Starch adhesive bonding

An apparatus for adhering substrates of paper, paperboard, and like cellulosic-fiber materials to each other by means of an adhesive composition therebetween, which apparatus comprises the following components:

• (a) means for applying a coating of an adhesive composition, which comprises starch and water, to a surface area of a first substrate;
• (b) means for positioning an uncoated surface area of another substrate in juxtapositional contact with the applied coating;
• (c) means for applying ultrasonic energy to one or the other or both of the first or the another positioned substrates at an exterior surface area thereof juxtapositional to the applied coating between the positioned substrates;
• (d) one or more means for preheating either or both of the first and the other substrates to a temperature less than the gelatinization temperature of the adhesive composition prior to applying of the coating to the first substrate and prior to contact of the another substrate with the applied coating;
• and
• (e) one or more roll means provided with flutes thereon for forming of a fluted corrugating medium to function as the first substrate, and with the (c) means for applying ultrasonic energy positioned in relation to other components so as to provide, between an output horn of the means for applying ultrasonic energy and a flute on a roll means, a nip space less than the combined thickness of the first substrate, the coating and the other substrate.

An apparatus for adhering substrates of paper, paperboard, and like cellulosic-fiber materials to each other by means of an adhesive composition therebetween, which apparatus comprises the following components:

• (a) means for applying a coating of an adhesive composition, which comprises starch and water, to a surface area of a first substrate;
• (b) means for positioning an uncoated surface area of another substrate in juxtapositional contact with the applied coating;
• (c) means for applying ultrasonic energy to one or the other or both of the first or the another positioned substrates at an exterior surface area thereof juxtapositional to the applied coating between the positioned substrates;
• and
• (d) one or more roll means provided with flutes thereon for forming of a fluted corrugating medium to function as the first substrate, and with the (c) means for applying ultrasonic energy positioned in relation to other components so as to provide, between an output horn of the means for applying ultrasonic energy and a flute on a roll means, a nip space less than the combined thickness of the first substrate, the coating and the other substrate.