Corrugated fabric and method of making same

Claim 1

A METHOD OF PRODUCING A FABRIC WHICH COMPRISES WEAVING A FABRIC INCLUDING A FIRST AND SECOND PLY, EACH PLY OF WHICH INCLUDES HEAT SHRINKABLE SYNTHETIC YARNS AND TRANSVERSE YARNS INTERLACED THEREWITH, THE HEAT SHRINKABLE SYNTHETIC YARNS IN THE FIRST PLY EXTENDING UNIDIRECTIONALLY WITH THE HEAT SHRINKABLE SYNTHETIC YARNS IN THE SECOND PLY, SAID FABRIC INCLUDING YARNS ARRANED UNDIRECTIONALLY WITH SAID HEAT SHRINKABLE SYNTHETIC YARNS EXTENDING BACK AND FORTH BETWEEN SAID PLIES WHICH SHRINK LESS THAN SAID HEAT SHRINKABLE SYNTHETIC YARNS AND WHICH ARE INTERLACED ALTERNATELY WITH TRANSVERSE YARNS IN SAID FIRST PLY AND WITH TRANSVERSE YARNS IN SAID SECOND PLY, A FIRST GROUP OF SAID LESS SHRINKABLE YARNS BEING INTERLACED WITH TRANSVERSE YARNS IN SAID FIRST PLY INTERMEDIATE THE TRANSVERSE YARNS IN SAID FIRST PLY WITH WHICH A SECOND GROUP OF LESS SHRINKABLE YARNS BEING INTERLACED WITH TRANSVERSE YARNS IN SAID SECOND PLY INTERMEDIATE THE TRANSVERSE YARNS IN SAID SECOND PLY WITH WHICH THE SECOND GROUP OF SAID LESS SHRINKABLE YARNS ARE INTERLACED, SAID FABRIC HAVING CROSSING YARNS INTERLACED WITH SAID LESS SHRINKABLE YARNS INTERMEDIATE THE PLACES WHERE THEY ARE INTERLACED WITH THE FIRST AND SECOND PLIES, HEATING SAID FABRIC TO SHRINK THE HEAT SHRINKABLE SYNTHETIC YARNS AND TO BUCKLE THE LESS SHRINKABLE SYNTHETIC YARNS INTO UNDULATIONS BETWEEN THE FIRST AND SECOND PLY TO SPACE THE FIRST AND SECOND PLIES FROM EACH OTHER, AND COOLING SAID FABRIC.