Polymer Filtration Industry

In industrial polymer production or processing, filtration is a key step to ensure product quality, protect downstream equipment (such as extruder heads, spinnerets, molds) and improve production efficiency. There are many types of filter consumables required, and the specific selection depends on the polymer form (melt, solution, suspension), temperature, pressure, viscosity, required filtration accuracy, chemical compatibility, processing volume and cost considerations.

The following are the main types of filter consumables commonly used in industrial polymer filtration:

1. Metal filter media (mainly used for polymer melt filtration):

Ø Metal filter/screen:

Material: stainless steel (most commonly used, such as 304, 316L), Inconel, Hastelloy and other high temperature and corrosion resistant alloys.

Structure: single or multi-layer woven mesh (plain, twill). Multi-layer combination (coarse-medium-fine) can improve dirt holding capacity and extend life.

Features: high strength, high temperature and high pressure resistance, can be washed and reused (reduced cost), wide range of filtration accuracy (usually from tens of microns to hundreds of microns).

Application: Melt filtration before extruder, melt pump, spinning assembly; granulator head filtration.

Ø Sintered metal filter material:

Material: Sintered stainless steel wire mesh, metal fiber (stainless steel, nickel-based alloy).

Structure: filter felt, filter disc, filter tube, filter cup, etc.

Features: More complex pore structure, deep filtration, extremely high dirt holding capacity, good mechanical strength, high temperature and high pressure resistance, backwashing or chemical cleaning regeneration (some types). The filtration accuracy can reach micron or even submicron level.

Application: Occasions with extremely high requirements for filtration accuracy, such as chemical fiber spinning, high-end films, medical catheters; hot melt filtration at the outlet of polymerization reactors; precision filtration of high value-added polymers.

Ø Perforated metal plate: Mainly used for coarse filtration or as a support plate.

2. Non-metallic disposable/replaceable filter element (mainly used for filtration of polymer solutions, suspensions, additives, monomers, etc.), Dashang wire mesh is not a professional field for non-metallic filter media, so it will not be introduced in detail here.

Key considerations for selecting filter consumables:

1. Filter object: Is it a molten polymer, solution, suspension, monomer or additive? What are the viscosity, solid content, and particle characteristics (hardness, shape) of the material?

2. Filtration accuracy (micron level): What is the minimum impurity particle size that needs to be removed? This directly determines the pore size or nominal filtration accuracy of the filter material.

3. Operating conditions:

Temperature: The filter material and seals must be able to withstand the highest operating temperature for a long time.

Pressure: The filter material and support structure must be able to withstand the maximum working pressure difference and possible pressure shocks.

Flow/processing capacity: Affects the selection of filter area.

4. Chemical compatibility: The filter material, seals, and shell materials must be able to resist chemical erosion by polymers, solvents, additives, cleaning agents, etc., and cannot swell, dissolve, or release harmful substances.

5. Dirt holding capacity: How much impurities can the filter material hold without clogging too quickly? This affects the replacement frequency and operating costs.

6. Cost and life:

Initial cost vs. operating cost: Metal filter screens have high initial costs but can be cleaned and reused; filter bag and filter element have low initial costs but are disposable consumables. Long-term costs need to be calculated.

Replacement frequency and downtime: Affect production efficiency.

7. Regulatory requirements: Food contact, pharmaceutical, electronic grade applications, etc. have strict material and dissolution requirements

8. Cleanability/renewability: Metal filter screens and some sintered filter materials can be cleaned and reused.

9. Installation and operation convenience: Is replacement convenient and fast?

The selection of industrial polymer filter consumables is a complex process that requires comprehensive consideration of process parameters, material properties, cost-effectiveness and compliance requirements. There is no "universal" choice, and the most suitable filter material type, material, precision grade and corresponding supporting sealing components must be matched according to the specific application scenario. Generally, melt filtration is mainly based on metal filter screens and sintered metals, while solution and suspension filtration widely uses filter bags, filter elements or plate and frame filter presses. As a professional supplier of metal filtration materials, Dashang Wire Mesh conducts in-depth technical exchanges with customers from different industries, provides professional industrial filtration and screening solutions, and ensures that the customer's filtration program system is efficient and stable.