Low Cost Red oxide Primer Formulation Card

Low-Cost Red Oxide Primer — Air-Drying Alkyd, 100 kg Batch

With Machinery Requirements for Small-to-Medium Production

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1. Formulation

Variant A — Ultra-Cheap Barrier Primer

(parts = kg per 100 kg)

• Long-oil soya alkyd (≈55% NV): 34.0
• Mineral turpentine (MTO): 16.2
• Xylene: 3.0
• Red iron oxide (synthetic, ~1 µm): 28.0
• Talc (325 mesh): 8.0
• Barytes (325 mesh): 6.0
• China clay: 3.0
• Organoclay (anti-settling, pre-gel): 0.30
• Wetting/dispersant: 0.30
• Anti-skin (MEKO): 0.20
• Driers:
  • Cobalt 6%: 0.11
  • Zirconium 12%: 0.55
  • Calcium 10%: 0.44
    Total ≈ 100.0

2. Machinery & Equipment List

Process Stage	Machinery	Capacity / Specs	Purpose / Notes
Pre-gel organoclay & solvent charging	High-Speed Disperser (HSD) with variable speed (10–20 HP)	100–200 L tank; SS 304 with cooling jacket optional	For dispersing organoclay in solvent and partial alkyd. Cowles disc blade Ø 200–300 mm.
Pigment grinding	Same HSD or Attritor / Sand Mill	If using attritor/sand mill: 15–25 HP, 50–100 L chamber	Achieve fineness ~25 µm (Hegman 5–6). In low-budget setups, HSD alone can be used.
Let-down & mixing	Slow-speed anchor stirrer or same HSD at low RPM	Anchor with scrapers, 2–5 HP	Incorporates remaining alkyd, solvent, additives without entraining air.
Filtration	Bag filter housing with 120–150 mesh bags	SS 304 or mild steel epoxy-coated	Removes agglomerates/foreign particles.
Weighing	Platform scale (100–300 kg) & bench scale (1–30 kg)	Accuracy ±0.05%	For precise raw material dosing.
Packing	Filling machine (semi-auto)	1–20 L pail/drum; pneumatic or gravity fill	Consistent weight; low spillage.
Compressed air supply	Compressor 3–5 HP	For pneumatic filler / spray testing.
Testing/QC	Ford Cup #4, KU Viscometer, Hegman gauge, Density cup, Gloss meter	QC lab table	Ensures batch meets specs.

3. Processing Steps with Machinery

1. Pre-mix / Organoclay Gel Preparation
   • Charge ~⅓ solvent (MTO + xylene) into HSD tank.
   • Start at low RPM, slowly add organoclay → raise speed to 1500–1800 rpm for 15–20 min until gel forms.
2. Pigment & Extender Dispersion
   • Add ½ alkyd + wetting agent to gel.
   • Add red oxide gradually → follow with talc, barytes, clay.
   • Disperse at 1500–2000 rpm until Hegman 5–6 (~30–45 min for HSD; 15–20 min if using sand mill).
3. Let-down
   • Reduce speed to ~300–400 rpm (or transfer to anchor stirrer).
   • Add remaining alkyd, solvent to adjust viscosity, mix 10–15 min.
4. Additives Last
   • Cool to <30 °C.
   • Add anti-skin → then cobalt, zirconium, calcium driers; stir for 5–10 min.
5. Filtration
   • Pass paint through 120–150 mesh bag filter into clean filling tank.
6. Packing
   • Fill into 1 L, 4 L, or 20 L tins using semi-auto filler; seal and label.

4. Target QC Parameters

Property	Target	Method
Viscosity (KU) @30 °C	80–90	KU viscometer
Fineness	≤25–30 µm	Hegman gauge
Non-volatile %	50–55	1 h @105 °C
Density (kg/L)	1.45–1.55	Pycnometer/density cup
Surface dry	30–60 min	Touch test
Hard dry	8–12 h	Crosshatch/tape test