Low-cost plastic-to-steel composite material for automobile pipeline joint and preparation method of low-cost plastic-to-steel composite material

Abstract

The invention provides a low-cost plastic-replacing-steel composite material for an automobile pipeline joint and a preparation method. The material comprises the following components in parts by weight: 0-100 parts of HDPE (High-Density Polyethylene), 0-50 parts of an auxiliary agent and 0.5-2 parts of an antioxidant. Compared with the prior art, the invention creatively provides a thought that the HDPE and the PA can be subjected to double-shot molding to prepare a product, and an HDPE material with good compatibility with the PA is invented, so that the interfacial compatibility of the two materials is greatly improved, and the excellent compatibility of the double-shot molding product and the comprehensive performance of the product are ensured. The double-color injection molding product can replace an original steel pipeline connector, the cost and weight of the product are effectively reduced, and the double-color injection molding product has important significance on the purpose of automobile light weight.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a low-cost composite material for replacing steel with plastic for automobile pipe joints and a preparation method thereof. Background Art

[0002] With the rapid development of the automobile industry, especially new energy vehicles, lightweight, functionalization and comfort have gradually become the goals that the automobile industry is constantly pursuing, which also puts higher requirements on automotive materials. In order to achieve various personalized needs of automobiles, pipelines are an important part of automobiles, and the materials used are also constantly being developed and iterated. Traditional pipe joints are mostly made of steel. In specific demand scenarios, the plastic pipes at both ends are combined together by steel, but steel is heavy and the process is complicated, which is not conducive to weight reduction and cost reduction of pipeline products. Through the present invention, this traditional structure of plastic-steel-plastic can be replaced by an innovative solution of 100% plastic. That is, the steel joint is replaced by a joint after double-color injection molding of modified HDPE and PA materials, and plastic pipes are welded at both ends for use. It can ensure that the performance of the product is not affected, and the weight is reduced while reducing costs, which is of great significance to the overall lightweight of the automobile. However, because HDPE is a non-polar material and PA is a polar material, the huge difference in polarity leads to almost no compatibility and adhesion between the two materials, which in turn leads to the fragility of the interface of double-color injection molding. Therefore, improving the interface compatibility of the two materials to achieve the best effect of two-color injection molding is a problem that the current solution needs to solve. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to propose a modified HDPE material and preparation method for automobile pipe joints based on an innovative solution of replacing steel joints with modified HDPE and PA double-color injection-molded products, and to carry out polarity modification on the basis of existing HDPE materials to improve compatibility with PA, thereby ensuring the interface sealing and medium resistance after double-color injection molding. Due to characteristic attribute problems, ordinary HDPE materials have poor compatibility with PA after double-color injection molding, and local cracking will occur during injection molding. The interface after medium resistance is even worse, with almost no compatibility, showing a state of complete separation of the two materials. After comparing various types of polar modified substances and addition ratios, the present invention has studied an optimal formula. The modified HDPE material has good compatibility with the PA material, and the product can still maintain excellent sealing performance and interface bonding after high-temperature medium resistance tests and temperature alternation tests.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A low-cost composite material for replacing steel with plastic for automobile pipe joints is composed of the following components in parts by weight: 0-100 parts of HDPE, 1-50 parts of an auxiliary agent, and 0.5-2 parts of an antioxidant.

[0006] The HDPE is high-density polyethylene.

[0007] The auxiliary agent is one of a certain graft or a certain copolymer.

[0008] The antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant and a thioether antioxidant.

[0009] The method for preparing the composite material of replacing steel with plastic at low cost for automobile pipe joints comprises the following steps:

[0010] Step 1: Put HDPE, additives and antioxidants in a high-speed mixer according to the weight ratio and mix for 4-6 minutes to obtain a uniform mixture of the above components.

[0011] Step 2: Add the above component mixture into a twin-screw extruder from a hopper, and melt, extrude, cool and pelletize the mixture through the twin-screw extruder to obtain a composite material.

[0012] The processing temperatures of zone IX of the twin-screw extruder are 80° C., 200° C., 200° C., 200° C., 190° C., 190° C., 190° C., 190° C., 190° C., 190° C. The main screw speed is 500-550 r / min, and the water tank temperature is 30° C.-60° C.

[0013] Compared with the prior art, the present invention has the following technical advantages:

[0014] 1. Compared with traditional HDPE materials, the modified HDPE material breaks its non-polar characteristic properties and can be used for two-color injection molding with PA materials to achieve excellent interface compatibility and two-color injection molding effects. After the product has undergone high-temperature medium resistance tests and temperature alternation tests, it can still maintain excellent sealing performance and interface bonding strength.

[0015] 2. The invention of modified HDPE materials with improved polarity provides the possibility of double-color injection molding of HDPE and PA, and the possibility of replacing the traditional plastic-steel-plastic pipe joint solution with 100% plastic. At the same time, it can ensure that the performance of the product is not affected, reduce the weight while reducing the cost, which is of great significance to the overall lightweighting of the automobile. DETAILED DESCRIPTION

[0016] Below in conjunction with specific embodiment, further elaborate content of the present invention.It should be emphasized that these embodiments are only used for further explanation of the present invention, and can not be interpreted as limiting the scope of protection of the present invention.In addition, it should be understood that after reading the content described in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0017] The maleic anhydride grafted product 1 in the embodiment is maleic anhydride grafted POE, brand: HW401; grafting rate> 0.5%;

[0018] Maleic anhydride grafted material 2 is: maleic anhydride grafted HDPE, brand: HW405, grafting rate>0.5%.

[0019] Example 1

[0020] Step 1: Put HDPE, maleic anhydride grafted product 1 and antioxidant into a high-speed mixer according to the weight ratio and mix for 4-6 minutes to obtain a uniform mixture of the above components.

[0021] Step 2: Add the above component mixture into a twin-screw extruder from a hopper, and melt, extrude, cool and pelletize the mixture through the twin-screw extruder to obtain a composite material.

[0022] The processing temperatures of zone IX of the twin-screw extruder are 80° C., 200° C., 200° C., 200° C., 190° C., 190° C., 190° C., 190° C., 190° C., 190° C. The main screw speed is 500-550 r / min, and the water tank temperature is 30° C.-60° C.

[0023] Embodiment 2-6

[0024] A low-cost composite material for replacing steel with plastic for automobile pipe joints. The preparation method of Examples 2-6 is the same as that of Example 1, and the only difference is the type or ratio of the auxiliary agent. The auxiliary agent of Examples 3 and 4 is maleic anhydride graft 2, and the auxiliary agent of Examples 5 and 6 is ethylene copolymer. The formula of Examples 2-6 is shown in Table 1, and the preparation method is the same as that of Example 1.

[0025] Comparative Example 1

[0026] This comparative example formulation does not contain any additives.

[0027] Step 1: Put HDPE and antioxidant into a high-speed mixer according to the weight ratio and mix for 4-6 minutes to obtain a uniform mixture of the above components.

[0028] Step 2: Add the above component mixture into a twin-screw extruder from a hopper, and melt, extrude, cool and pelletize the mixture through the twin-screw extruder to obtain a composite material.

[0029] The processing temperatures of zone IX of the twin-screw extruder are 80° C., 200° C., 200° C., 200° C., 190° C., 190° C., 190° C., 190° C., 190° C., 190° C. The main screw speed is 500-550 r / min, and the water tank temperature is 30° C.-60° C.

[0030] Table 1 Formula (parts by weight)

[0031] raw material Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 HDPE 69.3 59.3 69.3 59.3 69.3 59.3 99.3 Additive 1 30 40 Additive 2 30 40 Additive 3 30 40 Antioxidants 0.7 0.7 0.7 0.7 0.7 0.7 0.7

[0032] Embodiments 1-6 and comparative example 1 were double-color injection molded with PA, respectively. The products after double-color injection molding were subjected to 80°C / 1000h medium resistance test and double 85 test. The products after the test needed to be subjected to sealing test.

[0033] The sealing test is carried out under the conditions of 5 bar water pressure and 4 minutes.

[0034] Table 2 Performance test results

[0035] project 80℃ / 1000h Double 85 Sealing after 80℃ / 1000h Double 85 rear sealing Example 1 Good interface Good interface Water seepage Water seepage Example 2 Good interface Good interface Water seepage Water seepage Example 3 Good interface Good interface Local water seepage Local water seepage Example 4 Good interface Good interface Completely waterproof Completely waterproof Example 5 Good interface Good interface Water seepage Water seepage Example 6 Good interface Good interface Water seepage Water seepage Comparative Example 1 Poor interface Poor interface Water seepage Water seepage

[0036] From Examples 1-6 and Comparative Example 1 in Table 2, it can be seen that after adding the additive, the interface bonding strength of the material and PA is significantly improved, and the interface performance is good after the 80℃ / 1000h medium resistance test and the double 85 test. However, the sealing test of the products after the test shows differences, indicating that except for the formula system with maleic anhydride graft 2, which has stronger interface bonding strength, other interfaces have certain defects.

[0037] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

Claims

1. A low-cost composite material for replacing steel with plastic for automobile pipe joints, characterized in that: The invention is composed of the following components in parts by weight: 0-100 parts of HDPE, 1-50 parts of auxiliary agent and 0.5-2 parts of antioxidant.

2. The low-cost composite material for replacing steel with plastic for automobile pipe joints according to claim 1, characterized in that: The HDPE is high-density polyethylene.

3. The low-cost plastic-steel composite material for automobile pipe joints according to claim 1, characterized in that: The auxiliary agent is one of maleic anhydride grafted products or ethylene copolymers.

4. The low-cost plastic-steel composite material for automobile pipe joints according to claim 1, characterized in that: The antioxidant comprises at least one of a hindered phenol antioxidant, a phosphite antioxidant, and a thioether antioxidant.

5. A low-cost plastic-steel composite material for automobile pipe joints according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Put HDPE, additives and antioxidants in a high-speed mixer according to the weight ratio and mix for 4-6 minutes to obtain a uniform mixture of the above components. Step 2: Add the above component mixture into a twin-screw extruder from a hopper, and melt, extrude, cool and pelletize the mixture through the twin-screw extruder to obtain a composite material. The processing temperatures of zone IX of the twin-screw extruder are 80° C., 200° C., 200° C., 200° C., 190° C., 190° C., 190° C., 190° C., 190° C., 190° C. The main screw speed is 500-550 r / min, and the water tank temperature is 30° C.-60° C.