Stretchable spun bonded nonwoven web and method

A soft stretchable spun bonded nonwoven web comprising:

• a plurality of continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer forming a web;
• said web having a plurality of spaced spot bonds of autogenous releasable filament bonds having been formed by passing said web between a roll with a raised pattern thereon and another opposed roll exerting pressure and applying heat to said web;
• said spot bonds being distributed in a pattern providing continuous strips of unbonded filaments therebetween aligned in both the machine direction and in the cross direction throughout the web;
• said spot bonds being in rows and in side by side relation in both the machine direction and in the cross direction;
• said continuous strips being of such width that respective spot bonds are sufficiently close as to provide secondary bonding between said spot bonds resulting in enhanced stretchability in both the machine direction and in the cross direction without substantial loss of strength;
• said nonwoven web having been subjected to stretching in at least one direction axially of said rows resulting in permanent elongation in excess of about 30%;
• and
• said releasable filament bonds serving to hold the filaments for stabilizing the web and the release strength of the filaments being such that the bonded intensity approaches but is less than the pull required for fracturing the filaments when the web is subjected to strain.

A spun bonded nonwoven fabric comprising:

• continuous thermoplastic filaments substantially uniformly randomly oriented in the machine direction and in the cross direction;
• said filaments oriented in the machine direction crossing those oriented in the cross direction at locations across said fabric in the machine direction and in the cross direction;
• some of said filaments being autogenously fused and bonded at said locations across said fabric in the machine direction and in the cross direction;
• said locations being in rows and in side by side relation in both the machine direction and in the cross direction;
• and
• said fabric being axially stretched at least about 30% providing substantially increased cross sectional area thereof;
• whereby a softer hand is imparted to the fabric as well as increased loft.

A spun bonded nonwoven fabric comprising:

• continuous filaments substantially uniformly randomly oriented in the machine direction and in the cross direction;
• said filaments oriented in the machine direction crossing those oriented in the cross direction at locations across said fabric in the machine direction and in the cross direction;
• a plurality of spaced discrete areas wherein said filaments are autogenously bonded at said locations in said discrete areas by the application of heat and pressure;
• said locations being in rows and in side by side relation in both the machine direction and in the cross direction;
• and
• said discrete areas being oriented in side by side relation in the machine direction and in the cross direction forming continuous ribs aligned in both the machine direction and in the cross direction;
• whereby increased stretchability is imparted to the fabric.

The method of making a spun bonded fabric having continuous randomized filaments bonded by heat and pressure exerted by a patterned roll to afford tensile strength in the cross direction as well as in the machine direction at locations in rows in side by side relation in both the machine direction and in the cross direction in order to improve the hand and the loft of the spun-bonded fabric comprising the steps of:

• feeding said spun-bonded fabric in open width to a stretching apparatus for exerting a tensile force in the cross direction as well as in the machine direction;
• progressively increasing said tensile force in the cross direction as well as in the machine direction while moving said spun-bonded fabric through said stretching apparatus subjecting the fabric to the stretching action of such stretching apparatus;
• and
• packaging the spun-bonded fabric which has been thus treated;
• whereby such treatment results in a fabric having a softer hand and increased loft.

A spun bonded fabric comprising:

• continuous radomized filaments bonded by heat and pressure exerted by a patterned roll at locations in rows in side by side relation in both the machine direction and in the cross direction to afford tensile strength in the cross direction a well as in the machine direction;
• said continuous radomized bonded filaments being stretched in the cross direction and in the machine direction;
• and
• said continuous radomized bonded filaments having been stretched having a softer hand and increased loft in respect to a fabric which had not been so stretched.