Reactor process for coating preserved eggs

### Coating Methods for Preserved Eggs

#### **1. Collodion-Coated Preserved Eggs**

**Ingredients**:

- Ether: 70%

- Ethanol: 15%

- Nitrocellulose: 10%

- Rosin: 2%

- Castor Oil: 3%

**Preparation Steps**:

1. Mix the ingredients in the specified proportions.

2. Dissolve ether and ethanol in a millstone jar, then add nitrocellulose, rosin, and castor oil. Shake until fully dissolved.

- If nitrocellulose is dried, add 5% more ethanol (water content <5%).

- Ensure the container is sealed and fire-proof.

3. Pour the collodion solution into a container, cover with a glass sheet, and adjust consistency:

- Add ether if too thick.

- Add nitrocellulose if too thin.

4. Rinse preserved eggs with cold water, dry, and coat one end with collodion. Let dry for 10 minutes, then coat the other end. Ensure full coverage and allow the coating to dry completely before packaging.

**Quality Standards**:

- Coated eggs maintain quality for six months without mud or bran coating.

- Peel and slice for consumption.

**Challenges**:

- Manual coating is labor-intensive.

- Mature eggs must be coated promptly to prevent yolk issues.

- Raw materials are costly, and prolonged storage may cause egg white shrinkage.

#### **2. White Oil Paint for Preserved Eggs**

**Formula (32#)**:

- Liquid Paraffin: 29.71%

- Span: 2.60%

- Triethanolamine: 1.04%

- Tween: 3.90%

- Pepega: 0.67%

- Tap Water: 60%

- Stearic Acid: 2.08%

**Formula (33#)**:

- Liquid Paraffin: 39.71%

- Span: 4.6%

- Pepega: 2.57%

- Stearic Acid: 2.08%

- Triethanolamine: 1.04%

- Tap Water: 50%

**Preparation Steps**:

1. Mix liquid paraffin, span, Tween, peregal, and stearic acid in a double-layer reactor. Heat to 92–93°C (max 95°C) while stirring.

2. Heat water and triethanolamine separately to 94–95°C, then add to the reactor.

3. Stir evenly at 60 rpm until the temperature drops to room temperature, forming a stable white emulsion.

4. Cool further using cold water in the reactor interlayer if needed.

**Paint Properties**:

- Milky white, odorless, stable emulsion.

- Total concentration: 40% (#32) or 50% (#33).

- pH: 7.5–8.

**Usage**:

- Dilute with water to desired concentration.

- Dip mature preserved eggs, rinse off excess, and allow to dry before storage.

#### **3. Wax Emulsion (26#) Coating**

**Formula**:

- White Paraffin: 26.2%

- Oleic Acid: 9.75%

- Ammonia (25–28% NH3): 4.87%

- Water: 59.18%

**Preparation Steps**:

1. Dissolve white paraffin and oleic acid in a reactor at 95–100°C with stirring.

2. Boil water, add ammonia, and mix with the wax-oil solution above 95°C.

3. Stir rapidly for 5–10 minutes, then cool the mixture using cold water in the reactor jacket.

This method provides a stable, uniform coating for preserved eggs, ensuring quality and shelf life.