Calculating Substrate Compression Ratios in Embossing Operations
Substrate compression ratio measures z-axis compaction, balancing tool impression depth against fiber strain limits to maximize embossing height without shearing.
Springback Percentage
Structural Recovery
Paperboard and folding carton substrates possess a latent elastic memory that resists permanent deformation during the creasing and scoring process. This springback percentage quantifies the degree of angular recoil exhibited by a material once the mechanical pressure of a die or rule is removed. The measurement compares the angle of a creased fold under stress against its resting position after release.
High ratios indicate a lack of fold retention that hinders the speed and accuracy of automated folding and gluing equipment.
Conversion Tolerance
Finished cartons requiring precise dimensions depend on low recoil values for consistent geometry. Converting lines set machinery speeds based on the speed at which a substrate settles into a ninety degree angle without rebounding. Materials exhibiting high values force operators to increase dwell times or adjust channel widths to ensure the score holds its intended profile.
A failure to account for these specific material properties results in bowed flaps or off-square boxes that jam vertical form fill seal machines.
Performance Measurement
Testing procedures define the ratio through the subtraction of the final resting angle from the tool angle, divided by the total potential deformation of the fibre network. Standardized protocols utilize a consistent force applied for a fixed duration to ensure valid data points across varying calipers and grain directions. Technicians calculate the quotient to verify if a batch meets the stringent requirements for high speed carton assembly.
Lower values correlate directly with superior crease definition and enhanced performance during high speed cartoning.