support cores can be wound with a dense nonwoven covering in a spiral pattern for additional protection. For the nonwoven material, there is a choice of polypropylene, glass fiber or cotton, depending on the filter yarn and the application.

Special filters – customized

Decades of experience and the very large range of customers mean that Putsch® already offers hundreds of different versions of its filter cartridges as a standard. But still, we regularly encounter customers with special requests with regard to length, outer diameter or a special winding matrix. The innovative Putsch® team is happy to take on these challenges and creates customized solutions in a dialog with the customers.

The flexible winding machines can quickly be adapted to the requirements at hand, creating new products for new ideas.
The machines can be set up continuously for filter cartridges in different lengths from 78 mm to 2000 mm and outer diameters from 45 mm to 120 mm.


The string-wound filter cartridges from Putsch® are fully suitable for contact with food. All components comply with the regulations from the Food and Drug Administration (FDA).

RoHS requirements are met for use in the electronics and coating industry.

No substances that could interfere with adhesion, e.g. silicones, are permitted in paint coating systems, among others. All requirements in this regard are also met.


Putsch® supplies the string-wound filter cartridges with the standard adapters. Depending on the cartridge housing used, the matching adapters P0 (DOE), P7, P8 and M0 are available.

The adapter caps are made of polypropylene. The adhesive strength of the filter cartridges and the adapter caps is ensured by melted polypropylene granulate – no adhesives or foreign substances are used!

For certain adapters, O-rings made from different materials are available for sealing:
Silicone, NBR, FPM, EPDM for adapters

Quality control

Although the design of string-wound filter cartridges looks simple at first glance and they are manufactured by machine, compliance with the high quality requirements can only be ensured through constant monitoring and testing:

– Cross-wound pattern
– Yarn tension
– Visual purity
– Evenness
– Dimensional accuracy
– Tension

These parameters always have to be within the defined range. Quality control at Putsch® starts with delivery of the raw materials. Only longstanding, proven suppliers are approved to supply the individual components to Putsch® . Each suppliers has granted Putsch® insight into their supply chain, presented the manufacturing or machining processes and provided adequate replies to questions about their quality assurance. Putsch® uses only components which come from a fixed and verifiable supply chain and works only with original products – no recycled or reprocessed materials. We vouch for that!

Information material

Information material

Order the information package on Putsch® string-wound filter cartridges free of charge or download it directly here.

PDF, 2.6 MB

Technical data

Technical dataString-wound filter cartridges
Yarn materialsWashed polypropylene, high-pressure washed polypropylene, cotton/viscose, glass fiber, polyester, nylon®
Support core materialsPolypropylene or stainless steel
Filter grades (standard)1 µm – 600 µm
Length of filter cartridges (standard)127 mm, 250 mm, 500 mm, 750 mm, 1000 mm and 5“ , 10“, 20“, 30“, 40“
Inner diameterapprox. 27.2 mm
Outer diameter64 mm
Application exampleselectroplating baths, food & beverages, cooling water, chemicals

Recommended filter cartridge exchange at max. 2 bar differential pressure.

Filter cartridge product range

String-wound filter cartridges

Putsch® offers a very large selection of string-wound filter cartridges in many sizes, designs, materials and winding patterns.

Depth filter cartridges type “HP”

The depth filter cartridges type “HP” from Putsch® are special depth filters on polypropylene basis which are known for their particularly long useful life.

Depth filter cartridges type “CX”

The depth filter cartridge type “CX” is a 3D absolute filter for customers with very high cleanliness requirements.

Pleated depth filter cartridges type “K11”

The Putsch® depth filter cartridges type “K11” with their micro-polypropylene filter matrix are known to be particularly effective and are especially suitable for filtering out ultrafine particles.

Membrane filter cartridges type “K01”

Putsch® membrane filter cartridges “K01” use a polyethersulfone membrane, filter finest particles down to bacteria and have special adsorption properties.

Mesh filter cartridges type “PGP”

The mesh filter cartridge type “PGP” is a versatile, reusable filter cartridge made from polypropylene mesh. It is easy to clean and can quickly be converted.

Metal mesh filter cartridges type “MGG” + MGP”

Putsch® metal mesh filter cartridges type “MGG” + MGP” are special stainless steel cartridge filters for operation at high temperatures or with specific chemicals.

Activated carbon filter cartridges type “PA-G”

Putsch® activated carbon filter cartridges type “PA-G” are equipped with steam-activated coal pellets and specially designed for strongly contaminated liquids. The bulk form means that the activated carbon surface cannot become blocked by coarse dirt, making the useful life extremely long.

Activated carbon filter cartridges type “EPS”

Putsch® activated carbon filter cartridges type “EPS” are manufactured with activated coconut coal. The activated carbon block has a homogeneous layer with constant adsorption properties. In addition to applications in liquids, these filter cartridges are also suitable for air and gas purification.

Activated carbon filter cartridges type “GAC”

Putsch® activated carbon filter cartridges type “GAC” are made with activated coconut coal granulate and designed for low dynamic pressure and therefore a long useful life. The special design allows the liquid to pass through the entire filling, so the long contact times increase the adsorption effect.

Filter cartridges type “Pro”

Putsch® filter cartridges type “PRO” are cartridge filters on the basis of phenolic resin-bound acrylic fibers, designed for the special requirements of paint and varnish filtration.

Customer Service Center

Use our extensive range of services for solid/liquid separation. Your contact can help you with any questions and problems.

Please send any inquiry and order to

Customer Service Center

Christina Hölper
Phone: +49 (0) 23 31 / 3 99 1 53
Florian Ollesch

Customer Service Center

Phone: +49 (0) 23 31 / 3 99 – 1 50

Emergency number

If you need to contact us in emergencies outside office hours, the responsible Putsch® employee will be informed immediately and the required measures for solving your problem will be initiated.

Related products:

Cartridge housings type “4”

Cartridge housings type “4” are robust stainless steel filter housings which are modular and accordingly versatile.

Cartridge housings type “6”

Cartridge housings type “6” have been used widely in all industries for over 40 years and are particularly popular due to their solid, robust quality.

Cartridge housings type “D” and “D-G”

Cartridge housings type “D” and “D-G” from Putsch® are manufactured individually to meet the requirements and special requests of customers.

Polypropylene Cartridge housings

Housings type “SM”, “SL” and “PN” are polypropylene cartridge housings for use as water filters, each with individual filter cartridges. Their low weight makes them ideal for mobile use.

Cartridge housings “BB”

Cartridge housings type “BB” are made of polypropylene filter housings designed for filter cartridges with a larger diameter which have particularly long service lives.

Cartridge housings type “D-PP”

The customized cartridge housings type “D-PP” are made of polypropylene and are used wherever comparable metal housings are unsuitable, e.g. in an environment containing salt.