Apparatus and method for producing a nonwoven web of filaments

An apparatus for producing nonwoven fabrics comprising:

• a spinnerette having a plurality of orifices for extruding filaments;
• an attenuator for receiving and attenuating the filaments;
• a collection surface upon which the filaments are deposited to form a nonwoven web;
• a filament diffuser positioned between the attenuator and the collection surface in the path of filament travel, said diffuser comprising a pair of opposing divergingly arranged side walls and a pair of opposing end walls defining a filament passageway;
• a corona device cooperating with the filaments for imparting an electrical charge on the filaments, and
• means for imparting a like electrical charge on at least one of said side walls of said filament diffuser so as to thereby guide the filaments as they pass through the diffuser.

An apparatus for producing nonwoven fabrics comprising:

• a spinnerette having a plurality of orifices for extruding filaments;
• an slot-shaped pneumatic attenuator positioned beneath said spinnerette for receiving the filaments therefrom;
• an endless collection belt beneath said attenuator upon which the filaments are deposited to form a nonwoven web;
• a filament diffuser positioned between the attenuator and the collection surface in the path of filament travel, said diffuser comprising a pair of opposing divergingly arranged side walls each having a width dimension and a height dimension and a pair of opposing generally parallel solid end walls, each having a width dimension substantially less than that of said side walls and a height dimension substantially the same as that of said side walls, said side walls and end walls defining a filament passageway with a relatively narrow cross sectional area slot shaped open upper end positioned for receiving the filaments from said slot shaped attenuator and with a larger cross sectional area open lower end positioned above said collection belt for depositing the filaments thereon;
• an elongate slit formed in each of said side walls and in each of said end walls extending in the width dimension of the respective walls and oriented for injecting a flow of fluid along the walls in the direction of filament travel;
• and
• means for supplying fluid under pressure to said slits.

An apparatus for producing nonwoven fabrics comprising:

• a spinnerette having a plurality of orifices for extruding filaments;
• an slot-shaped pneumatic attenuator positioned beneath said spinnerette for receiving the filaments therefrom;
• an endless collection belt beneath said attenuator upon which the filaments are deposited to form a nonwoven web;
• a filament diffuser positioned between the attenuator and the collection surface in the path of filament travel, said diffuser comprising a pair of opposing divergingly arranged side walls each having a width dimension and a height dimension and a pair of opposing generally parallel solid end walls, each having a width dimension substantially less than that of said side walls and a height dimension substantially the same as that of said side walls, said side walls and end walls defining a filament passageway with a relatively narrow cross sectional area slot shaped open upper end positioned for receiving the filaments from said slot shaped attenuator and with a larger cross sectional area open lower end positioned above said collection belt for depositing the filaments thereon;
• a corona device cooperating with the filaments for imparting an electrical charge on the filaments;
• a first power supply electrically connected to one of said side walls and a second power supply electrically connected to the other of said side walls, said first and second power supplies being independently controllable for applying a variable electrical potential to the respective side walls for thereby electrostatically guiding the filaments as they pass through the filament diffuser.

A method for producing nonwoven fabrics comprising:

• extruding a plurality of filaments;
• attenuating the filaments;
• directing the filaments through a filament diffuser comprising a pair of opposing divergingly arranged side walls and a pair of opposing end walls defining a filament passageway, injecting a flow of fluid along the side walls in the direction of filament travel and injecting a flow of fluid along said end walls in the direction of filament travel;
• discharging the filaments from the filament attenuator and depositing the filaments on a collection surface to form a nonwoven web.

A method for producing nonwoven fabrics comprising:

• extruding a plurality of filaments;
• attenuating the filaments;
• directing the filaments through a filament diffuser comprising a pair of opposing divergingly arranged side walls and a pair of opposing end walls defining a filament passageway, injecting a flow of fluid along the side walls in the direction of filament travel and injecting a flow of fluid along said end walls in the direction of filament travel;
• discharging the filaments from the filament attenuator and depositing the filaments on a collection surface to form a nonwoven web.
• imparting an electrical charge on the filaments, and
• imparting a like electrical charge on at least one of said side walls of said filament diffuser so as to thereby guide the filaments as they pass through the diffuser.