Define the line boundary before selecting interfaces
List every item from product preparation to accepted finished-pack discharge: mixers or holding tanks, pumps, hoppers, feeders, the sachet machine, coder, inspection, reject, conveyor, counter, collator and any cartoning or case equipment. State what is included, what is existing and who owns each interface.
A clear boundary prevents gaps such as an unpowered transfer, missing low-level signal, incompatible discharge height or a downstream machine that cannot accept linked sachet strips. Use one controlled layout and interface schedule for all suppliers.
Integrate product feed with dosing and machine state
Liquid feed may involve a tank, pump, pressure control, agitation, temperature management or recirculation. Powder feed may use manual loading, screw transfer or vacuum conveying; granules may use elevators or controlled hoppers. The selected method changes the condition presented to the filler.
Define ready, demand, low-level, high-level, refill, fault and dose-complete behaviour. The sequence should prevent empty packs, overfill after a stop and uncontrolled product movement when guards are open or the bagger is not ready.
Treat film, coding and inspection as one timing chain
The film web carries the registration mark, artwork, seal areas and variable-code zone. The coder needs a trigger or encoder relationship; the inspection system needs to know what to check and which pack to reject. A web or pack can travel a significant distance between print, inspection and reject.
Document the pack-tracking method and challenge it at start-up, stop, restart and speed change. For multi-lane webs, identify how lanes are mapped through coding, cutting and rejection.
Design discharge around the actual finished format
Individual sachets, linked strips and stick packs behave differently after cutting. Lightweight packs can overlap, rotate or be affected by static; wet or oily contamination can change friction. Specify discharge height, direction, pitch, orientation and whether packs need counting or grouping.
The downstream machine must accept the peak and normal flow, including restart accumulation. Define what happens when the conveyor, counter or cartoner stops: immediate bagger stop, controlled run-out, buffer or another agreed response.
Write an interface and stop-state schedule
For every machine, list inputs, outputs, signal meaning, healthy state, timing, cable responsibility and response to loss. Include emergency-stop or safety interfaces only within an approved engineered architecture; ordinary control handshakes must not be treated as safety functions.
Record the intended states for start-up, normal run, product low, film low, coder fault, inspection fault, downstream stop, guard opening, emergency stop and power restoration. Recovery is part of the process and should avoid untracked or incorrectly coded packs.
Integrate quality control with a physical reject path
A detection device is useful only when the affected pack can be identified and controlled. Define detection point, pack tracking, reject mechanism, reject confirmation, reject bin access, full-bin response and how a failed reject is handled.
Some quality checks remain sampled or offline. The line specification should distinguish automatic controls from manual sampling and record the evidence expected at factory and site acceptance.
Use data interfaces only where the business process is defined
Recipe selection, batch codes, production counts, alarms and quality results can be exchanged with other systems, but the owner, source of truth and validation method must be agreed. Avoid broad requests for “Industry 4.0” without named data, purpose and acceptance criteria.
Keep critical machine operation independent of unreliable external services where appropriate. Define user permissions, change control, time synchronisation, data retention, network responsibility and cyber-security requirements with the site’s competent IT and controls teams.
Integration schedule for quotation and acceptance
| Mechanical | Footprints, heights, direction, transfer points, access, guarding boundaries, supports and change-part removal space. |
|---|---|
| Product | Feed connection, pressure or level range, refill rate, return/recirculation, dust/extraction and cleaning/drain-down. |
| Pack | Discharge height, format, orientation, pitch, strip/single setting, accumulation and downstream capacity. |
| Controls | Ready/run/fault/demand signals, timing, stop and restart states, cable/termination responsibility and network interfaces. |
| Coding | Data source, trigger/encoder, code area, printer-ready state, change control, verification and fault response. |
| Inspection/reject | Detection, pack tracking, lane identity, reject device, confirmation, containment and challenge tests. |
| Utilities | Electrical, compressed air, extraction, network and process-service connection points and isolation. |
| Acceptance | Integrated run case, normal events, induced faults, accepted output, evidence, open-action ownership and retest rules. |