Polyurethane test piece production device and preparation method thereof

Abstract

This invention provides a polyurethane test piece production apparatus, including a casting device and a post-curing device. The casting device includes a first cavity, a second cavity, a front fixing plate, a rear fixing plate, and a base plate. The front and rear fixing plates are detachably mounted on the base plate, and a plurality of first and second cavities are alternately installed between the front and rear fixing plates via ball-spline shafts. The post-curing device includes a receiving box and a clamping frame. This invention also provides a method for preparing polyurethane test pieces using this polyurethane test piece production apparatus. The polyurethane test piece production apparatus provided by this invention can simultaneously produce test pieces of multiple specifications, improving product reliability and work efficiency. It can also perform multi-layer curing on test pieces of multiple specifications to determine the tensile strength and tear strength of different parts of the polyurethane layer in the thickness direction, thereby guiding the design of NDI-type polyurethane rollers to obtain the optimal design scheme.

Description

Technical Field

[0001] This invention relates to the field of polyurethane test piece technology, and in particular to a polyurethane test piece production apparatus and its preparation method. Background Technology

[0002] NDI-type polyurethane rollers are made by casting NDI-type polyurethane raw material onto the outer cylindrical surface of a cylindrical metal core. After the polyurethane raw material cures, it requires multiple post-curing processes. The post-curing process is as follows: the cast roller is stored in a controlled temperature and humidity environment for several days, then placed in a 110-degree oven for a certain curing time; after being removed from the oven, it is stored in the controlled temperature and humidity environment for several days again, and then placed in a 110-degree oven for another certain curing time; this process is repeated multiple times, with the number of post-curing cycles determined by the thickness of the polyurethane layer on the roller surface. A typical post-curing process is: for every 5mm increase in the thickness of the polyurethane layer on the roller surface, the number of post-curing cycles increases by one. The principle of the post-curing process is as follows: when the NDI-type polyurethane roller is stored in a controlled temperature and humidity environment, the polyurethane layer absorbs moisture from the air. When placed in a 110-degree oven, during the heating process, the absorbed moisture reacts with excess isocyanate groups in the polyurethane. As the number of post-curing cycles increases, the physical properties of the internal polyurethane layer gradually increase, but the internal physical properties are difficult to reach the physical properties of the surface layer. When designing NDI type polyurethane rollers, it is necessary to understand the physical properties of different parts of the polyurethane layer in the thickness direction of the roller to ensure that the stress and strain of each part of the polyurethane layer do not exceed the allowable range when the designed roller is working.

[0003] Therefore, it is necessary to determine the physical properties of different parts along the thickness direction of the polyurethane layer. Currently, the physical properties of polyurethane materials are usually evaluated by testing tensile strength and tear strength. According to relevant testing standards, these two indicators need to be measured on a material testing machine using 2mm thick test pieces cut into a specified shape. However, 2mm thick polyurethane test pieces are difficult to fabricate from thicker polyurethane materials, and are generally produced by direct casting.

[0004] However, current equipment for producing polyurethane test pieces typically molds one test piece at a time, has a single function, and cannot determine the physical properties of different parts in the thickness direction of a thicker polyurethane layer through the produced polyurethane test piece.

[0005] Therefore, the present invention provides a polyurethane test piece production apparatus to solve the above-mentioned technical problems. Summary of the Invention

[0006] In view of the above-mentioned deficiencies of the prior art, the present invention provides a polyurethane test piece production apparatus and preparation method thereof to overcome the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A polyurethane test piece production apparatus is provided, comprising: a casting device and a post-curing device; wherein,

[0009] The casting device includes: a first cavity, a second cavity, a front fixing plate, a rear fixing plate, and a base plate; the front fixing plate and the rear fixing plate are detachably mounted on the base plate, and a plurality of first cavities and second cavities are alternately installed between the front fixing plate and the rear fixing plate via ball spline shafts; ball spline sleeves are provided at two opposite corners of the first cavity and the second cavity, and the ball spline shafts pass through the ball spline sleeves;

[0010] The post-curing device includes a receiving box and a pressing frame, the pressing frame being detachably mounted on the top of the receiving box.

[0011] Furthermore, the two ends of the ball spline shaft are respectively installed in the through holes of the front fixed plate and the rear fixed plate, and are fastened to the front fixed plate and the rear fixed plate by the first screw and the bushing.

[0012] Furthermore, the ball spline sleeve is mounted on the first cavity and the second cavity by a plurality of third screws.

[0013] Furthermore, threaded holes are provided on both sides of each of the first and second cavities, and a second screw is installed in the threaded hole, with a thin rope tied to the second screw.

[0014] Furthermore, screw fixing seats are installed on both sides of the second cavity near the rear fixing plate by fourth screws. The screw fixing seats are fastened with opening and closing screws by second nuts. The end of the opening and closing screw away from the screw fixing seat passes through the front fixing plate and is fastened to the handle by two first nuts.

[0015] Furthermore, a quick-release nut is fitted onto one end of the opening and closing screw that extends out of the front fixing plate.

[0016] Furthermore, the front fixing plate and the rear fixing plate are mounted on the base plate by a plurality of fifth screws, and the first cavity and the second cavity are provided with pouring ports for pouring liquid polyurethane raw materials.

[0017] Furthermore, the clamping frame is detachably mounted on the top of the receiving box by means of a wing screw. The clamping frame has a grid-shaped structure, and the clamping frame and the receiving box are provided with locking holes for fixing the wing screws.

[0018] The present invention also provides a method for preparing polyurethane test pieces using the above-mentioned polyurethane test piece production apparatus, comprising:

[0019] Step 1, Mold Closure: Pull the handle away from the front fixed plate to bring each second cavity and first cavity together and fit against the front fixed plate. Then tighten the quick nut to lock the second cavity and first cavity to the front fixed plate. Pour liquid polyurethane material into the pouring port of the first cavity and second cavity. After the polyurethane material has solidified, remove the polyurethane test piece from the pouring device.

[0020] Step 2, Demolding: After loosening the quick-release nut, turn it at a certain angle so that the axis of the smooth hole of the quick-release nut is parallel to the axis of the opening and closing screw. Then slide the quick-release nut to a position close to the handle and push the handle to move the second cavity on the side near the rear fixed plate away from the front fixed plate. The first cavity and second cavity of each piece are opened by the thin rope. Then take out the multiple test pieces and cut off the gate part on the test pieces.

[0021] Step 3, Post-curing: Place the multiple test pieces with the gates cut off in Step 2 into the receiving box of the post-curing device, place the clamping frame on top, and lock it with wing screws. Then place the post-curing device in an oven at 100-120 degrees Celsius to post-cur the test pieces. After multiple post-curing cycles, the test pieces are ready.

[0022] The present invention adopts the above technical solution and has the following technical advantages compared with the prior art:

[0023] The polyurethane test piece production apparatus provided by this invention can simultaneously produce multiple test pieces of the same specifications, improving the efficiency of test piece preparation. At the same time, it can perform multi-layer curing on multiple test pieces of the same specifications to determine the physical properties of different parts in the thickness direction of the polyurethane layer—tensile strength and tear strength—thereby guiding the design of NDI type polyurethane rollers to obtain the optimal design scheme. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the mold-closing state of the casting device in the polyurethane test piece production apparatus of the present invention;

[0025] Figure 2 yes Figure 1 Front view structural diagram;

[0026] Figure 3 yes Figure 2 A schematic diagram of the right-side view structure;

[0027] Figure 4 yes Figure 2 A schematic diagram of the left-side view structure;

[0028] Figure 5 This is a schematic diagram of the mold opening state of the casting device in the polyurethane test piece production apparatus of the present invention;

[0029] Figure 6 yes Figure 5A top-view structural diagram;

[0030] Figure 7 This is an isometric view of the casting device in the mold-opening state of the polyurethane test piece production apparatus of the present invention;

[0031] Figure 8 This is an exploded schematic diagram of the casting device in the polyurethane test piece production apparatus of the present invention;

[0032] Figure 9 This is a schematic diagram of the structure of the first cavity in the polyurethane test piece production device of the present invention;

[0033] Figure 10 This is a schematic diagram of the second cavity in the polyurethane test piece production device of the present invention without the screw fixing seat installed;

[0034] Figure 11 This is an exploded schematic diagram of the post-curing device in the polyurethane test piece production apparatus of the present invention.

[0035] Figure 12 This is a cross-sectional structural schematic diagram of the post-curing device in the polyurethane test piece production apparatus of the present invention.

[0036] Figure 13 yes Figure 12 A top-view structural diagram;

[0037] Figure 14 This is a schematic diagram of the polyurethane test piece production apparatus of the present invention after the casting device has cast and molded the test piece;

[0038] The reference numerals in the figures include:

[0039] Handle 1; Quick-release nut 2; First screw 3; Bushing 4; First nut 5; Ball spline shaft 6; Opening / closing screw 7; String 8; Second nut 9; First cavity 10; Second cavity 11; Second screw 12; Third screw 13; Ball spline sleeve 14; Fourth screw 15; Screw fixing seat 16; Rear fixing plate 17; Base plate 18; Fifth screw 19; Front fixing plate 20; Sprue 21; Wing screw 22; Clamping frame 23; Receiving box 24; Test piece 25; Sprue section 26. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be noted that the terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Example 1

[0044] refer to Figure 1-14 This embodiment provides a polyurethane test piece production apparatus, including: a casting device and a post-curing device; wherein,

[0045] The casting device includes: a first cavity 10, a second cavity 11, a front fixing plate 20, a rear fixing plate 17, and a base plate 18; the front fixing plate 20 and the rear fixing plate 17 are detachably mounted on the base plate 18, and a plurality of first cavities 10 and second cavities 11 are alternately mounted between the front fixing plate 20 and the rear fixing plate 17 via ball spline shafts 6. Ball spline sleeves 14 are provided at two opposite corners of the first cavity 10 and the second cavity 11, and the ball spline shafts 6 pass through the ball spline sleeves 14.

[0046] The post-curing device includes a receiving box 24 and a pressing frame 23. The pressing frame 23 is detachably installed on the top of the receiving box 24. Specifically, the pressing frame 23 is detachably installed on the top of the receiving box 24 by means of a wing screw 22.

[0047] In this embodiment, the two ends of the ball spline shaft 6 are respectively installed in the through holes of the front fixing plate 20 and the rear fixing plate 17, and are fastened to the front fixing plate 20 and the rear fixing plate 17 by the first screw 3 and the bushing 4.

[0048] In this embodiment, the ball spline sleeve 14 is mounted on the first cavity 10 and the second cavity 11 by a plurality of third screws 13.

[0049] In this embodiment, threaded holes are provided on both side walls of each of the first cavity 10 and the second cavity 11. A second screw 12 is installed in the threaded hole, and a thin rope 8 is tied to the second screw 12. In use, the length of the thin rope 8 between the first cavity 10 and the second cavity 11 is adjusted to be equal to the sum of the thickness of the first cavity 10 (the first cavity 10 and the second cavity 11 have the same thickness) and the mold opening distance between the first cavity 10 and the second cavity 11. The second screw 12 is then tightened to press the thin rope 8.

[0050] In this embodiment, screw fixing seats 16 are installed on both sides of the second cavity 11 near the rear fixing plate by fourth screws 15. The screw fixing seats 16 are fastened with opening and closing screws 7 by second nuts 9. The end of the opening and closing screw 7 away from the screw fixing seats 16 passes through the front fixing plate 20 and is fastened to the handle 1 by two first nuts 5.

[0051] In this embodiment, a quick nut 2 is fitted onto one end of the opening and closing screw 7 that extends out of the front fixing plate 20. By fitting the quick nut 2 onto one end of the opening and closing screw 7 that extends out of the front fixing plate 20, then installing a first nut 5, then installing the handle 1, then installing another first nut 5 and locking it to press the handle 1.

[0052] In this embodiment, the front fixing plate 20 and the rear fixing plate 17 are mounted on the base plate 18 by a plurality of fifth screws 19, and the first cavity 10 and the second cavity 11 are provided with pouring ports 21 for pouring liquid polyurethane raw materials.

[0053] In this embodiment, the clamping frame 23 has a grid-shaped structure, and the clamping frame 23 and the receiving box 25 are provided with locking holes for fixing the wing screws 22.

[0054] Example 2

[0055] The present invention also provides a method for preparing polyurethane test pieces using the polyurethane test piece production apparatus described in Example 1, comprising:

[0056] Step 1, Mold Closure: Pull handle 1 away from the front fixed plate 20 to bring each second cavity 11 and first cavity 10 together and fit against the front fixed plate 20. Then tighten quick nut 2 to lock the second cavity 11 and first cavity 10 to the front fixed plate 20. Pour liquid polyurethane raw material into the pouring port 21 of the first cavity 10 and second cavity 11. After the polyurethane raw material has solidified, remove the polyurethane test piece 25 from the pouring device.

[0057] Step 2, Demolding: After loosening the quick nut 2, turn the quick nut 2 at a certain angle so that the axis of the light hole of the quick nut 2 is parallel to the axis of the opening and closing screw 7. Then slide the quick nut 2 to a position close to the handle 1, push the handle 1 to move the second cavity 11 on the side close to the rear fixed plate 17 away from the front fixed plate 20. The first cavity 10 and the second cavity 11 of each piece are opened by the thin rope 8. Then take out the multiple test pieces 25 and cut off the gate part 26 on the test pieces 25.

[0058] Step 3, Post-curing: Place the multiple test pieces 25 from which the gate portion 26 was cut off in Step 2 into the receiving box 24 of the post-curing device, place the clamping frame 23 on top, and lock it with wing screws 22. Then place the post-curing device into an oven at 110 degrees Celsius to post-cur the test pieces. After multiple post-curing cycles, take out the test pieces 25 from the receiving box 24 and cut the corresponding samples according to the test standards. Perform relevant physical performance tests to obtain the true data of relevant physical performance indicators of different parts of the polyurethane layer in the thickness direction.

[0059] In this embodiment, the casting device can simultaneously prepare ten 2mm polyurethane test pieces of the same specification. Then, the curing device cures the ten 2mm polyurethane test pieces of the same specification to determine the physical properties of polyurethane layers of different thicknesses, thereby obtaining the physical properties of NDI polyurethane raw materials cast on NDI polyurethane rollers at different locations in the thickness direction.

[0060] In summary, the polyurethane test piece production apparatus provided by this invention can simultaneously produce multiple test pieces of the same specifications, improving the efficiency of test piece preparation. Furthermore, it can perform multi-layer curing on multiple test pieces of the same specifications to determine the tensile and tear strength of different parts in the polyurethane layer thickness direction, thereby guiding the design of NDI-type polyurethane rollers to obtain the optimal design scheme.

[0061] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A polyurethane test piece production apparatus, characterized in that, include: A casting device and a post-curing device; wherein the casting device includes: a first cavity (10), a second cavity (11), and a front fixing plate (20). Rear fixing plate (17) and base plate (18); the front fixing plate (20) and the rear fixing plate (17) are disassembled. The front fixing plate (20) and the rear fixing plate (17) are detachably mounted on the base plate (18). Several first cavities (10) and second cavities (11) are alternately installed via ball spline shaft (6). Ball spline sleeves (14) are provided on two opposite corners of the first cavity (10) and the second cavity (11). The ball spline shaft (6) passes through the ball spline sleeve (14); Each of the first cavity (10) and the second cavity (11) has a threaded hole on both sides of its sidewalls, and a second screw (12) is installed in the threaded hole. A thin rope (8) is tied to the second screw (12). The post-curing device includes: a receiving box (24) and a pressing frame (23), the pressing frame (23) being detachably mounted on the top of the receiving box (24); The clamping frame (23) is detachably mounted on the top of the receiving box (24) by means of a wing screw (22). The clamping frame (23) has a grid-shaped structure. The clamping frame (23) and the receiving box (24) are provided with locking holes for fixing the wing screw (22) in a one-to-one correspondence.

2. The polyurethane test piece production apparatus according to claim 1, characterized in that, The ball spline shaft (6) The two ends are respectively installed in the through holes of the front fixing plate (20) and the rear fixing plate (17), and through... The first screw (3) and the bushing (4) are fastened to the front fixing plate (20) and the rear fixing plate (17). catch.

3. The polyurethane test piece production apparatus according to claim 1, characterized in that, The ball spline sleeve (14) The first cavity (10) and the second cavity (11) are mounted by a plurality of third screws (13).

4. The polyurethane test piece production apparatus according to claim 1, characterized in that, On both sides of the second cavity (11) near the rear fixing plate, screw fixing seats (16) are installed by fourth screws (15). The screw fixing seats (16) are fastened with opening and closing screws (7) by second nuts (9). The end of the opening and closing screw (7) away from the screw fixing seats (16) passes through the front fixing plate (20) and is fastened to the handle (1) by two first nuts (5).

5. The polyurethane test piece production apparatus according to claim 4, characterized in that, The opening and closing screw (7) has a quick nut (2) fitted onto one end of the front fixing plate (20).

6. The polyurethane test piece production apparatus according to claim 5, characterized in that, The front fixing plate (20) and the rear fixing plate (17) are mounted on the base plate (18) by a plurality of fifth screws (19), and the first cavity (10) and the second cavity (11) are provided with pouring ports (21) for pouring liquid polyurethane raw materials.

7. A method for preparing polyurethane test pieces using the polyurethane test piece production apparatus according to claim 6, characterized in that the step... include: Step 1, Mold Closure: Pull the handle (1) away from the front fixed plate (20) to bring each second cavity (11) and first cavity (10) together and fit against the front fixed plate (20). Then tighten the quick nut (2) to lock the second cavity (11) and first cavity (10) with the front fixed plate (20). Pour liquid polyurethane raw material into the pouring port (21) of the first cavity (10) and second cavity (11). After the polyurethane raw material has solidified, remove the polyurethane test piece (25) from the pouring device. Step 2, Demolding: After loosening the quick nut (2), turn the quick nut (2) at a certain angle so that the axis of the light hole of the quick nut (2) is parallel to the axis of the opening and closing screw (7). Then slide the quick nut (2) to a position close to the handle (1) and push the handle (1) to move the second cavity (11) on the side close to the rear fixed plate (17) away from the front fixed plate (20). The first cavity (10) and second cavity (11) of each piece are opened by the thin rope (8). Then take out the multiple polyurethane test pieces (25) and cut off the gate part (26) on the polyurethane test pieces (25).

8. The preparation method according to claim 7, characterized in that, The steps also include: Step 3, post-curing: Place the polyurethane test pieces (25) from which the gate portion (26) was cut off in step 2 into the receiving box (24) of the post-curing device, place the clamping frame (23) on it, and lock it with the wing screw (22). Then place the post-curing device into the oven to post-cur the polyurethane test pieces (25). After multiple post-curing processes, it is ready.

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