Exploring the benefits of natural ingredients in bio-based hot melt packaging adhesives
The global shift towards sustainability has prompted researchers and manufacturers to explore bio-based alternatives in various industries. In the realm of adhesive technology, bio-based hot melt adhesives have gained significant attention for their potential to provide environmentally friendly and sustainable bonding solutions. This article delves into the research from 2023 conducted on bio-based adhesives and analyzes their properties and applications, with a focus on tannic acid, chitosan, and shellac as natural ingredients.
Bio-based hot melt adhesives have gained significant attention for their potential to provide environmentally friendly and sustainable bonding solutions.
Key ingredients for bio-based adhesives
Packaging adhesives can greatly benefit from bio-based ingredients such as:
Tannic Acid, derived from plants, is a key natural ingredient that offers several benefits in bio-based hot melt adhesives. Firstly, tannic acid provides excellent adhesive properties, enhancing the bonding strength and durability of the adhesive. Its polyphenolic structure enables it to form strong cross-links with substrates, resulting in improved adhesion. Additionally, tannic acid exhibits natural antimicrobial properties, preventing the growth of bacteria and fungi in adhesive applications. This feature is particularly advantageous in industries where hygiene and cleanliness are crucial, such as food packaging and medical devices.
Chitosan, derived from the deacetylation of chitin, is another natural ingredient that brings unique advantages to hot melt adhesives. One notable benefit of chitosan is its biocompatibility, making it an excellent choice for applications involving direct contact with living organisms or sensitive materials. Hot melt adhesives incorporating chitosan exhibit improved biodegradability, making them environmentally friendly and reducing the environmental impact of packaging waste. Moreover, chitosan possesses inherent antimicrobial properties, offering an additional layer of protection against microbial growth in adhesive applications.
Shellac, a natural polymer obtained from resinous secretions, offers distinctive benefits when used as a natural ingredient in hot melt adhesives. One significant advantage is its excellent film-forming properties, which contribute to the creation of a robust and uniform adhesive layer. Shellac-based hot melts provide exceptional moisture resistance, making them ideal for applications that require resistance to humidity or water exposure. Furthermore, shellac exhibits outstanding barrier properties, protecting the bonded materials from external factors such as oxygen and moisture.
The benefits of natural ingredients in bio-based adhesives
The bio-based adhesives produced and analyzed in the research mentioned are primarily designed for dry substrates. Within this research, tannic acid has emerged as a promising additive among the prepared adhesives. The inclusion of tannic acid has been shown to enhance the viscosity and adhesive strength, resulting in an impressive 15 to 30% improvement over commercial adhesives. Moreover, the tensile strength of adhesives containing tannic acid and chitosan demonstrated a remarkable 30% enhancement compared to commercial adhesives. Combinations of shellac and chitosan also exhibited a 23% increase in tensile strength. Notably, for paper made from Japanese Knotweed and Canadian Goldenrod, pure shellac emerged as the most durable adhesive. The microscopic analysis confirmed that the adhesives effectively filled the voids in the paper structure, highlighting their capability to penetrate and bond with porous substrates. These findings demonstrate the potential of bio-based adhesives to enhance adhesion between cellulosic materials and other polymers while exhibiting favourable thermal stability.
To wrap up
The pursuit of sustainable and eco-friendly packaging adhesives has paved the way for the development of bio-based adhesives. Natural ingredients, including tannic acid, chitosan, and shellac, have demonstrated remarkable benefits in enhancing adhesive properties and performance. The addition of tannic acid has been shown to improve adhesive strength and viscosity, while combinations of shellac and chitosan have exhibited superior tensile strength. Microscopic analysis has confirmed the effective penetration and filling of voids in paper substrates, promoting strong adhesion. With their favourable thermal stability, these bio-based adhesives offer promising potential for various packaging applications.
