In this guide 6 sections
A press cure record lists, for every run, the press, mould, compound lot, platen temperatures, pressure, cure time and bump cycles, signed by the operator. Kept per order instead of on the machine panel, it lets you trace any batch of parts back to the exact conditions that made it.
What the header block must carry
The header identifies the run. Write the press number, shift, date, mould number, part number and the order it belongs to. Without the order reference, the sheet is a log of a machine, not a record of a product.
Add the compound grade and the lot number from the batch tag on the strip or preform box. A lot number written once at the start is cheap. Hunting for it after a complaint is not.
Add the operator and the setter. If settings were changed during the run, you want to know who changed them.
- Press, shift, date and operator
- Mould number and part number
- Order reference and quantity planned
- Compound grade, lot number and preform weight
The cure readings that matter
Record top and bottom platen temperature separately. A difference between them points to a heater or thermocouple fault long before parts fail. Record the set value and the value read at the start, and again after the first hour.
Record hydraulic pressure on the gauge, not just what the programme says. Gauges drift and lines leak. A programmed pressure that was never actually reached explains a lot of porosity.
Cure time belongs here too, with the timer start. If the operator extended it by hand, write why.
Bumping, breathing and degassing
Many compression jobs need bump cycles to let trapped air and gas escape. The number of bumps, the interval and the pressure released each time all affect the finished part. Too few leaves blisters. Too many can start the cure before the rubber has flowed.
Write the bump count as a plain number per shot and note the rule for this job. If the rule is two bumps at the start, the sheet should show two.
Add a box for the demould note: sticking, tearing at the edge or flash thickness.
- Bump count and timing for the job
- Pressure at close and at final cure
- Demould notes and flash condition
- First-article approval initials
Take the readings off the panel and onto the order
The panel shows the present moment and forgets it at the next recipe. Paper fixes that, but only if you store it by order. Sheets filed by date can only answer questions about a day, not about a batch.
File the record with the order, whether on paper in the job folder or in the system. When a customer queries a lot of seals three months later, you can see the platen temperatures, bump counts and compound lot in one place.
Some presses can send values to a data logger. This is optional. A well-kept sheet already beats a panel nobody reads.
Review the sheets weekly
A record nobody reads is a chore. Set a short review with the process engineer, one sheet per press, looking for drift in temperature, creeping cure time or a recipe that moved without a reason.
Mark any sheet where the settings left the approved window. Note the action taken. Over a few weeks, patterns appear by press, by shift and by compound.
Start next shift with one press and one mould. Use the sheet there, fix what is awkward and then copy the layout to the others.
Compression press shift sheet
A wide page that opens with a header block listing press, mould, order and compound lot, followed by a grid. Each row is one shot or one hourly check, with columns for top platen, bottom platen, pressure, cure time, bump count, demould note and operator initials. The foot has a signature line for the setter and the quality check.
Open a blank worksheet to printQuestions owners ask
How often should readings be written on the sheet?
At the start of every run, after the first hour and whenever a setting changes. Some shops add a reading every hour for critical parts. The aim is to catch drift, not to fill the page.
Can I use the same template for silicone parts?
The structure fits, but silicone often needs different temperatures, post-cure steps and handling notes. Add a post-cure block for oven temperature and time.
Why record the compound lot on the press sheet?
Because lots vary in cure behaviour. If a defect follows one lot across presses, the lot number on each sheet makes the pattern visible.
Is a digital record required?
No. A paper sheet filed by order works. A digital record helps when you need to search by lot or customer across many orders, and the same fields carry over.