illustrated generally at 108 in fig1 is often loosely packed or unsettled after falling into the preform 22 this is particularly the case with product having a large particle size and relatively light weight such as tortilla chips potato chips corn chips and the like in order to settle or more compactly pack the product into the bottom of the tubular bag preform there is included the oscillating mechanism for example air cylinders not shown or an eccentric 112 driving a link 114 pivotally connected to the outer tube 104 for oscillating the outer tube up and down a plurality of link arrangements each having a pair of vertical links 118 and 120 pivotally connected to each other at their lower ends and having their upper ends pivotally connected to the bottom of the outer tube 104 and the bottom of the inner tube 102 respectively are spaced around the bottoms of the tubes for example there are provided four link pairs spaced 90 u00b0 apart these link arrangements are such that the links 118 and 120 pivot outward as shown in fig1 to engage the wall of the tubular bag preform 22 when the outer tube is in its uppermost position thus the vertical oscillation of the outer tube 104 results in the oscillation of the wall of the tubular bag preform which in turn shakes the bottom of the preform to settle and more closely pack the product 108 while the illustrated embodiment of fig1 and 12 moves the outer tube 104 up and down the oscillating could alternatively be performed by moving the inner tube.