Packaging design and testing

Printing and Packaging Technology (B.Tech) · Post-press and packaging · free study notes for exams, placements and interviews

In short

Packaging design is the engineering and graphic specification of a pack - its structure, material, dimensions, closure, graphics and declarations - so that it protects the product, sells it, and survives distribution at least cost. Packaging testing is the measurement that proves the design works: material tests (bursting strength, ECT, WVTR), pack tests (box compression, drop, vibration, leak) and whole-distribution simulations. Both are examined in AICTE/CBCS printing and packaging technology papers, in GATE-style packaging questions and in the technical rounds of ITC, TCPL Packaging, Huhtamaki, Uflex, Tetra Pak, Amcor, Hindustan Unilever and e-commerce packaging teams. Indian practice runs on BIS standards (IS 2771 for corrugated boxes, IS 7028 for transport packaging performance tests), Legal Metrology (Packaged Commodities) Rules 2011 declarations, and the Plastic Waste Management Rules with their EPR obligations.

Explained

Functions, levels and the design brief

Four functions: protection (shock, compression, moisture, light, pilferage), containment (no leakage, correct fill), convenience (open, dispense, reclose, carry, stack) and communication (brand, instructions, mandatory declarations, barcode).
Levels: primary (touches the product - bottle, sachet, blister), secondary (groups primaries - carton, shrink-wrapped tray), tertiary / transport (corrugated shipper, pallet, stretch wrap), plus unit load (pallet + load + wrap).
Design brief inputs: product properties (fragility, weight, moisture/oxygen sensitivity, corrosive/greasy nature), fill and closing line speed, distribution hazards, climate, shelf life required, retail display mode, cost per pack, statutory declarations, end-of-life route.
Design sequence: brief → product/hazard analysis → material and structure selection → dieline and 3D mock-up → prototype → laboratory testing → line trial → field/transit trial → specification freeze → artwork approval and print.
Fragility first: the design must match the product's critical acceleration (G-factor) and its compression strength; over-design wastes money, under-design returns damage.

Structural design: cartons, boxes and closures

Folding carton styles (ECMA/FEFCO-type codes): straight tuck end (STE), reverse tuck end (RTE), crash-lock bottom (auto-bottom, fast on line), seal end carton, tray-and-sleeve, gable top.
Corrugated box styles (FEFCO codes): 0201 RSC (regular slotted container - the commonest), 0200 HSC, 0203 FOL, 0300 series two-piece telescopic, 0400 one-piece folders, 0500 slide types, 0700 inserts (pads, partitions, U-boards).
Dieline / blank layout: flat development of the pack with cut lines, crease (score) lines, perforations, glue flaps and bleed; grain/flute direction must run vertically in the box wall so that the flutes take the stacking load like columns.
Blank size allowances: add material thickness (caliper) for each fold; corrugated blank length = 2(L+B) + joint allowance, blank width = H + 2 × flap depth (flaps = B/2 for an RSC, so width = H + B).
Flutes: A (~5 mm, best cushioning), B (~2.5 mm, good crush and printing), C (~4 mm, compromise - common in export), E (~1.5 mm micro-flute for retail cartons), F/N (finer still). Combination boards: single-face, single-wall, double-wall (BC, EB), triple-wall.
Closures and joints: stitched, glued or taped manufacturer's joint; tuck, glue, tape (H, L, U taping patterns), strapping; for primary packs - ROPP caps, CSR (child-resistant), induction seal wads, crown cork, flip-top, spout fitment.
Ergonomics and access: opening force, tear strip/laser scoring, one-hand operation, grip features; accessible design for elderly users.

Graphic design, artwork and statutory declarations

Artwork elements: brand block, product name, pack graphics, colour build (spot/Pantone vs CMYK), dieline layer, barcode, varnish/foil/emboss layers, legal copy panel.
Reproduction constraints: dot gain, trapping and registration tolerance (loose on flexo-printed corrugated), minimum type size for legal copy, white-ink layer on films, print direction vs web, varnish-free glue zones (glue will not hold on varnish).
Barcodes: EAN-13 retail, ITF-14 on shippers, GS1-128 for logistics data, QR/2D for traceability; keep magnification, bar width reduction and quiet zones per GS1 - verify grade (ISO/IEC 15416 A-F).
Legal Metrology (Packaged Commodities) Rules, 2011: declare name and address of manufacturer/packer/importer, common name of commodity, net quantity in SI units, month and year of manufacture/pack, retail sale price (MRP) inclusive of all taxes, consumer-care details, country of origin for imports; e-commerce listings must show the same declarations. Standard pack sizes apply to specified schedules; minimum height of numerals and principal display panel area are prescribed by the Rules.
Food packs: FSSAI Labelling and Display Regulations, 2020 - ingredient list, nutrition panel, allergen declaration, veg (green)/non-veg (brown) mark, FSSAI licence number and logo, best-before date, additive class names.
Other regimes: Drugs Rules labelling for pharmaceuticals (batch, mfg/exp, Rx symbol, retail price); BIS/ISI mark on products under mandatory certification; recycling triangle with resin code and the "recycled/compostable/biodegradable" marking and manufacturer registration number under the Plastic Waste Management Rules; hazardous goods marks per IS/UN packaging codes for dangerous goods.
EPR: producers, importers and brand owners must register on the CPCB portal and meet recycling/reuse targets for plastic packaging, with category-wise obligations and a labelling/barcode requirement - the targets and categories have been amended several times, so quote the current CPCB notification rather than a number from memory.

Material and barrier testing

Paper and board: grammage (IS 1060 series test methods), caliper, bursting strength (Mullen, kgf/cm²), ring crush (RCT), edge crush (ECT, kN/m), flat crush (FCT), Cobb water absorption (g/m², 60 s or 1,800 s), moisture content, ply bond, stiffness (Taber), smoothness, brightness.
Films and laminates: thickness, tensile strength and elongation, COF (coefficient of friction - too high jams the machine, too low makes bags slide off pallets), dart impact, puncture, tear (Elmendorf), gloss, haze.
Barrier: WVTR/MVTR (g/m²/day at stated temperature and RH, usually 38 °C/90% RH - gravimetric or sensor method) and OTR (cc/m²/day at stated RH, coulometric); grease resistance (Kit test); light transmission for photosensitive products.
Seal and bond: seal strength / heat-seal peel (N/15 mm), hot tack, seal integrity by dye penetration or burst/vacuum leak test, bond strength (lamination peel), delamination after retort.
Migration and safety: overall and specific migration limits for food-contact plastics under FSSAI's Packaging Regulations, 2018, which prescribe the IS standards each food-contact material must comply with, a positive list approach and restrictions on recycled plastic in direct food contact; printing inks on food packaging must not migrate - IS 15495 is the reference for inks on food-contact packaging.
Glass and metal: glass - internal pressure, thermal shock, impact, annealing, verticality; metal cans - double-seam teardown (overlap, seam thickness, tightness rating), enamel rater, lacquer adhesion, vacuum.

Performance testing of the pack and the unit load

Compression: Box Compression Test (BCT) on a compression tester at a platen speed of about 12.5 mm/min, fixed or floating platen; reports peak load (kgf/N) and deflection. Conditioning at 27 ± 2 °C and 65 ± 5% RH (IS tropical condition; ISO/TAPPI commonly 23 °C/50% RH) - always state the condition, as strength falls sharply with humidity.
Drop: free-fall drop from a specified height on faces, edges and corners (typically 1 corner, 3 edges, 6 faces sequence); height set by pack weight and handling mode. Incline impact (Conbur) and horizontal impact for rail/road shunting.
Vibration: fixed-displacement sinusoidal sweep (resonance search and dwell) or random vibration to a road/rail PSD profile, with and without top load.
Others: stack test (dead load for 24 h-30 days, simulating warehouse storage), clamp/ hand-truck handling, water spray/rain, revolving drum tumble for small parcels, puncture/pierce, pressure (altitude/aircraft) test, pilferage and tamper-evidence check.
Protocols: IS 7028 parts cover drop, vibration, compression and stacking for transport packages; ASTM D4169 (distribution cycle, assurance levels I-III), ISTA procedures (1A screening, 3A for parcel delivery, 6-Amazon / SIOC for e-commerce), ISO 4180 general rules for complete filled transport packages.
Shelf-life / accelerated storage: store at elevated temperature and RH (e.g., 38 °C/90% RH or 40 °C/75% RH) and extrapolate using a Q10 (rate doubling per 10 °C) rule; validate with real-time data because Q10 extrapolation is only indicative.
Pre-shipment and field: instrumented shipments with shock/temperature data loggers; damage audits and return analysis close the loop.

Cushioning and distribution-hazard design

Fragility (G-factor): the acceleration a product survives - electronics 40-80 G, appliances 60-100 G, delicate instruments 15-30 G; found from a damage boundary curve (critical velocity change and critical acceleration) on a shock machine.
Cushion curves: plots of transmitted peak G against static loading (kg/cm² or psi) for a given cushion thickness and drop height; select thickness and bearing area so transmitted G stays below the product's fragility.
Cushion materials: EPS, EPE, EPP, PU foam, moulded pulp, air pillows, honeycomb, corrugated pads and inserts; moulded pulp and honeycomb favoured now for recyclability.
Distribution hazards: drops and impacts (manual handling), vibration (vehicle), compression (stacking in warehouse), climate (temperature, humidity, rain), low pressure (air freight), contamination, pilferage.
Unit load design: Indian pallet sizes commonly 1,200 × 1,000 mm and 1,200 × 800 mm (ISO/IS pallet dimensions); design the box footprint so pallet area utilisation is high; column stacking retains far more compression strength than interlocked stacking.
Cube efficiency and cost: product volume ÷ shipper volume; dimensional (volumetric) weight pricing by couriers makes right-sizing a direct cost saving.
Sustainability in design: source reduction (down-gauging), mono-material structures for recyclability (all-PE laminates instead of PET/Al/PE), avoiding carbon black and dark pigments that defeat NIR sorting, design-for-disassembly, recycled content, and compliance with the Plastic Waste Management Rules and the Solid Waste Management Rules, 2026.

Key points

Packaging design - specifying structure, material, graphics and declarations so a pack protects, contains, conveys and sells at least total cost.
Three levels - primary touches the product, secondary groups it, tertiary moves it; tests differ at each level.
Dieline - flat blank drawing with cut, crease, perforation and glue areas; the master document for die-making and artwork.
Flute direction - must be vertical in the box wall; flutes act as columns and carry the stacking load.
FEFCO 0201 (RSC) - the default corrugated style; flaps are half the box width and meet at the centre.
ECT - edge crush resistance of the board in kN/m; the single best predictor of box compression strength.
McKee formula - estimates box compression strength from ECT, board caliper and box perimeter.
BCT - measured peak compression load of an empty conditioned box at ~12.5 mm/min platen speed.
Conditioning - 27 ± 2 °C/65 ± 5% RH in Indian practice; board loses roughly half its strength at high humidity.
Safety factor - BCT must exceed the actual stack load several times over to allow for humidity, storage time, pallet overhang and misalignment.
G-factor / fragility - the peak acceleration a product tolerates; cushioning must keep transmitted G below it.
Cushion curve - transmitted G vs static stress for a thickness and drop height; the design tool for foam selection.
WVTR and OTR - moisture and oxygen transmission rates per m² per day at a stated temperature and RH; drive shelf life.
IS 2771 - Indian Standard specification for corrugated fibreboard boxes (grades and requirements); IS 7028 parts cover transport-package performance tests.
ASTM D4169 / ISTA - distribution-cycle and pre-shipment test protocols, now routine for e-commerce packs.
Legal Metrology (Packaged Commodities) Rules, 2011 - mandatory declarations: net quantity, MRP inclusive of taxes, packer details, month/year of packing, consumer care, country of origin.
FSSAI Packaging Regulations, 2018 - food-contact material compliance, positive list and migration limits; labelling under the 2020 Regulations.
EPR under the Plastic Waste Management Rules - registration on the CPCB portal, category-wise recycling targets and packaging marking by producers, importers and brand owners.

Formulas and examples

McKee (simplified): BCT = 5.87 × ECT × √(caliper × perimeter)
BCT = box compression strength (N... see note), ECT in kN/m, caliper (board thickness) in mm, perimeter Z = 2(L + B) in mm. With these units BCT comes out in newtons when ECT is in kN/m. The 5.87 constant suits RSC boxes; it is empirical and errs on real boxes with vents, prints and poor flap fit.

Stack load: W_stack = w × (n − 1), where w = gross weight of one box (kg) and n = number of boxes high (the bottom box carries all above it).

Required BCT: BCT_req = W_stack × SF, where SF = combined safety factor = f_humidity × f_time × f_handling (commonly 1.6 for 65→85% RH, 1.6 for long storage, 1.3-1.5 for pallet misalignment/overhang; overall ~3 to 6).

Static loading on a cushion: σ = W / A, where W = product weight (kg or N) and A = cushion bearing area (cm² or m²).

Drop shock: peak acceleration G ≈ 2h / d for a linear (spring-like) cushion, where h = drop height and d = dynamic deflection of the cushion, both in the same unit. It follows from the energy balance W × h = ½ × (G × W) × d.

Cube efficiency: η_cube = (volume of product content) / (external volume of shipper) × 100.

Pallet area utilisation: η_pallet = (n_boxes/layer × L × B) / (pallet length × pallet width) × 100.

Accelerated shelf life: t_real = t_accel × Q10^{(T_accel − T_real)/10}, with temperatures in °C; Q10 typically 2-3.

Permeation / shelf life (moisture): t = (ΔW × L) / (P × A × Δp), i.e. shelf life = permissible moisture gain ÷ (transmission rate × pack area); with WVTR in g/m²/day and area in m², t comes out in days.

Seal strength: σ_seal = F / w, F = peel force (N), w = specimen width (usually 15 mm or 25 mm) → N/15 mm.

Example 1 - BCT by McKee and the required strength A single-wall C-flute RSC box is 400 × 300 × 250 mm, board ECT = 7.0 kN/m, caliper = 4.0 mm. Boxes are stacked 8 high; each gross weight 12 kg.

Perimeter Z = 2(400 + 300) = 1,400 mm.
caliper × perimeter = 4.0 × 1,400 = 5,600 mm² → √5,600 = 74.83.
BCT = 5.87 × 7.0 × 74.83 = 3,074 N ≈ 313 kgf.
Stack load on bottom box = 12 × (8 − 1) = 84 kg = 824 N.
Safety factor available = 3,074 / 824 = 3.7 - acceptable for short, air-conditioned warehousing, marginal for a humid Indian godown where a factor of 5 is preferred. Remedy: raise ECT to about 9.5 kN/m (BCT ≈ 4,172 N, SF ≈ 5.1) or reduce stacking to 6 high.

Example 2 - cushion design from fragility A 9 kg instrument with fragility 50 G is dropped from 750 mm. A foam with 50 mm thickness transmits 45 G at a static loading of 0.35 kg/cm² (from its cushion curve).

Required bearing area A = W/σ = 9 / 0.35 = 25.7 cm² per... use 4 corner blocks → ~6.4 cm² each, which is impractically small; so choose a lower-density foam or thinner pads.
Check with a practical layout: 4 pads of 40 × 40 mm = 4 × 16 = 64 cm² → σ = 9/64 = 0.141 kg/cm², which on the same curve sits in the under-loaded region where transmitted G rises above 50 G - so the pads must be reduced in area or the foam softened.
Design decision: use 4 pads of 25 × 25 mm (25 cm² total) → σ = 9/25 = 0.36 kg/cm², close to the curve's minimum, transmitted G ≈ 45 G < 50 G. Accept, and verify by an actual drop test.

Example 3 - shelf life from WVTR A 200 g biscuit pack in a metallised BOPP/PE laminate may gain only 2% moisture before going soft. Laminate WVTR = 2.5 g/m²/day at 38 °C/90% RH. Pack surface area = 0.045 m².

Permissible gain ΔW = 2% of 200 g = 4.0 g.
Ingress rate = 2.5 × 0.045 = 0.1125 g/day.
Shelf life t = 4.0 / 0.1125 = 35.6 days at that severe condition. At 27 °C/65% RH ingress is far lower, so the real shelf life is several months - this calculation sets the accelerated-test pass criterion, not the label claim.

Example 4 - cube efficiency and courier cost An e-commerce shipper is 350 × 250 × 200 mm and the product inside occupies 2.8 litres. Courier volumetric divisor is 5,000 (cm³ per kg); actual weight 1.2 kg; rate ₹45 per kg.

Shipper volume = 35 × 25 × 20 = 17,500 cm³ = 17.5 L → cube efficiency = 2.8/17.5 = 16%.
Volumetric weight = 17,500/5,000 = 3.5 kg > 1.2 kg actual → charged on 3.5 kg = ₹157.50.
Right-size to 220 × 160 × 120 mm = 4,224 cm³ → volumetric weight = 0.84 kg → charged on actual 1.2 kg = ₹54, a saving of ₹103.50 per parcel (about 66%), plus less void fill.

Test	What it measures	Typical unit	Reference
Bursting strength	Resistance of board to rupture	kgf/cm²	Mullen test method
ECT	Edgewise crush of board	kN/m	Board test method
BCT	Compression strength of the box	kgf or N	IS 7028 (compression)
Drop	Impact resistance of filled pack	pass/fail at height	IS 7028 (drop)
Vibration	Resonance and fatigue in transit	pass/fail, PSD profile	ASTM D4169 / ISTA
WVTR	Moisture barrier	g/m²/day	Gravimetric/sensor
OTR	Oxygen barrier	cc/m²/day	Coulometric
Seal strength	Heat-seal peel force	N/15 mm	Tensile peel

Stacking pattern	Strength retained (approx.)	Pallet utilisation
Column stack, aligned	~100%	Lower (less interlock stability)
Interlocked / cross stack	~50-70%	Higher, more stable without wrap
Overhanging the pallet edge	Can lose 20-40%	Poor - corners unsupported

Where it is used

FMCG and food brands (HUL, ITC, Britannia, Nestlé India, Amul): pack development engineers run artwork approval, migration compliance and accelerated shelf-life studies.
Corrugated and carton converters (TCPL Packaging, ITC PSPD, Parksons, Huhtamaki): structural design on CAD/CAM sample tables, board grade selection by McKee, BCT and ECT quality control.
Flexible packaging and laminators (Uflex, Cosmo, Jindal Poly, Amcor India): WVTR/OTR, seal strength, COF and bond-strength labs; mono-material redesign for EPR.
E-commerce and 3PL (Amazon India, Flipkart, Delhivery): ISTA 6-series / SIOC testing, right-sizing for volumetric weight, frustration-free and tape-free designs.
Pharmaceutical packaging (Sun, Cipla, Dr Reddy's): blister/strip seal integrity, child-resistant and senior-friendly closures, ICH-style stability packs, Drugs Rules labelling.
Testing and certification labs (NABL-accredited labs, IIP Mumbai, SIES/IIP packaging courses, BIS-recognised labs): third-party transit-worthiness certificates often demanded in export and government tenders.

Interview questions

Q: Why must corrugated flutes run vertically in a box wall? A: The flutes behave like small columns; loaded along their axis they carry the stacking load, whereas horizontal flutes buckle and the box loses most of its compression strength.
Q: What does the McKee formula give you and what are its limits? A: It estimates box compression strength from ECT, board caliper and box perimeter for an RSC. It assumes a plain, well-made, square box, so it over-predicts for boxes with vents, hand holes, poor flap fit or high moisture.
Q: Why is a safety factor of 4-6 applied to BCT? A: Because measured BCT is on a new, empty, conditioned box; real boxes lose strength to humidity, long storage creep, pallet misalignment, overhang and repeated handling.
Q: Difference between ECT and bursting strength as specifications? A: Bursting strength indicates puncture/rupture resistance and historically specified board grade; ECT measures edgewise crush and correlates far better with stacking performance, so it is now the preferred stacking criterion.
Q: What is a damage boundary curve? A: A plot from shock testing that defines the combinations of velocity change and peak acceleration at which the product fails, giving the critical velocity change and critical acceleration used for cushion selection.
Q: How do you choose cushion thickness? A: Take the drop height from the pack weight and handling, read the cushion curve for that thickness, and pick a bearing area whose static loading gives transmitted G below the product's fragility - then confirm by drop test.
Q: Which declarations are mandatory on a retail pack in India? A: Under the Legal Metrology (Packaged Commodities) Rules, 2011 - packer/manufacturer/importer name and address, common name of the commodity, net quantity in SI units, month and year of packing, MRP inclusive of all taxes, consumer-care contact, and country of origin for imports; food packs additionally follow the FSSAI Labelling and Display Regulations, 2020.
Q: WVTR and OTR - what are they and when does each decide the structure? A: WVTR is water-vapour transmission per m² per day, OTR is oxygen transmission per m² per day, both at stated temperature and RH. Crisp/dry foods and hygroscopic powders are WVTR-driven; fats, coffee and nuts that go rancid are OTR-driven.
Q: Why is a mono-material laminate preferred now even if it costs more? A: A single polymer family (e.g., all-PE) is mechanically recyclable, so it meets EPR recycling obligations under the Plastic Waste Management Rules, whereas PET/Al/PE multilayers are effectively non-recyclable.
Q: What is the difference between a laboratory test and a distribution simulation? A: A laboratory test measures one property (BCT, drop, WVTR); a distribution simulation such as ASTM D4169 or an ISTA procedure applies a sequence of hazards in the order and intensity the pack will actually meet, and judges the pack as a system.
Q: A pack passes every lab test but arrives damaged. What do you check? A: The hazard profile - send instrumented shipments with shock and climate loggers, check the actual stack height, pallet overhang, dwell humidity, vibration resonance and manual handling, then re-test to the real profile.
Q: How does conditioning affect test results? A: Paper-based packs are hygroscopic; strength falls steeply with rising humidity, so results are only comparable at a stated condition - Indian practice uses 27 ± 2 °C and 65 ± 5% RH, and the report must state it.
Q: What is cube efficiency and why does it matter commercially? A: Product volume divided by shipper volume; low cube efficiency wastes board, void fill and, with volumetric-weight courier pricing, directly inflates freight per order.

Common mistakes

Treating McKee's calculated BCT as a measured value - it is an estimate and must be confirmed on a compression tester.
Omitting the conditioning temperature and humidity when reporting BCT, ECT or bursting strength, making the number meaningless.
Forgetting that the bottom box carries (n − 1) boxes, not n, and ignoring creep over weeks of storage.
Quoting WVTR or OTR without the test condition (38 °C/90% RH, etc.) or mixing g/m²/day with g/pack/day.
Drawing a dieline without adding caliper allowances for folds, or placing glue flaps under varnish so the adhesive fails.
Running the flute or paper grain the wrong way, or designing graphics without checking registration tolerance on flexo-printed corrugated.
Over-cushioning: assuming more foam is always safer, when a too-large bearing area under-loads the cushion and transmits a higher G.
Treating a pass on a single drop test as proof of transit worthiness instead of running the full sequence of faces, edges and corners plus vibration and compression.