Multi-layer co-extruded blown film production
plant configured to co-extrude multiple
layers of molten materials to form a
plastic film bubble with a multi-layer
composite structure, the multi-layer co-extruded blown film production
plant comprising a
film blowing machine head, the
film blowing machine head being equipped with an annular
extrusion outlet, an annular converging flow channel and multiple sets of material spreading channels, each set of material spreading channels directing the flow of a layer of
molten material and spreading the layer of
molten material into an annular shape, the downstream end of each set of material spreading channels being connected to the annular converging flow channel, and the annular converging flow channel being connected to the annular
extrusion outlet; wherein the material propagation flow channel corresponding to the outermost layer of
molten material comprises an annular outermost material outlet slot cavity, wherein the outermost material outlet slot cavity is vertically joined by an annular outer upper module and an annular outer lower module, the outer upper module being located above the outer lower module, and a vertical gap being located between the inner parts of the outer upper module and the inner parts of the outer lower module, the vertical gap forming the outermost material outlet slot cavity, the outer edge of the outermost material outlet slot cavity being closed, and the inner edge of the outermost material outlet slot cavity being connected to the annular converging flow channel; wherein several internally rotating horizontal vortex flow channels are formed on the surface of the outermost material outlet slot cavity; characterized in that the proximal section of the outermost material outlet slot cavity has a smaller taper towards the top and a larger taper towards the bottom, wherein the part of the outermost material outlet slot cavity that is not the proximal section is referred to as the main section of the outermost material outlet slot cavity; wherein the outermost material outlet slot cavity is provided with a first filler piece, wherein the first filler piece comprises an inclined section of the first filler piece and a horizontal section of the first filler piece, which are formed in one piece, wherein the inclined section of the first filler piece is arranged in a proximal section of the outermost material outlet slot cavity and the horizontal section of the first filler piece is arranged in the main section of the outermost material outlet slot cavity; that the material propagation flow channel corresponding to the innermost layer of molten material comprises an annular innermost material outlet slot cavity, wherein the innermost material outlet slot cavity is vertically joined by an annular inner upper module and an annular inner lower module, the inner upper module being located above the inner lower module, the outer lower module being located at the outer edge of the inner lower module, and the outer upper module being located at the outer edge of the inner upper module; wherein a vertical gap is located between the outer part of the inner upper module and the outer part of the inner lower module, the vertical gap forming the innermost material outlet slot cavity; wherein the outer edge of the innermost material outlet slot cavity is closed, and the inner edge of the innermost material outlet slot cavity is connected to the annular converging flow channel;wherein several internally rotating horizontal vortex flow channels are formed on the surface of the innermost material outlet slot cavity; that the distal section of the outermost material outlet slot cavity has a larger taper towards the top and a smaller taper towards the bottom, wherein the part of the outermost material outlet slot cavity that is not the distal section is referred to as the main section of the innermost material outlet slot cavity;wherein the outermost material
discharge slot cavity is provided with a second filler piece, the second filler piece comprising an inclined section and a horizontal section of the second filler piece being formed in one piece, the inclined section of the second filler piece being arranged in a distal section of the innermost material
discharge slot cavity and the horizontal section of the second filler piece being arranged in the main section of the innermost material
discharge slot cavity; wherein the second filler piece and the first filler piece have the same orientation relative to the central axis of the
film blowing machine head.