Flange for tap water pipeline connection

Abstract

The invention relates to the technical field of tap water pipeline connecting flanges, in particular to a flange for tap water pipeline connection, which is prepared from the following raw materials in parts by mass: 100 parts of raw rubber, 80 to 90 parts of carbon black and 4 to 5 parts of vulcanizing agent. Additives, such as an anti-aging agent, a softening agent, a processing aid, an accelerant and the like, which influence the safety of a human body are not added into the flange formula; according to the flange, the formula is simple, the safety performance is easier to control, and in addition, the flange has excellent performance.

Description

Technical Field

[0001] The present disclosure relates to the technical field of water pipe connection flanges, and in particular to a flange for connecting water pipes. Background Art

[0002] The water supply pipeline system is one of the foundations of urban public service facilities. It is mainly composed of water sources, water supply pipelines, water plants, pressure regulating stations, etc. In the water supply pipeline network, pipeline connection is a very important part, and flange connection is a common connection method.

[0003] Flange is the main part of the connecting pipe, used to connect the two ends of the pipe. Flange connection is a way of connecting pipes and forming a seal by assembling flanges on both ends of the pipe diameter. Flange connection has the characteristics of easy connection, easy disassembly, and reliable sealing. At present, some flanges for connecting tap water pipes on the market often add some additives during processing to ensure the performance of the product, which may make the flange have a strong odor, which will not only affect the taste of tap water, but also may affect people's health. Summary of the invention

[0004] In view of the deficiencies or problems existing in the prior art, the present invention provides a flange for connecting a tap water pipe, which has a simple formula component and excellent performance.

[0005] The technical solution adopted by the present disclosure to solve the above technical problems is: a flange for connecting tap water pipes, which includes the following raw materials by mass: 100 parts of raw rubber, 80-90 parts of carbon black, and 4-5 parts of vulcanizing agent.

[0006] Preferably, the raw rubber is ethylene propylene diene monomer (EPDM).

[0007] Preferably, the EPDM rubber is EPT 4045M.

[0008] Preferably, the carbon black is N774 carbon black.

[0009] Preferably, the N774 carbon black is 83-87 parts.

[0010] This application improves the environmental performance of rubber by selecting N774 carbon black. N774 carbon black has low extractables in solvents and will not pollute rubber. In addition, N774 carbon black has a higher filling amount, which can improve the processability of the rubber and the elasticity of the rubber will also be better.

[0011] Preferably, the N774 carbon black is 85 parts.

[0012] Preferably, the vulcanizing agent is CA 18550D. The main component of the vulcanizing agent CA 18550D is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, which is environmentally friendly, has a small odor of the produced product, and can be used in the food-grade industry. In addition, the addition of CA 18550D can also make the vulcanized rubber have excellent heat resistance and aging resistance, thereby improving the service life of the product.

[0013] Preferably, the vulcanizing agent is 4.5 parts.

[0014] The amount of vulcanizing agent used in this application affects not only the performance but also the processing performance of the rubber compound. Too little amount may easily lead to insufficient vulcanization, low hardness, large compression set, etc.; too much amount may easily lead to poor processing performance (fast vulcanization speed, reduced fluidity, difficulty in edge removal, etc.) and high hardness, etc.

[0015] The raw rubber used is EPT 4045M, which is synthesized using the latest metallocene catalytic technology. The residual catalyst content in the rubber is small, the odor is low, and the environmental protection is relatively good; the rubber has relatively excellent weather resistance and chemical corrosion resistance, and can be used for a long time in various harsh environments. The raw rubber, carbon black, and vulcanizing agent are matched in appropriate proportions, which not only makes the products produced by the rubber meet the requirements of relevant performance tests, but also makes the rubber have better processability.

[0016] Compared with the prior art, the flange formula of the present application does not contain additives such as antioxidants, softeners, processing aids, promoters, etc. that may affect human safety; the formula of the present application is simple and easier to control in terms of safety performance. In addition, the flange of the present application has excellent performance. DETAILED DESCRIPTION

[0017] Example 1 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 80 parts of N774 carbon black, and 4 parts of vulcanizing agent CA 18550D.

[0018] Example 2 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 82 parts of N774 carbon black, and 4.5 parts of vulcanizing agent CA 18550D.

[0019] Example 3 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 83 parts of N774 carbon black, and 4.2 parts of vulcanizing agent CA 18550D.

[0020] Example 4 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 85 parts of N774 carbon black, and 4.6 parts of vulcanizing agent CA 18550D.

[0021] Example 5 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 90 parts of N774 carbon black, and 5 parts of vulcanizing agent CA 18550D.

[0022] Example 6 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 88 parts of N774 carbon black, and 4.8 parts of vulcanizing agent CA 18550D.

[0023] Example 7 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 86 parts of N774 carbon black, and 4.7 parts of vulcanizing agent CA 18550D.

[0024] Example 8 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 84 parts of N774 carbon black, and 4.3 parts of vulcanizing agent CA 18550D.

[0025] Example 9 This embodiment provides a flange for connecting a tap water pipe, which includes the following raw materials in parts by mass: 100 parts of EPDM rubber, 85 parts of N774 carbon black, and 4.5 parts of vulcanizing agent CA 18550D.

[0026] Comparative Example 1 This comparative example provides a flange for connecting a tap water pipe, which comprises the following raw materials in parts by mass: 100 parts of EPDM rubber, 60 parts of N550 carbon black, and 4.5 parts of vulcanizing agent CA 18550D.

[0027] Comparative Example 2 This comparative example provides a flange for connecting a tap water pipe, which comprises the following raw materials in parts by mass: 100 parts of EPDM rubber, 85 parts of N774 carbon black, and 3 parts of vulcanizing agent CA 18550D.

[0028] Comparative Example 3 This comparative example provides a flange for connecting a tap water pipe, which comprises the following raw materials in parts by mass: 100 parts of EPDM rubber, 100 parts of N774 carbon black, 4.5 parts of vulcanizing agent CA 18550D, and 8 parts of naphthenic oil.

[0029] The flanges of the above 9 embodiments and 3 comparative examples are now subjected to relevant performance tests: (1) The tensile strength and elongation at break shall be measured in accordance with GB / T 528-1998, and the international rubber hardness test shall be measured in accordance with ASTM D1415-06 (2012); (2) The static compression set test is carried out in accordance with GB / T 1683-81; (3) Singapore Standards SS 375:2015 Suitability of non-metallic products for use in contact with water intended for human consumption with regard to their effect on the quality of the water, also known as SS375 test. SS375 test is a test standard in Singapore, mainly used to test the effect of non-metallic products on water quality when in contact with drinking water for human consumption.

[0030] The test results are as follows:

[0031] From the test results of Example 1 to Example 9, it can be seen that the amount of carbon black mainly affects the hardness and elongation of the rubber. With the increase of the amount of carbon black, the hardness of the rubber slightly increases and the elongation slightly decreases. Since the fluctuation range of the amount of carbon black is not large, the compression permanent deformation and tensile strength do not change significantly. The amount of vulcanizing agent affects the degree of vulcanization of the rubber. With the increase of the amount of vulcanizing agent, the crosslinking density of the rubber increases, the hardness increases, the elongation decreases, and the compression permanent deformation decreases.

[0032] Comparative Example 1 uses N550 carbon black, which failed SS375. In the actual trial production process, it was found that the processability was also poor and the defect rate was high. This is because the extract content of N550 carbon black in water is higher than that of N774 carbon black, resulting in failure of SS375 test; the filling amount of N550 carbon black is smaller than that of N774 carbon black, and the rubber content will increase, but the processability will deteriorate, affecting the yield rate.

[0033] The amount of vulcanizing agent in Comparative Example 2 is 3 parts, the hardness is low (the qualified hardness range is 66IRHD-75IRHD), and the compression permanent deformation is large (the qualified index is ≤25%). This is mainly because the amount of vulcanizing agent directly affects the cross-linking density of the rubber compound. If the amount of vulcanizing agent is too small, the cross-linking density will decrease, resulting in low hardness and poor compression permanent deformation.

[0034] In Comparative Example 3, softener naphthenic oil was added mainly to improve processability, increase filling amount and reduce cost, but SS375 was not passed. This is because, on the one hand, naphthenic oil has the risk of precipitation. Once precipitated into water, it is not easy to degrade and will exist for a long time, affecting the water quality; on the other hand, naphthenic oil itself also contains some harmful substances (such as polycyclic aromatic hydrocarbons, etc.) that affect water quality. In addition, the addition of naphthenic oil will increase the filling amount of carbon black, and the total amount of carbon black extract in water will be at risk of being too high.

[0035] The present application is described in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the present application and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A flange for connecting a water pipe, characterized in that: Calculated by mass, the following raw materials are included: 100 parts of raw rubber, 80-90 parts of carbon black, and 4-5 parts of vulcanizing agent.

2. The flange for connecting a tap water pipe according to claim 1, characterized in that: The raw rubber is EPDM rubber.

3. The flange for connecting a tap water pipe according to claim 2, characterized in that: The EPDM rubber is EPT 4045M.

4. The flange for connecting a tap water pipe according to claim 1, characterized in that: The carbon black is N774 carbon black.

5. The flange for connecting a tap water pipe according to claim 4, characterized in that: The N774 carbon black is 83-87 parts.

6. The flange for connecting a water pipe according to claim 5, characterized in that: The N774 carbon black is 85 parts.

7. The flange for connecting a tap water pipe according to claim 1, characterized in that: The vulcanizing agent is CA18550D.

8. The flange for connecting a water pipe according to claim 1, characterized in that: The vulcanizing agent is 4.5 parts.

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