When should
a knife be replaced?
Clear field signs of star knife, circular knife and punch wear on thermoforming machines; when to replace them and how to choose compatible parts.
Cutting tool life varies with film type, production speed and number of shifts. So the better decision is to look at cutting quality, not the calendar.
Three clear signs
- Burrs and fraying appear on the film edge instead of a clean separation.
- Micro-tears are seen at the edges of the hanging holes.
- Pressure or air pressure has to be increased to get a clean cut.
What to check along with a knife change
When changing a knife, also check the counter surface, bearing and fixing parts. Fitting a new knife on a worn bearing shortens its life and does not guarantee cutting quality.
Dimensions and compatibility
When choosing a knife, diameter, thickness, inner bore and tooth structure must suit the machine model. Matching is done by OEM number or the dimensions of the existing part. In the EVOPAK catalog you can search by product name, dimension or OEM number.
Stocking recommendation
On continuously running lines, keeping some spare of the most worn cutting tools prevents unplanned downtime.
Frequently asked questions
Does a compatible knife do the same job as the original?
Yes, when the dimensions and material properties match; just share your machine model and part dimensions at the quote stage.
Can I change the knives myself?
This must be done according to the machine maintenance instructions; contact us for technical service support.
For parts or service needs: WhatsApp / phone +90 549 734 34 02, altay@evopak.com.tr or our spare parts catalog.
