Who Can Conquer High Temperature and High Pressure? A Close-Up Interview with the Filtration Expert in Industrial Production—The Melt Filter Cartridge

I. What is a Melt Filter Cartridge?

A melt filter cartridge, also known as a metal filter cartridge or stainless steel filter cartridge, is a precision filtration device made entirely of metal through argon arc welding. It is designed for filtering molten polymers under high-temperature and high-pressure conditions. Widely used in industries such as plastic extrusion, chemical fiber spinning, film production, and lithium battery separator manufacturing, it is a critical component for ensuring product purity, improving quality, and extending equipment lifespan.

II. Main Functions of Melt Filter Cartridges

· Improve Product Quality:

Removes foreign particles and gel particles, enhancing product transparency, uniformity, and physical properties.

· Protect Downstream Equipment:

Prevents clogging of nozzles, molds, and metering pumps, reducing the frequency of equipment maintenance.

· Extend Production Cycles:

Reduces the need for frequent screen changes due to impurity buildup, increasing continuous production time.

· Reduce Defect Rates:

Minimizes issues such as broken filaments, film rupture, and surface defects caused by impurities.

III. Main Types of Melt Filter Cartridges

1. Stainless Steel Woven Wire Cartridge:

· Made of woven stainless steel wire, it features smooth channels, easy cleaning, high-temperature resistance, corrosion resistance, high strength, no wire shedding, and long filtration cycles.

· Filtration Accuracy: 1–300 μm.

2. Stainless Steel Fiber Sintered Felt Cartridge:

· Made of sintered stainless steel fibers, it is a porous deep-filtering material with high porosity, good air permeability, high dirt-holding capacity, and reusability.

3. Multi-Layer Sintered Wire Mesh Cartridge:

· Typically a five-layer structure (protective layer, filtration layer, separation layer, support layer, etc.), it combines high-precision filtration with high mechanical strength and supports repeated cleaning and long-term use.

4. FC Alloy Cartridge:

· Sintered from copper-based alloy powder, it features regular pore shapes, uniform pore size, interconnected pores, low filtration resistance, and long service life. It is particularly suitable for filtering polyester melt and can withstand temperatures up to 700°C.

5. Metal Pleated Cartridge:

· Made of pleated stainless steel fiber sintered felt or multi-layer wire mesh, it offers a filtration area 3–10 times larger than standard cylindrical cartridges, making it suitable for high-viscosity fluid filtration.

Classification by Material:

· Sintered Metal Cartridge: Resistant to high temperatures (≤500°C) and high pressure, easily regenerated, suitable for high-precision filtration.

· Powder Metallurgy Cartridge: Uniform pores, high dirt-holding capacity, suitable for highly contaminated melts.

· Multi-Layer Wire Mesh Cartridge: Robust structure, suitable for high-flow, medium-to-low precision filtration.

· Ceramic Cartridge: High chemical corrosion resistance, suitable for special polymers (e.g., fluorinated materials).

Classification by Structure:

· Single-Layer Cartridge: Simple structure, low cost.

· Multi-Layer Composite Cartridge: High filtration efficiency, long service life.

· Cartridge with Support Frame: High compressive strength, resistant to deformation.

IV. Applications of Melt Filter Cartridges

Melt filter cartridges are widely used in the following industrial fields:

1. Chemical Fiber Spinning:

   · Used for impurity filtration in melt spinning processes of polyester (PET), polypropylene, nylon, etc., to improve product quality.

2. Petrochemical Industry:

   · Filtration of high-temperature corrosive liquids, separation, and recovery of intermediate products.

3. Metallurgical Industry:

   · Filtration of hydraulic system oil in rolling mills and continuous casting machines.

4. Pharmaceutical and Electronics Industries:

   · Pre-treatment filtration of reverse osmosis water, deionized water, cleaning solutions, and glucose.

5. Power Industry:

   · Oil purification in lubrication systems and speed control systems of thermal and nuclear power plants.

6. Environmental Protection and High-Temperature Gas Filtration:

   · Filtration of high-temperature steam and gases, purification of viscous liquids.

V. Cleaning and Maintenance

Melt filter cartridges are typically reusable. The cleaning process includes:

1. TEG Cleaning:

   · Boiling in TEG solvent at 285°C for 4–6 hours to dissolve polyester melt impurities.

2. High-Pressure Water Rinsing:

   · Rinsing from the inside out to remove surface residues.

3. Ultrasonic Cleaning:

   · Thoroughly removing particles embedded deep within the cartridge.

4. High-Temperature Calcination:

   · Restoring performance by high-temperature calcination for stubborn contaminants.

VI. Key Features of Melt Filter Cartridges

Melt filter cartridges are critical filtering components for high-temperature, high-pressure, and corrosive environments.

· Operating Temperature: -60°C to 700°C (depending on the material).

· Operating Pressure: Up to 30 MPa.

· Filtration Accuracy: 0.5–300 μm (commonly 1–200 μm).

· Porosity: 90% (FC alloy cartridge).

· Dirt Holding Capacity: 16.9–41 mg/cm² (stainless steel cartridge).

· Connection Methods: Threaded connections, quick connectors, flange connections, tie-rod connections, etc.

· Reusability: Can be reused after TEG cleaning, high-pressure water rinsing, ultrasonic cleaning, or high-temperature calcination.

VII. Related Manufacturing Equipment

1. Strengthen Knife Pleating Machine

2. Melt filter shrinking machine

3. Diesel Fuel Filter Cartridge

4. Melt Filter Extruder

5.Melt Filter Trimming Machine

For more details, please refer to the machine introduction