Application of DMF in leather processing
N, N-dimethylformamide (DMF) is a colorless transparent, highly polar organic solvent with excellent solubility and chemical stability, which is widely used in the leather processing industry. Its application is mainly reflected in the manufacture of artificial leather, synthetic leather and some special processing links.
First, the role of DMF in leather processing
Solvent action
DMF is an excellent solvent, can dissolve a variety of polymer materials, such as polyurethane (PU), polyvinyl chloride (PVC) and so on. In the production of artificial and synthetic leather, DMF is often used to prepare a coating solution or dipping solution, so that the polymer material can be evenly coated on the substrate.
Control workability
DMF has appropriate volatility and solubility parameters, which can adjust the dissolution rate of the polymer and the curing time of the coating during the production process, thus affecting the surface smoothness, gloss and feel of the artificial leather.
Permeability and uniformity
The polarity and low viscosity characteristics of DMF enable it to penetrate into the micropores of the substrate in the impregnation process, improve the bonding strength of the coating and the substrate, and ensure the uniformity of the product.
Second, the application of DMF in different leather processes
Production of artificial and synthetic leather
DMF is indispensable in the production of polyurethane synthetic leather. The solvent action allows the polyurethane to disperse uniformly and form a dense film during the coating process. In addition, the DMF solution is separated by contact with water in the wet production process, which gives the synthetic leather a microporous structure, improving air permeability and comfort.
Preparation of auxiliary agent
In the process of leather dyeing, finishing and finishing, DMF as an additive solvent can promote the uniform dispersion of various additives, such as pigments, additives, thixotropic agents, etc., to improve the adhesion and performance stability of the coating.
Plasticizer action
DMF can also be used as a solvent for plasticizers during processing to improve the flexibility and plasticity of polymers, thereby enhancing the elasticity and wear resistance of leather products.
Third, the advantages of DMF in leather processing
Excellent solubility
DMF can dissolve a variety of polar and non-polar substances, and has a wide range of applications. Its solubility parameter gives it an irreplaceable position in leather processing.
High processing stability
The chemical properties of DMF are stable, and it is not easy to react or decompose, which can ensure the safety of the production process and the stability of product quality.
Product performance improvement
Leather products processed with DMF have better comprehensive properties in feel, wear resistance, air permeability and other aspects, which meet the needs of the high-end market.
Environmental and health impacts of DMF
Although DMF plays an important role in leather processing, its potential environmental and health risks also require special attention:
Environmental pollution problem
DMF is volatile, and its exhaust gas will pollute the environment. In addition, improper treatment of DMF wastewater from the production process can also lead to soil and water pollution.
Occupational health risk
DMF is a certain toxic chemical, long-term exposure may cause damage to the human liver and nervous system. Therefore, the exposure concentration of DMF should be strictly controlled during production and use to ensure the occupational safety of workers.
- Substitution and development trend of DMF
With the increase of environmental protection and sustainable development requirements, the industry is gradually exploring DMF alternatives and improved processes, such as:
Alternative solvent
Develop and use more environmentally friendly, less toxic solvents to replace DMF, such as water-based solvents or other green solvents.
Improve the process
The use of DMF is reduced or completely avoided through innovative processes, such as solvent-free coating technology or dry production processes.
Waste management
Promote advanced waste gas and wastewater treatment technologies to reduce the environmental impact of DMF emissions while enabling solvent recycling.
Vi. Summary
The application of DMF in leather processing is of great significance, and its core position in the production of synthetic leather and artificial leather is irreplaceable. However, with the increasingly strict environmental protection policies and the development of green manufacturing technology, the industry needs to accelerate the pace of research and development of alternatives and process upgrades in order to achieve a balance between economic benefits and environmental protection.