Method and apparatus for making a shrink pack

Claim 5

The method of claim 2, and including the step of locally heating and bonding the pleat to adjacent sheet material prior to cluster envelopment.

Claim 6

The method of claim 3, in which the local heating and bonding is a longitudinally centrally located fraction of each selected length, said method including the additional step of orienting said fractional length along the top region of cluster envelopment, whereby upon exposure to said atmosphere, the locally bonded fraction of pleated length remains as a handle reinforcement at the top region, and whereby the shrink action in said atmosphere will dissolve the pleat at side and bottom cluster regions removed from said bonded fraction.

Claim 7

The method of claim 2, and including the step of locally compression-tacking the pleat to adjacent sheet material prior to cluster envelopment.

Claim 8

The method of claim 2, and including the step of continuously compression-roll tacking the pleat to adjacent sheet material prior to cluster envelopment.

Claim 9

The method of claim 2, and including the step of locally piercing single-thickness sheet material adjacent the pleated region at said one end.

Claim 10

Means for continuously packaging like generally rectangularly prismatically arrayed clusters of articles, comprising elongated conveyor means for supporting and transporting a continuous succession of clusters in equally spaced relation, an elongated supply of flexible heat-shrinkable and bondable envelope sheet material of width exceeding the cluster width transverse to the direction of conveyor transport, sheet-engaging and manipulating means operative upon sheet material from said supply and wrapping sheet material around successive clusters in the direction such that the width dimension of said material when wrapped is symmetrical with the cluster width transverse to the direction of conveyor transport, sheet-pleating means operative on sheet material from said supply and prior to engagement by said manipulating means, a locally heated environmental region in the path of conveyor movement after cluster-wrapping, the heating being sufficient to adhere the plastic sheet to itself at local regions of end and pleat overlap and to shrink the plastic into local contour-conformance with the cluster, and intermittently operative means for locally piercing said sheet material, said piercing means being positioned and synchronized with the wrapping cycle of said manipulating means such that single-thickness sheet material is locally pierced at a predetermined location along the wrap and adjacent the pleated region.

Claim 11

Means for continuously packaging like generally rectangularly prismatically arrayed clusters of articles, comprising elongated conveyor means for supporting and transporting a continuous succession of clusters in equally spaced relation, an elongated supply of flexible heat-shrinkable and bondable envelope sheet material of width exceeding the cluster width transverse to the direction of conveyor transport, sheet-engaging and manipulating means operative upon sheet material from said supply and wrapping sheet material around successive clusters in the direction such that the width dimension of said material when wrapped is symmetrical with the cluster width transverse to the direction of conveyor transport, sheet-pleating means operative on sheet material from said supply and prior to engagement by said manipulating means, a locally heated environmental region in the path of conveyor movement after cluster-wrapping, the heating being sufficient to adhere the plastic sheet to itself at local regions of end and pleat overlap and to shrink the plastic into local contour-conformance with the cluster, and intermittently operative means for locally piercing said sheet material, said piercing means being positioned and synchronized with the wrapping cycle of said manipulating means such that single-thickness sheet material is locally pierced at a predetermined location along the wrap and adjacent the pleated region.

Claim 12

Packaging means according to claim 8, in which said sheet-pleating means includes local-heating means to bond and thus retain pleating formations prior to cluster-wrapping.

Claim 13

Packaging means according to claim 9, in which said local-heating means is intermittently operative and has an intermittently operative cycle that is coextensive and synchronized with the wrapping cycle of said mAnipulating means, said intermittently operative cycle being operative to adhere passing pleat-overlapped material for only a predetermined fraction of the said intermittently operative cycle, thereby creating a bonded pleat of limited length, the phase relation of such synchronization being such that for each clusterwrapping operation the limited bonded pleat is located at least on the upper panel of the wrap.

Claim 14

Packaging means according to claim 10, in which the operative period of said local-heating means is the substantial equivalent of the span of the top panel in the wrap direction.

Claim 15

Packaging means according to claim 8, in which said articles are like prismatic containers and in which said sheet-pleating means includes means operative on said sheet material to define two pleats spaced substantially to the extent of the transverse dimension of each container.

Claim 16

Packaging means according to claim 8, in which said sheet-pleating means includes a pair of spaced compression rolls set in spaced relation at least to the extent of the sheet thickness of said material, said spaced relation being less than the combined multiple-ply thickness of the pleated region of said sheet, whereby said rolls will compress primarily only the pleated region of said sheet material.

Claim 17

Packaging means according to claim 13, in which one of said rolls has knurl formations.

Claim 18

Packaging means according to claim 13, in which said rolls are mounted for relative displacement of their axes, means preloading said rolls in the approach direction of such axis displacement, and stop means limiting the extent of such approach displacement to assure at least said spacing.