RT-137 synthetic fibers process uses a diameter 35 mm filter element

Metal filter candles are essential components used to remove contaminants from polymer melts in processes like plastic and synthetic fiber production. These filters are designed for high-efficiency filtration under extreme conditions, ensuring that contaminants like dirt, gels, and degraded polymer particles are removed before the melt is formed into final products. Here’s a detailed look at how metal filter candles function, their features, and their benefits in melt filtration:

1. Purpose of Metal Filter Candles in Melt Filtration

• Metal filter candles serve to purify molten polymers by removing solid contaminants, which helps prevent blockages, improve material consistency, and ensure product quality in downstream applications.

• They are particularly important in extrusion, injection molding, blow molding, and fiber production, where contaminant-free melts are essential to avoid product defects.

2. Construction of Metal Filter Candles

• Typically made from stainless steel, sintered metal powder, or woven metal mesh, metal filter candles are highly resistant to the high temperatures and pressures involved in melt filtration.

• The candle design often consists of a cylindrical metal body with fine openings or pores to capture particles as the melt flows through it.

• Metal filter candles come in a range of pore sizes (5 to 200 microns), allowing for precise filtration control based on the quality requirements of the polymer melt.

3. Working Principle

• As the polymer melt flows through the metal filter candle, solid contaminants are trapped in the filter’s pores or on its surface.

• These contaminants may include foreign particles, undispersed pigments, degraded polymer chunks, and gels.

• Filtered melt continues to downstream processing, where it is formed into products without the risk of defects caused by impurities.

4. Types of Metal Filter Candle Constructions

• Sintered Metal Candles: Made from metal powder that is sintered to form a rigid, porous structure. These candles offer excellent mechanical strength and fine filtration.

• Woven Wire Mesh Candles: Constructed from layers of woven metal wire that provide a specific pore size for filtration.

• Perforated Metal Support with Multi-Layer Media: These candles combine a perforated metal core with multiple filtration layers, allowing for both coarse and fine filtration in one unit.

5. Key Features

• High Temperature and Pressure Resistance: Suitable for melt filtration, withstanding temperatures above 300°C and high pressures.

• Chemical and Corrosion Resistance: Stainless steel or similar alloys resist corrosion, which is crucial when filtering chemically aggressive melts.

• Reusability: Metal filter candles are often cleaned and reused, making them a cost-effective option for industrial applications.

• Long Service Life: Designed to perform well under continuous use without degradation, which reduces maintenance frequency.

6. Benefits in Melt Filtration Applications

• Improves Product Quality: By removing contaminants, filter candles help produce defect-free final products, especially important in high-quality applications like fibers, films, and high-performance plastics.

• Consistent Melt Flow: Filtration prevents clogging and uneven flow, ensuring consistent material throughput and product quality.

• Cost-Effective Operation: The reusable nature of metal candles reduces operating costs and minimizes downtime.

• Flexibility in Filtration Levels: Available in multiple micron ratings, allowing for tailored filtration from coarse to very fine levels based on specific process requirements.

7. Applications

• Plastic and Polymer Processing: Used in extrusion and molding to remove impurities before forming pellets, sheets, or molded parts.

• Fiber Production: In the production of synthetic fibers, such as nylon, polyester, and polypropylene, where clean polymer melts ensure uniform fiber quality.

• Film and Sheet Manufacturing: Removing contaminants from the melt prevents defects in plastic films and sheets, which are critical for applications in packaging and automotive sectors.

• Polymer Recycling: In recycling plants, metal filter candles help filter contaminants from recycled polymers, ensuring high-quality output for secondary products.

8. Cleaning and Maintenance

• Metal filter candles are designed to be easily cleaned and reused. Common cleaning methods include:

• Backflushing: Reversing the flow to dislodge particles.

• Chemical Cleaning: Using solvents or cleaning agents compatible with the filter material.

• Ultrasonic Cleaning: Especially for fine contaminants, ultrasonic cleaning can help remove particles embedded in the filter pores.

9. Choosing the Right Metal Filter Candle

• Pore Size and Filtration Rating: Based on the desired melt purity, choose a filter with the appropriate micron rating to capture specific contaminants.

• Material Compatibility: Ensure the filter material withstands the specific temperature, pressure, and chemical properties of the melt.

• Flow Capacity and Pressure Drop: Consider the filter’s effect on melt flow rate and pressure drop, as this impacts both the efficiency of filtration and the overall process.

Stainless steel woven mesh is made of stainless steel wire.

First, the characteristics of stainless steel filter element

(1) All stainless steel structure, wide chemical compatibility.

(2) High porosity, good permeability, low resistance, low use pressure difference.

(3) Good regeneration performance, can be used repeatedly by chemical cleaning, high temperature and ultrasonic cleaning.

(4) After folding, the filtration area is large and the amount of pollution is large.

(5) High temperature resistance, corrosion resistance, suitable for high viscous liquid filtration.

Second, the application of stainless steel filter element

(1) Pharmaceutical industry: pre-filtration of various antibiotics and other pharmaceutical liquids.

(2) Chemical industry: filtration of various organic solvents, acids and lye.

(3) Food and beverage industry: wine, mineral water, drinking water filtration.

(4) Electronics industry: high purity water pre-filtration.

(5) Petroleum industry: oilfield water injection filtration.

Sintered Metal Filter Element

   - Variations: Sintered stainless steel filter, Sintered metal mesh filter, Sintered porous filter element.

   - Uses: These filters are used in high-pressure or high-temperature applications, such as chemical processing, oil and gas industries, and fluidized bed filtration.

Melt Filtration System

Melt process filtration system, Melt filtration unit, Polymer melt filtration system.

Describes a system designed to filter and remove impurities from molten polymers or other materials during their melt phase, improving production quality in industries like plastics extrusion.