The Utilization Value of Shellac
Research indicates that in China, the use of shellac, also historically known as "purple rivet," has been documented since before the Tang Dynasty. Notably, in the "Newly Revised Materia Medica" (commonly referred to as the "Tang Materia Medica") by Su Jing in the year 659 AD, it is recorded that in ancient China, shellac was primarily used for bonding gems in traditional Chinese medicine and for leather production. As a purely natural chemical raw material, shellac possesses excellent properties such as adhesion, moisture resistance, insulation, smooth coating, corrosion resistance, acid resistance, chemical stability, and non-toxicity and non-irritation to humans. These attributes confer significant economic value, leading to its widespread application in industries such as chemicals, electronics, military, pharmaceuticals, and food. In the daily chemical industry, shellac is used for polishing, bonding, and moisture-proofing of furniture and floors. In the realm of medicine, as early as the Tang Dynasty, Li Xun's "Materia Medica of Sea Drugs" mentioned shellac for its efficacy in treating damp itch and sores, recommending its inclusion in ointments.
In the "Compendium of Materia Medica," shellac is documented as primarily treating pathogenic qi of the five viscera, wounds, leukorrhea, and capable of breaking up blood stasis. It is indicated for treating bleeding gums, postpartum dizziness, and menstrual irregularities among other conditions. Beyond its use in traditional Chinese medicine, shellac also finds applications in protecting pills from moisture and preservation. In the military industry, shellac is utilized for bonding and moisture-proofing of bullets and shells. In the electronics industry, it serves for bonding, moisture-proofing, and insulation of integrated circuits. In the printing industry, shellac is used in inks to produce high-quality products. In the food industry, it is applied as a coating for candies.
Beyond the utilization of natural resin, the pigments extracted from shellac are extensively used in the food and cosmetics industries. Shellac wax, another derivative, finds widespread application in the daily chemical and cosmetics industries. The processed product of shellac, dewaxed and bleached shellac, is widely used as a preservative for fruits and vegetables. In agriculture, shellac can be used as a slow-release coating for fertilizers. Substances extracted from shellac, such as shellolic acid, are utilized in the fragrance industry, among others.
In the course of research and utilization of shellac, there was a period when its applications across various fields were rapidly supplanted by products of the burgeoning chemical industry. However, with technological advancements and a deepening understanding of nature, the recognition of the detrimental effects of chemical products on the environment and human health became apparent. Consequently, there has been a gradual increase in environmental consciousness among people, alongside a growing demand for natural products with higher standards. Shellac and its processed products, primarily composed of natural resin secreted by insects, have no adverse effects on human health and the environment, aligning with the modern pursuit for purely natural products. The significant resource value of shellac has been re-acknowledged and redeveloped by humanity, reflecting a shift back towards natural, sustainable resources in response to environmental and health considerations.
The shellac production system comprises three main components: the shellac insect, host plants, and the ecological environment, forming a relatively stable artificial ecological-economic forestry system. Shellac production necessitates the cultivation of a large number of host plants. With over 300 species of host plants for the shellac insect, many of these plants are characterized by their drought resistance, tolerance to poor soils, rapid growth, and strong sprouting ability. These traits not only facilitate the reforestation of barren hills and soil and water conservation but also yield considerable ecological benefits. A substantial number of host plants can also absorb CO2 from the air, effectively improving environmental quality. Additionally, the branches generated from shellac production can address the energy needs of rural communities.
Shellac has evolved into a unique insect-based industry. As an important industrial raw material, it generates significant economic value and has become a crucial source of income for farmers in South Asia and Southeast Asia. This industry not only supports the livelihoods of local communities but also contributes to environmental sustainability and the fight against climate change.