Polymeric buns and method and apparatus for its manufacture

A method of maufacturing a flat-topped polymeric bun comprising the steps of

• introducing liquid polymer to an expansion region in which said polymer expands and onto a supporting liquid which supports said polymer in a zone which is substantially coextensive with at least a major portion of said expansion region, said supporting liquid having a specific gravity higher than that of said polymer, whereby said polymer floats on and advances across said supporting liquid in the form of an expanding mass having left and right sides, a flat bottom and a top which slopes upwardly in the direction of advance,
• bringing conveying means into supporting relation to said expanding mass at said respective left and right sides of said expanding mass, said conveying mass having polymer-supporting active surfaces which respetively lie in substantially vertical planes extending in the direction of advance,
• interposing a protective film between said polymer and each of said polymer-supporting active surfaces,
• advancing said polymer-supporting active surfaces of said conveying means to move along with said expanding mass with respect to said supporting liquid, the interposed protective films being thereby advanced therewith, and
• orienting said conveying means so that the direction of advance of said polymer-supporting active surfaces is substantially parallel to said sloping top.

Apparatus for manufacturing a flattopped polymeric bun comprising

• trough means,
• means for dispensing into said trough means liquid polymer which expands on reaction,
• said through means being inclined to cause flow of said polymer to an expansion region wherein said polymer expands,
• means providing a supporting liquid for supporting said polymer in a zone which is substantially coextensive with at least a major portion of said expansion region, said supporting liquid having a specific gravity which is higher than that of said polymer, whereby said polymer floats on and advances across said supporting liquid in the form of an expanding mass having left and right sides, a flat bottom and a top which slopes upwardly in the direction of advance,
• conveying means having relatively firm polymer-supporting active surfaces,
• means mounting said conveying means in supporting relation to said expanding mass at said respective left and right sides of said expanding mass with said polymer-supporting active surfaces lying in substantially vertical planes extending in the direction of advance,
• a protective film interposed between said polymer and each of said polymer-supporting active surfaces, and
• means for advancing said polymer-supporting active surfaces of said conveying means so that they move along with said expanding mass with respect to said supporting liquid, the interposed protective film being thereby advanced therewith,
• said conveying means being oriented so that the direction of advance of said polymer-supporting active surfaces is substantially parallel to said sloping top, the lower ends of said conveying means being submerged in said supporting liquid and being upstream of the higher ends thereof,
• whereby, upon completion of said expansion, a polymeric bin is formed having bottom, left, right, and top surfaces that are substantially flat.

Apparatus for manufacturing a flat-topped polymeric bun comprising:

• means for dispensing liquid polymer which expands on reaction,
• means providing a supporting liquid for supporting said polymer in a zone which is substantially coextensive with at least a major portion of an expansion region wherein said polymer expands, said supporting liquid having a specific gravity which is higher than that of said polymer, whereby said polymer floats on and advances across said supporting liquid in the form of an expanding mass having left and right sides, a flat bottom and a top which slopes upwardly in the direction of advance,
• conveying means having relatively firm polymer-supporting active surfaces,
• means mounting said conveying means in supporting relation to said expanding mass at said respective left and right sides of said expanding mass with said polymer-supporting active surfaces lying in substantially vertical planes extending in the direction of advance,
• a protective film interposed between said polymer and each of said polymer-supporting active surfaces, and
• means for advancing said polymer-supporting active surfaces of said conveying means so that they move along with said expanding mass with respect to said supporting liquid, the interposed protective film being thereby advanced therewith,
• said conveying means being oriented so that the direction of advance of said polymer-supporting active surfaces is substantially parallel to said sloping top,
• whereby, upon completion of said expansion, a polymeric bun is formed having bottom, left, right, and top surfaces that are substantially flat.

Apparatus for manufacturing a polymeric bun comprising:

• means for dispensing liquid polymer which expands on reaction,
• means providing a supporting liquid for supporting said polymer in a zone which is substantially coextensive with at least a major portion of an expansion region wherein said polymer expands, said supporting liquid having a specific gravity which is higher than that of said polymer, whereby said polymer floats on and advances across said supporting liquid in the form of an expanding mass having left and right sides, a flat bottom and a top which slopes upwardly in the direction of advance,
• wall means having relatively firm polymer-supporting active surfaces, and
• means mounting said wall means in supporting relation to said expanding mass at said respective left and right sides of said expanding mass with said polymer-supporting active surfaces lying in substantially vertical planes extending in the direction of advance, said mounting means including means for selectively adjusting the distance between said polymer supporting active surfaces.