Shellac Extracting Process: The Only Guide You’ll Need!

Shellac Extracting Process: A Comprehensive Guide to Harvesting and Refining

This guide details the entire shellac extracting process, from identifying suitable trees to refining the final product. We aim to provide a clear understanding of each stage involved in transforming the raw material – lac – into usable shellac.

Understanding Lac and Shellac

Before diving into the shellac extracting process, it’s crucial to understand what these materials are and where they come from.

What is Lac?

Lac is a resinous secretion produced by lac insects (primarily Kerria lacca). These tiny insects infest certain trees, feeding on their sap and secreting lac as a protective shell. Over time, these secretions accumulate on the branches, forming a crusty coating. This raw, unprocessed material is known as sticklac.

What is Shellac?

Shellac is a refined form of lac. The shellac extracting process removes impurities like insect bodies, tree bark, and other debris, leaving behind a purer, more versatile resin suitable for various applications, including wood finishing, food glazing, and electrical insulation.

Locating and Identifying Suitable Trees

The first step in the shellac extracting process is identifying trees that are heavily infested with lac insects.

Preferred Host Trees

Lac insects thrive on specific host trees, and knowing which trees to look for is essential. Common host trees include:

• Kusum (Schleichera oleosa): Highly prized for producing high-quality lac.
• Palas (Butea monosperma): Another common and valuable host tree.
• Ber (Ziziphus mauritiana): A widely distributed host tree.

Identifying Lac Infestation

Identifying lac infestation involves visually inspecting the branches of these trees. Look for:

• Thick, encrusted coatings: The branches will be covered in a resinous, reddish-brown crust.
• Small, visible insect cells: Close inspection may reveal tiny cells containing the lac insects.
• A sticky or gummy texture: The lac secretion can feel sticky to the touch.

Harvesting Sticklac

Once suitable trees are identified, the next step is harvesting the sticklac.

Timing of Harvest

The timing of the harvest significantly impacts the quality and quantity of lac.

• Optimal Harvest Times: Harvesting usually occurs twice a year, coinciding with the maturity of the lac insects. Local knowledge is crucial for determining the precise timing, but generally, harvests take place after the rainy season and again during the spring.
• Signs of Maturity: The lac is ready for harvest when the color darkens, and the resin becomes harder. Also, small yellow spots often appear on the surface of the lac crust indicating that the larvae are ready to leave the cells.

Harvesting Techniques

The harvesting process involves carefully cutting the infested branches from the tree.

1. Pruning: Use sharp pruning shears or a saw to cut the branches. Be careful not to damage the tree unnecessarily.
2. Collection: Gather the harvested branches and transport them to a processing area.
3. Stripping: Remove the sticklac from the branches. This can be done by hand or using a scraping tool. Care should be taken to minimise contamination with bark and other debris.

Processing Sticklac: From Raw Material to Seedlac

The next stage in the shellac extracting process is transforming the raw sticklac into seedlac – a partially refined product.

Crushing and Sieving

This process removes larger debris from the sticklac.

1. Crushing: The sticklac is crushed using a mortar and pestle, or a mechanical crusher to break it into smaller pieces.
2. Sieving: The crushed material is then sieved to remove larger pieces of bark, twigs, and dead insects. Different mesh sizes may be used for varying degrees of refinement.

Washing and Grinding

Washing removes water-soluble impurities and helps to further separate the lac resin.

1. Washing: The crushed and sieved lac is washed in water, often using a foot-operated washing tub or a specialized washing machine. Agitation is used to dislodge impurities.
2. Grinding (Optional): Sometimes, the washed lac is ground into a finer powder to improve the efficiency of the subsequent melting process.

Drying the Seedlac

After washing, the seedlac needs to be thoroughly dried.

1. Sun Drying: The washed seedlac is spread out on mats or tarps and left to dry in the sun. This process typically takes several days, depending on the weather.
2. Mechanical Drying (Optional): In some cases, mechanical dryers are used to accelerate the drying process.

Refining Seedlac into Shellac

The final step in the shellac extracting process involves refining the seedlac into marketable shellac.

The Bag Melting Method

This is a traditional method of refining shellac, often used in smaller-scale production.

1. Filling the Bag: Seedlac is placed inside a long, narrow cotton cloth bag.
2. Melting: The bag is held over a source of heat (traditionally charcoal or wood fire), and the seedlac is gradually melted.
3. Squeezing: As the lac melts, it is squeezed out of the bag using a stick or lever.
4. Spreading: The molten shellac is spread onto a smooth surface (often a ceramic tile) to cool and harden into thin sheets.
5. Flaking: Once cooled, the shellac is broken into flakes, which are then packaged for sale.

Modern Extraction Techniques

Modern techniques employ advanced equipment for greater efficiency and quality control.

• Solvent Extraction: Solvents like ethanol are used to dissolve the lac resin, separating it from impurities. The solvent is then evaporated, leaving behind pure shellac. This method often produces a lighter-colored shellac.
• Centrifugal Separation: A mixture of lac and solvent is spun at high speed in a centrifuge, separating the shellac from impurities based on density.
• Automated Melting and Flaking: Large-scale operations often use automated machinery to melt, spread, and flake the shellac, resulting in consistent product quality and reduced labor costs.

Grading and Packaging

After refining, the shellac is graded based on color, purity, and other characteristics. It is then packaged in airtight containers to prevent moisture absorption and degradation. Grades are typically differentiated by color, ranging from lemon (lightest) to orange (darkest).

So, there you have it – your comprehensive guide to the shellac extracting process! Hopefully, you now feel confident understanding the steps involved. Happy crafting, and don’t hesitate to revisit this guide if you need a refresher on the shellac extracting process down the road!