UST857038I4 - St available copy - Google Patents

Description

BEST AVAILABLE COPY DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the appllcantor owner in accordance with the Notice of Apr. 11, 1968, 849 0.6. 1221. Identification is by serial number orthe application and the heading indicates the number or pages or specification, including claims, and of sheets of drawing contained in the application as originally tiled. The die or this application is available to the public for inspection; reproduction may be purchased for 80 cents persheet.

Applications published under the Defensive Publication Program have not been examined as to the merits or alleged invention. The Patent Ofllce makes no assertion as to the novelty or the disclosed subject matter.

PUBLISHED DECEMBER 24, 1968 544,271 APERTURED NON-WOVEN STRUCTURE FROM A FILM-FIBRE. SHEET AND METHOD OF MAKING Millsd lhvid Zeisherg, N war-h, DeL, m to E. L

e dal'ontdeNernonrsandConspaay,Wihniagiols,DeL, a

All A KSILIEIT "If"! Of 9561"! I51".

PEIFOIUEI sum Ifll I005 SLITS Allllfil II A emu- IOIE Plllill.

IIAIIAL SYIUOIIIG 5-30! LEIGTIIISE A" S-ZN 5 GS-SE.

50", mm IOIIWEI Fill FIIIIL 5!!!! This invention relates to a process for making a soft, apertnred, fibrous, nonwoven structure having a high strength per-unit weight from a film-fibril sheet. The basic film-fibril sheet is prepared from flash-spun continuous fibrillated strands, preferably of linear high den sity polyethylepe, according to the method of Steuber US. Patent 3,169,899. The process of the present invention comprises hot-slit perforating the nonwoven filmiibril sheet by pressing between a supported hot wire screen and a resilient surface. Suflicient heat is supplied and suficient pressure is exerted between the two surfaces to provide an embossed sheet having numerous perforations in the form of slits. The slits are arranged in twoseriesasinaherringbonepatternwithstlcastone slit per square centimeter in the useable area of the sheet, the slits being at least 0.2 cm. long. The sheet is fused around the edges of the slits, but is unrused elsewhere. Theslitshedisthenstretched5-30% inadirection which is within 5-45 of the orientation of one of the two series of slits, this direction being usually along the longitudinal axis of the sheet. Optionally, the product is then stretched $-200% in a second direction at about 90 to the first stretch direction.

E COPY 967058 BEST AVATLABL a a q 1 FlG.l

IDIIDVEI FILH -F|BRIL SHEET TREATED IITH HEAT AID PRESSURE DETIEEI AR EMBOSSED SURFACE AHD efigEllklElT SURFACE OF SPECIFIC PERFDRATED SHEET IITH IUHERDUS SLITS ARRANGED IR A HERRIHG- DDIE PATTERN.

BIAXIAL STRETCHIHD 5-307. LEIDTHIISE AND 5-200 7. CROSS-15E.

SOFT, APERTURED IDIIDVEI FILI FIDRIL SHEET LOHGTTUDIIAL I J suaossuc scam snaosszo sum IX sumac, IX 5 6 znaossso snmcnso sum mm mm ZEISBERG i BY 8M rr-rnovrv

Images