Hot-gas welding press fit device for valve strips or bag bottom covering sheets of block bottom valve bags

Abstract

The invention provides a hot-gas welding press fit device suitable for valve strips or bag bottom covering sheets of woven plastic block bottom valve bags. The hot-gas welding press fit device is low in pressure and capable of achieving short stroke clutching. The hot-gas welding press fit device comprises a lower press fit roller corresponding to a negative-pressure transferring roller, a gap formed between the lower press fit roller and the negative-pressure transferring roller corresponds to a gap set on a rack flat pallet, the tangent of the lower press fit roller and the rack flat pallet are on the same horizontal line, and cylindrical bag sheets and valve strips or covering sheets pass through the gap; and the lower press fit roller implements clutch pressing actions with the negative-pressure transferring roller through a pair of four-bar mechanisms with cylinders serving as executive components.

Description

technical field

[0001] The invention relates to a packaging machine, in particular to a pressing device for hot air welding of a bag bottom cover sheet in a bag making machine for a square bottom valve bag. Background technique

[0002] The square bottom valve bag made of plastic composite woven cloth, the production steps are as follows figure 1 As shown, first, both ends of the tubular sheet are opened and folded into a hexagonal shape. The symmetrical triangular area in the hexagon is called "wrap angle" or "corner flap", and the rectangular part that is symmetrical up and down in the hexagon is called "horizontal flap"; the dividing line of the middle rectangular part of the hexagon Call it the "Bottom Fold Centerline". Secondly, at one end of the tube, a valve strip needs to be pasted; then, the two horizontal flaps are respectively folded along the center line of the bottom of the bag, cross-folded towards each other, and overlapped a little to form a rectangular bag...

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