If you’ve spent any time configuring a Pelican case for field deployment, you’ve probably defaulted to foam. It’s the obvious choice considering that it is widely available, easy to cut, and good at protecting fragile equipment. But foam isn’t always the right answer, and for certain applications, thermoformed plastic trays outperform it on nearly every metric that matters.
This guide breaks down the practical decision-making behind choosing a thermoformed tray insert over a custom foam insert and the situations where foam is still the better call.
What Is a Thermoformed Plastic Tray?
Thermoforming is a manufacturing process in which a flat plastic sheet is heated until pliable, then shaped over a mold and trimmed to final dimensions. The result is a rigid tray with precisely formed cavities, channels, ribs, and finger pulls designed around specific parts or components.
For case interiors, thermoformed trays are typically produced in ABS (acrylonitrile butadiene styrene), a thermoplastic known for its rigidity, impact resistance, and dimensional stability. ABS maintains its shape through years of repeated use and is fully recyclable, an advantage over most foam materials, which are notoriously difficult to recycle.
When Thermoformed Plastic Trays Are the Right Choice
1. You’re Organizing Hardware, Small Parts, or Multi-Component Kits
When a package contains multiple components such as fasteners, fittings, adapters, tools, or accessories, organization becomes just as important as protection. Foam inserts can secure larger individual items, but they often fall short when managing collections of smaller parts that need consistent placement and easy identification.
This is why thermoformed inserts are common in field service technician kits, OEM equipment packages, and calibration accessory sets where organization matters as much as protection.
2. The Kit Will Be Used in Dirty or Fluid-Exposed Environments
Oil, hydraulic fluid, solvent residue, and contaminated water can be difficult to fully remove from many foam inserts, particularly open-cell foams commonly found in pick-and-pluck or off-the-shelf case interiors. A thermoformed ABS tray has a non-porous surface that wipes clean with common cleaners or disinfectants.
For industrial, medical, or field service environments where cleanliness is a requirement, this is a meaningful functional difference.
3. You’re Running Medium to High Production Volumes
Custom foam inserts have low tooling costs and fast turnaround, which makes them efficient for small runs.
Thermoforming has a higher upfront tooling investment, typically under $5,000 to $10,000 for simpler designs but per-unit costs drop quickly as volume increases. For programs producing 250 units or more, thermoformed trays often deliver a better cost-per-unit than foam over the life of the program.
4. Long-Term Durability Is a Priority
Foam compresses, tears, and sheds particles over time. In a kit that sees heavy daily use, foam inserts often need to be replaced within a year or two. A well-designed ABS thermoformed tray holds its geometry through years of repeated part removal and reinsertion, resisting the wear patterns that degrade foam under regular field conditions.
When to Stick With Foam (Or Use Both)
Thermoformed trays are designed for organization and part separation, not shock absorption. If your Pelican case is protecting a fragile optical instrument, a precision electronic assembly, or anything sensitive to drops or vibration, foam remains the appropriate choice. A tight foam fit suspends a part and absorbs impact energy in a way that a molded plastic cavity cannot replicate.
The good news is these approaches are not mutually exclusive. Hybrid systems that combine a thermoformed tray for organization with foam padding for cushioning are a practical solution when an application demands both. Stackable tray configurations can also be combined with foam layers in a multi-tier case setup.
For a detailed comparison of insert types, the C.H. Ellis custom case and foam guide walks through decision criteria for foam, thermoformed trays, and hybrid systems.
Common Applications Inside Pelican Cases
Thermoformed tray inserts are well-suited for the following use cases inside Pelican and similar hard cases:
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- Field service tool kits: Defined cavities for wrenches, drivers, probes, and spare hardware that technicians pull from repeatedly in the field
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- OEM accessory kits: Standardized packaging for cables, fittings, and components shipped with equipment
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- Calibration and measurement accessories: Adapters, fittings, and reference standards that travel alongside primary instruments
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- Multi-layer case systems: Stackable trays that separate components by type or assembly step within a single case
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- Aerospace ground support kits: High-use tool sets requiring clean, auditable organization
Because these applications often involve precise fitment and repeatable packaging requirements, coordination between the case and insert becomes equally important.
Working With a Single Vendor for Case and Insert
One practical advantage of sourcing thermoformed inserts from C.H. Ellis is that the same vendor can supply both the tray and the hard case. As an authorized Pelican distributor, we can design the insert and source the case in a single order, eliminating the dimensional tolerance risk that comes from sourcing them separately.
This integrated approach also simplifies communication, shortens development timelines, and improves overall fit consistency. With two in-house thermoforming machines and in-house soft tooling capabilities, we maintain direct control over production lead times, tooling adjustments, and manufacturing quality throughout the project lifecycle.
Making the Right Call
Choosing between foam and thermoformed trays ultimately depends on how the case will be used in the field.
Thermoformed plastic trays are the right choice when the application involves repeated access, contamination risk, branding requirements, or medium-to-high production volumes. Foam remains the appropriate choice when fragile items require shock absorption and cushioning.
When the requirements include both, a hybrid system delivers the organization and cleanability of thermoformed plastic alongside the protective properties of foam.To discuss which insert type fits your specific Pelican case configuration, request a custom quote from the C.H. Ellis team.