In this guide 6 sections
Give every resin lot a number at goods receipt and carry it through five links: dryer, hopper, press run, shift output and shipped carton. Record each link at the moment it changes. Then a recall query starts from the lot and ends at customer cartons.
Start at the goods receipt, not at the press
Traceability breaks first at the dock. The supplier’s certificate of analysis lists a lot number, a melt flow index and a grade. If the receiving clerk types only the delivery note number, the chain is dead before it starts.
Record the supplier lot, the grade, the colour masterbatch lot and the bag or octabin count. Print an internal label for each pallet. Stick it where a forklift driver cannot miss it.
Keep short sentences on the label. Lot, grade, date, bay. Anything more gets ignored.
- Supplier lot number from the certificate of analysis
- Resin grade and melt flow index
- Masterbatch or additive lot, if used
- Count of bags or octabins received
- Storage bay and the date received
Link the lot to the dryer and the hopper
Hygroscopic resins such as nylon, PET and polycarbonate go through a desiccant dryer before they reach the press. The dryer log is where one lot meets another. When an operator tops up a hopper loader with fresh material while old pellets still sit inside, two lots mix.
Record every load event. Capture the lot, the dryer number, the time in and the target dew point. At the press, record which hopper took which dryer batch.
Do not assume first in, first out. Prove it with timestamps.
Tie the lot to the press run and the mould
A press run is a work order on one machine with one mould, one material and one setup. This is the record that holds everything together. It carries the mould number, cavity count, cycle time and the lot or lots loaded during the run.
Where a run consumed two lots, say so, with the changeover time. Guessing which lot went into which shot is how a narrow recall turns into a wide one.
Regrind needs its own identity. Give each regrind bin a number, note which parent lots went into it and the blend ratio used at the press.
- Work order number and press
- Mould number and cavity count
- Every lot loaded, with clock times
- Regrind bin number and blend ratio
- Operator and shift
Carry the lot through shift output to the shipped carton
Each shift’s good output goes into cartons or gaylords. Assign a carton or pallet label at the press or the packing bench, and link it to the run. The label is the bridge between the shop floor record and the dispatch note or delivery docket.
Ship by carton label, not by part number alone. When a customer reports a cracked boss, they can read you the carton number. You then see the run, the lot and the dryer batch in one view.
Test the chain once a quarter. Pick a finished carton and walk it back to the supplier certificate. Time it.
Run the recall query before you need it
A recall has two directions. Forward from a bad resin lot to every carton and customer. Backward from a failed carton to the lot, the dryer and the operator. Software should answer both from the same records.
Set a target. A quality manager should be able to name the affected customers within an hour. If it takes a day of reading shift sheets and phoning stores, the links are missing somewhere.
Start this week with one product family. Trace three cartons end to end by hand and note which link needed guessing. That list is your first set of fields to capture.
Resin lot trace sheet
Five blocks fill the page, one per link: receipt, dryer, hopper, press run and carton. Each block has columns for lot number, date and time, quantity, person and location. A bottom row records the quarterly test: the carton picked, the minutes taken to reach the supplier certificate and the missing links found.
Open a blank worksheet to printQuestions owners ask
Do we need barcodes to trace resin lots?
No, but they cut typing errors. A printed lot label with a plain number works first. Scanning the same label at the dryer, hopper and packing bench removes mistyped digits.
How do we trace lots when regrind is blended in?
Give each regrind bin its own number and record which parent lots fed it. Then the blend ratio at the press links regrind back to those lots.
What if two lots were in the hopper at once?
Record both lots against the run with the changeover time. A recall then covers the shots made after the switch, rather than the whole shift.
Which customers ask for lot traceability?
Automotive, medical and food contact buyers ask most often, and their quality manuals usually name the records. Check your customer’s supplier requirements for the exact fields.