The "Solvent-Free" Principle of Solvent-Free Laminating Machines: Why Zero VOC Emissions Are Achievable?

I. First, Understand: What is VOC? Why Do Solvent-Based Laminating Machines Generate VOC?

Definition of VOC: VOC (Volatile Organic Compounds) refers to organic chemical substances that are easily volatile at room temperature, including benzene, toluene, ethyl ester, etc. These substances not only have a pungent odor but some are also toxic. Long-term exposure can harm human health and are also important contributors to ozone pollution and smog.

'VOC Sources' of Solvent-Based Laminating Machines:
Traditional solvent-based laminating machines require the use of solvent-based adhesives (such as polyurethane adhesives) during the lamination process, which contain a large amount of organic solvents (accounting for 50%-70% of the total adhesive volume). The role of these solvents is to 'dilute the adhesive' so that it can be evenly coated on the film surface; however, after lamination, the solvents must be evaporated through high-temperature drying (60-90°C) to achieve film adhesion.
During this process, the evaporated solvents are the main source of VOC, and 100% recovery is impossible (recovery rate is usually only 60%-80%). The unrecovered portion is directly emitted into the air, causing pollution.

II. The Core of 'Solvent-Free' in Solvent-Free Laminating Machines: Full-Link Innovation from Adhesives to Processes

The key to achieving 'zero VOC emissions' in solvent-free laminating machines lies in completely abandoning the use of 'solvents' and optimizing the entire chain from adhesive formulation to lamination processes:

1. Core: '100% Solid Content' Characteristic of Solvent-Free Adhesives

The adhesive used in solvent-free lamination is solvent-free polyurethane adhesive, with a solid content of 100% (without any organic solvents).

· This type of adhesive consists of 'isocyanate component (Part A)' and 'polyol component (Part B)'. It is a viscous liquid at room temperature and can be evenly coated through a dedicated coating system without solvent dilution (viscosity is controlled by fine temperature adjustment rather than solvents).

· After coating, Part A and Part B undergo a chemical reaction (cross-linking and curing) between the films, achieving adhesion through chemical bond combination between molecules. The entire process does not require high-temperature drying and can be cured naturally (curing time is usually 24-48 hours, which can be accelerated by heating).

Since there are no solvents in the adhesive, there is no link of 'solvent evaporation,' cutting off the source of VOC from the root.

2. Supplementary: 'Low-Temperature, No-Drying' Process of Solvent-Free Laminating Machines

· Compared with solvent-based laminating machines, solvent-free laminating machines do not have a drying channel (which is also a significant difference in equipment structure). After coating and lamination, the film is directly wound up without high-temperature heating to evaporate solvents.

· The entire process is carried out at room temperature or medium-low temperature (usually not exceeding 50°C), which not only avoids solvent evaporation but also saves energy required for drying (energy consumption is only 1/5-1/3 of that of solvent-based laminating machines).

III. Why Are Solvent-Free Laminating Machines Considered to Achieve 'Genuine Zero VOC Emissions'?

Some may ask: Do solvent-free adhesives themselves contain trace volatile substances?
In fact, solvent-free adhesives may retain extremely small amounts of low-boiling monomers (such as isocyanates) during production, but the content is extremely low (usually ≤0.1%). Moreover, after lamination and curing, they will fully participate in chemical reactions to form stable polymer structures and no longer volatilize.
Industry test data shows that the total residual volatile substances (including VOC) in solvent-free laminated products are usually ≤1mg/m², far lower than 50-100mg/m² in solvent-based laminated products, fully meeting strict standards for food and pharmaceutical packaging (such as EU EU 10/2011 and China's GB 4806.10).

Therefore, in terms of actual emissions and final product safety, solvent-free laminating machines can be regarded as a 'zero VOC emission' technology.

IV. Practical Value of Zero VOC Emissions for Enterprises

· Environmental Compliance: Easily meet national environmental policies (such as China's 'Standards for the Control of Volatile Organic Compounds Unorganized Emissions' and EU REACH regulations), avoiding the risk of fines or production suspension.

· Cost Reduction: Eliminate costs for solvent procurement, drying energy consumption, and investment in VOC treatment equipment (such as RTO incinerators), with comprehensive costs reducible by 20%-30%.

· Workshop Health: Eliminate the impact of solvent odors on workers' health, improve the production environment, and reduce the risk of occupational diseases.

In summary, the 'zero VOC emissions' of solvent-free laminating machines is not a marketing gimmick but a technological breakthrough based on 'solvent-free adhesive formulations' and 'no-drying processes.' It is also a core choice for flexible packaging enterprises to achieve green production.