What type of materials are required for fabrication of dairy equipment? Make a product flow line diagram for a dairy plant receiving 10,000 litre milk and manufacturing butter

/ 4 minutes of reading

Materials Required for Fabrication of Dairy Equipment

Dairy equipment must meet the highest standards of hygiene, corrosion resistance, ease of cleaning, and durability, as they are used in the handling and processing of perishable products like milk. The selection of suitable materials is critical for ensuring food safety, equipment life, and maintenance.

Below are the commonly used materials for fabricating dairy equipment:

1. Stainless Steel (SS)

This is the most preferred material in the dairy industry due to its superior hygienic properties.

Common Grades Used:

  • SS 304: Most widely used; excellent corrosion resistance and weldability.
  • SS 316: Used in areas with exposure to saline water or acidic conditions; contains molybdenum for extra corrosion resistance.
  • SS 304L / SS 316L: Low carbon versions; used to prevent sensitization during welding.

Advantages:

  • Non-reactive to milk and cleaning chemicals.
  • Easy to clean and sanitize.
  • Resistant to corrosion, pitting, and rust.
  • Long-lasting and aesthetically clean surface.

2. Mild Steel (MS)

Used for non-product contact parts such as frames, base stands, and structural support.

Note: If used, MS should be painted or powder coated to avoid rust.

3. Food-Grade Plastic and Rubber

Used for:

  • Gaskets, seals, and pipes
  • Valves and insulation materials
  • Components of milking machines

Materials:

  • PTFE (Teflon)
  • Silicone rubber
  • HDPE (High-density polyethylene)

These materials must be food-grade certified and resistant to heat and chemicals.

4. Glass and Borosilicate Glass

Used in:

  • Sight glasses, instrumentation
  • Laboratory equipment within dairy plants

They must be heat-resistant and easy to sterilize.

5. Aluminum

Rarely used in modern dairies but may still be found in some small-scale or old dairy units.

  • Must be anodized if used in contact with milk.
  • Not preferred due to corrosion and reaction with acidic products.

6. Copper and Brass

Previously used but now almost obsolete due to:

  • Reactivity with milk
  • Toxicity of heavy metal residues
  • High maintenance

Conclusion on Materials:

  • For product-contact surfaces, SS 304 or SS 316 is ideal.
  • For non-product-contact structures, mild steel or aluminum (coated) may be used.
  • Gaskets and seals should be made of food-grade plastic or rubber.

Product Flow Line Diagram for a Dairy Plant Manufacturing Butter from 10,000 Litres Milk

Here is a step-by-step process flow chart (text format, suitable for MS Word) for a dairy plant that receives 10,000 litres of milk per day and produces butter:

Milk to Butter – Process Flow Line

Step 1: Milk Reception
→ Milk is received at the dairy plant (10,000 litres)
→ Weighing & sampling for quality (fat, SNF, temperature)

Step 2: Preliminary Filtration
→ Removal of visible impurities using filters or clarifiers

Step 3: Chilling (if needed)
→ Immediate cooling to 4°C to 6°C to prevent bacterial growth
→ Stored in chilled raw milk tanks

Step 4: Cream Separation (Cream Separator)
→ Milk is passed through a cream separator
→ Cream collected for butter production
→ Skimmed milk sent for by-product use (e.g., curd, powder, or disposal)

Step 5: Cream Standardization
→ Cream is standardized to 35%–40% fat for butter manufacturing

Step 6: Pasteurization of Cream
→ Heating at 80°C for 15 seconds (high temp short time)
→ Cooling to 8°C to 10°C

Step 7: Cream Ageing
→ Cream is aged for 8–16 hours at 5°C to 8°C in ageing vats
→ This helps in crystal formation and improves churning efficiency

Step 8: Churning
→ Cream is churned in butter churners or continuous butter makers
→ Fat particles coalesce to form butter granules

Step 9: Butter Washing & Working
→ Butter is washed to remove buttermilk
→ Kneading/Working to get uniform texture and salt mixing (if required)

Step 10: Butter Packaging
→ Packed in butter wrap, cartons, or plastic containers
→ Weighed and labeled for retail/wholesale

Step 11: Cold Storage
→ Stored at below 4°C till dispatch

Text Flow Diagram Format for MS Word:

Milk Reception (10,000 litres)
          ↓
Preliminary Filtration
          ↓
Chilling (4°C to 6°C)
          ↓
Cream Separation
          ↓
Cream Standardization
          ↓
Cream Pasteurization (80°C for 15 sec)
          ↓
Cream Ageing (5°C to 8°C)
          ↓
Churning
          ↓
Butter Washing and Working
          ↓
Butter Packaging
          ↓
Cold Storage and Dispatch

Conclusion

For a dairy plant processing 10,000 litres of milk per day, stainless steel (SS 304/316) is the most suitable material for all product-contact equipment due to its hygienic and corrosion-resistant nature. A structured flow line for butter production helps ensure efficient operations, hygiene, quality control, and product consistency.

Scroll to Top