Polypropylene wrap end seals and process for making same
AssigneeInternational Playtex, Inc.
InventorsWillard A. Ingersoll, Robert C. Norquest, Richard A. Weber
Life of this patent
Estimating the term…
Abstract
A voided polypropylene film tampon wrap having end seals which are formed by mechanical crimping and a process for sealing the ends of the voided polypropylene film tampon wrap by mechanical crimping. A notch is formed adjacent to each end seal but remote from the enclosed tampon. Each end seal is formed by a pair of horizontal teeth wheels each having a pitch of 50 teeth per inch. One of the pair of wheels is heated to a temperature of 125.degree..+-.15.degree., and force is applied to at least one wheel to seal that end of the wrap by the pair of wheels.
Claims17
A process for sealing an end of a voided polypropylene film wrap comprising the steps of:
- (a) inserting said end of said polypropylene wrap between a 50 pitch knurl wheel and a 50 pitch idler wheel;
- (b) pressing at least one of said knurl and idler wheels against said polypropylene wrap and said other wheel so as to effect a mechanically crimped seal;
- and
- (c) heating said knurl wheel prior to and during said pressing step (b) to a temperature from 110.degree. F. to 140.degree. F. in order to increase the flexibility of said polypropylene wrap but not form a heat seal.
A process for forming a voided polypropylene film wrap adapted to receive and have sealed therein an article, said process comprising the steps of:
- (a) sealing a sheet of voided polypropylene film along its longitudinal edges to form a tube;
- (b) cutting said tube into an individual wrap so that each wrap has an alternative row of notches at each end;
- (c) inserting a first end of said wrap between a 50 pitch knurl wheel and a 50 pitch idler wheel;
- (d) pressing at least one of said knurl and idler wheels against said first end of said wrap and said other wheel so as to effect a mechanically crimped seal;
- (e) and (f) repeating steps (c) and (d), respectively, for a second end of said wrap;
- and
- (g) heating said knurl wheel prior to and during said pressing steps to a temperature from 110.degree. F. to 140.degree. F. in order to increase the flexibility of the polypropylene wrap but not form a heat seal.
Apparatus for use in inserting and sealing an article within a voided polypropylene film wrap comprising:
- (a) means for forming a sheet of voided polypropylene film into a tube;
- (b) means for cutting said tube into individual wraps so that each wrap has an alternative row of notches at each end;
- (c) a rotating turret sealing device including a plurality of transverse acruate grooves adapted to receive each wrap;
- (d) means for introducing at least one of said individual wraps into at least one of said transverse acruate grooves;
- (d) means for rotating said turret sealing device such that said at least one of said transverse arcuate grooves is positioned relative to a first sealing station which includes a heated knurl wheel and an idler wheel for sealing at least one end of said at least one wrap;
- (e) means for sealing said at least one end;
- (f) means for inserting said article into a second end of said at least one wrap;
- (g) means for further rotating said turret sealing device such that said at least one transverse arcuate groove is positioned relative to a second sealing stating which includes a heated knurl wheel and an idler wheel for sealing said second end;
- and
- (h) means for sealing said second end.
Dependencies are inferred from the claim text.