Can I trust the volume printed on a medical case?

Answer: Only as a rough guide. It comes from outside dimensions and ignores walls, radii and ribs. Two cases of the same envelope can differ by more than 15 percent inside.

Does a medical case need four clamp points?

Answer: It depends on length. Two suit 400 mm, 470 mm wants four, and beyond 550 mm add a seam rib. Too few clamps make that seam a moisture path.

What foam density should the tray use?

Answer: Closed-cell foam at 30 kg per cubic metre or above. Lighter material collapses within a season, and deformed pockets let bottles tip.

How much reserve should the handle have?

Answer: At least twice the loaded weight. With 11 kg inside, a 30 kg rating keeps carrying from marking the roots.

What is the fastest sealing check on a medical case?

Answer: The paper strip. Trap it across the rim, latch the lid, pull it out; if it slides, that section is unclamped. Lifting one end for a 2 mm gap works.

How to Choose a Medical Case: Five Tests You Can Run on the Dock

Quick answer: Judge a medical case by interior space, wall stiffness, clamp points, tray interchange and handle reserve, in that order. The five checks take half an hour and need no instruments.

Measure the Interior, Not the Outside
Stiffness: Press the Wall With Both Hands
Sealing Is Set by Clamp Points
Dividers Only Matter If the Tray Swaps
Handle, Stacking and Transport Interfaces
FAQ

1. Measure the Interior, Not the Outside

A medical case is sold on its outside length. Take a body of 470 x 350 x 185 mm with a 3.5 mm wall, 12 mm corner radii and floor ribs: the opening measures 420 x 300 x 160 mm, and usable volume lands under 62 percent.

Measure usable height separately, because lid foam eats it. A 20 mm layer of convoluted foam leaves about 140 mm from rib tops to foam face. A 150 mm bottle upright fouls the lid, the latches stop short and the gasket never seats.

Figure	How to measure	Example	What it decides
Outside	Widest point, latches included	470 x 350 x 185 mm	Shelf depth
Interior	Opening edge	420 x 300 x 160 mm	What fits
Usable height	Rib top to foam face	140 mm	Upright bottles

Work backwards: list the longest item, then derive the opening. A 300 mm tray needs 10 mm of foam per side, so the opening must reach 320 mm.

2. Stiffness: Press the Wall With Both Hands

Thickness is half of stiffness; geometry is the rest. A 3.0 mm polypropylene wall with 8 mm ribs resists bending better than a 3.5 mm flat wall, so read the figure with the rib layout: pitch under 80 mm.

No equipment is needed. Press both side walls inward and release. A crisp return with no white stress marks means wall and ribs are matched. If the rim bows and the lid gap is uneven, the gasket leaks there.

Then load it. A filled medical case weighs about 11 kg, carried between the handle mounts, where bulging appears. Substitute two 5 litre bottles and a 1 kg weight, walk 20 m, and check the bottom corners for blush.

3. Sealing Is Set by Clamp Points

The gasket is made by even compression, not loop count. A 6 mm cord section needs 25 to 30 percent compression for a continuous contact band. Less leaves a gap; more takes a permanent set and the second closure leaks.

Long cases are where clamping goes wrong. A 470 mm body with two end latches leaves 300 mm in the middle relying on wall stiffness, and it does not hold; vapour enters along that seam.

Case length	End latches	Clamp points	Note
400 mm	2	3	Centre catch
470 mm	2	4	Two per side
550 mm	2	4 plus seam rib	Long body

Two field checks settle it. Trap a paper strip across the rim, latch the lid, then pull: if it slides out, that section is unclamped. Or lift one end; a gap over 2 mm marks the leak.

4. Dividers Only Matter If the Tray Swaps

More compartments is not the goal; replaceable ones are. A medical case earns its life from a foam tray that lifts out in one piece and trays that interchange between bodies. A moulded-in grid is scrap the first time the list changes.

Slot pitch is commonly 25 mm. Specify closed-cell foam at 30 kg per cubic metre or denser; lighter material compresses at the pockets in a season. Leave a 15 mm finger notch for gloved hands.

5. Handle, Stacking and Transport Interfaces

The handle is the most neglected load path. At 11 kg loaded, one-handed carrying peaks above twice the static load, so a 30 kg rating is the sensible floor. Lift, hold ten seconds, and check the roots for blush.

The base should carry stacking grooves so five units stack without sliding, and the sides need strap channels for 25 mm webbing. Without them, a loaded medical case is located only by neighbouring cargo.

Conclusion

Run the tests in this order: interior, walls, clamps, tray interchange, handle and interfaces. Interior comes first because the wrong size ends the conversation, tray interchange decides service life, and the handle decides whether the case ever leaves the store. A medical case is judged by what it does under load.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.