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T7 · Transport / BarrierPlastic Packaging EngineeringGATE 2027 Syllabus (XE5)Shop-Floor Standard

Fickian Film Oxygen Transmission Rate (OTR)

Calculates the steady-state volumetric flux of oxygen gas passing through a flexible packaging film per unit area per day (cc/m²/day).

Mathematical Canonical Relation
OTR=PO2⋅ΔptOTR = \frac{P_{O2} \cdot \Delta p}{t}
Plain Formula: OTR = (P_O2 * DeltaP) / t

Live Engineering Parameter Solver

Input your production or test values below for instant, verified output.

Verified Engine
P_O2
Range: 0.01 – 3000 cc·mil/(m²·day·atm)
DeltaP
Range: 0.05 – 1 atm
t_mil
Range: 0.1 – 10 mil
Calculated Engineering Result:
0.32 cc/(m²·day)
Engineering Verification:High-barrier food packaging classification.

When & Where to Apply

Use when designing food, snack, or pharmaceutical multi-layer packaging to determine barrier layer thickness required for target shelf-life.

Common Engineering Pitfalls

  • Confusing material permeability coefficient PO2 with total film transmission rate OTR
  • Ignoring relative humidity effects on EVOH moisture sensitivity

Physical Assumptions & Validity Limits

  • Steady-state Fickian diffusion
  • Henry’s law gas solubility relationship
  • Constant gas partial pressure differential

Variable Symbols, SI Units & Dimensional Specifications

SymbolVariable MeaningSI UnitTypical Industrial Range
OTROxygen transmission ratecc/(m²·day)—
P_{O2}Permeability coefficientcc·mil/(m²·day·atm)3.0
\Delta pOxygen partial pressure differenceatm0.21
tBarrier layer thicknessmil (1 mil = 25.4 μm)2.0

Worked Industrial Numerical Example: EVOH vs LLDPE Barrier Packaging OTR Comparison

Problem Statement:

Compare the OTR of (a) a 2.0 mil LLDPE film (PO2 = 2,500 cc·mil/m²·day·atm) versus (b) a 0.2 mil EVOH barrier layer (PO2 = 0.05 cc·mil/m²·day·atm) under ambient air (0.21 atm O2).

Step-by-Step Numerical Solution:
  1. LLDPE OTR = (2500 * 0.21) / 2.0 = 262.5 cc/(m²·day)
  2. EVOH OTR = (0.05 * 0.21) / 0.2 = 0.0525 cc/(m²·day)
Final Answer: LLDPE = 262.5 cc/m²/day; EVOH = 0.0525 cc/m²/day
💡 Engineering Interpretation: A 0.2 mil (5 micron) EVOH layer provides a 5,000x barrier improvement over PE, preventing lipid oxidation in snack food.

Authoritative Technical Reference & Source Provenance

Plastic Packaging: Materials, Processing, Applications by O. G. Piringer & A. L. Baner (Wiley-VCH, 2008), 2nd Edition, Page 110-118.
Connected Curriculum Lesson

Barrier Polymers (EVOH, PVDC) & Gas Permeability Math

Study Full Lesson