What Is a Bag Cutting Machine?

A bag cutting machine is equipment that cuts continuous tubular fabric or printed sheets into individual bag blanks of precise lengths. In PP woven bag production, the cutting machine sits between the circular loom (or printer) and the sewing machine, converting rolls of woven fabric into correctly sized pieces ready for sewing.

Precision cutting is critical — inconsistent bag lengths lead to wasted material, poorly sewn seams, and bags that fail quality inspections. Modern automatic cutting machines achieve ±1mm accuracy at speeds of 40–80 cuts per minute.

Cutting Machine in Production Line

From LoomFabric Roll OptionalPrinter ✂ CUTTING40–80 cuts/min±1mm accuracy Next stepSewing FinishedBags 🔥 Hot KnifeSeals PP edgesBest for PP woven 🔪 Cold KnifeClean cutsBest for paper 〰️ Ultrasonic±0.5mm precisionPremium grade

Types of Cutting Machines

By Cutting Method

MethodSpeedAccuracyPrice Range
Hot Knife40–60 cuts/min±2mm$5,000–$10,000
Cold Knife40–80 cuts/min±1mm$8,000–$18,000
Ultrasonic30–50 cuts/min±0.5mm$12,000–$25,000

By Automation Level

  • Manual — Operator measures and cuts with guided blade ($1,000–$3,000)
  • Semi-Automatic — Auto length measurement, manual fabric feed ($3,000–$8,000)
  • Fully Automatic — Auto feed, measure, cut, stack, and count ($8,000–$18,000)

By Material

  • PP/HDPE Cutting Machines — Handle woven polypropylene and high-density polyethylene fabrics
  • Paper Cutting Machines — Handle kraft paper sheets/rolls for paper bag production
  • Multi-Material — Can process both PP fabric and paper (less common)

Key Specifications

  1. Cutting Speed — 40–80 cuts per minute for fully automatic models
  2. Cutting Width — Maximum fabric width: 300–800mm (standard) or up to 1500mm (wide-format)
  3. Bag Length Range — Adjustable from 300mm to 1500mm
  4. Length Accuracy — ±0.5mm to ±2mm depending on method
  5. Cutting Method — Hot knife, cold knife, or ultrasonic
  6. Counter Display — Digital counter showing pieces cut
  7. Stacking System — Auto stacking of cut pieces
  8. Power — 3–8 kW depending on model

Automatic Bag Cutting Machine (ACM-600)

Specifications

  • Speed: 40–80 cuts/min
  • Width: Up to 800mm
  • Length: 300–1500mm adjustable
  • Features: Auto cut, precise length control, stacking, digital count display
  • Price: $8,000–$18,000
  • Best for: PP woven bag factories, medium to large scale

Key Features

  • Photoelectric length sensor — Detects printed marks for precise registration
  • Auto stacking — Neatly stacks cut pieces for easy transfer to sewing
  • Digital counter — Tracks production count with batch totals
  • Edge trimming — Optional side trimmer for clean edges
  • Variable speed — Adjustable to match upstream loom output

Pricing Guide

CategoryPrice Range (USD)Features
Manual Cutter$1,000–$3,000Guided blade, ruler
Semi-Auto$3,000–$8,000Auto measure, manual feed
Standard Auto$8,000–$14,000Auto feed, cut, stack
Premium Auto$14,000–$18,000Photoelectric, high accuracy
Wide-Format Auto$15,000–$25,000>1000mm width capability

Operating Costs

  • Blades: $10–$50 per blade, replaced every 1–3 days (hot knife) or 1–2 weeks (cold knife)
  • Power: 3–8 kW, approximately $2–$8 per day in electricity
  • Maintenance: Minimal — primarily blade replacement and belt tension

Integration in Production Line

A cutting machine fits into the PP woven bag production line as follows:

Circular Loom → (Laminator) → Printer → CUTTING MACHINE → Sewing Machine

Matching Capacity

Your cutting machine should match or exceed the output of your upstream equipment:

  • 4 looms producing 300,000 bags/month → Need cutting capacity of ~15,000 cuts/day
  • At 60 cuts/min × 8 hours = 28,800 cuts/day → 1 cutting machine is sufficient

Most factories need only 1 cutting machine for every 6–8 circular looms.

How to Choose

Step 1: Material Type

  • PP woven fabric → Hot knife or cold knife cutter
  • Paper sheets → Cold knife cutter (hot knife melts paper glue)
  • Coated/laminated fabric → Cold knife or ultrasonic recommended

Step 2: Speed Requirements

Match cutting speed to your loom+printer output. For most medium factories, a standard 40–60 cut/min machine is sufficient.

Step 3: Accuracy Needs

  • Standard bags → ±2mm is acceptable
  • Export/premium bags → ±1mm recommended
  • Printed registration cutting → Photoelectric sensor required

Step 4: Budget

Cutting machines are one of the lowest-cost components in a production line. Don’t over-economize here — poor cutting accuracy wastes more material in the long run.

Maintenance Tips

  1. Daily: Replace or sharpen blades, clean blade guides, check belt alignment
  2. Weekly: Lubricate guide rails, inspect feed rollers, clean sensors
  3. Monthly: Calibrate length measurement, inspect motor and drive, replace worn belts
  4. Quarterly: Full machine cleaning, bearing check, electrical inspection

Frequently Asked Questions

Hot knife vs cold knife — which is better? Hot knife is better for PP woven fabric because it heat-seals the cut edge, preventing fraying. Cold knife is better for paper and coated materials. For most PP woven cement bag factories, hot knife is the standard choice.

Can one cutting machine serve multiple looms? Yes. Since cutting speed (40–80/min) far exceeds per-loom fabric output, a single cutting machine can easily handle fabric from 6–10 circular looms.

How often do blades need replacement? Hot knife blades typically last 1–3 days of continuous operation. Cold knife blades last 1–2 weeks. Blade cost is $10–$50 per replacement. Keeping a stock of 20+ blades ensures uninterrupted production.

Can cutting machines handle different fabric widths? Yes. Most machines have adjustable guides and can accommodate various fabric widths within their specified range (e.g., 300–800mm). Width changes take only a few minutes.

Learn about the complete PP woven production line in our PP Woven Bag Machine Guide or explore all equipment in the machine directory.