What should be considered when choosing environmentally friendly adhesives?

For packaging, the adhesive must first effectively adapt to the current situation. For example, the adhesive used on sticky notes (low viscosity and relocatable) is not suitable for self sealing adhesives on mail.

The function of environmentally friendly adhesives depends on their formula and the degree of adhesion they have with the specific substrate at hand (as well as the weight of the substrate). For example, some adhesives work well on stainless steel but not on paper.

It must also be consistent with its application method. For example, we cut; RSC  The boxes are then glued together using a hot melt machine. We need adhesive to bond the corrugated paper together as soon as possible, in order to achieve the desired effect; 5-10  The hot melt adhesive that solidifies within seconds is very ideal. Using dry adhesive is meaningless for us, as it usually takes several minutes or even hours to dry (we have a warehouse filled with boxes waiting to dry before we can fold or send them out)!

Sustainability and Health

In addition to matching the functionality and application requirements of the situation, there is also a necessary consideration of sustainability.

Release of volatile organic compounds (VOCs): VOCs; （VOC）  Discharging in gas form from certain solids or liquids. Volatile organic compounds include various chemical substances, some of which have adverse effects on health. When combined with nitrogen oxides, they produce smoke. For example, dry adhesives may be volatile and release when the carrier dries; VOC。 In contrast, hot melt adhesives are non-volatile.

How adhesives are obtained: As mentioned above, adhesives can be made from renewable resources, natural but non renewable resources, or can be synthetic or artificial (usually from polymers).

Ecologically, adhesives derived from renewable materials may have benefits. However, in certain situations, they are more problematic than their counterparts in renewable energy. For example, gelatin and casein are two examples of renewable adhesives derived from animal protein, and are generally considered more unsustainable than synthetic counterparts such as acrylic lotion adhesives. However, in other cases, such as water activated adhesives typically derived from plant starch, renewable resources are environmentally friendly and efficient.

Similar to the complexity of bioplastics, it must be noted that “natural” adhesives are not necessarily biodegradable, and synthetic adhesives are not necessarily non biodegradable. In addition, each formula (and countless adhesive formulas!) is unique. More importantly, the scrap situation related to adhesives is not necessarily driven by the material of the adhesive. This brings us to the following content.

End of service life: The service life of environmentally friendly adhesives is similar to that of ink.

In most cases, the individual and isolated end-of-life characteristics of adhesives are not as important as the consistency and degree of support between the adhesive’s end-of-life path and the ideal end-of-life of the substrate material.

People often demand biodegradable adhesives, but they are likely to demand packaging whose components (main materials, adhesives, ink, etc.) are biodegradable. Since adhesives are a small part of the entire item, their presence usually does not change the way you handle the item.

For example, suppose you have a standard corrugated cardboard box with a shipping label. In this case, you can either degrade the entire packaging (if your local degradation machine accepts corrugated paper, which many people do now) or recycle it.

This does not mean that a large amount of adhesive itself is necessarily compostable or recyclable, or that even when technically “accepted” by recyclers or degradation machines, the adhesive will not cause problems or pollution.

A major degradability certification agency tests materials by ensuring that they biodegrade within a set time frame. Here, biodegradation means that the material has no physical residues. Then, they confirmed that tomato plants could be grown using the output of biodegradable materials. This method is certainly thorough, but due to the small percentage of these substances, it can eliminate pollutants such as ink and adhesives. Even if the certification process allows for the presence of these pollutants, typical adhesive components remain in degradation.

During the recycling process, paper is pulping and then screened, ideally removing the adhesive during this process. However, historically, pressure-sensitive adhesives (such as stamps on envelopes) have been torn into small particles during the pulping process. Because they are finely cut and then pass through a sieve into pulp, ready to be remade into paper. This can lead to the accumulation of “adhesive” on the process equipment and result in defects in the final paper product.

This concern led to the development of reusable adhesives for paper to paper bonding; （RCA）。

RecyclableEnvironmentally friendly adhesivesresist the force of making them into pulp and remain large enough to be removed by the sieve.

Most packaging, labels, and stickers are made with adhesives that react well in the recycling environment, making them compatible with recycling.