The lowest price per tonne does not necessarily give the lowest facing cost per finished insulation panel. Aluminum foil thickness changes the area obtained from a given metal weight, while coatings, trimming and conversion losses change the usable yield. Buyers need both a material specification and an area-based comparison.
For insulation-panel facing, first establish what the quoted thickness represents. Base aluminum gauge, coated thickness and the height of an embossed profile are different measurements. Comparing them as if they were equivalent can turn a seemingly attractive quotation into a goods-in dispute.
Keep millimeters and microns consistent
One millimeter equals 1,000 microns. Therefore, 0.035 mm is 35 microns, 0.037 mm is 37 microns and 0.040 mm is 40 microns. By contrast, 0.0037 mm is 3.7 microns. A misplaced decimal changes the specification by a factor of ten.
Put both units on the purchase specification and label the value as base metal where that is the intended requirement. Agree the tolerance and the measurement method before production. A caliper reading across embossed peaks should not silently replace a flat-gauge measurement.
Calculate the metal weight per square meter
Using an approximate aluminum density of 2,700 kg/m³, the theoretical mass of flat, uncoated metal is:
Metal mass in g/m² = thickness in microns × 2.70.
For a calculation example, 35-micron metal weighs approximately 94.5 g/m², 37-micron metal 99.9 g/m² and 40-micron metal 108.0 g/m². These are calculated values, not measured coating-system weights or guaranteed delivered yields.
One tonne of bare 35-micron metal corresponds to approximately 10,582 m²; one tonne of bare 40-micron metal corresponds to approximately 9,259 m². At identical metal price per tonne, the thicker option contains about 14.3% more metal per square meter. That percentage describes metal consumption only, not the final panel cost difference.
Add the coatings before comparing delivered rolls
Coated foil contains more than aluminum. Request the topcoat and back-coating contributions separately, or ask for a measured total mass per unit of usable area. If the invoice is based on coated-product weight, dividing that weight by bare-metal GSM will overstate the available area.
Embossing can also affect the relationship between the flat input area and the finished projected area. For an accurate purchasing comparison, use the supplier’s agreed measurement basis and verify the actual usable width and length during the trial. Treat the theoretical metal calculation as a screening tool.
Compare usable output rather than nominal weight
A practical comparison is:
Facing material cost per accepted m² = total facing material cost consumed ÷ accepted panel area produced.
Keep the scope consistent. For a full conversion-cost comparison, add agreed handling, downtime and disposal costs separately. Do not include them in one supplier’s calculation while excluding them from another’s.
For example, a trial consuming USD 1,000 of facing material and producing 1,900 accepted square meters has a facing-material cost of about USD 0.526 per accepted m². If the same spend produces 1,800 accepted square meters, the figure becomes USD 0.556. This hypothetical example shows why yield can matter even when the quoted material prices look similar.
Qualify a thinner option before changing the order
Choose the thinnest construction that meets the actual process and finished-product requirements, rather than selecting the smallest number in a catalog. Compare handling damage, surface appearance, bonding results and losses during startup and normal running.
Keep other trial variables as consistent as practical. If thickness, coating and line speed all change together, it becomes difficult to identify which change caused a different result. The approved gauge should be supported by the trial record, not solely by a material-saving estimate.
Common buyer questions
Does GSM mean thickness
GSM is mass per unit area. It can be converted to approximate thickness only when the material composition and density are known. A coated or laminated facing needs its additional layers accounted for.
Is 40 microns always better than 35 microns
No universal answer applies. The specification should match handling, surface and finished-panel requirements. A heavier facing costs more metal per square meter but still needs the appropriate coating and process approval.
What should a comparable quote show
Ask for base-metal gauge and tolerance, coating basis, net invoiced weight, usable width, roll configuration and the pricing basis. Include any agreed allowances for joints and trial material.
Ask KONCEN to compare facing options using your required gauge, width and production quantity. Our insulation-panel facing page provides the starting product range; the best commercial comparison is the cost of usable material on your line.
Related guides
- Once the specification is fixed, see reducing foil wrinkles and splice waste on insulation panel lines for roll cores, diameter and splice controls.