Fabrication: Die-Cutting
- Basic Process Overview
- Rule Designs and Functions
- Ejection Rubber
Basic Process
Plywood die with steel rule is used to cut out various shapes (see figure above)
- Gives a "finished" look to rectangular signs with graphics to the edge
- Gives "pop" to displays using more complex shapes
- Ties graphic and overall sign shape together.
- Removes "register" detail on lithograph mounts and direct prints
Process Overview
- Flat die shown (see figure above)
- Upper and lower platen
- Upper platen has die with steel rule and rubber
- Lower platen may or may not have a recess matching the rule
As the upper platen closes: (see figure above)
- Rubber compresses vertically and takes up space around the rule
- Foamboard compresses under the rubber and under the steel rule
- Paper stretches under the force of the rule and the rubber.
Process continues until the steel rule nearly bottoms out in the press
- Once the limit strength of the paper and foam is reached, the material essentially "bursts" apart.
As the upper platen retreats:
(see figure above)- Rubber expands vertically, and pushes the part from the rule and from the plywood die
- Parts are separated from scrap
Rule Design
There are several different styles of steel rule used to die cut.
Three basic types:
- Cutting rules
- Scoring rules
- Creasing rules
Within these types, there are several different options
Cutting Rules
Center Bevel
- Known as: center bevel, standard bevel, double bevel, center face, or A bevel.
- Most popular type – use for most paperboard cutting
Long Center Bevel
- Known as: double double bevel, center face double bevel or AA bevel
- Effective for hard-to-cut substrates
- Effective for thick materials
- Reduces cutting pressure
Single Bevel
- Known as: side bevel, side face bevel or B bevel.
- Produces a square finish
- Used for tighter bends
- Bevel side faces the scrap portion of the foamboard
Long Single Bevel
- Known as: long side bevel, side face double bevel or BB bevel.
- Also used for thicker, harder to cut substrates
- Used for tighter bends
- Reduces crush when bevel faces the scrap portion of the foamboard
- Scoring and Creasing Rules
Scoring Rule
- Same as cutting rule, but more shallow
- Goal is to cut through the top portion of the piece without bursting through the entire sheet
- Score provides easy fold in the finished display
Creasing Rule
- Rule has no cutting edge
- Should be used in tandem with a recess in the bottom platten
- Objective is to crush the cell structure of the foam without cutting the paper
- Crease provides an easy fold in the finished display
Rubbering Dies
- Maintains register on the part as the die descends
- Restrains movement of the substrate for a clean cut
- Compresses a general region to prevent cracking
- Ejects the finished part from the die.
Rubber for Foamboard
(see figure above)
- Rubber should be 3/8" to ½" wide
- Gap between rubber and rule should be about 1/32"
- Hardness should be 35 to 50 "Shore Durometer"
- This is a "medium" hardness
- Foam can be "open" or "closed" cell (like PVC)
- Open cell has better durability, but not flexible enough for rotary dies
- Closed cell foam suitable for flat or rotary dies
- Geometry should be "fully rubbered"
- No breaks in the rubber where the product will not be compressed
Rubber for Foamboard
• Rubber should be 1/16" to 1/8" above the rule (see figure above)Contact part with the restraining rubber prior to the steel rule making contact
For tight areas, it may be necessary to build up with additional soft rubber (see figure above)
Provides additional support in tight corners to prevent cracking.
The information below provides further direction for fabricating KomaFoam. Click on the fabrication category for detailed instructions.
- Die-Cutting
- Die-Cutting Troubleshooting
- Laminating
- Laminating Troubleshooting
- Printing
- Printing Troubleshooting
