Case Foam Types: EPE, EVA, PU, PE, XLPE - Which Foam for Your Application?

The foam insert inside a protective case is what actually protects your equipment. The wrong foam choice can result in damage despite a $500 case shell. This guide helps you choose the right foam for 12 common B2B applications.

5 Common Foam Types Used in B2B Cases

There are dozens of foam types, but B2B protective cases use primarily these 5:

1. EPE (Expanded Polyethylene) Foam

• Density: 18-35 kg/m³
• Cell structure: Closed-cell
• Color: White (standard), black/dark gray (industrial)
• Cost: $3-8 per board foot
• Pros: Lightweight, water-resistant, non-abrasive, recyclable, low cost
• Cons: Lower impact absorption than PU or XLPE, limited chemical resistance
• Best for: Light-to-medium equipment, camera bodies, drone cases, medical device transport

2. EVA (Ethylene-Vinyl Acetate) Foam

• Density: 33-200 kg/m³
• Cell structure: Closed-cell
• Color: Black, white, custom
• Cost: $5-15 per board foot
• Pros: Excellent flexibility, chemical resistance, UV resistance, low water absorption
• Cons: Higher cost than EPE, slightly heavier, may deform under sustained heavy load
• Best for: Premium cases, military/law enforcement, sports equipment, camera cases

3. PU (Polyurethane) Foam

• Density: 16-80 kg/m³
• Cell structure: Open-cell or closed-cell
• Color: Yellow-tan (open-cell), gray (closed-cell)
• Cost: $8-25 per board foot
• Pros: Highest impact absorption per weight, customizable density, slow recovery (excellent for fragile items)
• Cons: Absorbs water (open-cell), degrades with UV exposure, higher cost
• Best for: Fragile equipment, glassware, optics, precision instruments, medical devices

4. PE (Polyethylene) Foam

• Density: 25-70 kg/m³
• Cell structure: Closed-cell (cross-linked or non-cross-linked)
• Color: White, gray, black
• Cost: $4-12 per board foot
• Pros: Excellent chemical resistance, water resistance, dimensional stability
• Cons: Stiffer than EPE/EVA, moderate impact absorption
• Best for: Medical transport, industrial equipment, automotive parts, military

5. XLPE (Cross-Linked Polyethylene) Foam

• Density: 25-200 kg/m³
• Cell structure: Closed-cell (chemically or radiation cross-linked)
• Color: White, gray, black
• Cost: $10-30 per board foot
• Pros: Highest chemical resistance, closed-cell water resistance, excellent impact absorption, FDA-grade options
• Cons: Highest cost, requires specialized tooling
• Best for: Military, aerospace, medical, food/pharma, high-end industrial

Direct Comparison: 8 Attributes

Layered Foam Systems: The Pro Approach

For mission-critical equipment, single-layer foam is rarely optimal. Pro B2B cases use layered foam systems:

1. Top layer (convoluted "egg crate"): PU or EVA, 10-20mm, absorbs initial impact and distributes load
2. Middle layer (densified): PU, PE, or XLPE, 20-50mm, main impact absorption
3. Bottom layer (custom-cut cavity): PE or XLPE, 30-100mm, custom-shaped to cradle equipment
4. Lid foam (pluck-and-pull or convoluted): PU or EVA, 20-40mm, holds equipment down and prevents shifting

6 Common B2B Use Cases: Which Foam?

1. Camera body + 2-3 lenses: PU egg-crate top + PE custom cavity. PU absorbs impact, PE cradles lenses securely.
2. DJI drone (Mavic/Phantom): EPE custom cavity + EPE pluck. Lightweight, water-resistant, low cost.
3. Medical device transport: XLPE custom cavity (FDA-grade) + PU egg-crate top. Chemical resistance, sterilization compatibility.
4. Military weapons/optics: EVA layered (high density) + custom cavity. Impact absorption, chemical resistance, durability.
5. Industrial equipment/tools: PE custom cavity + EPE pluck. Cost-effective, durable, water-resistant.
6. Marine/oceanographic: XLPE custom cavity + XLPE lid. Maximum water/chemical resistance, salt-spray tolerance.

3-Question Foam Selection Framework

Question 1: What is the value of the protected equipment?

• <$1,000: EPE or PE
• $1,000-10,000: EVA or PE + PU top
• >$10,000: XLPE or PU layered system

Question 2: What is the worst-case environment?

• Indoor/office: EPE or PU
• Outdoor/field: PE or XLPE
• Marine/chemical: XLPE only
• Medical/sterile: XLPE FDA-grade

Question 3: What is the weight of the equipment?

• <2kg: EPE sufficient
• 2-10kg: PU or EVA
• 10-50kg: PE or XLPE densified
• >50kg: XLPE layered, often with plywood or metal reinforcement

Foam Tooling: CNC vs Waterjet vs Die-Cut

Three methods are used to shape foam:

• CNC routing: Most precise, best for complex shapes. Cost: $200-1,500 per design. Lead time: 5-10 days.
• Waterjet cutting: Faster than CNC, good for medium complexity. Cost: $150-800 per design. Lead time: 3-7 days.
• Die-cutting: Lowest cost for high volume, less precise. Cost: $500-2,000 (one-time die) + $0.50-2.00 per cut. Lead time: 15-25 days for die.
• Pluck-and-pull foam: Pre-scored foam that user customizes by hand. Cost: lowest. Lead time: 1-3 days.

Conclusion

The right foam depends on equipment value, environment, and weight. For most B2B applications, a layered PU+PE or PE+XLPE system provides the best balance. At KeXinMaterials, we offer all 5 foam types with CNC, waterjet, and die-cut tooling. Contact kexin@beeaa.com for a 12-hour response on the right foam for your application.

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Contact KeXinMaterials for a 12-hour response on your B2B case needs. ISO 9001, Berry Amendment, WHO PQS certified.