Cigarette filter micropleated web and method of manufacture
First Claim
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1. A process for manufacturing a pleated web suitable for the manufacture of cigarette filters which comprises:
- (a) selecting a nonwoven web having from 10 to 50 bend lines per inch extending generally in the MD and spaced transversely across the web,(b) heating the web to a temperature equal to or greater than the softening temperature of the polymer while drawing the web in the MD by at least 10% to cause micropleats to form at the bend lines, thereby reducing the width of the web by at least 15% and condensing the micropleats thereby forming a pleated web; and
(c) cooling the tow pleated web.
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Abstract
A meltblown pleated web suitable for manufacturing cigarette filters or filter rods is prepared by drawing a meltblown web having longitudinal bend lines under thermal conditions to impart micropleats along the bend lines. Preferably the drawn and heated and pleated web is passed through an electric field to impart an electrostatic charge to its fibers.
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Citations
18 Claims
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1. A process for manufacturing a pleated web suitable for the manufacture of cigarette filters which comprises:
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(a) selecting a nonwoven web having from 10 to 50 bend lines per inch extending generally in the MD and spaced transversely across the web, (b) heating the web to a temperature equal to or greater than the softening temperature of the polymer while drawing the web in the MD by at least 10% to cause micropleats to form at the bend lines, thereby reducing the width of the web by at least 15% and condensing the micropleats thereby forming a pleated web; and (c) cooling the tow pleated web. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18)
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16. A process for applying an electrostatic charge to a meltblown tow of a propylene homo or copolymer which comprises:
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(a) drawing and heating the tow to a temperature between 110°
C. and 165°
C.; and(b) passing the drawn and heated tow through an electric field.
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17. A process for manufacturing a pleated web suitable for the manufacture of cigarette filters which comprises:
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(a) selecting a nonwoven web having from 10 to 50 bend lines per inch spaced transversely across the web and extending generally in the MD of the direction of the bend lines, the bend lines having a major direction component in the MD; and (b) heating the web to a temperature equal to or greater than the softening temperature of the polymer while drawing the web in the MD from 10 to 300% to cause micropleats to form at the bend lines, thereby reducing the width of the web in a ratio of the micropleated web width to original web width of 1.15;
1 to 4;
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Specification