A fiber-reinforced organic polymer high-temperature anti-friction slider and its preparation method

Abstract

The present invention provides a fiber-reinforced organic polymer high-temperature anti-friction slider and a preparation method thereof. The slider is hot-pressed and formed from a fiber-reinforced organic polymer composite material. The fiber-reinforced organic polymer composite material comprises the following components according to volume percentage: 10-15% of an organic polymer material, 62-68% of aramid pulp, 6-8% of carbon fiber, 5-7% of natural graphite, 0.3% of a plasticizer, and the balance is fly ash. The sum of the volume percentages of all components is 100%. The technical solution of the present invention solves the problems that the track sliders configured on the existing horizontal stretching machines have relatively large brittleness and poor anti-fatigue ability.

Description

Technical Field

[0001] The present invention relates to the field of transverse stretching machines, and in particular, to a fiber-reinforced organic polymer high-temperature anti-wear slider and a preparation method thereof. Background Art

[0002] At present, China's polymer film industry is booming, and the demand for accessories of film biaxial stretching production lines is huge. The track sliders configured on the current transverse stretching machines have problems of relatively large brittleness and poor fatigue resistance. When the sliders are repeatedly subjected to impact forces under high-temperature conditions, brittle fractures are likely to occur, resulting in local damage or even overall damage of the sliders, and the service life of the sliders is relatively short.

[0003] The service life of the slider mainly depends on the impact resistance and fatigue resistance of the slider material at high temperatures. In view of this, it is necessary to provide a new fiber-reinforced organic polymer high-temperature anti-wear slider and a preparation method thereof to solve the deficiencies of the prior art. Summary of the Invention

[0004] According to the technical problems existing in the track sliders configured on the current transverse stretching machines mentioned above, a fiber-reinforced organic polymer high-temperature anti-wear slider and a preparation method thereof are provided. The organic polymer composite material used for the slider has good toughness and excellent comprehensive performance, is not easily damaged when subjected to alternating forces in a high-temperature environment, has a low friction coefficient, and effectively improves the service life of the slider.

[0005] The technical means adopted by the present invention are as follows:

[0006] A fiber-reinforced organic polymer high-temperature anti-wear slider is hot-pressed and formed from a fiber-reinforced organic polymer composite material. The fiber-reinforced organic polymer composite material contains the following components according to volume percentage: 10-15% of organic polymer material, 62-68% of aramid pulp, 6-8% of carbon fiber, 5-7% of natural graphite, 0.3% of plasticizer, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0007] Further, the organic polymer material is phenolic resin, and the plasticizer is stearic acid.

[0008] Further, it also includes 0.7% of curing agent and 0.5% of size stabilizer. The curing agent is hexamethylenetetramine, and the size stabilizer is polyol.

[0009] The present invention also provides a preparation method of a fiber-reinforced organic polymer high-temperature anti-wear slider, including the following steps:

[0010] S1. Weigh each component raw material according to the volume percentage of each component of the fiber-reinforced organic polymer composite material;

[0011] S2, uniformly stirring aramid pulp, carbon fiber, natural graphite, organic polymer material and plasticizer in a mixer;

[0012] S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider;

[0013] The pressing pressure of the hot press is 7-13N, the pressing temperature is 160-200℃, and the holding time is 3-5min;

[0014] The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h and 150-170°C for 1 h.

[0015] Furthermore, in step S3, the pressure holding process is carried out in two stages. The first stage is pressure holding for 20 to 25 seconds and then air release for 15 to 20 seconds. The second stage is pressure holding for 25 to 30 seconds and then air release for 20 to 25 seconds, and then the pressure holding continues until the set pressure holding time.

[0016] Furthermore, step S1 also includes pre-treating the aramid pulp: opening the aramid pulp by an opener to obtain loose aramid pulp fibers.

[0017] Furthermore, step S2 specifically includes the following contents: putting phenolic resin, natural graphite and plasticizer into a mixer, starting the machine to mix for 3 to 5 minutes until the mixture is uniformly mixed, and then adding carbon fiber and pretreated aramid pulp, starting the machine to mix for 5 to 10 minutes until the mixture is uniformly mixed.

[0018] Furthermore, in step S3, the mixed raw materials need to be placed on an open mill for open refining before pressing: the mixed raw materials are placed on the open mill, the roller speed ratio of the open mill is set to 1:1, the rollers are preheated to a certain temperature before refining, the spacing between the rollers is adjusted for refining, and the refining is repeated until the raw materials are tightly combined and not loose.

[0019] Furthermore, step S3 specifically includes: placing the mixed raw materials in a preheated mold on a hot press for pressing to form a semi-solid preform, and then placing the preform in a preheated molding mold for pressing, and performing heat treatment at the same time, and after complete curing, a fiber-reinforced organic polymer high-temperature anti-friction slider is obtained.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The fiber-reinforced organic polymer high-temperature anti-friction slider and preparation method thereof provided by the present invention have good mechanical properties, high temperature resistance and self-lubricating properties, and the uniform distribution of fibers and phenolic resin greatly improves the comprehensive performance of the slider.

[0022] Based on the above reasons, the present invention can be widely promoted in the field of sliders of horizontal stretching machines. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a flowchart of the preparation method of the fiber-reinforced organic polymer high-temperature anti-friction slider described in the present invention.

[0025] Figure 2 (a)-(b) respectively show the comparison diagrams of the microscopic tissue structures of the fiber-reinforced organic polymer high-temperature anti-friction slider described in the present invention and the prior art slider slices. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. The description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0027] The present invention provides a fiber-reinforced organic polymer high-temperature anti-friction slider, which is hot-pressed and formed from a fiber-reinforced organic polymer composite material. The fiber-reinforced organic polymer composite material contains the following components by volume percentage: 10-15% of organic polymer material, 62-68% of aramid pulp, 6-8% of carbon fiber, 5-7% of natural graphite, 0.3% of plasticizer, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0028] Further, the organic polymer material is phenolic resin, and the plasticizer is stearic acid.

[0029] Further, it also includes 0.7% of curing agent and 0.5% of dimensional stabilizer. The curing agent is hexamethylenetetramine, and the dimensional stabilizer is polyol.

[0030] The fiber-reinforced organic polymer high-temperature anti-friction slider provided by the present invention has fibers as the main body and organic polymer resin as the binder. The fibers have various orientations and are isotropic inside the composite material. The organic polymer resin firmly bonds the fibers together to ensure that the fibers do not fall off. Moreover, since the fibers have elasticity and toughness, when subjected to external force, the force can be evenly transmitted to the entire structure, so that the slider is evenly stressed, thus avoiding local damage or even overall damage caused by excessive local force. Moreover, the deformation of the slider caused by the large impact force will also be restored to its original shape due to the elasticity of the fiber, thus ensuring the working efficiency and accuracy of the slider. Since the binder is phenolic resin, the cured phenolic resin has good mechanical properties, high temperature resistance and self-lubricating properties. The uniform distribution of fibers and phenolic resin can greatly improve the comprehensive performance of the slider.

[0031] like Figure 1 As shown, the present invention also provides a method for preparing a fiber-reinforced organic polymer high-temperature anti-friction slider, comprising the following steps:

[0032] S1. Weighing the raw materials of each component according to the volume percentage of each component of the fiber-reinforced organic polymer composite material;

[0033] S2, uniformly stirring aramid pulp, carbon fiber, natural graphite, organic polymer material, plasticizer, curing agent and dimensional stabilizer in a mixer, specifically comprising the following steps:

[0034] S2.1. Put 10-15% phenolic resin, 5-7% natural graphite, 0.7% hexamethylenetetramine as a curing agent, 0.5% polyol as a dimensional stabilizer and 0.3% stearic acid as a plasticizer into a mixer, and mix for 3-5 minutes until the mixture is uniform.

[0035] S2.2, pour in the opened 62-68% aramid pulp, start the machine and mix for 5-10 minutes until it is evenly mixed;

[0036] S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider;

[0037] The pressing pressure of the hot press is 7-13N, the pressing temperature is 160-200℃, and the holding time is 3-5min;

[0038] The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h and 150-170°C for 1 h.

[0039] Further, in step S3, the pressure holding process is carried out in two stages. After the first stage of pressure holding for 20 - 25 s, air is released for 15 - 20 s. After the second stage of pressure holding for 25 - 30 s, air is released for 20 - 25 s, and then the pressure is continuously held until the set pressure holding time is reached.

[0040] Further, step S1 further includes pretreating the aramid pulp: The aramid pulp is opened by a fluffing machine to obtain aramid pulp fibers with a loose texture. Since the aramid pulp agglomerates seriously and is not conducive to uniform mixing, it needs to be opened in a fluffing machine. The fluffing process adopted by the fluffing machine is a pulling and fluffing process, and the speed of the spiked roller for fluffing is controlled at 40 times / min to obtain aramid pulp with a loose texture.

[0041] Further, step S2 specifically includes the following content: Put phenolic resin, natural graphite and a plasticizer into a mixer, turn on the machine and mix for 3 - 5 min until evenly mixed, then add carbon fiber and the pretreated aramid pulp, turn on the machine and mix for 5 - 10 min until evenly mixed.

[0042] Further, in step S3, the mixed raw materials also need to be kneaded on a kneader before pressing: Place the mixed raw materials on the kneader, set the roller speed of the kneader to 70 / rad, the roller speed ratio to 1:1, preheat the rollers to 80 - 90 °C before kneading, the initial distance between the rollers is 7 mm, adjust the distance between the rollers to carry out kneading, and knead repeatedly until the distance between the rollers gradually shrinks to 3 mm until the raw materials are tightly combined and not loose.

[0043] Further, step S3 specifically includes: Place the mixed raw materials in a mold preheated to 100 - 110 °C on a hot press for pressing, with a pressure of 7 KN to form a semi-solid preform, and then place the preform in a forming mold preheated to 100 - 110 °C for pressing, with a pressure of 7 - 13 N, and at the same time carry out heat treatment. After complete curing, a fiber-reinforced organic polymer high-temperature anti-friction slider is obtained.

[0044] Further, it further includes step S4: Measure the size of the obtained fiber-reinforced organic polymer high-temperature anti-friction slider. When the difference between the size and the standard size is within ±0.05 mm, the product is qualified.

[0045] Figure 2 This is a comparison diagram of the microscopic tissue structure of the fiber-reinforced organic polymer high-temperature anti-friction slider of the present invention and the slider section of the prior art. It can be seen that:

[0046] (1) The fiber content of the slider in the prior art is small, and the fiber distribution uniformity is poor, resulting in low strength, high brittleness and short service life of the slider material;

[0047] (2) The slider provided by the present invention has dense and orderly distributed fibers, and has a significant fiber reinforcement effect, which greatly enhances the high-temperature mechanical properties and self-lubricating properties of the slider and greatly prolongs the service life of the slider.

[0048] The technical solution of the present invention is described below with reference to specific examples.

[0049] Example 1

[0050] The fiber-reinforced organic polymer high-temperature anti-friction slider provided in this embodiment adopts a fiber-reinforced organic polymer composite material comprising the following components in volume percentage: 10% phenolic resin, 62% aramid pulp, 8% carbon fiber, 5% natural graphite, 0.3% stearic acid, and the remainder is fly ash, and the sum of the volume percentages of each component is 100%.

[0051] The method for preparing the fiber-reinforced organic polymer high-temperature anti-friction slider described in this embodiment comprises the following steps:

[0052] S1. Weighing the raw materials of each component according to the volume percentage of each component of the fiber-reinforced organic polymer composite material;

[0053] S2, uniformly stirring the weighed raw materials in a mixer;

[0054] S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider;

[0055] The pressing pressure of the hot press is 7KN, the pressing temperature is 160℃, and the holding time is 3min;

[0056] The pressure holding process is divided into two stages. The first stage is to hold pressure for 20 seconds and release air for 15 seconds. The second stage is to hold pressure for 25 seconds and release air for 20 seconds, and then continue to hold pressure until the set pressure holding time.

[0057] The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h and 150°C for 1 h.

[0058] Example 2

[0059] The fiber-reinforced organic polymer high-temperature anti-friction slider provided in this embodiment adopts a fiber-reinforced organic polymer composite material comprising the following components in volume percentage: 13% phenolic resin, 65% aramid pulp, 7% carbon fiber, 6% natural graphite, 0.3% stearic acid, and the remainder is fly ash, and the sum of the volume percentages of each component is 100%.

[0060] The method for preparing the fiber-reinforced organic polymer high-temperature anti-friction slider described in this embodiment comprises the following steps:

[0061] S1. Weighing the raw materials of each component according to the volume percentage of each component of the fiber-reinforced organic polymer composite material;

[0062] S2, uniformly stirring the weighed raw materials in a mixer;

[0063] S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider;

[0064] The pressing pressure of the hot press is 10KN, the pressing temperature is 180℃, and the holding time is 4min;

[0065] The pressure holding process is divided into two stages. The first stage is to hold pressure for 23 seconds and release air for 20 seconds. The second stage is to hold pressure for 27 seconds and release air for 25 seconds, and then continue to hold pressure until the set pressure holding time.

[0066] The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h and 150°C for 1 h.

[0067] Example 3

[0068] The fiber-reinforced organic polymer high-temperature anti-friction slider provided in this embodiment adopts a fiber-reinforced organic polymer composite material comprising the following components in volume percentage: 15% phenolic resin, 68% aramid pulp, 6% carbon fiber, 7% natural graphite, 0.3% stearic acid, and the remainder is fly ash, and the sum of the volume percentages of each component is 100%.

[0069] The method for preparing the fiber-reinforced organic polymer high-temperature anti-friction slider described in this embodiment comprises the following steps:

[0070] S1. Weighing the raw materials of each component according to the volume percentage of each component of the fiber-reinforced organic polymer composite material;

[0071] S2, uniformly stirring the weighed raw materials in a mixer;

[0072] S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider;

[0073] The pressing pressure of the hot press is 12KN, the pressing temperature is 200℃, and the holding time is 5min;

[0074] The pressure holding process is divided into two stages: the first stage is to hold pressure for 25 seconds and release air for 20 seconds; the second stage is to hold pressure for 30 seconds and release air for 25 seconds, and then continue to hold pressure until the set pressure holding time;

[0075] The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h and 150°C for 1 h.

[0076] Comparative Example 1

[0077] The slider provided in this comparative example uses a composite material that contains the following components by volume percentage: phenolic resin 13%, aramid pulp 70%, natural graphite 6%, stearic acid 0.3%, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0078] The preparation method of the slider in this comparative example is the same as that of Example 2.

[0079] Comparative Example 2

[0080] The slider provided in this comparative example uses a composite material that contains the following components by volume percentage: phenolic resin 13%, aramid pulp 40%, carbon fiber 30%, natural graphite 6%, stearic acid 0.3%, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0081] The preparation method of the slider in this comparative example is the same as that of Example 2.

[0082] Comparative Example 3

[0083] The slider provided in this comparative example uses a composite material that contains the following components by volume percentage: phenolic resin 13%, aramid pulp 75%, carbon fiber 7%, natural graphite 3%, stearic acid 0.3%, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0084] The preparation method of the slider in this comparative example is the same as that of Example 2.

[0085] Comparative Example 4

[0086] The slider provided in this comparative example uses a composite material that contains the following components by volume percentage: phenolic resin 13%, aramid pulp 65%, carbon fiber 7%, natural graphite 10%, stearic acid 0.3%, and the balance is fly ash. The sum of the volume percentages of each component is 100%.

[0087] The preparation method of the slider in this comparative example is the same as that of Example 2.

[0088] Comparative Example 5

[0089] This comparative example provides a composite material that contains the following components by volume percentage: phenolic resin 13%, carbon fiber 70%, natural graphite 6%, stearic acid 0.3%, and the balance is fly ash. The sum of the percentage contents of each component is 100%.

[0090] The preparation method of the slider in this comparative example is the same as that of Example 2.

[0091] The components and contents of Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 1:

[0092] Table 1 Components and Contents (volume percentage) of Examples and Comparative Examples

[0093]

[0094] Note: D in Table 1 represents Comparative Example; the same components in Examples and Comparative Examples are not shown in Table 1

[0095] Table 2 Performance Comparison Data of Examples and Comparative Examples at Different Temperatures

[0096]

[0097] Note: D in Table 2 represents Comparative Example

[0098] It can be seen from the data in Table 2 that as the temperature increases from 100°C to 300°C:

[0099] (1) The impact strength of the samples of Examples 1 to 3 changes little.

[0100] (2) By comparing Examples 1 to 3 with Comparative Example 2 and Comparative Example 5, the following conclusions can be obtained: Aramid pulp can improve the impact strength of the slider; the content of aramid pulp in the composite material has a great influence on the impact strength of the prepared slider. Only within the content range of aramid pulp defined in the present invention can it be ensured that the impact strength of the prepared slider does not change significantly with the increase of temperature.

[0101] It can be seen from the data in Table 2 that as the temperature increases from 100°C to 350°C:

[0102] (1) The friction coefficients of the samples of Examples 1 to 3 do not change significantly.

[0103] (2) By comparing Examples 1 to 3 with Comparative Example 3 and Comparative Example 4, the following conclusions can be obtained: The addition of natural graphite can increase the self-lubricity of the slider, and the content of natural graphite has a significant influence on the friction coefficient of the prepared slider. Only within the graphite content range defined in the present invention can it be ensured that the prepared slider maintains the best self-lubricating performance.

[0104] (3) The friction coefficients of the samples of Comparative Examples 1 to 5 decrease significantly with the increase of temperature, indicating that there is an obvious high-temperature decline phenomenon for the samples of the comparative examples.

[0105] It can be seen from the data in Table 2 that as the temperature increases from 100°C to 300°C:

[0106] (1) The Rockwell hardness of the samples of Examples 1 to 3 changes little.

[0107] (2) Comparing Examples 1 to 3 with Comparative Example 1 and Comparative Example 2, the following conclusions can be drawn: The addition of carbon fiber can increase the Rockwell hardness of the slider; the content of carbon fiber has a significant effect on the Rockwell hardness of the prepared slider; only within the carbon fiber content defined in the present invention can it be ensured that the Rockwell hardness of the prepared slider does not change significantly with the increase in temperature.

[0108] In summary, the fiber-reinforced organic polymer high-temperature anti-friction slider provided by the present invention still has a stable friction coefficient at high temperatures, and also has relatively stable Rockwell hardness and impact strength at high temperatures, which indicates that it still has good mechanical properties at high temperatures.

[0109] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fiber-reinforced organic polymer high-temperature anti-friction slider used in a transverse stretching machine of a film biaxial stretching production line. It is characterized in that The slider is formed by hot pressing of a fiber-reinforced organic polymer composite material, and the fiber-reinforced organic polymer composite material comprises the following components in volume percentage: 10-15% organic polymer material, 62-68% aramid pulp, 6-8% carbon fiber, 5-7% natural graphite, 0.3% plasticizer, and the balance is fly ash, and the sum of the volume percentages of each component is 100%; the organic polymer material is phenolic resin, and the plasticizer is stearic acid; it also includes 0.7% curing agent and 0.5% dimensional stabilizer, the curing agent is hexamethylenetetramine, and the dimensional stabilizer is polyol; The method for preparing the fiber-reinforced organic polymer high-temperature anti-friction slider comprises the following steps: S1, weighing the raw materials of each component according to the volume percentage of each component of the fiber-reinforced organic polymer composite material; step S1 also includes pre-treating the aramid pulp: opening the aramid pulp through an opener to obtain loose aramid pulp fibers; S2, uniformly stirring aramid pulp, carbon fiber, natural graphite, organic polymer material and plasticizer in a mixer; Step S2 specifically comprises: placing phenolic resin, natural graphite and plasticizer in the mixer, starting the mixer to mix until the mixture is uniform, then adding carbon fiber and pretreated aramid pulp, starting the mixer to mix until the mixture is uniform; S3, pressing and heat treating the mixed raw materials through a hot press to obtain a fiber-reinforced organic polymer high-temperature anti-friction slider; The pressing pressure of the hot press is 7-13 kN, the pressing temperature is 160-200°C, and the holding time is 3-5 min; The heat treatment includes four stages, namely, 100°C for 0.5 h, 120°C for 0.5 h, 140°C for 1 h, and 150-170°C for 1 h. In step S3, the pressure holding process is divided into two stages: the first stage is pressure holding for 20 to 25 seconds and then air is released for 15 to 20 seconds; the second stage is pressure holding for 25 to 30 seconds and then air is released for 20 to 25 seconds, and then the pressure is continued to the set pressure holding time; In step S3, the mixed raw materials need to be placed on an open mill for open refining before pressing: the mixed raw materials are placed on the open mill, the roller speed ratio of the open mill is set to 1:1, the rollers are preheated to a certain temperature before refining, the spacing of the rollers is adjusted for refining, and the refining is repeated, and the spacing between the rollers is gradually reduced until the raw materials are tightly combined and not loose; Step S3 specifically includes: placing the mixed raw materials in a preheated mold on a hot press for pressing to form a semi-solid preform, and then placing the preform in a preheated molding mold for pressing, while performing heat treatment, and after complete curing, a fiber-reinforced organic polymer high-temperature anti-friction slider is obtained.

2. The fiber-reinforced organic polymer high-temperature anti-friction slider used in a transverse stretching machine of a film biaxial stretching production line according to claim 1, It is characterized in that Step S2 specifically includes the following contents: Put phenolic resin, natural graphite and plasticizer into a mixer, turn on the machine and mix for 3 - 5 minutes until evenly mixed, then add carbon fiber and pretreated aramid pulp, turn on the machine and mix for 5 - 10 minutes until evenly mixed.

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