Find HS Code and trade information for filter paper

Filter Paper

Filter paper is a specialized porous material used for separating solid particles from fluids (liquids or gases). It is widely employed in laboratories, manufacturing, and everyday applications for purification, analysis, and clarification.

Material

Traditionally, filter paper is made from cellulose fibers, typically derived from wood pulp. However, various other materials are used to impart specific properties:

• Cellulose: Most common, offering good general filtration.
• Cotton: Provides higher purity and is used for critical applications.
• Glass Fiber: Offers high temperature resistance and chemical compatibility.
• Synthetic Polymers (e.g., PTFE, Nylon, Polypropylene): Used for aggressive chemicals or when low extractables are required.
• Mixed Materials: Combinations of materials are used to optimize performance.

Purpose

The primary purpose of filter paper is separation. This can be for:

• Qualitative Analysis: Removing insoluble impurities to obtain a clear filtrate for further testing.
• Quantitative Analysis: Accurately collecting a specific solid precipitate for weighing and determining its mass.
• Purification: Removing contaminants from a liquid or gas.
• Sterilization: Removing bacteria and other microorganisms from liquids or gases.
• Clarification: Removing suspended particles to improve the appearance of a liquid.

Function

Filter paper functions through a combination of mechanisms:

• Mechanical Retention: Pores within the paper physically trap particles larger than their pore size.
• Adsorption: Some particles adhere to the fiber surface.
• Absorption: The paper material can absorb some liquids.
• Depth Filtration: Particles are trapped within the matrix of the paper fibers, not just on the surface.

Usage Scenarios

• Laboratory Filtration: Separating precipitates from solutions, filtering samples for analysis (e.g., water quality testing, environmental monitoring), performing hot filtration to remove insoluble impurities during recrystallization.
• Brewing: Separating coffee grounds from brewed coffee, filtering beer to remove yeast and sediment.
• Chemical Industry: Clarifying chemicals, removing catalysts from reaction mixtures.
• Pharmaceutical Industry: Sterilizing liquids, removing particulate matter from drug solutions.
• Automotive: Oil filters use specialized filter paper to remove contaminants from engine oil.
• Air Filtration: HEPA filters (High-Efficiency Particulate Air filters) utilize fine filter paper to remove airborne particles.
• Everyday Use: Coffee filters, tea bags, vacuum cleaner filters.

Common Types

Filter paper is categorized based on various properties:

• Flow Rate: Fast, Medium, and Slow flow rates are available, influencing filtration speed.
• Pore Size: Ranges from coarse (for large particles) to fine (for microscopic particles), typically measured in micrometers (µm).
• Ash Content: The amount of residue remaining after ignition, important for quantitative analysis. Low-ash paper is preferred when precise weighing is required.
• Wet Strength: Indicates the paper's ability to withstand tearing when wet.
• Specialty Papers:
  • Whatman Filter Paper: A widely recognized brand known for consistent quality.
  • Syringe Filters: Pre-sterilized filters used with syringes for small-volume filtration.
  • Buchner Funnel Filters: Used with a Buchner funnel for vacuum filtration.
  • Glass Fiber Filters: For high-temperature applications or aggressive chemicals.
  • PTFE Filters: Chemically inert filters for harsh solvents.

Filter paper is categorized under paper pulp blocks, slabs and plates.

• 4812000000: This HS code covers filter blocks, slabs and plates, of paper pulp.
  • 48: Chapter 48 relates to Paper or paperboard; articles of paper pulp, paper, paperboard, cellulose wadding or fibres thereof.
  • 12: Heading 12 specifically covers Paper and paperboard; articles of paper pulp, paper, paperboard, cellulose wadding or fibres thereof, not containing cellulose fibres.
  • 000000: This further specifies filter blocks, slabs and plates made of paper pulp.

Tax Details: The base tariff is 0.0%, with an additional tariff of 25.0%. After April 2, 2025, the additional tariff will increase to 30.0%, resulting in a total tariff of 55.0%.