What is the difference between string wound and melt blown filter cartridges

Jul 23, 2025

Both string wound and melt-blown filter cartridges are used to purify liquids. They have key differences, and understanding these differences can help you choose the right deep filtration element. Here is a detailed comparison:

 

1. Structural Differences: Process Determines The Essence

The core manufacturing process of melt-blown filter elements is to heat and melt the polypropylene raw material, and then make the filter material through spraying, pulling and receiving molding processes. The fiber structure formed by this technology has the characteristics of uniform pore size and deep filtration, and the filtration efficiency can reach a precision range of 1-100 microns, which can effectively intercept suspended matter, particles and impurities such as rust in the liquid.

String-wound filter cartridges are manufactured using a precision winding process, with polypropylene fibers or absorbent cotton fibers as the filter medium, and the precision adjustment range of 5-100μm is achieved by controlling the winding density and tightness of the yarn on the porous skeleton.

 

2. Performance Comparison: Which Is Better?

Parameter	String wound Filter Cartridge	Melt Blown Filter Cartridge
Filtration Accuracy	0.5–150μm	1–100μm
Pollution Holding Capacity	Medium	High
Maximum Positive Pressure Difference	0.3-0.5MPa	0.4MPa
Chemical Compatibility	Temperature resistance ≤120℃	Strong acid and alkali resistance
Risk of Fiber Shedding	May "wire" under pressure	No shedding; fibers are bonded

 

3. Applicable Scenarios: Choose The Right One To Use It Well

Select a string-wound depth cartridge if your conditions include:

✅ High-precision deep filtration (like pharmaceutical pure water pretreatment).

✅ Improving water taste (better organic odor absorption).

✅ Medium impurity load environment.

Choose a melt blown polypropylene filter cartridge if your conditions include:

✅ Large flow and long life (like reverse osmosis security filter pretreatment)

✅ Filtering strong corrosive liquids (acids, alkalis, organic solvents)

✅ High cost performance with low replacement frequency

⚠️ Be cautious using wound filter cartridges at the front stage of reverse osmosis systems! Pressure may cause fiber shedding, leading to membrane clogging. Meltblown structures are more stable and provide reliable water quality.

 

4. Selection Guide: 3 Steps to Lock in Demand

Assess Water Quality:

Many suspended particles, dispersed impurity size → meltblown (gradient contamination)

Many colloids/organic matter, heavy taste → string wound (strong adsorption)

Consider Cost:

Low unit price → string wound (but may need frequent replacements)

Long-term cost → meltblown (long life, low overall loss)

Examine Environment:

High temperature/corrosive conditions → choose stainless steel string wound or melt blown filter cartridges

Compliance with food/pharmaceutical standards → melt blown (no adhesives)

There Is No Best, Only the Most Suitable

 

String wound cartridges excel in deep purification, while meltblown filter elements shine in stability and durability. Your needs will guide the right choice.

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