Ask Canmaking AIby Innosen

Canmaking AI is AI for canmakers. It answers technical questions on coating, enamel rating, welding, curing, inspection and measurement. Innosen built it on our own technical documentation and approved expert knowledge. Because a wrong answer costs a line, our engineers review what Canmaking AI says.

Questions canmakers ask most

Canmaking AI answers each one in the Knowledge Hub, and in the FAQ of the product it relates to.

Why do coating thickness readings vary from spot to spot — on a formed can or across flat sheet?
Why do missing lacquer defects slip through on fast lines even with visual inspection?
What is the actual cost of a missed coating defect that reaches the seamer?
What is Gauge R&R, and why does it matter for coating equipment?
What are the most commonly missed defects in enamel rating, and why do they get through?

Open the Canmaking AI Knowledge Hub — all 44 answers by canmaking stage · Canpedia® glossary

What Canmaking AI covers

Canmaking AI covers these areas, and each one links to the Innosen product that measures it.

Canmaking quality assuranceIS1100 Innolytix® Canmaking QA Software →
Coil and sheet measurementCoil Translation Measurement System IS1270 MK II →
Double sheet detectionIS231 Double Sheet Detector for Canmaking Lines →
Sheet skew and registrationIS416 Sheet Skew Measurement System →
Coating thicknessCoatPro™ IS860 Coating Thickness Gauge →
Lacquer integrityIS651 Missing Lacquer Detector →
Plain margin inspectionPlain Margin Inspector IS610 →
Coating defectsHoverprobe® II IS9651 →
Side seam stripe integrityIS670 Missing Side Seam Lacquer Detector →
Missing lacquer detectionIS651 Missing Lacquer Detector →
Can ends and componentsEnd Adapter for Enamel Rater IS9020TMR →
Enamel ratingEnamelPro™ IS810 Enamel Rating Gauge →
Gauge R&RCoatPro™ IS860 Coating Thickness Gauge →
Measurement systems analysisIS1100 Innolytix® Canmaking QA Software →
Calibration and metrologyCoating Thickness Measurement Switchbox IS228C →
TroubleshootingKnowledge Hub →

Where Canmaking AI stops, our engineers start

Some questions depend on the geometry of your can, the condition of your line or the history of your process. Canmaking AI says so rather than guessing, and hands the conversation to someone who has seen it before — with the full context already attached.

Luc Nelen

Founder · 40 years in canmaking

Upload a defect

A coating skip, a missing stripe, a mark you have not seen before — send a photo and what you know about it. This is the one thing Canmaking AI will not answer on the spot: reading a defect from an image needs an engineer, not a search.

What happens next. Your report and the photo go to Luc Nelen and Lars Skade. You get an acknowledgement with a reference straight away, and a reply by email — usually within one working day. Nothing is published, and the image is not shared outside Innosen.

How Canmaking AI works

Ask in plain language

Describe the problem to Canmaking AI the way you would describe it to a colleague. No special terminology required.

Get the answer and its source

Canmaking AI takes you straight to the answer in the Knowledge Hub, and then to the FAQ of the Innosen product that measures it.

Escalate when it matters

When a question depends on your specific application, Canmaking AI says so and connects you with an Innosen specialist.

Where canmaking and AI actually meet

AI for canmakers only earns its place if it knows where its own knowledge ends. A general-purpose assistant will answer a question on enamel rating whether or not it has grounds to, and checking that answer costs the time the tool was meant to save.

Canmaking AI is limited to what Innosen has published and reviewed. Ask it something outside coating, enamel rating, inspection or measurement and it says so, then puts you in front of an engineer rather than filling the gap.

That boundary is what makes canmaking and AI useful together. A canmaker AI earns its place when every answer carries a source you can open and a limit you can see.

What Canmaking AI doesn't cover

Canmaking AI is deliberately narrow. It covers quality assurance, measurement, coating and inspection — the areas where Innosen has direct engineering authority. It does not answer questions on bodymaker tooling, seaming, curing chemistry or filling operations, and it will tell you so rather than attempting an answer.

Canmaking AI also does not give a verdict on whether a specific pack is fit for a specific product, shelf life or market. Those decisions belong to the canmaker, the filler, the coating supplier and the applicable regulations.

Canpedia® — the canmaking glossary

Canpedia® is Innosen's canmaking glossary, and it lives here as part of Canmaking AI. 140 terms in one place: the canmaking process and defect vocabulary, plus the measurement and quality-assurance terminology the answers are written in. Updated continuously. Where a term also carries a formal metrology definition, the international vocabulary published by the BIPM is the reference we follow.

140 terms

Canpedia — canmaking process, defect, measurement and quality-assurance terms
Term	Definition
AbrasionProcess and defects	A serious container-handling defect, where mechanical wear thins the metal plate to less than 50% of its normal thickness, so the plate loses strength.
AccuracyMeasurement and QA	How close a measured value sits to the true value of the thing measured, so laboratories express accuracy as bias against a traceable reference standard.
Acid Salts CorrosionProcess and defects	A serious three-piece body defect that appears when acidic residues outside the side seam area cause rusting, or when salts deposit inside the can.
AdjustmentMeasurement and QA	Changing an instrument so that it reads correctly. By comparison, calibration only compares and records.
Aerosol CanProcess and defects	A gas-tight container with a valve that holds the product and the propellant gas under pressure. When the user presses the valve, the pressure dispenses the product.
AluminumProcess and defects	A metal that electrolysis refines from bauxite ore into ingots, which rolling mills then reduce to thin sheet before canmakers draw and form it into can bodies.
Aluminum Foil ContainerProcess and defects	A shaped container formed in a die cavity, where mechanical force and air pressure work light-gauge aluminum foil into shape.
As-found and as-leftMeasurement and QA	The readings a technician records before and after a calibration. The as-found result matters most, because it tells you whether product measured since the last calibration was judged correctly.
Attribute inspectionMeasurement and QA	A pass or fail judgement rather than a measured value: present or absent, correct or incorrect. Most in-line detection on a canmaking line works this way.
BeadingProcess and defects	Forming concave or convex rings around the can circumference, so a thinner wall carries the same load while the body keeps its strength and stability.
Beverage EndsProcess and defects	Ends with an easy-opening feature, so the drink pours out over the can perimeter.
BiasMeasurement and QA	The consistent difference between what an instrument reads and the true value, so a biased gauge can repeat perfectly and still read wrong.
BlankProcess and defects	A pre-cut metal sheet, sheared to a specified size before it forms the body of a can.
Blown CanProcess and defects	A serious manufacturing defect where cans swell or their ends distend. Common causes include overfilling, vacuum failure, microbial growth, internal corrosion, and chemical reaction between product and plate that generates hydrogen gas.
Body BeadProcess and defects	Ridges or rib-like indentations on the can body, singly or in clusters, that resist lateral abuse such as denting.
Broken ChuckProcess and defects	A serious double seam defect, where a void in the chuck lip or insufficient tightness leaves part of the seam not properly ironed out, so an irregularity appears on the countersink wall.
Buckled (Double) BodyProcess and defects	A serious body defect where two body blanks form the body of one can. The seams run thicker and longer than normal but otherwise look ordinary, so the outer body often buckles while the side seam appears mislocked.
Burned-Through WeldProcess and defects	A serious body-making defect, where foreign material such as coating, dirt, oil, grease or contaminated weld wire concentrates heat locally, so the weld burns through.
Burrs on CurlProcess and defects	A can end defect that appears when the end press fails to shear the curl cleanly to size, so rough metal protrudes from the cut edge.
CalibrationMeasurement and QA	Comparing an instrument against a traceable reference and recording the difference, although calibration by itself does not correct the instrument.
Can BodyProcess and defects	The cylindrical part of a can. Double seaming then attaches the top and bottom ends to it.
Capacitance measurementMeasurement and QA	Coating thickness measurement that treats a non-conductive coating on a conductive substrate as the dielectric of a capacitor, so capacitance falls as the film thickens.
Check standardMeasurement and QA	A stable reference sample measured at set intervals between calibrations, so that drift or damage shows up before it reaches product decisions.
ClinchingProcess and defects	The step before double seaming. The seamer bends the curl of the end under the flange of the body, which holds the end loosely in place.
Clipped (Incomplete) CurlProcess and defects	A can end defect that appears when plate misfeeds under the die, so clips or cuts show in the curl and the seam loses overlap.
Clipped (Incomplete) FlangeProcess and defects	A body defect where clips or cuts in the flange reduce double seam overlap to little or nothing. Common causes include plate misfeed under the die, inadequate trip allowance, and plate movement during drawing.
CoaterProcess and defects	A roller machine that applies lacquer to coils or sheets.
Coater DripProcess and defects	A coating application defect that appears when drips or splashes during coating leave tiny hard metallic bubbles of coating on the can surface.
CoatingProcess and defects	Covering metal with another material for protection against corrosion, so that the finished container is safe to fill.
Coating AshProcess and defects	A coating application defect showing small, often black particles on the coating surface, because charred coating, dirt or other foreign particles settle on the wet film before it cures.
Coating SkipsProcess and defects	Any discontinuity in the coating, such as bare spots, hairline skips or eyeholing. Dirt, grease or other foreign material on the plate, or misapplication at the coater, causes it.
Coating weightMeasurement and QA	The mass of dry coating per unit area, in milligrams per square inch or grams per square metre. Film density then links it to thickness.
CodingProcess and defects	Lettering, numbering or designs stamped permanently into either end of the can, either raised (embossed) or indented (in relief).
Coil LineProcess and defects	A machine that handles metal coils for coating or cutting, and that also feeds sheet metal fabrication.
Coil translationMeasurement and QA	Lateral wander of the strip as it runs through a coil line, also called steering. As a result, the shear cut lands in the wrong place across the width.
Cold SolderProcess and defects	A critical three-piece defect that appears when solder temperature runs too low, so gaps, voids or a rough, spongy fillet form along the side seam.
Cone EndProcess and defects	A tapered lid shaped like the frustum of a cone, used mainly on general line cans.
Control chartMeasurement and QA	A time-ordered plot of a measured characteristic with statistically derived limits, so it separates normal process variation from a real change.
Control limitMeasurement and QA	A limit calculated from the process data itself, showing when a process no longer behaves as it did. It is not the same as a specification limit.
CorrosionProcess and defects	A critical container defect that appears when chemical reaction attacks the plate from inside or outside the container, so the metal deteriorates.
CountersinkProcess and defects	The part of an integral two-piece end that gives the end its strength.
CpkMeasurement and QA	A process capability index comparing the spread and centring of a process against its specification limits. A capable process can sit off-centre and still fail Cpk.
Crossover (Juncture)Process and defects	The part of the double seam that crosses the side seam or lap of a three-piece can body.
Crown Cork EndProcess and defects	A metal closure lined with cork or plastic, so crimping its rim over the bottle finish creates a hermetic seal.
CurlProcess and defects	The extreme edge of the can end, which seaming turns inward so that it becomes the end hook.
CurlingProcess and defects	Turning the extreme edge of the end component inward to give a safe, finished curved edge. Later, that curl forms the cover hook of the double seam.
DestackerMeasurement and QA	The station that separates sheets from a stack and feeds them one at a time into a coater, printer or press. Also called a depalletizer or feeder.
Destructive testMeasurement and QA	A test that leaves the sample unusable, so sample size and cost always form part of the decision to use one.
DielectricMeasurement and QA	An insulating material between two conductors. Because an organic coating on metal behaves as a dielectric, capacitance measurement works on it.
Distorted Reform RidgeProcess and defects	A major three-piece defect, where improper flattening of the body cylinder creases the body and flange area on the reform ridge, so the double seam loses integrity or the plate fractures.
Dome EndProcess and defects	A closure fitted to the can base so that it withstands internal pressure.
Double EndProcess and defects	A critical end-making defect, where two independently formed ends stick together and go onto the body as one, so the double seam runs thicker and longer while only the inner end carries compound.
Double SeamProcess and defects	The joint that attaches an end to the can body. The seamer interlocks the edges of the end and the flanged body, then folds and rolls them firmly together.
Double sheetMeasurement and QA	Two sheets or blanks fed where one was intended. Feeders watch for it, because a double thickness entering tooling costs far more than the metal.
DrawingProcess and defects	Reforming sheet metal without changing its thickness. On a two-piece line, for example, drawing forms cups from circular blanks cut from sheet.
DRD CanProcess and defects	A container formed by drawing and then redrawing.
DriftMeasurement and QA	A slow, directional change in the readings of an instrument over time. Check standards reveal it, whereas product results do not.
DroopProcess and defects	A double seam defect where the end hook projects smoothly below the bottom of the normal seam. Product or foreign material in the seam, too much or unevenly spread compound, or an over-long body hook can each cause it.
Dry film thicknessMeasurement and QA	The thickness of the coating after curing, which is what a specification normally refers to. Usually abbreviated DFT.
DWI CanProcess and defects	A container drawn and wall-ironed, so the cup gains height and thinner walls at a smaller diameter.
EaringProcess and defects	Slight waviness or small ripples, called ears, around the top of a drawn and ironed can, because the crystalline structure of the aluminum sheet produces them.
Easy Open EndProcess and defects	A can end scored around its circumference and fitted with a tab, so the user can remove the end by hand.
Eddy current measurementMeasurement and QA	A non-destructive method that induces currents in a non-ferrous conductive substrate such as aluminum, then infers coating thickness from the coupling between coil and metal.
ElectrolyteMeasurement and QA	The conductive solution used in an enamel rating test. Its concentration, temperature and cleanliness therefore form part of the measurement, not a background detail.
Enamel raterMeasurement and QA	The instrument used for an enamel rating test. It applies a low fixed voltage between the electrolyte and the metal of the can, then reads the resulting current.
Enamel RatingProcess and defects	A test of the integrity of the lacquer layer inside a can. Because bare metal conducts and cured lacquer does not, the current that flows indicates how much metal lies exposed.
Extruded CanProcess and defects	A container taller than its diameter, formed only in aluminum. Also called an aluminum monobloc can, it suits pressurised aerosols, spray dispensing, compressed gas and gasless products.
False acceptMeasurement and QA	A defective unit that an inspection system passed. It is the failure mode that matters most, so nobody widens detection thresholds casually.
False rejectMeasurement and QA	A good unit that an inspection system rejected. Product variation, contamination, presentation, or thresholds set for a different variant usually explain it.
Film weightMeasurement and QA	See coating weight, since most canmaking coating specifications use this term.
FlangeProcess and defects	The outward flared edge of the can body, which then becomes the body hook of the double seam.
FlangingProcess and defects	Bending the rim of the can body cylinder outwards to form a projecting edge, so that ends can be double seamed to the body.
FlexiblesProcess and defects	Containers made from flexible materials, namely aluminum foil, plastic or paper.
Fractured (Cut or Torn) SeamProcess and defects	A serious double seam defect, where the outer layer of plate tears or cuts through, so the inner layers lie exposed and the seam loses integrity.
Full Aperture Easy Open Ends (Key-Open Style)Process and defects	Ends opened with a key. The user fits the key onto the tab and rotates it, which rolls up the tab, tears the metal along the scoreline and then rolls the end off the can.
Full Aperture Easy Opening Ends (FAEO)Process and defects	Ends with a ring pull that detaches the complete end, leaving a full aperture. Foodstuffs such as pet food, soup and vegetables commonly use them.
Gauge R and RMeasurement and QA	A study that separates measurement system variation into repeatability and reproducibility, then compares it against the process variation or the tolerance.
HeadspaceProcess and defects	The empty space in the can that product does not fill.
Hermetic SealProcess and defects	A seal that excludes air and so stays leakproof at normal temperature and atmospheric pressure.
In-line inspectionMeasurement and QA	Checking every unit as it passes a point on the production line, rather than measuring a sample away from the line.
Inverted blankMeasurement and QA	A blank presented the wrong way up, so the external coating or print lands on the face that should carry the internal coating. That makes it a product-contact fault rather than a cosmetic one.
Inverted Inside Coating (Inverted Body Blank)Process and defects	A serious defect on soldered three-piece cans, and a minor one on welded cans unless product and container prove incompatible. Misfeed or backward feed of sheets to the slitter, or of body blanks to the body maker, causes it.
IroningProcess and defects	Thinning the wall of a two-piece can by pushing it through hardened circular dies, so the wall lengthens as it thins.
Key TabProcess and defects	The part of the can end projecting from the double seam, where the key for key-open style ends fits.
LacquerProcess and defects	A solvent-based clear protective layer applied to metal surfaces. It guards against corrosion, limits interaction between the can and the food product, and also stops food pigments discoloring.
Laminated PlateProcess and defects	A serious plate defect, where folds or layers roll into a single plate thickness without bonding, so they separate when can manufacture works the metal.
LinearityMeasurement and QA	Whether the bias of an instrument stays consistent across its measuring range. A gauge can still read correctly at one thickness and biased at another.
LithographyProcess and defects	Printing or decorating flat surfaces from plates. It remains the prime method for printing metal cans, although the printer must work the flat sheet before anyone forms the can.
Magnetic induction measurementMeasurement and QA	A non-destructive coating thickness method for ferrous substrates such as steel and tinplate. It reads the magnetic coupling between probe and substrate.
Measurement system analysisMeasurement and QA	The set of studies, including Gauge R and R, linearity, bias and stability, that establish whether a measurement system suits the decisions made with it. Abbreviated MSA.
Metal CoilProcess and defects	Sheet metal rolled from slab or ingot and wound into a coil, so it stores and transports far more efficiently than flat sheet.
Metal SheetProcess and defects	Thin, flat metal cut from a coil by an industrial process, then sheared to form blanks.
MicronMeasurement and QA	One thousandth of a millimetre, the usual unit for dry film thickness. Also written micrometre.
MilliampMeasurement and QA	One thousandth of an ampere, namely the unit for enamel rating results.
MisfeedMeasurement and QA	A feeder cycle that delivers no sheet, two sheets, or a sheet out of position. The feeder that occasionally takes two also occasionally takes none.
Mislocked Side SeamProcess and defects	A critical three-piece defect where the side seam hooks fail to interlock along their whole length. Damage before assembly, or misassembly, usually causes it.
MisnotchProcess and defects	A critical three-piece defect, where body blank misalignment during notching leaves a gap in the lap area with no overlapping plate, so the flange comes out incomplete.
Necked-in CanProcess and defects	A major three-piece defect where the body ends up with an unintentionally smaller diameter than the main cylinder. The body blank edges come apart during side seam formation.
NeckingProcess and defects	Reducing the diameter of a cylindrical can by bending the upper rim inwards, so a smaller end will fit.
Non-destructive testMeasurement and QA	A test that leaves the unit fit for use. Most coating thickness measurement on cans is non-destructive, whereas enamel rating is not.
NotchProcess and defects	The small cut-away part of the body blank in the lap area, so that less material sits where the double seam will form.
Number of distinct categoriesMeasurement and QA	A Gauge R and R result showing how many separate levels the measurement system can reliably distinguish within the process spread. Usually abbreviated ndc.
Off-line measurementMeasurement and QA	Measurement made away from the line on sampled units, usually in a quality laboratory under controlled conditions.
Off-Register Body Blank CoatingProcess and defects	A critical three-piece defect that appears when inside or outside coating lands out of place, or when slitting into body blanks runs off register, so coating covers the margins along the edges that form the side seam.
Offset PrintingProcess and defects	Printing by indirect image transfer. A metal or paper plate inks a smooth rubber cylinder, which then transfers the ink to the substrate.
Panelling (Buckled Can)Process and defects	A serious profile defect where the body collapses or distorts sharply, so the internal coating fractures or the double seam or side seam distorts. It appears as flat vertical panels or indentations.
PanelsProcess and defects	Raised or depressed surfaces on the integral end of a two-piece can, so they add strength or alter container capacity.
Peaked Can (Buckled End)Process and defects	A major profile defect, where the can end distorts permanently outwards into pyramid-like deformities near the double seam, so the seam loses integrity.
Peel-off membrane EndProcess and defects	A closure whose membrane seals the contents from the outside environment. The membrane sometimes sits inside a penny lever opening, but a plastic cap more often protects it. Milk powder uses these lids most.
Penny Lever EndsProcess and defects	A reclosable cover for containers such as paint cans, opened with a coin as a lever.
Pin-HoleProcess and defects	A serious plate defect, where foreign particles roll into the plate without bonding, then pop out and leave a hole when can manufacture works the metal or retorting flexes it.
Plain marginMeasurement and QA	The deliberately uncoated strip along the edge of a coated sheet or blank, left bare so the metal can be welded. Its width and position are quality characteristics.
PrecisionMeasurement and QA	How closely repeated measurements of the same thing agree with each other. It is independent of accuracy, so a precise instrument can be consistently wrong.
Pull TabProcess and defects	A ring-shaped feature that the rivet attaches to the end panel, although it may use a different material from the end.
Pull Tab Rivet FractureProcess and defects	A critical end-making defect showing a break in the part of the end panel that forms the rivet. Causes such as a tab misaligned with the rivet maker, an over-flattened rivet, or missing lubricant during drawing all produce it.
Reference standardMeasurement and QA	A sample or artefact of known value, traceable to a national or international standard, so calibration compares the instrument against it.
RepeatabilityMeasurement and QA	The variation that appears when the same operator measures the same unit with the same instrument more than once. It belongs to the equipment and to how the unit presents to it.
ReproducibilityMeasurement and QA	The variation that appears between different operators measuring the same units with the same instrument, so it belongs to method and training.
ResolutionMeasurement and QA	The smallest change an instrument can display or detect. Inadequate resolution relative to the tolerance will therefore fail a Gauge R and R study on its own.
RibsProcess and defects	Indentations applied to a metal can so that it resists deformation from handling and from pressure changes during the shelf life of the product.
Sampling planMeasurement and QA	The rule defining how many units you take, from where, how often, and what you do with the result. A sampling plan is what turns measurement into evidence.
Sheet length measurementMeasurement and QA	On-line measurement of sheet length after shearing, rather than sampling sheets from the stack. Errors in sheet dimension propagate into every later station.
Sheet registrationMeasurement and QA	The position of an applied layer relative to what went down before it: color to color, varnish to print, or the printed image to the line where the slitter will cut.
Sheet skewMeasurement and QA	Angular misalignment of a sheet or blank against its intended direction of travel or the machine reference edge. The error grows across the sheet, so coating, print and plain margin all land at an angle.
Sheet translationMeasurement and QA	Lateral displacement of a sheet across the direction of travel, so image, coating and plain margin all shift sideways by the same amount.
Side seam stripeMeasurement and QA	The coating applied over the internal or external weld area of a three-piece can, so it restores the barrier that welding required to be absent.
SlitterMeasurement and QA	The station that cuts coated and printed sheets into body blanks, so it is the last point at which anyone can catch a sheet-level fault before the metal becomes a can body.
Specification limitMeasurement and QA	A limit set by the customer, the product or the standard, defining acceptable product. Unlike a control limit, it comes from outside the process.
StabilityMeasurement and QA	Whether a measurement system returns the same result on the same reference over time, so charting check standard readings shows it.
SubstrateMeasurement and QA	The metal underneath the coating: tinplate, TFS or ECCS, or aluminum. Therefore both measurement method and calibration depend on which one you have.
TFSMeasurement and QA	Tin-free steel, also called ECCS or electrolytically chromium-coated steel. This chromium and chromium-oxide coated steel serves widely for ends and for some can bodies.
TinplateMeasurement and QA	Low-carbon steel carrying a thin layer of tin on both faces, and still the traditional substrate for food cans and three-piece bodies.
ToleranceMeasurement and QA	The permitted range between the upper and lower specification limits. A measurement system must therefore be adequate relative to the tolerance, not in the abstract.
TraceabilityMeasurement and QA	An unbroken chain of comparisons linking a measurement back to a national or international standard, where each comparison carries a stated uncertainty.
Uncertainty of measurementMeasurement and QA	A quantified doubt about a measurement result. Without it, nobody can judge a result that sits close to a specification limit.
UV ovenMeasurement and QA	A curing station that uses ultraviolet light rather than heat, after certain printing and varnishing operations.
VerificationMeasurement and QA	Confirming that an instrument still performs within its permitted error, usually between formal calibrations and using a check standard.
Wet film thicknessMeasurement and QA	The thickness of the coating before the solvent evaporates and the film cures. It serves as a process control during application rather than as a specification check.
Wicket ovenMeasurement and QA	An oven that carries coated sheets on wickets, so both faces stay exposed while the coating cures. Oven loading and position affect the cure a sheet receives.
ZeroingMeasurement and QA	Setting the reference point of an instrument on an uncoated sample of the same substrate before measuring. Because a zero taken on the wrong substrate invalidates every reading after it, always zero on the material you are about to measure.

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