What is the minimum a Foam Cutting spec sheet needs?

Answer: Outer size, wall thickness and load per point, plus density and tolerance for quoting.

The interior is 540×340 mm. How large is the block cut?

Answer: 538×338 mm, giving 1 mm per side. Under 0.5 mm the lid squeezes it; over 2 mm it slides.

Can higher density make thinner walls work?

Answer: Partly. Moving from 38 to 45 kg/m³ lets a rib drop from 12 mm to about 10 mm, not further.

What does an 8 kg load rating mean?

Answer: A static 8 kg at one point with no more than 3 mm of set in 24 hours.

Should the spec state a service temperature?

Answer: Yes. The 60 °C and -20 °C endpoints change springback, and without them load data cannot be reproduced.

Foam Cutting Specifications: Sizes, Wall Thickness and Load

Quick answer: Three lines decide a Foam Cutting spec: outer size, wall thickness and load per point. Outer size is subtracted from the case interior, wall thickness keeps cavities apart, load sets density and base thickness.

The Three Numbers That Set a Foam Cutting Spec
Sizing: Outer Dimensions and Clearance
Wall Thickness: Base, Ribs and Lid Gap
Load Rating: Stacking and Drop
From Spec Sheet to Machine Settings
FAQ

1. The Three Numbers That Set a Foam Cutting Spec

An enquiry for Foam Cutting usually arrives complete: EVA, 38 kg/m³, black, 35 Shore 00, 30 mm. Five lines, none missing, and the part still will not seat. Those lines describe material, never size or load.

The three lines move together: raise the load and density, base thickness and cavity depth follow.

Spec line	Typical value	What fails when omitted
Outer size	538×338×193 mm	Will not enter, or slides
Wall thickness	12 mm rib, 20 mm base	Corners crush
Load per point	8 kg	Base punches through

2. Sizing: Outer Dimensions and Clearance

Outer size is subtracted, not measured. A 600×400×230 mm case with a 540×340×195 mm interior takes a 538×338×193 mm block: 1 mm per side, 2 mm at the bottom for the ribs.

Foam Cutting: two grey hard case columns stacked six high on a timber pallet, black straps down the stack, racking and a forklift behind

Cavities are built by addition: 1.5 mm around the item outline, then depth by subtracting compression, so a 210 mm item in a 195 mm cavity leaves 15 mm for the lid pad.

The tolerance chain breaks plans: interior ±1.5 mm, cutting ±0.8 mm and springback 0.5 mm come to roughly 2.8 mm, more than any single allowance.

3. Wall Thickness: Base, Ribs and Lid Gap

Wall thickness is the material between cavity and cavity, and between cavity and case wall. At 38 kg/m³, a rib under 10 mm over a 300 mm span sags visibly and the wall bows inward.

Wall location	Value	What it does
Base	20 mm	Impact travel
Side wall	15 mm	Resists wall pressure
Rib	12 mm	Braces cavities
Lid gap	1.5 mm	Limits vertical play

The base is where projects save: cut from 20 mm to 12 mm for one more layer and corner travel halves. For a case rated to 1.2 m on six faces, 15 mm is the floor.

The lid gap belongs in the spec: under 1 mm the foam shears at the rim, over 3 mm the item polishes the cavity floor.

4. Load Rating: Stacking and Drop

Load runs two ways: stacking up and impact down. A 12 kg case stacked five high puts 60 kg on the bottom unit, 15 kg per corner, and a formulation creeping past 3 mm in 24 hours tilts by the third tier.

Density is the lever: 30 and 45 kg/m³ of one formulation differ twofold in compression set. An 8 kg rating means 38 kg/m³ with a 20 mm base; 15 kg needs 45 kg/m³ and a 25 mm base.

Foam Cutting: four silver spindles under a red gantry, black bellows across the frame, orange machine bed with routed grooves

Temperature rewrites it: 72 hours at 60 °C must stay inside 0.5% size change, and a 1.2 m drop at -20 °C stiffens the foam until a 1.5 mm gap stops closing.

5. From Spec Sheet to Machine Settings

A spec only counts if it reaches the machine. The 538×338×193 mm block needs kerf compensation first: a 1.2 mm tool cuts a 1.4 mm slot, so every outline is offset 0.6 mm per side.

Spec item	Parameter	Value
Outer size	Nesting pitch	6 parts per 2500×1300 mm bed
Block height	Layers	193 mm in 4 passes
Cavity outline	Kerf offset	0.6 mm per side
Thin walls	Feed rate	8 m/min down to 5

Layered cutting hides a cost: four layers bonded back with more than 0.3 mm misalignment leave a step you can feel, so write that tolerance beside the layer limit.

Nesting belongs in the spec stage as well: six parts on a 2500×1300 mm bed leave 12% waste, while 520×320 mm lets the same bed take seven. In Foam Cutting, placement often beats the cut.

Conclusion

A Foam Cutting spec is not a longer list; it is three lines checked against one another. Size comes from the case interior, thickness from span and density, load from stack and drop height. When they agree, the quote holds and every unit matches.

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.