Method and apparatus for making on-line stabilized absorbent materials

A method for forming a stabilized airlaid layer, comprising:

• a providing of absorbent fibers with a fiberizer;
• a directing of said absorbent fibers into a forming chamber;
• an introducing of binder-fibers into said forming chamber by directing said binder-fibers into said forming chamber at an binder-fiber inlet location that is closely adjacent said fiberizer;
• an airforming of a fibrous layer which includes a mixture of said absorbent fibers and binder-fibers, said absorbent fibers and binder-fibers arranged substantially free of active inter-fiber bonds;
• a moving of said fibrous layer at a fibrous layer speed of at least a minimum of about 0.5 m/sec;
• an exposing of said fibrous layer to high-frequency electromagnetic energy during an activation period of not more than a maximum of about 3 sec to thereby activate said binder-fibers to provide said stabilized, airlaid layer.

A method for forming an airlaid layer, comprising:

• an airforming of a fibrous layer which includes absorbent fibers and binder-fibers;
• a moving of said fibrous layer at a fibrous layer speed of at least a minimum of about 0.5 m/sec;
• an exposing of said fibrous layer to high-frequency electromagnetic energy during an activation period of not more than a maximum of about 3 sec to activate said binder-fibers to provide a stabilized, airlaid layer;
• a presenting of said stabilized layer at a setting temperature of not more than about 200° C. which is provided within a period of not more than about 3 sec after an ending of said exposing of the fibrous layer to high-frequency electromagnetic energy;
• a debulking of said stabilized layer to increase a density thereof, said debulking occurring at a temperature that is not higher than said setting temperature.

A method for forming an airlaid layer, comprising:

• a providing of absorbent fibers from a fiberizer into a forming chamber;
• an introducing of a metered amount of binder-fibers into said forming chamber by directing said binder-fibers into said forming chamber at an binder-fiber inlet location that is closely adjacent said fiberizer;
• an airforming of an fibrous layer within said forming chamber, said fibrous layer including a mixture of said absorbent fibers and said binder-fibers, said absorbent fibers and binder-fibers arranged substantially free of active inter-fiber bonds;
• a scarfing of said fibrous layer to provide
• an average fibrous layer density of not more than a maximum of about 0.1 g/cm3, and
• a fibrous layer, basis weight of at least about 100 g/m2;
• a moving of said fibrous layer at a fibrous layer speed of at least a minimum of about 0.5 m/sec;
• an exposing of said fibrous layer to high-frequency electromagnetic energy during an activation period of not more than a maximum of about 3 sec to thereby activate said binder-fibers and provide a stabilized, airlaid layer, said electromagnetic energy having a frequency of at least about 0.3 MHz;
• a debulking of said stabilized layer to provide a debulked, stabilized layer having a relatively greater average density.

A method for forming an airlaid layer, comprising:

• an airforming of a fibrous layer which includes absorbent fibers and binder-fibers, said absorbent fibers and binder-fibers arranged substantially free of active inter-fiber bonds;
• a moving of said fibrous layer at a fibrous layer speed of at least a minimum of about 0.5 m/sec;
• an exposing of said fibrous layer to high-frequency electromagnetic energy in a tuned activation chamber during an activation period of not more than a maximum of about 3 sec to activate said binder-fibers to provide a stabilized, airlaid layer, said electromagnetic energy having a frequency of at least about 0.3 MHz;
• a tuning of said activation chamber to provide a Q-factor of at least about 200 when activating said binder-fibers, said tuning employing a variable geometry activation chamber:

A method for forming an airlaid layer, comprising:

• a providing of absorbent fibers with a fiberizer;
• a directing of said absorbent fibers into a forming chamber;
• an introducing of a metered amount of binder-fibers into said forming chamber by directing said binder-fibers into said forming chamber at an binder-fiber inlet location that is closely adjacent said fiberizer, said metered amount of binder-fibers arranged to provide not more than about 30 wt % of said stabilized airlaid layer;
• an airforming of a fibrous layer within said forming chamber, said fibrous layer including a mixture of said absorbent fibers and said binder-fibers, said absorbent fibers and binder-fibers arranged substantially free of active inter-fiber bonds, and said fibrous layer formed with a cross-directional width that substantially corresponds to a selected single-article dimension;
• a scarfing of said fibrous layer to provide at least a portion of said fibrous layer with a basis weight of at least about 100 g/m2;
• a moving of said fibrous layer to provide a fibrous layer speed of at least a minimum of about 0.5 m/sec;
• an exposing of said fibrous layer to high-frequency electromagnetic energy within a tuned activation chamber during an activation period of not more than a maximum of about 3 sec to activate said binder-fibers to provide a stabilized, airlaid layer, said electromagnetic energy having a frequency of at least about 0.3 MHz;
• a tuning of said activation chamber to provide a Q-factor of at least about 200 when activating said binder-fibers, said tuning employing a variable geometry activation chamber and a variable impedance;
• and
• a debulking of said stabilized layer to provide a debulked, stabilized layer having an average density of at least a minimum of about 0.05 g/cm3.