Definition
The minimum temperature at which a sealant begins to form a measurable seal under defined pressure/dwell conditions.
Applications
- Optimizing FFS speed
- Choosing sealants for cold-fill vs hot-fill
- Tuning seal windows
Benefits
- Enables faster line speed
- Reduces energy use
- Lowers risk of burn-through or distortion
Industry Examples
- Medical: control to achieve validated peel strength without damaging sterile webs.
- Industrial: robust SIT window for dusty products where contamination risk exists.
- Electronics: optimized to achieve hermetic seals without damaging temperature-sensitive battery components.
FAQ
Q: Is low SIT always better?
A: Not if it increases blocking or reduces hot-tack—balance matters.
Q: How is SIT measured?
A: Standardized seal tests across a temperature ladder with peel evaluation.