Candle filter supports and plate assemblies for polymer melts

Abstract

A polymer melt candle filter having a support, the support comprising a hollow cylindrical body (101) defined by a first end (102), a second end (103), and a cylindrical wall (104) having a first end portion (105) and a second end portion (106). The first end portion (105) comprises a screw thread (107) on its outer surface and optionally a hexagonal fitting (203) on its inner surface for receiving a hexagonal wrench. The second end portion (106) comprises a plurality of holes (108) in the cylindrical wall (104). The area of ​​the openings (301, 302) of the holes (108) on the outer surface of the cylindrical wall (104) may be greater than the area of ​​the openings (301, 302) of the corresponding holes (108) on the inner surface of the cylindrical wall (104). The shape of the openings of the holes (108) on the outer surface may be non-circular.

Description

[0001] Related Applications

[0002] This application is a divisional application of Chinese invention patent application No. 201780081513.1, which entered the Chinese national phase on June 28, 2019 and is entitled "Candle filter support and plate assembly for polymer melts". Technical Field

[0003] The present invention generally relates to filters for polymer melts. Background Art

[0004] Thermoplastic polymers in the molten state are often filtered to remove impurities, such as solids and / or gels, before they are delivered to a mold cavity or through a die plate. Examples of polymer filtering devices are shown in US 4,701,118, US 5,004,414 and US 6,641,728.

[0005] The filter portion of these devices typically includes a support plate with small holes and multiple filters like sticks or candles. The filters themselves consist of a tubular support structure with one or more filter media in the form of sleeves wrapped around these tubular support structures.

[0006] However, both the porous support plates and tubular support structures currently available on the market suffer from a number of disadvantages. For example, the design of the tubular support structure is not very efficient for filtering or displacement. In addition, the porous support plates and tubular support structures are susceptible to cracking and breakage under normal use.

[0007] Therefore, there is a need in the art for improved perforated support plates and tubular support structures for filtering polymer melts.

[0008] The present invention addresses this need as well as other needs, which will become apparent from the following description and the appended claims. Summary of the invention

[0009] The invention is as set out in the appended claims.

[0010] Briefly, in a first aspect, the present invention provides a polymer melt filter support. In one embodiment, the filter support comprises:

[0011] a hollow cylindrical body defined by a first end, a second end, and a cylindrical wall having a first end portion and a second end portion;

[0012] screw threads on an outer surface of the first end portion; and

[0013] a plurality of holes in the cylindrical wall at the second end portion,

[0014] wherein the holes allow the polymer melt outside the cylindrical body to flow to the inside of the cylindrical body,

[0015] wherein the first end comprises an opening for allowing the polymer melt inside the cylindrical body to flow to the outside of the cylindrical body,

[0016] wherein the opening area of ​​the hole on the outer surface of the cylinder wall is larger than the opening area of ​​the corresponding hole on the inner surface of the cylinder wall, and

[0017] Wherein, the shape of the opening of the hole on the outer surface is non-circular.

[0018] In a second aspect, the present invention provides a polymer melt filter. The filter comprises a filter support according to the present invention and one or more filter elements surrounding the second end portion of the cylindrical body.

[0019] In a third aspect, the present invention provides a polymer melt filtration plate assembly. The plate assembly comprises:

[0020] (a) a support plate comprising a plurality of threaded holes; and

[0021] (b) At least one filter according to the present invention is screwed into at least one of the threaded holes via a screw thread on the outer surface of the first end portion of the cylindrical body.

[0022] In a fourth aspect, the present invention provides a process for filtering a polymer melt, comprising: passing the polymer melt through one or more filter elements surrounding a second end portion of a cylindrical body of a polymer melt filter according to the present invention; and withdrawing the filtered polymer melt from the interior of the cylindrical body. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a front view of a polymer melt filter support according to one embodiment of the present invention;

[0024] Figure 2 is a plan view of a bottom end of a polymer melt filter support according to one embodiment of the present invention;

[0025] Figure 3 The polymer melt filter support is along Figure 1 A cross-sectional view of line AA in FIG.

[0026] Figure 4 The polymer melt filter support is along Figure 1 A cross-sectional view of line CC in FIG.

[0027] Figure 5 Is from Figure 4 An enlarged view of cutout D of the cross-sectional view in FIG.

[0028] Figure 6 Is from Figure 1 an enlarged view of a region B of the cylindrical wall of the second end portion of FIG.

[0029] Fig. 6A is Figure 1 an enlarged view of a hole on an outer surface of a cylindrical wall of a second end portion of the embodiment;

[0030] Figure 7 is a front view of a tapered insert according to an embodiment of the present invention;

[0031] Figure 8 yes Figure 7 a plan view of the top of the tapered insert in;

[0032] Fig. 9 Is from Figure 7 An enlarged view of the cutout E of the tapered insert in FIG.

[0033] Fig.10 is a front view of a filter support cap according to an embodiment of the present invention;

[0034] Fig.11 yes Fig.10 A plan view of the cap shown in ;

[0035] Fig.12 yes Fig.10 A plan view of the bottom of the cap shown in ;

[0036] Fig.13 Is from Fig.10 An enlarged view of the cutout G of the cap shown in FIG.

[0037] Fig.14 yes Figure 1 A plan view of a polymer filter support shown in FIG. 1 , the polymer filter support being equipped with a tapered insert and a cap;

[0038] Fig.14A yes Fig.14 A plan view of a polymeric filter support as shown in FIG. 1 , the polymeric filter support being provided with a filter sleeve sleeved on a second end portion;

[0039] Fig.15 The polymer filter support is along Fig.14 A cross-sectional view of line AA in FIG.

[0040] Fig.16 is a perspective (perspective) view of a shaft of a filter device having a polymer melt filter plate assembly according to an embodiment of the present invention in a connecting channel;

[0041] Fig.17 Is has Fig.16 A detailed perspective view of the inlet of the connecting channel of the filter plate assembly depicted in FIG.

[0042] Fig.18 is Fig.16 A cross-sectional view of the filter plate assembly within the shaft depicted in FIG.

[0043] Fig.19 Is has Fig.16 A detailed perspective view of the outlet of the connecting channel of the filter plate assembly depicted in FIG.

[0044] Fig. 20 is a perspective view of a crossbar according to an embodiment of the present invention, the crossbar spanning Fig.19 The width of the outlet of the connecting channel depicted in FIG. DETAILED DESCRIPTION

[0045] In a first aspect, the present invention provides a polymer melt filter support. In one embodiment, the filter support comprises:

[0046] a hollow cylindrical body defined by a first end, a second end, and a cylindrical wall having a first end portion and a second end portion;

[0047] screw threads on an outer surface of the first end portion; and

[0048] a plurality of holes in the cylindrical wall at the second end portion,

[0049] wherein the holes allow the polymer melt outside the cylindrical body to flow to the inside of the cylindrical body,

[0050] wherein the first end comprises an opening for allowing the polymer melt inside the cylindrical body to flow to the outside of the cylindrical body,

[0051] wherein the opening area of ​​the hole on the outer surface of the cylinder wall is larger than the opening area of ​​the corresponding hole on the inner surface of the cylinder wall, and

[0052] Wherein, the shape of the opening of the hole on the outer surface is non-circular.

[0053] In another embodiment, the polymer melt filter support comprises:

[0054] a hollow cylindrical body defined by a first end, a second end, and a cylindrical wall having a first end portion and a second end portion;

[0055] screw threads on an outer surface of the first end portion;

[0056] a hexagonal fitting on an inner surface of the first end portion for receiving a hexagonal wrench; and

[0057] a plurality of holes in the cylindrical wall at the second end portion,

[0058] wherein the holes allow the polymer melt outside the cylindrical body to flow to the inside of the cylindrical body,

[0059] The first end includes an opening for allowing the polymer melt inside the cylindrical body to flow to the outside of the cylindrical body.

[0060] Figure 1 A polymer melt filter support 100 according to an embodiment of the present invention is shown. The filter support 100 includes a hollow cylindrical body 101, which is similar to the shape of a tube. The body 101 includes or is defined by a first end 102, a second end 103 (opposite to the first end 102), and a cylindrical wall 104 (disposed between the two ends 102 and 103). The cylindrical wall 104 includes a first end portion 105 close to or adjacent to the first end 102 and a second end portion 106 close to or adjacent to the second end 103. The first end portion 105 includes a screw thread 107 on at least a portion of its outer surface. The screw thread 107 is suitable for engaging the filter support 100 with a threaded hole in the support plate 1604 and firmly holding it in place (see Figures 16 to 19 ).

[0061] The second end portion 106 of the cylindrical wall 104 includes a plurality of holes 108. The holes 108 extend through the cylindrical wall 104 to allow the polymer melt from the outside of the body 101 to flow to the inside of the body 101. Arrow F shows the direction of polymer flow during normal operation. In one embodiment, as described below in conjunction with Figure 3 and Figure 6 As will be explained in more detail, the area of ​​the opening 301 of the hole 108 on the outer surface of the cylindrical wall 104 (or the area defined by the opening) is greater than the area of ​​the opening 302 of the corresponding hole on the inner surface of the cylindrical wall 104 (or the area defined by the opening). Additionally, in a preferred embodiment, the shape of the opening 301 of the hole 108 on the outer surface of the cylindrical wall 104 is non-circular. By "non-circular", it is meant any geometric shape other than a perfect circle. Examples of non-circular shapes include triangles, squares, rectangles, ovals, ellipses, quatrefoil, rhombuses, pentagons, hexagons, etc.

[0062] The number of holes in the second end portion 106 can be any number desired. In one embodiment, the second end portion 106 includes 288 holes arranged in 18 rows of 16 holes. In another embodiment, the second end portion 106 includes 400 holes arranged in 25 rows of 16 holes.

[0063] The cylindrical body 101 can be made of any material that can withstand the conditions inside the filtering device for polymer melts for an extended period of time. Such conditions include operating temperatures up to 400°C and operating pressures up to 7,500 psi (or about 50 MPa). Preferably, the cylindrical body 101 is made of 17-4 PH stainless steel, which has been heat treated according to condition H 900 after the body 101 has been machined. 17-4 PH stainless steel is a precipitation hardening martensitic stainless steel. It typically contains 15-17.5% by weight of chromium, 3-5% by weight of copper, 3-5% by weight of nickel, 0.15-0.45% by weight of niobium + tantalum, and the balance of iron. 17-4 PH stainless steel may contain up to 0.07% by weight of carbon, up to 1% by weight of manganese, up to 0.04% by weight of phosphorus, up to 0.03% by weight of sulfur, and up to 1% by weight of silicon. 17-4 PH is commercially available. It is typically provided in the annealed condition. This is also referred to as the solution heat treated condition or Condition A. According to Condition A, annealing is performed by heat treating at about 1900°F (1040°C) to 1950°F (1065°C) and cooling to room temperature. In this condition, the material possesses a martensitic structure. To further increase its strength, preferably after machining, the cylindrical body 101 is precipitation hardened by heat treating at 900°F + / - 10°F (482°C + / - 5°C) in air for 60 minutes + / - 5 minutes, which is referred to as Condition H 900.

[0064] The cylindrical body 101 can have any desired dimensions. In one embodiment, the height of the body 101 is 4.97 inches (12.62 cm). In another embodiment, the height of the body 101 is 6.40 inches (16.256 cm). Preferably, the height of the first end portion 105 is the same regardless of the overall height of the body 101. In one embodiment, the height of the first end portion 105 is 0.88 inches (2.24 cm). In this case, the height of the second end portion 106 can be 3.97 inches (10.08 cm) or 5.4 inches (13.72 cm).

[0065] Preferably, the ratio of the outer diameter of the cylindrical wall 104 to the inner diameter of the cylindrical wall 104 ranges from 1.35 to 1.65. In one embodiment, the outer diameter of the cylindrical wall 104 is 1.75 inches (4.445 cm). In this case, the inner diameter of the cylindrical wall 104 can be 1 inch (2.54 cm) to 1.25 inches (3.175 cm). Preferably, the inner diameter of the cylindrical wall 104 is 1.125 inches (2.858 cm).

[0066] As from Figure 2 , Figure 4 and Figure 5 As can be seen, the first end 102 includes an opening 202 for allowing the polymer melt inside the body 101 to flow to the outside of the body 101. In one embodiment, the inner surface of the first end portion 105 includes a hexagonal fitting 203 for receiving and engaging a hexagonal wrench (not shown). The hexagonal fitting 203 enables the filter support 100 to be easily attached to and removed from the support plate 1604 via the use of a hexagonal wrench (not shown). Figures 16 to 19 In the case where the inner diameter of the cylindrical wall 104 is 1.125 inches (2.858 cm), the maximum distance between any two opposing points of the hexagonal fitting 203 can be, for example, 1.27 inches (3.226 cm).

[0067] Figure 3 A cross-sectional view of the filter support 100 is shown, in particular, the second end portion 106 of the cylindrical body 101 is shown along Figure 1 1. A cross-sectional view of the cylindrical wall 104 taken along line AA in FIG. 1. The cylindrical wall 104 is represented by the solid areas. The blank areas between the solid areas represent the holes 108 in the cylindrical wall 104. From this view, it can be seen that this embodiment of the filter support 100 contains 16 holes in the row (the number of holes per row and the number of rows of holes can vary as desired). In addition, it can be seen that the size or area of ​​the openings 301 of the holes 108 on the outer surface of the cylindrical wall 104 is larger than the size or area of ​​the openings 302 of the corresponding holes 108 on the inner surface of the cylindrical wall 104. The direction in which the polymer melt flows through the holes 108 is indicated by arrow F. It has been surprisingly found that the larger size of the openings 301 on the outer wall surface increases the cross-sectional area for the polymer melt to flow and be filtered, thereby improving the overall filtration efficiency of any filter employing a filter support according to the present invention.

[0068] Figure 4 yes Figure 1FIG. 1 is a cross-sectional view of the filter support 100 along line CC. From this view, the hollowness of the cylindrical body 101 and the opening 202 at the first end 102 and the opening 403 at the second end 103 can be seen. From this view, the hexagonal fitting 203 on the inner surface of the first end portion 105 of the cylindrical body 101 can also be seen. Figure 4 Also shown is an optional recess, indentation or notch 404 along the inner surface of the cylindrical wall 104 at the opening 403 .

[0069] Figure 5 The second end portion 106 of the cylindrical wall 104 is along Figure 4 1 is an enlarged view of circle D. In this view, several rows of holes 108 in the second end portion 106 of the cylindrical wall 104 can be seen.

[0070] Figure 6 The second end portion 106 of the cylindrical wall 104 surrounds Figure 1 106. From this view, it is possible to see several rows of holes 108 in the second end portion 106 of the cylindrical wall 104 and details of the holes 108. As described above, according to one embodiment of the present invention, the size or area of ​​the opening 301 of the hole 108 on the outer surface of the cylindrical wall 104 is greater than the size or area of ​​the opening 302 of the corresponding hole 108 on the inner surface of the cylindrical wall 104. The openings 301 and 302 can take any shape as long as the size of the opening 301 on the outer surface is greater than the size of the opening 302 on the inner surface. The shape of the opening can be formed by any known machining technology. In one embodiment, the shape of the opening 301 on the outer surface of the cylindrical wall 104 is non-circular. Preferably, the opening 301 has a shape similar to an oval or elliptical. As used herein, the terms "oval" and "elliptical" (and variations thereof) are intended to include shapes that are generally or substantially oval and generally or substantially elliptical, respectively. When modifying a geometric shape, the terms "generally" and "substantially" mean that the actual shape is more similar to the named shape than any other basic geometric shape, such as triangle, square, rectangle, circle, and oval / ellipse.

[0071] Preferably, the maximum distance between any two relative points on the perimeter of the oval or elliptical opening 301 in the horizontal direction is greater than the maximum distance between any two relative points on the perimeter of the oval or elliptical opening 301 in the vertical direction. In other words, the horizontal diameter (D H ) is preferably larger than the vertical diameter (D V ). D H / D VThe ratio may be at least 1.05, at least 1.10, at least 1.15, at least 1.20, at least 1.21, at least 1.22, at least 1.23, or at least 1.24. Vertical refers to a direction along (or parallel to) the axis of the cylindrical body 101, and horizontal refers to a direction perpendicular to the axis of the cylindrical body 101.

[0072] In one embodiment, the oval or elliptical shape of the opening 301 is formed by first forming a circular opening and then making scalloped cuts on opposite sides of the circular opening to form the oval or elliptical opening. Figure 6 In the case of , scalloped cuts are made on the left and right sides of the initially circular opening. The scalloped cuts give the left and right sides of the opening 301 a generally chamfered profile.

[0073] Fig. 6A is an exploded view of one of the oval / elliptical openings 301, wherein the markings indicate D V and D H . As from Fig. 6A As can be seen, the shape of the opening 301 is not a perfect oval or ellipse, but to the naked eye, it is more similar to an oval or ellipse than other basic geometric shapes. H is 0.236 inches (6 mm), and D V is 0.290 inches (7.4 mm), resulting in a 0.05165 square inch (33.3 mm 2 ) of the open area. In another embodiment, D H is 0.250 inches (6.35 mm), and D V is 0.310 inches (7.87 mm), resulting in a 0.05859 square inch (37.8 mm 2 ) of open area.

[0074] Preferably, the shape of the opening 302 corresponding to the hole 108 on the inner surface of the cylinder wall 104 is circular. As used herein, the term "circular" is intended to include generally circular or substantially circular shapes.

[0075] The area or size of the opening (inlet) 301 can be, for example, at least 25%, 50% or 75% larger than the area or size of the opening (outlet) 302 of the corresponding hole 108 .

[0076] Moreover, if Figure 6 As shown in , in order to maximize the size and number of holes 108, each row of holes 108 can be staggered or offset from the rows immediately above and below it. For example, each row of holes 108 can be staggered or offset from the next row by the radius of the opening 302.

[0077] Figure 7 A tapered insert 701 is shown according to an embodiment of the present invention. Fig.15 As can be seen, the tapered insert 701 is adapted to fit inside the second end opening 403 of the cylindrical body 101, wherein the apex 702 of the tapered insert 701 points toward the first end opening 202. Figure 7 , Fig. 9 and Fig.15 As can be seen, the tapered insert 701 includes a curved side surface 703 toward, near, or adjacent to its base 704. The curved side surface 703 serves to gradually guide the polymer melt flowing toward the center of the cylindrical body 101.

[0078] The diameter of the base 704 is about the same as or slightly smaller than the inner diameter of the cylindrical body 101. Any gap between the diameter of the base 704 and the inner diameter of the cylindrical body 101 should be minimized to avoid polymer melt from accumulating in or passing through the gap. The thickness of the base 704 should be such that the holes 108 of the top row 1501 direct the flow of polymer melt toward the curved side surface 703 inside the cylindrical body 101. The curved side surface 703, together with the non-curved side surface 706 of the tapered insert 701, gradually directs the flow of the incoming polymer melt toward the direction of the first end opening 202, where the filtered polymer melt finally exits the filter support 100.

[0079] The tapered insert 701 further includes a base plate 705 located on the other side of the base 704 (i.e., opposite the side having the curved side surface 703). The diameter of the base plate 705 is preferably greater than the inner diameter of the cylindrical body 101, but smaller than the outer diameter of the cylindrical body 101. The peripheral portion 707 of the base plate 705 (see Figure 8 ) is designed to abut or lean against the annular recess 404 in the cylindrical wall 104 adjacent to the second end opening 403. Preferably, the thickness of the base plate 705 is such that the top surface 708 of the plate 705 is flush or on the same level as the remaining cylindrical wall 104 at the second end opening 403.

[0080] As from Figure 7 , Figure 8 and Fig. 9 As seen, the base plate 705 preferably includes one or more chamfers or recesses 709 around the perimeter of the top surface 708. The recesses 709 form reservoirs for solder, welding metal, or some other bonding material to couple the tapered insert 701 to the filter support 100.

[0081] As from Figure 7 , Figure 8 and Fig.15As can be seen, the tapered insert 701 may also include screw holes 710 for fixing the cap 1001 to the insert 701 .

[0082] Fig.10 , Fig.11 and Fig.12 Various views of a filter support cap 1001 according to an embodiment of the present invention are shown. Fig.14 , Fig.14A and Fig.15 As can be seen, the cap 1001 is adapted to fit over the second end 103 of the cylindrical body 101 and the base plate 705 of the tapered insert 701. Fig.10 and Fig.13 As seen, cap 1001 has a generally frustoconical shape with an inclined side portion 1002, a curved side portion 1003 below the inclined side portion 1002, and a vertical side portion 1004 below the curved side portion 1003. Cap 1001 includes a hole 1005 through its central axis for passing a screw body (rod). The screw (not shown) screws directly into the screw hole 710 in the tapered insert 701 and secures cap 1001 to the tapered insert 701. When the tapered insert 701 has been welded or otherwise secured to the cylindrical body 101, the screw will also secure cap 1001 to the cylindrical body 101. Cap 1001 may include a recessed area 1006 having a generally inverted frustoconical shape in the top portion around the hole 1005 for receiving the tapered portion of a flat head or countersunk screw (not shown).

[0083] As from Fig.10 and Fig.13 As seen, the bottom portion 1007 of the cap 1001 includes a curved side portion 1003 and a vertical side portion 1004. The outer diameters of the curved side portion 1003 and the vertical side portion 1004 are greater than the outer diameter of the cylindrical body 101. The interior of the bottom portion 1007 includes a recess 1008 for receiving the second end 103 of the cylindrical body 101. The interior of the bottom portion 1007 includes an inclined surface 1009 that is inclined away from the outer surface of the cylindrical wall 104. The space created between the inclined surface 1009 and the outer surface of the cylindrical wall 104 allows one or more filter elements to be held in place around the second end portion 103 of the cylindrical body 104.

[0084] In another embodiment of the present invention, the conical insert 701 and the cap 1001 include holes passing through their axes for accommodating the tie rods. Figures 16 to 19 Let's discuss this embodiment in more detail.

[0085] In a second aspect, the present invention provides a polymer melt filter. The filter comprises a filter support according to any one of the embodiments of the present invention and one or more filter elements surrounding the second end portion of the cylindrical body. There are no particular restrictions on the filter elements that can be used with the filter support of the present invention, as long as they can be adapted to fit around the second end portion of the cylindrical body. Examples of filter element media include metal fiber felt, wire knitted mesh, wire mesh, screen, metal fiber fleece and perforated metal plate. Combinations of filter elements can be used. The filter element can be flat or pleated. The filter element can have any desired fineness, such as from 0.5 to 500 μm or from 0.5 to 200 μm.

[0086] Fig.14A An embodiment of the second aspect of the present invention is illustrated. Fig.14A A filter element 1401 in the form of a sleeve is shown, which is adapted to be mounted on / around the second end portion 106 of the filter support 100. The filter element 1401 has perforations 1402 to let the polymer melt pass through but filter out impurities in the melt, such as solids and / or gels.

[0087] The type of polymer melt that can be filtered using the filter according to the present invention is not particularly limited. Examples of suitable polymers include poly (acrylonitrile butadiene styrene), ethylene-vinyl acetate copolymers, polyethylene (including HDPE, LDPE and LLDPE), polyamide (including PA 6 and PA 66), polybutadiene, polyester (including PET and PBT), polypropylene and polystyrene (including HIPS).

[0088] In use, the polymer melt first passes through one or more filter elements to remove any undesirable solids and / or gels in the melt. The melt then enters the interior of the hollow cylindrical body 101 of the filter support 100 via the holes 108 in the cylinder wall 104. The polymer melt then exits the interior of the hollow cylindrical body 101 via the opening 202 in the first end 102 of the body 101.

[0089] In a third aspect, the present invention provides a polymer melt filtration plate assembly. The plate assembly comprises:

[0090] (a) a support plate comprising a plurality of threaded holes; and

[0091] (b) At least one filter according to the present invention is screwed into at least one of the threaded holes via a screw thread on the outer surface of the first end portion of the cylindrical body.

[0092] The support plate may have two or more threaded holes into which the filter may be screwed. The number of threaded holes can vary, for example from 2 to 50. In one embodiment, the support plate includes 24 to 26 holes. The threaded holes are typically oriented perpendicular to the planar surface of the support plate.

[0093] The support plate can be made of any material that can withstand the conditions inside the polymer filtration system for an extended period of time. Such conditions include operating temperatures up to 400°C and operating pressures up to 7,500 psi (or about 50 MPa). In one embodiment, the support plate is made of Custom 465® stainless steel, which has been heat treated according to condition H 900 or H 950. Custom 465® stainless steel typically contains 11.00 to 12.50 weight % chromium, 10.75 to 11.25 weight % nickel, 0.75 to 1.25 weight % molybdenum, 1.50 to 1.80 weight % titanium, and the balance iron. Custom 465® stainless steel may contain up to 0.02 weight % carbon, up to 0.015 weight % phosphorus, up to 0.25 weight % silicon, up to 0.25 weight % manganese, and up to 0.010 weight % sulfur. Custom 465® stainless steel is commercially available. It is typically provided in the annealed / CT condition. This condition consists of heating to 1800°F ± 15°F (982°C ± 8°C), holding at that temperature for one hour, and rapidly cooling. Solution annealing is usually followed by cooling to −100°F (−73°C), holding at that temperature for eight hours, and then warming to room temperature (CT). Sub-zero cooling is usually performed within 24 hours after solution annealing.

[0094] Condition H 900 refers to heat treatment at 900°F + / - 10°F (482°C + / - 5°C) in air for 60 minutes + / - 5 minutes. Condition H 950 refers to heat treatment at 950°F + / - 10°F (510°C + / - 5°C) in air for 4 hours + / - 0.25 hours.

[0095] In one embodiment, a filter plate assembly includes at least one filter including a conical insert and a cap having holes through their axes for accommodating tie rods. The tie rods have a first end extending through the holes in the conical insert and the cap, and a second end extending through a support plate of the assembly. The assembly also includes a cross bar attached to the second end of the tie bar for retaining the support plate inside the shaft of the apparatus for filtering polymer melts. Fig.16 , Fig.17 , Fig.18 and Fig.19 This embodiment of a filter panel assembly is illustrated in FIG.

[0096] As background, polymer melt filtration equipment generally includes: (a) a housing including an inlet channel for receiving a flow of polymer melt, a transverse hole for accommodating a movable shaft, and an outlet channel for discharging the filtered polymer melt; (b) a movable shaft including a plurality of connecting channels arranged side by side and spanning the thickness of the shaft for connecting the inlet channel to the outlet channel. Each connecting channel includes a filter support plate assembly that is in a flow direction across the polymer melt for filtering the polymer melt. The shaft is mounted in the transverse hole of the housing and is movable in an axial direction so that each connecting channel can be moved between a filtering position and a cleaning position, in which the inlet channel is connected to the outlet channel through the connecting channel, and in the cleaning position, the connection from the inlet channel to the outlet channel is interrupted and the plate assembly is accessible from the outside for cleaning.

[0097] Fig.16 , Fig.17 , Fig.18 and Fig.19 A movable shaft 1601 is shown with two connecting channels 1602 and 1603 arranged side by side and spanning the thickness of the shaft 1601 for connecting the inlet channel to the outlet channel. The connecting channel 1603 is provided with a filter plate assembly according to the present invention. In the embodiment shown, the plate assembly comprises a support plate 1604, two filter supports 1605, two tie rods 1606 and a crossbar 1607.

[0098] The support plate 1604 has a planar support surface 1608 on one side, a convex surface 1609 on the other side, and a plurality of threaded holes 1610. In the embodiment shown, the filter support 1605 is attached to two adjacent centrally located threaded holes 1610. Each filter support 1605 is provided with a tapered insert 1619 and a cap 1611. The tapered insert 1619 and the cap 1611 have holes through their centers for accommodating the tie rods 1606. The inner surface of the through hole in the tapered insert 1619 may be tapered to help guide the tie rods 1606 through the tapered insert 1619. The larger end of the taper is toward the apex of the tapered insert 1619.

[0099] The tie rod 1606 may be threaded at both ends. One end of the tie rod 1606 engages with a nut 1612. A washer 1613 may be placed between the nut 1612 and the cap 1611. The other end of the tie rod 1606 screws into a threaded hole 1614 in the cross bar 1607. The body of the tie rod 1606 passes through the center of the filter support 1605.

[0100] The connecting channel 1603 in the shaft 1601 has an inlet 1615 and an outlet 1616. The connecting channel 1603 also includes a protrusion or projection 1618 extending radially and protruding into the channel 1603 for supporting the support plate 1604. The crossbar 1607 has a length sufficient to span the width of the outlet 1616. The shaft 1601 includes a recess 1617 adjacent to the outlet 1616 (the opening on the downstream side of the connecting channel 1603) for accommodating the crossbar 1607. The tie rod 1606, together with the crossbar 1607 and the nut 1612, firmly holds the support plate 1604 against the protrusion 1618 inside the shaft 1601. This mechanism for holding the support plate 1604 in place has many advantages, including minimizing or preventing the support plate from substantially moving (e.g., vibrating) during filtration, which can lead to premature cracking or breakage.

[0101] Fig. 20 An exemplary shape of a crossbar 1607 is shown having two threaded holes 1614 for engaging with the threaded ends of the tie rods 1606 .

[0102] although Figures 16 to 19 Two tie rods 1606 are depicted in FIG, but one or more than two may be used.

[0103] The cap 1001, cap insert 701, tie rods 1606 and crossbars 1607 may be made of any suitable material capable of withstanding the described operating conditions. An example of such a material is 17-4 PH stainless steel which has been heat treated according to condition H 900.

[0104] In a fourth aspect, the present invention provides a process for filtering a polymer melt, comprising: passing the polymer melt through one or more filter elements surrounding a second end portion of a cylindrical body of a polymer melt filter according to the present invention; and withdrawing the filtered polymer melt from the interior of the cylindrical body.

[0105] The present invention includes and explicitly contemplates any and all combinations of the embodiments, features, characteristics, parameters and / or ranges disclosed herein. That is, the present invention can be limited by any combination of the embodiments, features, characteristics, parameters and / or ranges mentioned herein.

[0106] As used herein, the indefinite articles "a" and "an" mean one or more, unless the context clearly suggests otherwise. Similarly, singular forms of nouns include their plural forms and vice versa, unless the context clearly suggests otherwise.

[0107] Although attempts have been made to be precise, the numerical values ​​and ranges described herein should be considered approximate (even if not modified by the term "about"). These values ​​and ranges may vary from the numbers for which they are stated, depending on the desired properties that the invention seeks to obtain and the variations caused by the standard deviation found in the measurement technique. In addition, the ranges described herein are intended and specifically contemplated to include all subranges and values ​​within the stated ranges. For example, a range of 50 to 100 is intended to describe and include all values ​​within that range, including subranges such as 60 to 90 and 70 to 80.

[0108] The contents of all documents (including patents and non-patent literature) cited herein are incorporated herein by reference in their entirety. To the extent that any incorporated subject matter conflicts with any disclosure herein, the disclosure herein shall take precedence over the incorporated content.

[0109] The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Claims

1. A polymer melt filter support, comprising: a hollow cylindrical body defined by a first end, a second end, and a cylindrical wall having a first end portion and a second end portion; screw threads on an outer surface of said first end portion; a plurality of holes in said cylindrical wall at said second end portion; an opening at the second end; and a tapered insert adapted to fit within the interior of the second end opening, wherein the tapered insert comprises a base plate, wherein the perimeter of the top surface of the substrate includes one or more recesses, and wherein the recess and the inner surface of the cylindrical body define a reservoir for containing solder for coupling the tapered insert to the cylindrical body, wherein the holes allow the polymer melt outside the cylindrical body to flow to the inside of the cylindrical body, wherein the first end comprises an opening for allowing the polymer melt inside the cylindrical body to flow to the outside of the cylindrical body, wherein the opening area of ​​the hole in the cylindrical wall on the outer surface of the second end portion is larger than the opening area of ​​the corresponding hole on the inner surface of the second end portion, and Wherein, the shape of the opening of the hole in the cylindrical wall on the outer surface of the second end portion is non-circular.

2. The filter support according to claim 1, wherein: The cylindrical body is made of 17-4 PH stainless steel which has been heat treated according to condition H 900.

3. The filter support according to claim 1, wherein: The ratio of the outer diameter of the cylindrical wall to the inner diameter of the cylindrical wall ranges from 1.35 to 1.

65. 4 . The filter support of claim 1 , further comprising a hexagonal fitting on an inner surface of the first end portion of the cylindrical body for receiving a hexagonal wrench.

5. The filter support of claim 1, further comprising a cap for securing one or more filter elements around the second end portion of the cylindrical body.

6. The filter support according to claim 1, wherein: The tapered insert includes curved side surfaces toward its base.

7. The filter support according to claim 5, wherein: The tapered insert and the cap have holes through their axes for receiving tie rods.

8. The filter support according to claim 1, wherein: The opening area of ​​the hole in the cylindrical wall on the outer surface of the second end portion is at least 25% larger than the opening area of ​​the corresponding hole on the inner surface of the second end portion.

9. The filter support according to claim 1, wherein: The opening area of ​​the hole in the cylindrical wall on the outer surface of the second end portion is at least 50% larger than the opening area of ​​the corresponding hole on the inner surface of the second end portion.

10. The filter support according to claim 1, wherein The opening area of ​​the hole in the cylindrical wall on the outer surface of the second end portion is at least 75% larger than the opening area of ​​the corresponding hole on the inner surface of the second end portion.

11. The filter support according to claim 1, wherein: The shape of the opening of the hole in the cylindrical wall on the outer surface of the second end portion is oval or elliptical, and the shape of the opening of the hole in the cylindrical wall on the inner surface of the second end portion is circular.

12. A polymer melt filter comprising the filter support according to claim 1 and one or more filter elements surrounding the second end portion of the cylindrical body.

13. The filter according to claim 12, wherein The filter element comprises metal fiber felt, metal wire mesh or perforated metal sheet.

14. The filter according to claim 12, wherein The filter element is flat or pleated.

15. The filter according to claim 12, wherein The cylindrical body is made of 17-4 PH stainless steel which has been heat treated according to condition H 900.

16. A polymer melt filter comprising the filter support according to claim 7 and one or more filter elements surrounding the second end portion of the cylindrical body.

17. The filter according to claim 16, wherein The cylindrical body is made of 17-4 PH stainless steel which has been heat treated according to condition H 900.

18. A polymer melt filter plate assembly comprising: (a) a support plate comprising a plurality of threaded holes; as well as (b) At least one filter according to claim 12, which is screwed into at least one of the plurality of threaded holes via a screw thread on the outer surface of the first end portion of the cylindrical body.

19. The plate assembly of claim 18, wherein: The support plate is made of stainless steel comprising 11.00 to 12.50 wt. % chromium, 10.75 to 11.25 wt. % nickel, 0.75 to 1.25 wt. % molybdenum, 1.50 to 1.80 wt. % titanium, and the balance iron; and wherein the stainless steel has been heat treated according to condition H 900 or H 950.

20. A polymer melt filter plate assembly comprising: (a) a support plate comprising a plurality of threaded holes; (b) at least one filter according to claim 16, which is screwed into at least one of the plurality of threaded holes via screw threads on the outer surface of the first end portion; (c) a tie rod having a first end extending through holes in the tapered insert and the cap, and a second end extending through the support plate; as well as (d) a crossbar attached to the second end of the tie rod for holding the support plate inside the shaft of the apparatus for filtering a polymer melt.

21. The plate assembly of claim 20, wherein: The support plate is made of stainless steel comprising 11.00 to 12.50 wt. % chromium, 10.75 to 11.25 wt. % nickel, 0.75 to 1.25 wt. % molybdenum, 1.50 to 1.80 wt. % titanium, and the balance iron; and wherein the stainless steel has been heat treated according to condition H 900 or H 950.

22. A method for filtering a polymer melt, the method comprising: passing the polymer melt through one or more filter elements surrounding the second end portion of the cylindrical body of the polymer melt filter according to claim 12; and withdrawing the filtered polymer melt from the interior of the cylindrical body.

23. A method for filtering a polymer melt, the method comprising: passing the polymer melt through one or more filter elements surrounding the second end portion of the cylindrical body of the polymer melt filter according to claim 16; and withdrawing the filtered polymer melt from the interior of the cylindrical body.

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