In this field note

An erector trial on perfect sample blanks can miss the material variation that stops production later. Select the machine around the actual case style and board supply, and agree how the erected case will be inspected before asking for a speed demonstration.

Stack of flat scored blanks
Flat scored corrugated blanks at a roller conveyor. Their construction and condition are inputs to the forming task.

A case erector opens and forms supplied corrugated blanks; its input is part of the application. Give the supplier controlled drawings plus representative physical lots, then inspect separation, opening, flap alignment and squareness at discharge. The records below help define that trial without inventing minimum sizes, board tolerances or guaranteed rates.

Define the case before selecting the erector

Confirm the case style, not just its length, width and height. Wexxar’s Case & Tray Forming 101 describes different forming approaches for regular slotted cases, Bliss boxes and trays. A supplier’s ability to form one construction does not establish compatibility with another.

Input or item Value or source Why it matters
Case style and closure Approved blank drawing Defines how the case opens and closes
Dimensions and tolerances Controlled specification, with measurement convention Allows the actual range to be assessed
Board and scores Converter specification and samples Defines the material and folding behaviour
Blank supply Lot, storage history and observed condition Preserves what was demonstrated
Required output Case loading and bottom-closure requirements Defines the discharge acceptance task

Include the widest and narrowest relevant constructions and the transitions that matter to production. Let the supplier identify unsupported combinations rather than assuming that independent maximum dimensions can be combined into one permissible box.

Include variation from the real board supply

Wexxar identifies scoring, material type, material age and box design as factors affecting forming. Its guide also notes changes in corrugated behaviour under dry and wet conditions. This supports a representative sampling approach; it does not provide a universal humidity limit or prove that one mechanism will handle every blank.

Create a sample matrix with the converter. Include normal production lots and any documented problem material you want the system to address. Do not damage blanks artificially and then treat the outcome as a production failure-rate estimate.

Sample reference Style / drawing Lot and condition Reason for inclusion Result reference
___ ___ ___ Main production case ___
___ ___ ___ Relevant size or score variation ___
___ ___ ___ Documented difficult incoming lot ___
___ ___ ___ Next-format transition ___

Inspect the case where loading receives it

Judge the formed output at a defined location. Opening a blank successfully is only part of the task if the case later twists, loses alignment or presents a poor bottom to the loading station.

Open formed case
An open corrugated shipping case beside a roller conveyor. Inspect the formed output at the handoff; this sample is not an acceptance result.

Check squareness using the measurement convention and tolerance agreed with the case supplier and project team. Comparing top-view diagonals can help reveal skew, but equal diagonals alone do not establish every dimensional or flap condition. Record the full inspection rather than replacing it with a single “square” checkbox.

Top view of square and skewed cases with diagonals
Top views compare a square opening with a skewed one. Diagonal observations support an agreed inspection method; no acceptance tolerance is shown. Schematic, not to scale.
Observation Record Agree before the trial
Separation Doubles, missed blanks and interruptions What counts as an intervention
Opening Incomplete opening or damaged panels Accepted condition and retained sample rule
Squareness Measurement points and observed result Inspection method and allowable deviation
Flap alignment Overlap, gap or interference Case specification
Bottom closure Tape or glue result, if included Closure acceptance method
Discharge Case orientation and receiving stability Handoff point and support arrangement

Check changeover and replenishment too

A selection trial should include the work that happens between successful cycles. Record magazine loading, replenishment and at least the relevant format transition under the supplier’s approved procedures. Keep normal replenishment separate from fault recovery in the observation log.

Ask which adjustments require a part change, which use retained settings and how an operator confirms the next case is ready. An empty magazine or an unprepared blank supply can interrupt output even when opening mechanics perform well. Assign responsibility for those inputs in the project scope.

If the supplier demonstration omits bottom sealing or uses a separate downstream unit, carry that exclusion into the comparison. The case-packer cost worksheet provides a scope record so a forming module is not confused with a complete case-handling project.

Methods and sources

This selection guide uses Wexxar’s published Case & Tray Forming 101 and Flex E Pack catalog for case styles, material variation and forming/packing/sealing boundaries. The diagonal illustration and acceptance tables are editorial inspection proposals, not a published tolerance standard. Older source material is used for these physical distinctions; current model capability still requires current supplier confirmation. Source files were retrieved on 16 October 2026. Return to case erectors for the input-selection context.

Source documents read: