4 Types of Packaging Cushioning Materials Selection: EPE/EPS/Air Column Bag/Honeycomb Cardboard — The Most Common Mistake Print Shops Make Is Calculating the Cushioning Coefficient Wrong

In June 2024, a high-end ceramics customer came to us. The customer's exact words were:

"We make a set of 8-piece ceramic tea ware, with a single set weighing 4.5kg. Previously we used EPE pearl cotton for cushioning, and the breakage rate during transport was 18%. After switching to air column bags, the breakage rate dropped to 2% — but the cost of air column bags is 3 times that of EPE."

This is a real cushioning material selection case. Before packaging print shops take cushioning packaging orders, they must understand the real data on these 4 types of cushioning materials.

Material Type 1: EPE Pearl Cotton (Polyethylene Foam)

Properties: closed-cell structure, medium cushioning performance, moisture-proof and shock-proof. Common uses: electronic cushioning, glassware cushioning, furniture cushioning.

Performance data:

• Cushioning coefficient: 1.5-2.5 N/cm² (density 25-35kg/m³)
• Compressive strength: 30-80 kPa
• Operating temperature: -40°C to 80°C
• Cost: 8-25 元/m²

Applicable scenarios: lightweight fragile goods (<5kg), short-distance transport, wholesale distribution. EPE is the cheapest among the 4 types of cushioning materials, but its cushioning performance is average.

Print shop note: The key parameter for EPE is density. EPE at 25kg/m³ density has poor cushioning performance, while EPE at 35kg/m³ density has good cushioning performance. Print shops must confirm which density the customer requires when purchasing raw materials.

Material Type 2: EPS Foam (Polystyrene Foam)

Properties: closed-cell structure, good cushioning performance, lightweight. Common uses: appliance cushioning (TVs, refrigerators), fresh produce packaging, disposable tableware.

Performance data:

• Cushioning coefficient: 2.5-4.0 N/cm² (density 15-25kg/m³)
• Compressive strength: 60-150 kPa
• Operating temperature: -20°C to 70°C
• Cost: 5-15 元/m²

Applicable scenarios: medium fragile goods (5-20kg), home appliance packaging, fresh produce cold chain. EPS has the strongest cushioning performance among the 4 types of cushioning materials, but the worst environmental performance — EPS does not degrade for 500 years in the natural environment.

Print shop note: For EPS cushioning material orders, 3 things must be clarified: 1) Product weight (determines EPS density); 2) Drop height (determines EPS thickness); 3) Environmental requirements (some countries ban EPS after the EU single-use plastics directive).

Material Type 3: Air Column Bag (Inflatable Cushioning)

Properties: forms shape after inflation, excellent cushioning performance, lightweight. Common uses: e-commerce logistics cushioning, electronics cushioning, precision instrument cushioning.

Performance data:

• Cushioning coefficient: 3.0-5.0 N/cm² (inflation pressure 0.5-1.5 bar)
• Compressive strength: 100-300 kPa
• Operating temperature: -20°C to 60°C
• Cost: 15-50 元/m² (depending on thickness and layers)

Applicable scenarios: high-end fragile goods (>5kg), e-commerce logistics, precision instruments. Air column bags have the best cushioning performance/cost ratio among the 4 types of cushioning materials, but inflation is cumbersome (requires inflation equipment).

Print shop note: The key parameter for air column bags is inflation pressure. Inflation pressure of 0.5bar is too soft, with insufficient cushioning performance; inflation pressure of 1.5bar is too hard, and can easily crush the product. It is recommended that print shops provide customers with an inflation pressure range of 0.8-1.2bar.

Material Type 4: Honeycomb Cardboard

Properties: paper-based structure, above-average cushioning performance, environmentally friendly and recyclable. Common uses: heavy product cushioning, export packaging, green packaging.

Performance data:

• Cushioning coefficient: 1.5-3.0 N/cm² (depending on honeycomb core paper grammage)
• Compressive strength: 50-200 kPa
• Operating temperature: -30°C to 80°C
• Cost: 12-30 元/m²

Applicable scenarios: heavy products (>20kg), export packaging, customers with high environmental requirements. Honeycomb cardboard has the best environmental performance among the 4 types of cushioning materials (recyclable and biodegradable), but average cushioning performance.

Print shop note: The key parameter for honeycomb cardboard is the honeycomb core paper grammage. Honeycomb core paper at 100g/m² has poor cushioning performance, while honeycomb core paper at 200g/m² has good cushioning performance. Print shops must confirm which honeycomb core paper the customer requires when purchasing raw materials.

4 Core Variables in Cushioning Coefficient Calculation

Before selecting cushioning materials, print shops must calculate 4 variables:

1. Product weight G: Net weight of the customer's product (kg); an error of 1kg means the cushioning material model must be changed
2. Drop height H: Maximum drop height during transport (m), generally taken as 0.8-1.5m
3. Cushioning material thickness t: Thickness of the cushioning material (cm); the thicker, the better the cushioning performance
4. Cushioning coefficient C: The cushioning coefficient of the cushioning material (N/cm²), differing for each material

Calculation formula: G × H = C × A (cushioning area). If G is calculated incorrectly, the cushioning area will be wrong — either insufficient cushioning (product damage) or excessive cushioning (cost increase).

4 Practical Suggestions for Print Shops Selecting Cushioning Materials

1. Lightweight fragile goods (<5kg): EPE pearl cotton or honeycomb cardboard
2. Medium fragile goods (5-20kg): Air column bag or EPS foam
3. Heavy fragile goods (>20kg): Honeycomb cardboard + EPS combination
4. Export packaging: Honeycomb cardboard (environmentally friendly and recyclable, complies with EU Packaging Directive)

3 Iron Rules for Print Shops Taking Cushioning Material Orders

1. Clarify the product weight: Must be accurate to 0.5kg; too large an error and the cushioning coefficient will be calculated wrong
2. Clarify the transport method: Domestic transport drop height 0.8m, international transport 1.5m, air transport 1.8m
3. Clarify environmental requirements: EU bans EPS, must use EPE or honeycomb cardboard; China allows EPS but it must be labeled

Further Reading

• Air Column Bag / EPE / EPS / Honeycomb Cardboard: Real Recycling Data Comparison Across 4 Cushioning Materials — The Numbers Eco Ads Don't Tell You
• 3 Categories of Real Data on Packaging Box Transport Box-Collapse Rate: How to Bring It Down for 500km / 1500km / Cross-Province
• What to Do When Packaging Box Transport Damage Rate Is Too High? 8 Specific Improvement Points Across 3 Stages