Environmentally friendly, High efficiency will be the main trend of future packaging industries. In terms of composite adhesives, solvent-free adhesives will replace traditional solvent-based adhesives, which has become a consensus of the packaging industry. The solventless adhesive is more widely used in the flexible packaging industry.
What Are Solvent-free Adhesives
Solvent-free adhesives are a viscous substrate, which can connect together by means of their viscosity. They are viscous liquid at normal temperatures, such as an epoxy resin which Is one of the most important auxiliary materials and has extremely wide applications in the packaging industry. Solvent-free adhesive mostly is adopted for the solventless laminating machine, also can be used on existing solvent drying compound equipment which is suitable for many color printing plants to improve the high residual solvent, reducing production costs, no need to input new equipment.
Composite adhesive for flexible packaging is constantly undergoing technical improvement and innovation. The new type of solventless adhesive performance can completely meet the dry composite requirements among the most flexible packaging materials and can be used on a solvent dry compound machine. It can meet the requirements of drug & food packaging.
Features And Advantages Of Solvent-free Adhesives
Solvent-free adhesive is an ideal replacement for solvent adhesive.
1. Effectively reducing the residual solvent
Since it is a solvent-free adhesive, the adhesive itself does not bring the second solvent contamination, the printed film can further decrease the residual solvent when passing through the drying oven, adopting a solventless adhesive is quite effective to control residual solvent.
2.High initial adhesion
The high initial shear strength of solventless adhesives makes it possible for real-time slitting and delivery without curing. This performance is quite effective for shortening delivery time.
3.Relatively low cost
Usually, the required coating amount is 1.6g to 2.4 g per square meter, not any solvent used, so its composite cost per square meter will significantly lower than solvent-based composite.
4.Improving the working environment, reducing pollution, reducing work strength, and avoiding the risk of the fires
Since the solventless adhesive does not need to be diluted, it can be directly used for production, reducing the labor of the operating worker and also avoiding the concentration of solvent in air, which is advantageous for workers. Of course, without the existence of solvent, it also can avoid the hidden risks of fire.
5.Effectively reducing the occurrence of quality accidents
With a solvent-free composite product, it can directly see the quality of the product. Only the appearance and composite intensity of the product should be carefully checked when going off the production line. After a period of time, as the increase of adhesive composite strength among the adhesive molecules, the appearance will become better. For the composite of the aluminized product, the solventless adhesive can effectively prevent aluminizing transfer.
Development Trend Of Solvent-free Adhesives
In the flexible packaging color printing composite industry, the solvent-free adhesive will be the direction of future development, affecting the development trend of the flexible packaging industry. As the enhanced awareness for environmental protection and the importance for the safety of food packaging, how to reduce costs and improve competitive advantage, producing the commodities conforming to the hygienic requirements for food packaging, is the problem of most food manufacturer concerning. The promotion of solventless adhesive in the market is in line with this trend. In Europe, the solvent-free adhesive has a share of 40% in the flexible packaging composite adhesive market.
High-temperature resistant solvent-free adhesive
The universal solvent adhesive is suitable for general flexible packaging composite applications, not suitable for cooking with a temperature above 100 ° C . Usually the solventless adhesive can be classified into 3 grades. Low-grade type is generally used for dry content packaging with lightweight and simple structures. Medium grade type is typically applied to multi-layer composite products which can withstand load or having a liquid content and is resistant to cooking and steaming. High-grade types could have adhesive applications with certain tolerances. Currently, the solvent-free adhesive is rarely used for high-temperature cooking, but the solventless composite material completely replacing the dry composite material and developing high temperature resistant solventless adhesive will be inevitable trends.
Two-component coating solvent-free adhesive
Two-component coating solvent-free adhesive is developed in 2016. The so-called two-component coating, that is, a primary agent, a curing agent, is a separate coating, when the two-component adhesives are mixed, the curing reaction is rapidly generated and the corresponding mechanical strength is achieved. The entire composite process does not require an ultraviolet lamp. It is a new type of flexible packaging composite technology. It has been widely concerned in the flexible packaging industry, mainly because it has the advantages of separate coating, quickly curing at normal temperature, easy to operate. It is clear that the two-component coating type will become the trend of solvent-free adhesive in the future.
Solvent-free adhesives are the trend and direction of flexible packaging composite adhesives, with the advantages of high efficiency, environment-friendly, lost-cost, no residual solvent, high safety, and high initial adhesion.
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Sinstar Packaging Machinery Co., Ltd is a professional supplier who’s engaged in the research, development, production, sales and service of non solvent laminating machines with annual production capacity of 200 sets.