Plant for making spunbond type polymeric filament
A plant for making spunbond type polymeric filament defining an extrusion direction and including, in order along the extrusion direction, an extrusion head including at least one main channel to allow the passage of polymeric fluid through the extrusion head, a distributor including at least one distribution conduit in fluid passage connection with the main channel to distribute the fluid, at least one spinneret having holes each running parallel to the extrusion direction in fluid passage connection with the distribution conduit and suitable for extruding the fluid to make a respective polymeric filament, at least one distribution tank between the distributor, downstream of the conduit, and the spinneret, upstream of the holes, connecting, in fluid passage connection, the conduit and holes and defining a first thickness along the extrusion direction between 3 and 5 mm.
1 . A plant for making spunbond type polymeric filament defining an extrusion direction and comprising in order along said extrusion direction:
an extrusion head including at least one main channel suitable for allowing the passage of polymeric fluid through said extrusion head,
a distributor being a breaker plate including at least one distribution conduit in fluid passage connection with said main channel and suitable for distributing said fluid, wherein the breaker plate includes a cavity and a filter, the cavity defining a distributor housing adjacent to said extrusion head and arranged between said main channel and said distribution conduit, and the filter housed and supported within said distributor housing;
at least one spinneret including a plurality of holes, each of the holes developing parallel to said extrusion direction in fluid passage connection with said distribution conduit and suitable to extrude said fluid to make a respective polymeric filament,
at least one distribution tank realised between said distributor, downstream of said distribution conduit, and said spinneret, upstream of said holes, and connecting, in fluid passage connection, said distribution conduit and said holes,
wherein said distribution tank defines a first thickness along said extrusion direction between 3 mm and 5 mm.
2 . The plant according to claim 1 , wherein said distributor housing is configured to distance said filter and said distribution conduit to achieve at least one separation space.
3 . The plant according to claim 2 , wherein said separation space defines a second thickness between 500 μm and 8 mm.
4 . The plant according to claim 1 , wherein said filter include a porous element defining a plurality of non-rectilinear and irregularly sized passageways.
5 . The plant according to claim 4 , wherein said porous element comprises a plurality of adjacent pores, defining said passageways, having a porosity greater than or equal to 18 μm.
6 . The plant according to claim 4 , wherein said porous element comprises a plurality of sintered particles.
7 . The plant according to claim 4 , wherein said porous element comprises metallic material.
8 . The plant according to claim 4 wherein said polymeric fluid is selected from at least one member of the group polypropylene, polyester, nylon, cellulose, polyethylene, viscose and PLA.
9 . The plant according to claim 1 , wherein said first thickness is between 3 and 4 mm.
10 . The plant according to claim 1 , wherein said first thickness is between 4 and 5 mm.
11 . The plant according to claim 1 , wherein said extrusion head is a common distributor which is a coat hanger, and wherein said distributor is a breaker plate.
12 . The plant according to claim 5 , wherein said porous element comprises a plurality of sintered particles.
13 . The plant according to claim 1 , wherein said first thickness is between 3 and 5 mm, wherein said distributor comprises at least one housing adjacent to said extrusion head and arranged between said main channel and said distribution conduit and filtering means housed within said housing, wherein said housing is configured to distance said filter means and said distribution conduit so as to achieve at least one separation space, wherein said separation space defines a second thickness between 500 μm and 8 mm, wherein said filtering means include a porous element defining a plurality of non-rectilinear and irregularly sized passageways, wherein said porous element comprises a plurality of adjacent pores, defining said passageways, having a porosity greater than or equal to 18 μm, wherein said porous element comprises a plurality of sintered particles, wherein said porous element comprises metallic material.
14 . The plant according to claim 13 , wherein said polymeric fluid is selected from at least one member of the group polypropylene and polyethylene.
15 . The plant according to claim 13 , wherein said polymeric fluid is selected from at least one member of the group polyester, nylon, cellulose, viscose and PLA.
16 . The plant according to claim 1 ,
wherein said main channel of said extrusion head defines:
a vertical inlet channel having an upstream end and a downstream end,
first and second intermediate channels that each have an inlet end and a discharge end, and
a transverse lower channel having opposed first and second inlet ends and a discharge opening between said opposed first and second inlet ends,
wherein the vertical inlet channel downstream end is in fluid communication with the first intermediate channel inlet end and the second intermediate channel inlet end,
wherein the first intermediate channel discharge end is in fluid communication with the transverse lower channel first inlet end,
wherein the second intermediate channel discharge end is in fluid communication with the transverse lower channel second inlet end,
wherein the first and second intermediate channels and the transverse lower channel define a flow path shaped as an isosceles triangle having legs and a base for the passage of polymeric fluid through said extrusion head, wherein the first intermediate channel and the second intermediate channel are the legs of the isosceles triangle, and the transverse lower channel is the base of the isosceles triangle; and
wherein said distributor is a breaker plate.
17 . The plant according to claim 16 , wherein said distribution tank is positioned in the distributor and/or in the spinneret as a cavity defined by the distributor and/or the spinneret.
18 . The plant according to claim 1 , wherein said distribution tank is positioned in the distributor and in the spinneret as a cavity defined by complimentary cavities of the distributor and the spinneret.