Claims
- 1. A method of cutting a laminated web structure comprising the steps of:
(a) engaging a first side of the laminated web with a first crack initiator having a high rake angle, the first crack initiator extending from a first cutter base having a low rake angle, the laminated web including at least a support web, and an upper layer, the upper layer being thinner than the support web, the upper layer being located at the first side of the laminated web structure; simultaneously engaging a second side of the laminated web with a second cutter; (b) generating a first crack in the first side of the laminated web with the first crack initiator completely through the upper layer; (c) engaging the laminated web with the cutter base of the first cutter; and (d) further propagating the first crack using the first cutter base while disengaging the first crack initiator of the first cutter.
- 2. A method as recited in claim 1 further comprising the step of:
propagating the crack through to the second side of the laminated web.
- 3. A method as recited in claim 1 further comprising the steps of:
(a) generating a second crack in the second side of the web with the second cutter; and (b) propagating the first crack to intersect with the second crack.
- 4. A method as recited in claim 1 wherein:
the second cutter includes a second crack initiator.
- 5. A method as recited in claim 1 wherein:
the first crack initiator has a height that is greater than a thickness of the upper layer on the first side of the laminated web structure and is at least 5 microns.
- 6. A method as recited in claim 1 wherein:
the high rake angle of the first crack initiator is in the range of from about 45° to about 70°.
- 7. A method as recited in claim 6 wherein:
the low rake angle of the first cutter is at least about 15° less the high rake angle of the first crack initiator.
- 8. A method as recited in claim 4 wherein:
the second crack initiator has a high rake angle in the range of from about 45° to about 70°.
- 9. A method as recited in claim 6 wherein:
the first crack initiator has a relief angle of not more than about 30°.
- 10. A method as recited in claim 7 wherein:
the first cutter base has a relief angle of not more than about 30°.
- 11. A method as recited in claim 3 wherein:
the first crack initiator includes a relief edge that is either straight or curved.
- 12. A method as recited in claim 1 wherein:
the first cutter base has a rake edge that is either straight or curved.
- 13. A method as recited in claim 12 wherein:
the first cutter base has a relief edge that is either straight or curved.
- 14. A method as recited in claim 1 wherein:
the laminated web structure includes at least one additional layer residing between the support web and the upper layer.
- 15. A method as recited in claim 1 wherein:
the laminated web structure is an imaging element and the upper layer is a protective layer.
- 16. A method as recited in claim 1 wherein:
the laminated web structure is an imaging element and the upper layer is a polymeric material.
- 17. A method as recited in claim 16 wherein:
the polymeric material is coated onto the support web or onto an intermediate layer.
- 18. A method as recited in claim 16 wherein:
the polymeric material is a separate web laminated onto the support web or onto an intermediate layer.
- 19. A method as recited in claim 1 wherein:
the upper layer is a laminate is polyethylene, polypropylene, or polystyrene, or a blend thereof, or a copolymer thereof.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to U.S. application Ser. No. ______ filed same day herewith by Yeh-hung Lai, et al and entitled, “APPARATUS AND METHOD FOR CUTTING SHEET MATERIALS”.