Process for making expanded synthetic resinous beads

Claim 2

IN A METHOD FOR THE PREPARATION OF FOAMED BEADS OF SYNTHETIC RESINOUS THERMOPLASTIC MATERIAL FROM A FOAMABLE, EXTRUDABLE SYNTHETIC THERMOPLASTIC RESINOUS COMPOSITION WHEREIN THE RESINOUS COMPOSITION IS INTERMITTENTLY EXTRUDED IN A HEAT PLASTIFIED FORM, THE COMPOSITION COMPRISING A SYNTHETIC THERMOPLASTIC RESINOUS COMPOSITION WHICH IS EXTRUDABLE AND FOAMABLE, THE RESINOUS COMPOSITION BEING INTERMITTENTLY EXTRUDED UNDER CONTINUOUSLY APPLIED PRESSURE THROUGH A PLURALITY OF CONSTRICTED PASSAGEWAYS BY A VALVING MEANS INTO A PLURALITY OF OPEN OUTLETS IN A ZONE OF LOWER PRESSURE TO PROVIDE A PLURALITY OF CLOSELY ADJACENT SEQUENTIALLY EXTRUDED GLOBULES, THE IMPROVEMENT WHICH CMPRISES PERMITTING IN SAID ZONE OF LOWER PRESSURE THE SEQUENTIALLY EXTRUDED GLOBULES OF THE COMPOSITON IN CLOSELY ADJACENT RELATIONSHIP TO EXPAND AND CAUSE THE GLOBULES TO THEREBY ADHERE TOGETHER TO FORM STRANDS, THE STRANDS CONSISTING ESSENTIALLY OF A PLURALITY OF FOAMED PARTICLES ADHERED TOGETHER, AND SUBSEQUENTLY APPLYING MECHANICAL AGITATION TO SAID STRANDS SUFFICIENT TO SEPARATE THE STRANDS INTO INDIVIDUAL PARTICLES.

Claim 3

The method of claim 1 wherein the mechanical agitation is applied by turbulent air.

Claim 4

The method of claim 1 wherein mechanical agitation is applied by means of a centrifugal blower.

Claim 5

The method of claim 1 wherein the synthetic resinous composition is an alkenyl aromatic resin.

Claim 6

The method of claim 4 wherein the alkenyl aromatic resin is a styrene polymer.

Claim 7

The method of claim 5 wherein the styrene polymer is polystyrene.

Claim 8

In a method for the preparation of foamed beads of synthetic thermoplastic alkenyl aromatic resinous compositions from a foamable, extrudable synthetic thermoplastic resinous composition wherein the resinous composition is intermittently extruded in a heat plastified form as a plurality of sequentially extruded globules, the composition comprising a synthetic thermoplastic resinous composition of alkenyl aromatic resin which is extrudable and foamable, wherein the alkenyl aromatic resin comprises in chemically combined form at least 50 percent by weight of at least one alkenyl aromatic compound having the general formula

Claim 9

In a method for the preparation of foamed beads of synthetic thermoplastic alkenyl aromatic resinous compositions from a foamable, extrudable synthetic thermoplastic resinous composition wherein the resinous composition is intermittently extruded in a heat plastified form as a plurality of sequentially extruded globules, the composition comprising a synthetic thermoplastic resinous composition of alkenyl aromatic resin which is extrudable and foamable, wherein the alkenyl aromatic resin comprises in chemically combined form at least 50 percent by weight of at least one alkenyl aromatic compound having the general formula

Claim 10

In a method for the preparation of foamed beads of synthetic thermoplastic polystyrene resinous compositions from a foamable, extrudable synthetic thermoplastic polystyrene resinous composition wherein the resinous composition is intermittently extruded in a heat plastified form as a plurality of sequentially extruded globules, the composition comprising a synthetic thermoplastic resinous compostion of polystyrene which is extrudable and foamable, the polystyrene composition being intermittently extruded under continuously applied pressure through a plurality of constricted passageways by a valving means into a plurality of open outlets in a zone of lower pressure, the improvement which compries permitting in said zone of lower pressure the sequentially extruded globules of the composition in closely adjacent relationship to expand and cause the blobules to thereby adhere together to form strands, the strands consisting essentially of a plurality of foamed particles adhered together, and subsequently applying mechanical agitation to said strands sufficient to separte the strands into individual particles.

Claim 11

In a method for the preparation of foamed beads of synthetic thermoplastic polystyrene resinous compositions from a foamable, extrudable synthetic thermoplastic polystyrene resinous composition wherein the resinous composition is intermittently extruded in a heat plastified form as a plurality of sequentially extruded globules, the composition comprising a synthetic thermoplastic resinous compostion of polystyrene which is extrudable and foamable, the polystyrene composition being intermittently extruded under continuously applied pressure through a plurality of constricted passageways by a valving means into a plurality of open outlets in a zone of lower pressure, the improvement which compries permitting in said zone of lower pressure the sequentially extruded globules of the composition in closely adjacent relationship to expand and cause the blobules to thereby adhere together to form strands, the strands consisting essentially of a plurality of foamed particles adhered together, and subsequently applying mechanical agitation to said strands sufficient to separte the strands into individual particles.