Method of packaging fibrous mat structure

In a method for packaging a continuous length of bonded glass fiber insulating mat product having a facing of sheet material bonded to one major surface of the mat wherein the mat is advanced toward a winding operation having a winding axis normal to the direction of advance, the mat is perforated normal to a major face of the mat and in a line transverse of its direction of advance whereby subsequent separation of the mat into discrete lengths at the point of use is facilitated, and the mat is turned solely upon itself in the winding operation to form a multi-layered roll, the improvement comprising:

• a. guiding and turning the mat solely upon itself to form a roll with an open center core which is defined by the mat and permits the roll to assume an elliptical shape after it has been formed,
• b. driving the mat being wound on the roll and forming a peripheral layer of the roll at a speed substantially the same as the speed at which mat is fed into the winding operation to loosely wind the mat on the roll,
• c. confining the roll being formed to a volume which increases in diameter at a rate substantially equal to the rate that the diameter of the roll being formed increases to loosely wind the mat on the roll, producing a compression of the mat of less than 2:1,
• d. compressing the open-centered roll of mat formed in steps (a), (b), and (c) in a direction normal to its wound axis, to compress the mat under a compression ratio of at least 6:1 without separating the mat into discrete lengths, and
• e. applying constraining means to the compressed roll.