Production method of low-noise chain roller

Abstract

The invention discloses a production method of a low-noise chain roller, which comprises the following steps of: S1, sequentially performing roughening, gluing and glue layer pre-curing treatment on a rim surface of a metal core wheel to obtain a pre-treated metal core wheel; s2, preparing a mixed solution of an MDI polyester prepolymer, color paste, a curing agent and a cross-linking agent; s3, the mixed liquid is guided into a pouring mold where the pretreated metal core wheel is fixed, the rim face of the pretreated metal core wheel is coated with the mixed liquid, a tire is formed after the mixed liquid is cured, the mold is disassembled, and a semi-finished chain roller is obtained; s4, the semi-finished chain roller is put into a drying oven to be heated, and a vulcanized chain roller is obtained; and S5, cooling and trimming the vulcanized chain roller, and assembling a bearing to obtain the low-noise chain roller. According to the production method of the low-noise chain roller, the rim surface is sequentially subjected to roughening, gluing and glue layer pre-curing treatment and then is connected with a tire formed by casting MDI polyester prepolymer. According to the structure, the peel strength between the tire and the core wheel is high, and the noise generated when the chain roller runs is effectively reduced due to the use of the polyurethane material.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane product processing technology, and specifically relates to a production method of a low-noise chain roller. Background Art

[0002] The step chain roller of an escalator for subway consists of a core wheel and a tire. The main performances of the step chain roller include the peel strength between the core wheel and the tire, roller life, oil resistance, water resistance, hydrolysis resistance and overload performance. In order to create a quiet environment, some subway stations require the escalator to have low-noise performance. Summary of the Invention

[0003] The purpose of the present invention is to provide a production method of a low-noise chain roller, and the produced chain roller has excellent low-noise performance.

[0004] In order to achieve the above technical effects, the technical solution of the present invention is: a production method of a low-noise chain roller, comprising the following steps:

[0005] S1. Rough the rim surface of the metal core wheel, apply glue and pre-cure the glue layer in sequence to obtain a pre-treated metal core wheel;

[0006] S2. Prepare a mixed solution of MDI polyester prepolymer, color paste, curing agent and cross-linking agent;

[0007] S3. Pour the mixed solution into a casting mold with the pre-treated metal core wheel fixed, the mixed solution covers the rim surface of the pre-treated metal core wheel and forms a tire after curing, disassemble the mold to obtain a semi-finished chain roller;

[0008] S4. Put the semi-finished chain roller into an oven for heating to obtain a vulcanized chain roller;

[0009] S5. Cool and trim the vulcanized chain roller and then assemble bearings to obtain a low-noise chain roller.

[0010] The preferred technical solution is that the specific operation of the roughing treatment in step S1 is:

[0011] S11. Sandblast the rim surface of the metal core wheel with 20-40 mesh quartz sand;

[0012] S12. Rinse the metal core wheel with trichloroethylene;

[0013] S13. Vacuum dry the metal core wheel;

[0014] The operations of S11, S12 and S13 are carried out in a workshop with a temperature of 15-17°C and a humidity of 30-35%RH. Further, the operations of S11, S12 and S13 are carried out in a workshop with a temperature of 15-16°C and a humidity of 30-32%RH.

[0015] The preferred technical solution is that the specific operation of the glue coating treatment in step S1 is as follows:

[0016] S14. Apply a heat-curable metal primer on the rim surface of the metal core wheel;

[0017] S15. After the metal primer dries, apply a heat-curable surface glue on the surface of the metal primer, and finally dry the surface glue.

[0018] The preferred technical solution is that the thickness of the heat-curable metal primer and the heat-curable surface glue is 45-55 μm, and the thickness ratio of the heat-curable metal primer to the heat-curable surface glue is 1:(0.9-1.1). Further, the thickness of the heat-curable metal primer and the heat-curable surface glue is 47-53 μm, and the thickness ratio of the heat-curable metal primer to the heat-curable surface glue is 1:(0.95-1.05).

[0019] The preferred technical solution is that the specific operation of the pre-curing treatment of the glue layer is as follows: Place the metal core wheel coated with glue in an oven at 120-150 °C and heat for 1-2 h. Further, the specific operation of the pre-curing treatment is as follows: Place the metal core wheel coated with glue in an oven at 120-130 °C and heat for 1-1.5 h, then raise the temperature to 140-150 °C and keep it warm for 0.3-0.5 h.

[0020] The preferred technical solution is that in step S3, the temperature of the mixed liquid when it is introduced into the casting mold is 105-110 °C, the mold is closed after part of the mixed liquid is cured, the closing pressure is 4-5 Mpa, and the temperature of the mold and the pre-treated metal core wheel during the curing process of the mixed liquid is 106-110 °C. Further, the closing pressure is 4.5-5 Mpa.

[0021] The preferred technical solution is that the specific operation of step S4 is as follows: Place the semi-finished chain roller in an oven at 75-85 °C and heat for 9.5-10 h to obtain a vulcanized chain roller. Further, the specific operation of step S4 is as follows: Place the semi-finished chain roller in an oven at 77-83 °C and heat for 10 h to obtain a vulcanized chain roller.

[0022] The preferred technical solution is that in step S5, the curing agent is a diamine chain extender, the color paste is a polyurethane color paste, and the cross-linking agent is a diamine cross-linking agent.

[0023] The preferred technical solution is that the diamine chain extender is at least one of dichlorodiphenylmethane, diethyltoluenediamine, and 4,4'-methylene-bis(3-chloro-2,6-diethylaniline), and the diamine cross-linking agent is at least one of dimethylthiomethylenediamine, N1-(4-bromobenzyl)-N3-(4-bromophenyl)-N1,N1,N3,N3-tetramethylpropane-1,3-diamine, and methylcyclohexanediamine.

[0024] Preferably, the mass ratio of the MDI polyester prepolymer, dichlorodiphenylmethane, polyurethane color paste and dimethylthiotoluenediamine is 1:(0.17 - 0.19):(0.07 - 0.09):(0.05 - 0.07).

[0025] The advantages and beneficial effects of the present invention are as follows:

[0026] In the production method of the low-noise chain roller, after the rim surface is successively subjected to roughening, gluing and pre-curing of the glue layer, it is connected to a tire cast from an MDI polyester prepolymer. This structure not only provides a high peel strength between the core wheel and the tire, but also effectively reduces the noise during the operation of the chain roller due to the use of MDI polyurethane material.

[0027] The production method of the low-noise chain roller has low difficulty, and the produced low-noise chain roller is easy to maintain. Detailed implementation manners

[0028] The following describes the detailed implementation manners of the present invention in conjunction with embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0029] Chain extender

[0030] A chain extender refers to a compound that can promote the extension and expansion of molecular chains, usually a small molecule binary or ternary compound, such as a diol, a diamine, etc. The main function of the chain extender is to increase the molecular weight of the polyurethane and provide the hard segment content, thereby enhancing the strength and rigidity of the material.

[0031] Curing agent

[0032] A curing agent refers to a compound that can promote the cross-linking reaction of polymers, usually used in a two-component system. In a polyurethane system, the curing agent can be a chain extender, such as MOCA (an aromatic diamine), which forms physical cross-linking points by reacting with isocyanate to increase the hardness and strength of the material.

[0033] Raw materials:

[0034] MDI polyester prepolymer: WANNATE 3W3616T, WANHUA;

[0035] TDI polyester prepolymer: MDH, Maidhao;

[0036] Polyurethane color paste: PURS, Xinjin Polymerization;

[0037] Heat-curable metal primer: Chemlok 219, Chemlok;

[0038] Hot vulcanized surface glue: Chemlok 213, Chemlok;

[0039] o-Chlorodiphenylmethane: industrial grade, Shandong Tongxin;

[0040] Dimethylthiotoluenediamine: industrial grade, Sheng'an Biology;

[0041] Methylcyclohexanediamine: industrial grade, Yuyi.

[0042] I. Examples and comparative examples

[0043] Example 1

[0044] The production method of the low-noise chain roller in Example 1 is as follows:

[0045] S1. In a constant temperature and humidity workshop with an average temperature of 15°C and a humidity of 30% RH, first use 30-mesh quartz sand to sandblast the rim surface of the aluminum core wheel. The width of the aluminum core wheel is 32 mm, and the diameter is 62 mm. After sandblasting, rinse the aluminum core wheel with trichloroethylene, and immediately put the aluminum core wheel into a vacuum drying oven for drying after rinsing. The vacuum degree of the vacuum drying oven is set to 6 Pa, and the temperature is set to 60°C.

[0046] After the aluminum core wheel is dried, first coat the rim surface of the aluminum core wheel with Chemlok 219 glue. The coating thickness of Chemlok 219 glue is 50 μm, and then put the aluminum core wheel into a vacuum drying oven for drying. The vacuum degree of the vacuum drying oven is set to 5 Pa, and the temperature is set to 70°C.

[0047] After the Chemlok 219 glue is dried, coat Chemlok 213 glue on the surface of the Chemlok 219 glue. The coating thickness of Chemlok 213 glue is 50 μm, and finally put the aluminum core wheel into a vacuum drying oven for drying. The vacuum degree of the vacuum drying oven is set to 7 Pa, and the temperature is set to 70°C.

[0048] After the Chemlok 213 glue is dried, raise the temperature of the vacuum drying oven to 120°C, keep it warm for 1 h, and obtain a pretreated aluminum core wheel. Then put the aluminum core wheel into a casting mold and fix it. The casting mold is a constant temperature casting mold at 108°C.

[0049] S2. First, heat 100 g of the viscous MDI polyester prepolymer of model WANNATE 3W3616T to 80°C. At this time, the fluidity of the MDI polyester prepolymer becomes better. Then add 8 g of the PUR polyurethane color paste to the MDI polyester prepolymer and stir and heat. After the temperature of the mixed liquid of the polyurethane color paste and the MDI polyester prepolymer reaches 110°C, add 18 g of o-chlorodiphenylmethane and 6 g of dimethylthiotoluenediamine and quickly stir to obtain a mixed liquid.

[0050] S3. Rapidly introduce the mixture into the casting mold with the pretreated aluminum core wheel fixed. When part of the mixture solidifies to the gel state, close the mold under a pressure of 5 Mpa. After the mixture completely solidifies to form a tire, disassemble the casting mold to obtain semi-finished chain rollers.

[0051] S4. Place the semi-finished chain rollers in an oven at 80 °C and heat for 10 h to obtain vulcanized chain rollers.

[0052] S5. Cool and trim the vulcanized chain rollers and then assemble bearings to obtain low-noise chain rollers.

[0053] Example 2

[0054] Based on Example 1, the difference lies in S1:

[0055] After the aluminum core wheel is dried, first coat the rim surface of the aluminum core wheel with Chemlok 219 adhesive, with a thickness of 100 μm. Then place the aluminum core wheel in a vacuum drying oven for drying, with the vacuum degree of the vacuum drying oven set at 5 Pa and the temperature set at 70 °C.

[0056] After the Chemlok 219 adhesive is dried, raise the temperature of the vacuum drying oven to 120 °C, keep it warm for 1 h, to obtain a pretreated aluminum core wheel. Subsequently, place the aluminum core wheel in the casting mold and fix it. The casting mold is a constant-temperature casting mold at 108 °C.

[0057] Example 3

[0058] Based on Example 1, the difference lies in S1: The thickness of the Chemlok 219 adhesive coated on the rim surface of the aluminum core wheel is 53 μm, and the thickness of the Chemlok 213 adhesive coated on the surface of the Chemlok 219 adhesive is 47 μm.

[0059] Example 4

[0060] Based on Example 1, the difference lies in S1: The thickness of the Chemlok 219 adhesive coated on the rim surface of the aluminum core wheel is 47 μm, and the thickness of the Chemlok 213 adhesive coated on the surface of the Chemlok 219 adhesive is 53 μm.

[0061] Example 5

[0062] Based on Example 1, the difference lies in S2:

[0063] S2. First, heat 100 g of the viscous MDI polyester prepolymer of model WANNATE 3W3616T to 80 °C. At this time, the fluidity of the MDI polyester prepolymer becomes better. Then, add 8 g of the PUR polyurethane color paste to the MDI polyester prepolymer and stir and heat. After the temperature of the mixed solution of the polyurethane color paste and the MDI polyester prepolymer reaches 110 °C, add 18 g of di(o-chlorophenyl)methane and 6 g of methylcyclohexanediamine and quickly stir to obtain a mixed solution.

[0064] Example 6

[0065] Based on Example 1, the difference lies in S1:

[0066] After the Chemlok 213 glue is dried, raise the temperature of the vacuum drying oven to 120 °C, keep it warm for 1 h, then raise the temperature to 145 °C and keep it warm for 0.4 h to obtain a pretreated aluminum core wheel. Subsequently, put the aluminum core wheel into a casting mold and fix it. The casting mold is a constant-temperature casting mold at 108 °C.

[0067] Comparative Example 1

[0068] Based on Example 1, the difference is that: use the TDI polyester prepolymer of model MDH. Second, the performance detection and qualification criteria of the low-noise chain rollers in the examples and comparative examples are as follows:

[0069] 1. Detection of the peel strength between the core wheel and the tire

[0070] Test conditions:

[0071] 1) The number of specimens is 15.

[0072] 2) The indoor environmental temperature for testing: 25 °C ± 3 °C.

[0073] Test requirements:

[0074] 1) Cut a slit at a 45° angle to the running surface and perform peeling along the circumferential direction at a speed of 50 mm / min ± 5 mm / min starting from the cut.

[0075] 2) The test combinations are shown in Table 1.

[0076] Table 1 Test combinations for the peel strength of the low-noise chain roller tire

[0077]

[0078]

[0079] Table 2 Peel strength of the low-noise chain roller

[0080]

[0081] 2. Low-noise chain roller life test

[0082] Test conditions:

[0083] 1) The number of tests is 5;

[0084] 2) Indoor test environment temperature: 25°C ± 3°C.

[0085] 3) Test machine drum diameter: 500 mm to 900 mm.

[0086] Passing criteria:

[0087] At a linear speed of 0.8 m / s and a load of 1300 N, run for 5000 h. After the test, the low-noise chain roller should be able to operate normally. Fine cracks are allowed on the tire surface, but there should be no local concavities, convexities, degumming, etc.

[0088] 3. Oil resistance test

[0089] Test conditions:

[0090] 1) The number of tests is 5;

[0091] 2) Indoor test environment temperature: 25°C ± 3°C.

[0092] Passing criteria:

[0093] Immerse the unpretreated low-noise chain roller in the step-chain lubricating oil at 50°C for 48 h, then take it out and place the low-noise chain roller at room temperature of 25°C ± 3°C for 48 h, and then run at a linear speed of 0.8 m / s and a load of 1300 N for 250 h. After the test, the low-noise chain roller should have no local concavities, convexities, degumming, cracking, etc.

[0094] 4. Water resistance test

[0095] Test conditions:

[0096] 1) The number of tests is 5;

[0097] 2) Indoor test environment temperature: 25°C ± 3°C.

[0098] Passing criteria:

[0099] Immerse the unpretreated low-noise chain roller in hot water at 75°C for 250 h, then take it out and place the low-noise chain roller at room temperature of 25°C ± 3°C for 48 h, and then run at a linear speed of 0.8 m / s and a load of 1300 N for 250 h. After the test, the low-noise chain roller should have no local concavities, convexities, degumming, cracking, etc.

[0100] 5. Hydrolysis resistance test

[0101] Test conditions:

[0102] 1) The number of tests is 5;

[0103] 2) Test the indoor ambient temperature: 25°C ± 3°C.

[0104] Passing criteria:

[0105] Assemble the low-noise chain roller onto the pin shaft with a rotating function, and then place it in a thermostatic and humidistatic chamber at 80°C to 85°C and 95% RH to 98% RH, where the low-noise chain roller does not touch the water surface. During the entire fumigation test, the low-noise chain roller rotates at a speed of 0.01 m / s and is completely enveloped by water vapor. After 1000 h of water vapor fumigation, take out the low-noise chain roller and conduct an appearance inspection. There should be no phenomena such as degumming or cracking on the surface of the low-noise chain roller.

[0106] 6. Overload test of the low-noise chain roller

[0107] Test conditions:

[0108] 1) The number of tests is 5;

[0109] 2) Test the indoor ambient temperature: 25°C ± 3°C.

[0110] Passing criteria:

[0111] Operate at a linear speed of 0.8 m / s and a load of 2500 N for 16 h. After the test, there should be no phenomena such as local concavity and convexity, degumming, or cracking on the low-noise chain roller.

[0112] 7. Noise test

[0113] After assembling the low-noise chain roller onto the escalator, measure the sound pressure level at an open position 1 m horizontally from the surface of the drive main unit and 1.6 m above the floor slab.

[0114] Passing criteria:

[0115] Sound pressure level ≤ 70 dB(A)

[0116] III. Detection result tables 3 and 4 of the low-noise chain rollers in the examples and comparative examples:

[0117] Table 3 Detection results of the examples and comparative examples

[0118]

[0119]

[0120] Table 4 Detection results of the examples and comparative examples

[0121]

[0122] Compared with Example 1, Example 2 only uses Chemlok 219 glue, the peel strength between the core wheel and the tire is reduced, and the noise is significantly increased. The possible reason is that the use of Chemlok 219 metal base glue and Chemlok 213 surface glue combination is conducive to improving the bonding quality between the aluminum core wheel and the polyurethane tire, reducing the noise caused by structural looseness; at the same time, when sound propagates from one medium to another, reflection, refraction and absorption will occur, resulting in energy loss, further reducing the noise emitted by the low-noise chain roller.

[0123] Compared with Example 1, the thickness of the Chemlok 219 metal base glue of Example 3 increases, the thickness of the Chemlok 213 surface glue decreases, the peel strength between the core wheel and the tire decreases, and the noise increases. The possible reason is that the active groups in the Chemlok 213 surface glue will react with the corresponding active groups of the polyurethane prepolymer in the mixed solution. This reaction is a competitive reaction with the reaction of dichlorodiphenylamine and the polyurethane prepolymer. Too little Chemlok 213 surface glue and polyurethane have a low crosslinking density at the interface. Compared with Example 1, the thickness of the Chemlok 219 metal base glue of Example 4 decreases, the thickness of the Chemlok 213 surface glue increases, the peel strength between the core wheel and the tire decreases, and the noise increases. The possible reason is that the overly thick Chemlok 213 surface glue is prone to internal stress during the curing process, resulting in insufficient bonding strength between the Chemlok 213 surface glue and the polyurethane. Compared with Example 1, Example 5 uses methylcyclohexanediamine as a diamine crosslinking agent. It shows that in Example 1, dimethylthiotoluenediamine is preferably used as the diamine cross-linking agent, which is beneficial to producing a low-noise chain roller with a larger bonding strength between the rim surface and the polyurethane tire, and is beneficial to reducing the noise of the escalator.

[0124] Compared with Example 1, the curing treatment of the adhesive layer in Example 6 increases the temperature rise and heat preservation in the second stage, the peel strength between the core wheel and the tire is increased, and the noise is reduced. The possible reason is that the 120°C heat preservation stage can initially activate the cross-linking reaction between the Chemlok 219 metal base glue and the Chemlok 213 surface glue, and the subsequent high-temperature treatment at 145°C further accelerates the cross-linking reaction and increases the cross-linking density of the Chemlok 219 metal base glue and the Chemlok 213 surface glue. In addition, the high temperature of 145°C promotes the penetration of the Chemlok 219 metal base glue into the microscopic pores of the aluminum substrate, enhances the mechanical interlocking effect, and improves the compatibility of the Chemlok 213 surface glue with the polyurethane prepolymer.

[0125] Compared with Example 1, the toluene diisocyanate polyester prepolymer of model MDH was used in the comparative example. It shows that under the process of Example 1, using the MDI polyester prepolymer is beneficial to producing low-noise chain rollers with a relatively high bonding strength between the rim surface and the polyurethane tire, and is also beneficial to reducing the noise of the escalator.

[0126] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A production method of a low-noise chain roller, characterized in that, It includes the following steps: S1. Roughness treatment, glue coating, and pre-curing treatment of the rim surface of the metal core wheel are carried out in sequence to obtain a pre-treated metal core wheel; S2. Prepare a mixed solution of MDI polyester prepolymer, color paste, curing agent, and cross-linking agent; S3. Import the mixed solution into the casting mold with the pre-treated metal core wheel fixed. The mixed solution coats the rim surface of the pre-treated metal core wheel and forms a tire after curing. Disassemble the mold to obtain a semi-finished chain roller; S4. Put the semi-finished chain roller into an oven for heating to obtain a vulcanized chain roller; S5. Cool and trim the vulcanized chain roller and then assemble bearings to obtain a low-noise chain roller.

2. The production method of the low-noise chain roller according to claim 1, characterized in that, The specific operation of the roughness treatment in step S1 is as follows: S11. Carry out sandblasting treatment on the rim surface of the metal core wheel with 20 - 40 mesh quartz sand; S12. Rinse the metal core wheel with trichloroethylene; S13. Vacuum-dry the metal core wheel; The operations of S11, S12, and S13 are carried out in a workshop with a temperature of 15 - 17 °C and a humidity of 30 - 35%RH.

3. The production method of the low-noise chain roller according to claim 1, characterized in that, The specific operation of the glue coating treatment in step S1 is as follows: S14. Coat a heat-curable metal primer on the rim surface of the metal core wheel; S15. After the metal primer dries, coat a heat-curable topcoat on the surface of the metal primer, and finally dry the topcoat.

4. The production method of the low-noise chain roller according to claim 3, characterized in that, The thickness of the heat-curable metal primer and the heat-curable topcoat is 45 - 55 μm, and the thickness ratio of the heat-curable metal primer to the heat-curable topcoat is 1:(0.9 - 1.1).

5. The production method of the low-noise chain roller according to claim 1, characterized in that, The specific operation of the pre-curing treatment of the glue layer is: Place the glue-coated metal core wheel in an oven at 120 - 150 °C and heat for 1 - 2 h.

6. The production method of the low-noise chain roller according to claim 1, characterized in that In step S3, when the mixed solution is imported into the casting mold, the temperature is 105 - 110 °C. After partial curing of the mixed solution, close the mold. The closing pressure is 4 - 5 Mpa, and the temperature of the mold and the pre-treated metal core wheel during the curing process of the mixed solution is 106 - 110 °C.

7. The production method of the low-noise chain roller according to claim 1, characterized in that, The specific operation of step S4 is: Put the semi-finished chain roller into an oven at 75 - 85 °C and heat for 9.5 - 10 h to obtain a vulcanized chain roller.

8. The production method of the low-noise chain roller according to claim 1, characterized in that, In step S2, the curing agent is a diamine chain extender, the color paste is a polyurethane color paste, and the cross-linking agent is a diamine cross-linking agent.

9. The production method of the low-noise chain roller according to claim 8, characterized in that The diamine chain extender is at least one of bis(o-chlorophenyl)methane, diethyltoluenediamine, and 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and the diamine cross-linking agent is at least one of dimethylthiotoluenediamine, N1-(4-bromobenzyl)-N3-(4-bromophenyl)-N1,N1,N3,N3-tetramethylpropane-1,3-diamine, and methylcyclohexanediamine.

10. The production method of the low-noise chain roller according to claim 9, characterized in that, The mass ratio of the MDI polyester prepolymer, bis(o-chlorophenyl)methane, polyurethane color paste, and dimethylthiotoluenediamine is 1:(0.17 - 0.19):(0.07 - 0.09):(0.05 - 0.07).

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