PET Blow Moulding Machine Buying Guide: Linear vs Rotary, Cavity Selection & Cost
The decision tree most buyers don't think through
Choosing a PET blow moulding machine is a 4-axis decision: output, cavity count, machine type (linear/rotary), and bottle profile. Get any one wrong and the rest become irrelevant.
Step 1: Match output to your filling line
Always size the blow moulding machine 15-20% above your filling line. Why: planned downtime, mould changeovers, and natural rejection.
| Filling line | Recommended blow moulding |
|---|---|
| 30 BPM (1,800 BPH) | Semi-auto 1-cavity (2,200 BPH) |
| 60 BPM (3,600 BPH) | Linear 4-cavity (4,200 BPH) |
| 90 BPM (5,400 BPH) | Linear 4-cavity high-speed (6,200 BPH) |
| 120 BPM (7,200 BPH) | Rotary 6-cavity (8,200 BPH) |
| 240 BPM (14,400 BPH) | Rotary 8-cavity (16,000+ BPH) |
Step 2: Linear vs Rotary
Linear machines are simpler, preforms are conveyed in a straight line through heating, blowing, and ejection. They are cheaper, easier to maintain, and suitable up to 8,000 BPH.
Rotary machines use a continuously rotating blowing wheel. They are more efficient at high speed, hold tighter wall thickness control, and are required at > 8,000 BPH.
Rule of thumb: rotary above 8,000 BPH, linear below. Cost difference at the same output: ~28-40% premium for rotary.
Step 3: Cavity selection
Cavities determine how many bottles are blown per cycle. A 4-cavity linear at 18 cycles/minute = 72 BPM = 4,320 BPH.
Higher cavity count = higher BPH but also:
- Higher tooling cost (₹1.8-2.5 Lakhs per cavity)
- Higher heating zone power
- Larger compressed-air consumption
- Tighter tolerance demands on preform supplier
Step 4: Bottle profile constraints
Each mould is bottle-specific. If you plan to run 200ml, 500ml, 1L AND 2L SKUs, plan for mould inventory (₹6-12 Lakhs across 4 SKUs). Quick-change tooling saves changeover time.
Air consumption, the hidden cost
PET blowing is air-hungry. Typical numbers:
- 1L bottle: 1.0-1.4 Nm³ HP air per kg of preform
- 30 bar working pressure (industry standard)
A 6-cavity rotary running 7,000 BPH consumes ~85-100 Nm³/min of HP air. The compressor cost (₹6-12 Lakhs) and electricity cost (₹2.5-3.5 Lakhs/month) is a real, recurring number.
Air recovery systems (40-50% saving) are now standard on serious rotary machines. They pay back in 8-14 months at Indian electricity tariffs.
Price ranges (2026, India)
| Type | Output | Price |
|---|---|---|
| Semi-auto 1-cav | 600-1200 BPH | ₹3.8-6 Lakhs |
| Semi-auto 2-cav | 1200-1800 BPH | ₹6-9 Lakhs |
| Auto linear 4-cav | 3600-4800 BPH | ₹22-32 Lakhs |
| Auto linear 6-cav | 5500-6800 BPH | ₹38-55 Lakhs |
| Rotary 6-cav | 6000-7800 BPH | ₹65 Lakhs - 1.1 Cr |
| Rotary 8-cav | 9600-12800 BPH | ₹1.4-2.2 Cr |
| Rotary 10-12 cav | 13500-18000 BPH | ₹2.4-3.8 Cr |
| 20L jar 1-cav | 80-120 jars/h | ₹14-22 Lakhs |
Service & spares, ask before you buy
- Where is the nearest spare-parts depot to your plant?
- Is the heating-oven IR lamp a standard part or proprietary?
- Is the servo drive a Yaskawa/Mitsubishi/Allen-Bradley unit (replaceable globally) or proprietary?
- What's the engineer dispatch SLA?
A cheap machine with poor parts availability will cost you 3x in downtime.
Bottom line
Match output to your filling line +20%, choose linear under 8,000 BPH, plan for mould inventory across SKUs, and don't ignore air consumption. Get our PET blow moulding sizing guide as a PDF here.