Tea Bag Materials Series: Filter Paper

Filter paper is one of the most traditional and widely used tea bag materials in the tea industry today. It remains the primary choice for producing single-chamber and double-chamber tea bags, thanks to its excellent permeability, fast infusion, and reliable performance during repeated brewing.

Compared with other tea bag materials, filter paper is simple in structure, easy to process, and highly compatible with various tea bag machines. Depending on the machine technology and sealing method, tea bag filter paper can be broadly divided into non-heat seal filter paper and heat seal filter paper.

Below is a clear overview of the two main types of tea bag filter paper and their typical applications.

1. Non-Heat Seal Tea Bag Filter Paper

Non-heat seal filter paper refers to tea bag paper that does not require heat sealing during the bag-forming process. It is mainly made from wood pulp blended with natural plant fibers, such as abaca (Manila hemp).

Instead of heat sealing or adhesives, this type of filter paper relies on folding and mechanical pressure during processing. Through this process, the natural fibers physically interlock and create a secure structure, forming the tea bag without the need for heat.

Non-heat seal filter paper is most commonly used for double-chamber tea bags, especially in traditional tea bag formats.

Key Advantages

  • Excellent air permeability for fast and efficient infusion
  • Strong resistance to repeated brewing
  • Allows tea leaves or powders to release flavor quickly
  • Does not rely on heat sealing or chemical adhesives
  • Typically free from plastic sealing layers, offering better environmental performance

Typical Applications

  • Tea bag types: Double-chamber tea bags, single-chamber traditional tea bags
  • Processing equipment: Non-heat seal tea bag machines
  • Filling materials: Powdered or fine-cut tea and herbal blends
  • Common specifications: 12.5 gsm, width 90–140 mm

Non-heat seal filter paper is especially suitable for brands that value traditional tea bag appearance, natural materials, and sustainability.

2. Heat Seal Tea Bag Filter Paper

Heat seal filter paper is designed to form tea bags through a controlled heating and pressure process. Its structure is based on a blend of wood pulp and heat-sealable fibers, such as PP (polypropylene) or PLA (polylactic acid).

When exposed to heat during packaging, the heat-seal fibers soften and bond with adjacent paper layers, creating a strong and consistent seal. As a result, heat seal filter paper is currently the most widely used solution in automated tea bag production, especially on high-speed, continuous packaging lines.

Key Advantages

  • Good permeability and fast infusion performance
  • High wet strength and durability for multiple brews
  • Excellent mechanical properties, including strong MD and CD tensile strength and tear resistance
  • Stable and consistent sealing quality
  • Suitable for medium- to high-speed tea bag machines

Typical Applications

  • Tea bag types: Single-chamber and double-chamber tea bags, square or rectangular tea bags
  • Processing equipment: Heat seal tea bag machines, traditional vertical tea bag machines
  • Filling materials: Powdered or fine-cut tea and herbal ingredients
  • Common specifications: 16.5 gsm, width around 140 mm

Heat seal filter paper is ideal for large-scale production, where efficiency, consistency, and production stability are key priorities.

How to Choose the Right Tea Bag Filter Paper

The selection of tea bag filter paper should always be based on production equipment first, followed by environmental requirements and desired production speed and stability.

  • If your production line relies on traditional or non-heat seal tea bag machines, non-heat seal filter paper is the appropriate choice.
  • If you operate automated or high-speed packaging lines and require strong, consistent sealing, heat seal filter paper offers higher efficiency and stable quality.

For brands with strong sustainability goals, it is important to evaluate fiber composition and consider options with reduced or bio-based sealing fibers, such as PLA.

By matching the right filter paper to your machine technology and brand positioning, you can achieve optimal brewing performance, reliable production, and a better consumer experience.