Since ordinary paper is combustible, a significant number of fires in daily life are caused by paper and packaging materials. To reduce fire hazards, many countries have introduced various fire safety regulations, and the flame-retardant requirements for paper and cardboard have become increasingly stringent. In this context, TCEP flame retardants have become particularly important. Let’s take a closer look at the application and development of TCEP flame retardants in the paper industry!

Flame-retardant paper mainly falls into two categories: one is paper produced primarily from inorganic fibers such as asbestos, mineral wool, and glass fiber; the other is paper made from plant fiber pulp with various flame retardants added, which achieves flame-retardant effects through impregnation or coating. Paper made from inorganic fibers has excellent flame-retardant performance, but fibers like asbestos are harmful to the health of producers and have poor papermaking and forming properties. With increasing attention to environmental protection, the application of inorganic-fiber paper is limited, while plant-fiber paper with TCEP flame retardants has developed rapidly.

I. Flame-Retardant Mechanism of TCEP

Flame-retardant treatment of paper and paper products involves hindering the thermal decomposition of fibers, suppressing the generation of flammable gases, or achieving flame retardancy through insulation and dilution of combustible gases by air or non-flammable gases.

The main flame-retardant mechanisms of flame retardants include:

• Heat absorption effect
• Dilution effect
• Inhibition effect
• Barrier (isolation) effect

II. Production Methods of Flame-Retardant Paper

There are several methods and technologies to impart flame retardancy to paper, regardless of whether the approach is based on coating theory, non-combustible gas theory, heat absorption theory, or chemical reaction theory. Common methods include:

1. Using flame-retardant or non-combustible fibers as raw materials
2. Adding flame-retardant additives to the pulp
3. Impregnation method
4. Coating method

III. Selection of TCEP Flame Retardants

Although there are thousands of flame retardants on the market, only a few are suitable for flame-retardant paper. In general, the selection of TCEP flame retardants should meet the following requirements:

• The addition amount is less than 10% of the total weight of the paper product
• Low toxicity, colorless and odorless
• Non-halogen-releasing and moisture-resistant
• Oxygen index greater than 27%

IV. Development Directions for TCEP Flame Retardants

With the increasing use of specialty and flame-retardant papers, the demand for papermaking flame retardants is also rising. According to the performance requirements of flame-retardant paper, the development directions mainly include:

1. Use of composite flame retardants
   • Composite flame retardants combine the characteristics of multiple flame retardants. Research focuses on maximizing the advantages of each component in the composite.
2. Development of smoke-suppressing agents
   • Since flame retardancy and smoke suppression are closely related, smoke-suppressing agents are expected to be among the fastest-growing types of flame retardants in the near future.
3. Development of low-cost flame retardants
   • Producing flame-retardant paper requires a large quantity of flame retardants, which increases production costs. Therefore, finding inexpensive flame retardants is necessary.
4. Research on TCEP flame retardants
   • From the perspectives of safety and environmental protection, halogen-free flame retardants have become a global focus in the industry. It is essential to develop and use environmentally friendly “green” products throughout the production–transportation–use–recycling lifecycle. Thus, the goal of halogen-free flame retardants is a key direction for future research.