Apparatus and method for forming foam cushions for packaging purposes

A method of successively forming foam cushions and protectively packaging one or more articles in each of a series of containers with such cushions, said method comprising the steps of

• advancing a pair of webs of plastic film along predetermined paths of travel from respective supply sources, and including guiding the advancing webs into opposing face to face contact at a first heat sealing station, while
• heat sealing the opposing longitudinal side edges of the advancing pair of webs to each other at the first heat sealing station to sealingly interconnect the opposing webs along opposite side edges, while
• periodically introducing a predetermined amount of foamable composition between the advancing pair of webs of plastic film and so as to be deposited in each bag being formed, while
• periodically and momentarily interrupting the heat sealing of the pair of webs to each other along at least one of said side edges during the advancement of the webs through the first heat sealing station so as to form at least one unsealed longitudinal side edge portion which defines at least one side edge opening for each bag, while
• advancing the sealingly interconnected webs to and through a second heat sealing station and transversely heat sealing the webs together upstream of the unsealed side edge portions at the second heat sealing station to form a sealed top edge for each successive bag of foamable composition and including severing each bag from the next succeeding bag while forming a sealed bottom edge for the next succeeding bag to thereby form separate and individual bags having at least one ventillation opening in at least one longitudinal side edge,
• successively moving open-topped containers in a predetermined path of travel to and beneath the second heat sealing station to receive the separated bags of foamable composition in the containers before the foamable composition in the bags has completely foamed, and
• positioning an article to be packaged in each of said containers, and then successively closing and sealing the containers before the foamable composition forming the cushion in each container has completely foamed.

An apparatus for successively forming foam cushions for packaging purposes wherein each cushion comprises a closed plastic bag filled with foam and having a ventilation opening along at least one side edge thereof for escapement of gas generated during foam formation, said apparatus comprising

• means for advancing two webs of plastic film along predetermined paths of travel from respective supply sources, and for guiding the advancing webs into opposing face to face contact,
• first heat sealing means positioned along said path of travel for heat sealing longitudinal side edges of the advancing plastic webs, while they are in opposing face to face contact,
• means for periodically introducing a predetermined amount of foamable composition between the opposing webs at a location upstream of the location at which the two webs are guided into opposing face to fact contact and so as to be deposited in each bag being formed, and as the webs are being advanced and sealed along said longitudinal side edges,
• control means for periodically and momentarily interrupting operation of said first heat sealing means to provide a ventilation opening along at least one side edge of each bag being formed to thereby allow gas generated during foam formation to escape from within each bag, and
• second heat sealing means positioned along said path of travel for heat sealing said webs together transversely thereof to form a sealed top edge of a foam filled bag while also forming the sealed bottom edge of the next succeeding bag and for severing each formed bag from the next succeeding bag to thereby form separate and individual bags having at least one ventillation opening in at least one longitudinal side edge.

An apparatus for successively forming foam cushions and protectively packaging one or more articles in each of a series of containers, said apparatus comprising

• means for advancing two webs of plastic film along predetermined paths of travel from respective supply sources, and for guiding the advancing webs into opposing face to face contact,
• first heat sealing means positioned along said path of travel for heat sealing longitudinal side edges of the advancing plastic webs, while they are in opposing face to face contact,
• means for periodically introducing a predetermined amount of foamable composition between the opposing webs at a location upstream of the location at which the two webs are guided into opposing face to face contact and so as to be deposited in each bag being formed, and as the webs are being advanced and sealed along said longitudinal side edges,
• control means for periodically and momentarily interrupting operation of said first heat sealing means to provide a ventilation opening along at least one side edge of each bag being formed to thereby allow gas generated during foam formation to escape from within each bag,
• second heat sealing means positioned along said path of travel for heat sealing said webs together transversely thereof to form a sealed top edge of a foam filled bag while also forming the sealed bottom edge of the next succeeding bag and for severing each formed bag from the next succeeding bag to thereby form separate and individual bags having at least one ventillation opening in at least one longitudinal side edge,
• conveyor means for successively moving open-topped containers with one or more articles therein in a predetermined path of travel to and beneath said second heat sealing means in a coordinated manner for receiving successively formed foam cushions in the respective containers before the foamable composition in the cushions has completely formed, and
• means for successively closing and sealing the containers before the foamable composition forming the cushion in each container has completely formed.