A method for plasma treatment of injection molded parts

Abstract

The present invention relates to the technical field of automotive plastic part processing, and more specifically, to a method for plasma processing injection molded parts, comprising: injection molding the automotive injection molded parts, constructing a mathematical model of surface tension, determining plasma processing equipment, processing the automotive injection molded parts using the plasma processing equipment at a set plasma processing speed, monitoring the distance between the plasma and the automotive injection molded parts in real time, calculating a target distance between the plasma and the automotive injection molded parts based on a target surface tension and the constructed mathematical model, and adaptively adjusting the distance to the target distance. The present invention utilizes plasma to bombard the surface of the automotive injection molded parts to achieve deburring of the automotive injection molded parts. Simultaneously, the plasma introduces oxygen- and nitrogen-containing functional groups into the surface of the automotive injection molded parts, increasing surface polarity and improving coating adhesion. Furthermore, the pre-constructed mathematical model allows adaptive adjustment to achieve the target surface tension, thereby increasing the degree of automation in the plasma processing process.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile plastic parts processing, and more particularly to a method for plasma processing injection molded parts. Background Art

[0002] Among automotive parts made of plastic, exterior parts require pre-treatment to remove burrs and flash before being painted to enhance their functionality and aesthetics. However, injection molded parts often lack adhesion to paint, necessitating the application of a primer to improve adhesion between the two. This process involves multiple steps and is time-consuming.

[0003] Plasma is the fourth state of matter. When gas molecules absorb a certain amount of energy, they exist in the form of charged particles (anions or cations, free radicals, electrons) and electrically neutral particles (atoms). Because this plasma exists in a high-energy, highly reactive state, it has the property of reacting rapidly with other materials. By utilizing the properties of this plasma, the properties of solid surfaces can be chemically changed.

[0004] The prior art discloses a method for coating plastic wheel covers using flame plasma surface treatment. This method utilizes the air / LPG or air / LNG mixture ratio introduced into an external plastic injection-molded product, the distance between the plasma source and the external plastic injection-molded product, the plasma treatment speed, and the gas mixture amount as variables for flame plasma surface treatment. This method eliminates the need for conventional pretreatment and primer processes by using flame plasma surface treatment. However, this method lacks the ability to adaptively adjust the variable values, resulting in a low degree of automation. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology of low automation level of plasma treatment of injection molded parts, and provide a method for plasma treatment of injection molded parts. While using plasma to treat the surface of automotive injection molded parts to improve the adhesion of paint, the plasma processing equipment can be adaptively adjusted to improve the automation level of the plasma processing process.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for plasma treating an injection molded part is provided, comprising the following steps:

[0008] S1: According to the process requirements, select the resin raw materials for automobile injection molding processing, and produce automobile injection molding parts by injection molding;

[0009] S2: Construct a mathematical model for the plasma processing equipment, which relates the surface tension Y to the distance D between the plasma and the automotive injection molded part and the plasma processing speed V, and determine the plasma processing equipment;

[0010] S3: Processing the automotive injection molded part using a plasma processing device at a set plasma processing speed V, monitoring the distance D between the plasma and the automotive injection molded part in real time during the processing, and calculating the target distance between the plasma and the automotive injection molded part based on the target surface tension and the constructed mathematical model;

[0011] S4: Adaptively adjusting a plasma gun head for emitting plasma in the plasma processing equipment according to the calculated target distance so that a distance D between the plasma and the surface of the automobile injection molded part is the target distance.

[0012] The plasma treatment method for injection molded parts of the present invention utilizes plasma emitted by plasma processing equipment to bombard the surface of automobile injection molded parts to achieve deburring of the automobile injection molded parts. At the same time, the plasma introduces oxygen- and nitrogen-containing functional groups into the surface of the automobile injection molded parts, increasing the surface polarity and improving the coating adhesion. Moreover, through a pre-constructed mathematical model, adaptive adjustment can be made during the processing to obtain the target surface tension, thereby improving the degree of automation of the plasma processing process.

[0013] Preferably, in step S2, the mathematical model constructed is:

[0014] Y=k1D 2 +k2D+k3V -0.143 -146

[0015] Where Y represents the surface tension of the automotive injection molded part; D represents the distance between the plasma and the automotive injection molded part; V represents the plasma processing speed; k1, k2, and k3 are all constants, and the value range of k1 is -0.425 to -0.490, the value range of k2 is 18.00 to 18.50, and the value range of k3 is 11.00 to 12.00.

[0016] Preferably, in step S1, the resin raw material is modified polypropylene.

[0017] Preferably, in step S1, the thickness of the automobile injection molded part is 2.0 mm to 3.4 mm.

[0018] Preferably, in step S3, the parameters of the plasma processing equipment include: plasma flame width of 5mm to 15mm, plasma flame height of 30mm to 40mm, plasma power of 100W to 1000W, input gas pressure of not less than 0.6MPa, input voltage of 220V, and input voltage frequency of 50Hz.

[0019] Preferably, in step S3, the distance between the plasma and the automobile injection molded part allowed by the plasma processing equipment is 10 mm to 24 mm.

[0020] Preferably, in step S3, the plasma processing speed allowed by the plasma processing equipment is 275 mm / s to 625 mm / s.

[0021] Preferably, in step S3, the plasma power is 900W.

[0022] Preferably, the value of k1 is -0.475, the value of k2 is 18.27, and the value of k3 is 11.87.

[0023] Preferably, in step S2, the process of constructing the mathematical model is:

[0024] S201: Start the plasma processing equipment to grab the test injection molded parts, and determine the basic process parameters of the plasma processing equipment according to the burr treatment effect of the test injection molded parts and the required coating adhesion test quality requirements;

[0025] S202: Using a controlled variable method, the plasma processing equipment is activated for testing, and the test injection molded part is subjected to plasma treatment. During the test, different distances D between the plasma and the test injection molded part and different plasma treatment speeds V are set. A laser displacement sensor is used for data collection, and the surface tension Y of the test injection molded part is measured after each parameter adjustment test.

[0026] S203: According to the parameters adjusted each time and the measured surface tension, the relationship between the surface tension Y and the distance D between the plasma and the test injection molded part and the plasma processing speed V is measured.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] Plasma is used to bombard the surface of automotive injection-molded parts to achieve deburring of the parts. At the same time, plasma will introduce oxygen- and nitrogen-containing functional groups to the surface of the parts, increasing the surface polarity and improving the adhesion of the coating. Through the pre-built mathematical model, the plasma processing equipment can be adaptively adjusted during the processing to obtain the target surface tension, thereby improving the degree of automation of the plasma processing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Flowchart of a method for plasma treatment of injection molded parts in an embodiment of the present invention;

[0030] Figure 2 This is a fitting curve diagram of surface tension and the distance between plasma and automobile injection molded parts in Example 1 of the present invention;

[0031] Figure 3 This is a fitting curve diagram of surface tension and plasma processing speed in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with specific embodiments.

[0033] Example 1

[0034] This embodiment is the first embodiment of the method for plasma treatment of injection molded parts. Figure 1 As shown, the following steps are included:

[0035] S1: According to the process requirements, select the resin raw materials for automobile injection molding processing, and produce automobile injection molding parts by injection molding;

[0036] S2: Construct a mathematical model for the plasma processing equipment, which relates the surface tension Y to the distance D between the plasma and the automotive injection molded part and the plasma processing speed V, and determine the plasma processing equipment;

[0037] S3: Processing the automotive injection molded part using a plasma processing device at a set plasma processing speed V, monitoring the distance D between the plasma and the automotive injection molded part in real time during the processing, and calculating the target distance between the plasma and the automotive injection molded part based on the target surface tension and the constructed mathematical model;

[0038] S4: Adaptively adjusting a plasma gun head for emitting plasma in the plasma processing equipment according to the calculated target distance so that a distance D between the plasma and the surface of the automobile injection molded part is the target distance.

[0039] The above-mentioned method of plasma treatment of injection molded parts uses plasma emitted by plasma processing equipment to bombard the surface of automobile injection molded parts to achieve deburring of automobile injection molded parts. At the same time, the plasma will introduce oxygen- and nitrogen-containing functional groups into the surface of automobile injection molded parts, increase surface polarity, and improve coating adhesion. Through a pre-constructed mathematical model, adaptive adjustments can be made during the processing process to obtain the target surface tension, thereby improving the degree of automation of the plasma processing process.

[0040] In step S2, the mathematical model constructed is:

[0041] Y=k1D 2 +k2D+k3V -0.143 -146

[0042] In the formula, Y represents the surface tension of the automotive injection molded part; D represents the distance between the plasma and the part; V represents the plasma processing speed; k1, k2, and k3 are all constants, with the value range of k1 being -0.425 to -0.490, the value range of k2 being 18.00 to 18.50, and the value range of k3 being 11.00 to 12.00. It should be noted that if different types and brands of resin raw materials are used for plasma treatment, the constants k1, k2, and k3 can vary accordingly within the corresponding numerical ranges.

[0043] In step S1, the resin raw material is modified polypropylene, the modified polypropylene material nose is 1.03-1.05, the melt index MI is 40g / min-48g / min, and the modified polypropylene has good dimensional and chemical stability, meeting the mechanical properties, impact resistance, and mechanical performance requirements required by the product.

[0044] In step S1, the thickness of the automobile injection molded part is 2.0 mm to 3.4 mm.

[0045] In step S2, the parameters of the plasma processing equipment include: plasma flame width of 5mm to 15mm, plasma flame height of 30mm to 40mm, plasma power of 100W to 1000W, input gas pressure of not less than 0.6MPa, input voltage of 220V, and input voltage frequency of 50Hz.

[0046] The distance between the plasma and the automotive injection molded parts allowed by the plasma processing equipment is 10mm to 24mm, the plasma processing speed allowed by the plasma processing equipment is 275mm / s to 625mm / s, and the plasma power is 900W, which not only ensures the resin burr treatment, but also avoids the impact of excessive temperature on the quality of automotive injection molded parts due to over-fire.

[0047] In this embodiment, the process of constructing the mathematical model is:

[0048] S201: Start the plasma processing equipment to grab the test injection molded parts, and determine the basic process parameters of the plasma processing equipment based on the burr treatment effect of the test injection molded parts and the required coating adhesion test quality requirements; among them, the vacuum pressure is selected to be 2.0MPa and the plasma power is 900W;

[0049] S202: Using a controlled variable method, the plasma processing equipment is activated for testing, and the test injection molded part is subjected to plasma treatment. During the test, different distances D between the plasma and the test injection molded part and different plasma treatment speeds V are set. A laser displacement sensor is used for data collection, and the surface tension Y of the test injection molded part is measured after each parameter adjustment test. Specifically:

[0050] While the plasma processing speed V is kept constant, the distance D between the plasma and the test injection molded part is varied from 10 mm to 24 mm, with each 1 mm interval being used as a data point. After each parameter adjustment, the appearance quality of the test injection molded part is confirmed and the surface tension is measured. The appearance quality test includes testing the appearance for burr residue and over-burning conditions. A dyne pen is used to test the treated position, and the relationship between the surface tension Y and the distance D between the plasma and the test injection molded part is recorded. After measuring one set of curves, the plasma processing speed V is adjusted to another constant value, and the next set of curves is measured. Similarly, while the distance D between the plasma and the test injection molded part is kept constant, the plasma processing speed V is varied from 275 mm / s to 625 mm / s, with a step size of 25 mm / s, and the relationship between the surface tension Y and the plasma processing speed V is measured. The test was conducted on a test injection molded part with a thickness of 2.2 mm. The test results are shown in Table 1:

[0051] Table 1 Changes in surface tension of injection molded parts after testing

[0052]

[0053] According to the test data in Table 1, a fitting curve of the YDV relationship is drawn, as shown in Figure 2 、 Figure 3 shown.

[0054] S203: Based on the parameters adjusted each time and the measured surface tension, the relationship between the surface tension Y and the distance D between the plasma and the test injection molded part and the plasma processing speed V is measured:

[0055] Y=-0.475D 2 +18.27D+11.87V -0.143 -146.

[0056] Example 2

[0057] This embodiment is the second embodiment of a method for plasma processing an injection molded part. An injection molded part with a thickness of 2.2 mm is prepared to ensure that its surface is smooth and defect-free. The injection molded part is placed on a plasma processing device and the target surface tension is adjusted to 57 dynes / cm to ensure that the injection molded part is stable during processing. The plasma processing speed is set to 500 mm / s so that the plasma processing device performs uniform processing along the surface of the injection molded part. The flame width is adjusted to 10 mm to ensure that the flame covers the surface of the injection molded part during processing. The plasma height is adjusted to 35 mm to maintain an appropriate distance between the plasma and the surface of the injection molded part. The plasma processing device is turned on and the plasma power is set to 900 W. The injection molded part is processed and the plasma pressure is adjusted to 0.6 MPa to optimize the processing effect. The processing process shows that the adjusted distance between the plasma and the injection molded part is 18 mm. Upon inspection, the injection molded part has burrs removed and the surface tension is improved, achieving the expected effect.

[0058] Example 3

[0059] This embodiment is the third embodiment of the method for plasma processing injection molded parts. This embodiment is similar to the second embodiment, except that an injection molded part with a thickness of 3.4 mm is prepared to ensure that its surface is smooth and defect-free; the injection molded part is placed on the plasma processing equipment, and the target surface tension is adjusted to 59 dynes / cm to ensure that the injection molded part is stable during the processing; the plasma processing speed is set to 625 mm / s so that the plasma processing equipment performs uniform processing along the surface of the injection molded part, and the flame width is adjusted to 15 mm to ensure that the flame covers the surface of the injection molded part during the processing; the plasma height is adjusted to 40 mm to maintain an appropriate distance between the plasma and the surface of the injection molded part; the plasma processing equipment is turned on, the plasma power is set to 1000 W, the injection molded part is processed, and the plasma pressure is adjusted to 2.0 MPa to optimize the processing effect. The processing process shows that the adjusted distance between the plasma and the injection molded part is 20 mm. Upon inspection, the burrs of the injection molded part are removed and the surface tension is improved, achieving the expected effect.

[0060] Example 4

[0061] This embodiment is the fourth embodiment of the method for plasma processing injection molded parts. This embodiment is similar to the second embodiment, except that an injection molded part with a thickness of 2.0 mm is prepared to ensure that its surface is smooth and defect-free; the injection molded part is placed on the plasma processing equipment, and the target surface tension is adjusted to 43 dynes / cm to ensure that the injection molded part is stable during the processing; the plasma processing speed is set to 275 mm / s so that the plasma processing equipment performs uniform processing along the surface of the injection molded part, and the flame width is adjusted to 5 mm to ensure that the flame covers the surface of the injection molded part during the processing; the plasma height is adjusted to 30 mm to maintain an appropriate distance between the plasma and the surface of the injection molded part; the plasma processing equipment is turned on, the plasma power is set to 1000 W, the injection molded part is processed, and the plasma pressure is adjusted to 0.6 MPa to optimize the processing effect. The processing process shows that the adjusted distance between the plasma and the injection molded part is 14 mm. Upon inspection, the burrs of the injection molded part are removed and the surface tension is improved, achieving the expected effect.

[0062] Example 5

[0063] This embodiment is the fifth embodiment of the method for plasma processing injection molded parts. This embodiment is similar to the second embodiment, except that an injection molded part with a thickness of 2.8 mm is prepared to ensure that its surface is smooth and defect-free; the injection molded part is placed on the plasma processing equipment, and the target surface tension is adjusted to 52 dynes / cm to ensure that the injection molded part is stable during the processing; the plasma processing speed is set to 500 mm / s so that the plasma processing equipment performs uniform processing along the surface of the injection molded part, and the flame width is adjusted to 9 mm to ensure that the flame covers the surface of the injection molded part during the processing; the plasma height is adjusted to 35 mm to maintain an appropriate distance between the plasma and the surface of the injection molded part; the plasma processing equipment is turned on, the plasma power is set to 1000 W, the injection molded part is processed, and the plasma pressure is adjusted to 0.65 MPa to optimize the processing effect. The processing process shows that the adjusted distance between the plasma and the injection molded part is 15 mm. Upon inspection, the burrs of the injection molded part are removed and the surface tension is improved, achieving the expected effect.

[0064] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for plasma treatment of injection molded parts, characterized in that: The following steps are involved: S1: According to the process requirements, select the resin raw materials for automobile injection molding processing, and produce automobile injection molding parts by injection molding; S2: Building Surface Tension for Plasma Processing Equipment The distance between plasma and automotive injection molded parts and plasma processing speed Mathematical model and determine the plasma processing equipment; S3: Use plasma processing equipment to set the plasma processing speed Processing of automotive injection molded parts, real-time monitoring of the distance between plasma and the automotive injection molded parts during processing , the target distance between plasma and automotive injection molded parts is calculated based on the target surface tension and the constructed mathematical model; S4: Adaptively adjust the plasma gun head used to emit plasma in the plasma processing equipment according to the calculated target distance, so that the distance between the plasma and the surface of the automobile injection molded part is is the target distance; In step S2, the mathematical model constructed is: Where, Indicates the surface tension of automotive injection molded parts; Indicates the distance between plasma and automotive injection molded parts; Indicates the plasma processing speed; 、 、 are constants, and The value range is -0.425~-0.490, The value range is 18.00~18.50, The value range is 11.00~12.00; In step S2, the process of constructing the mathematical model is: S201: Start the plasma processing equipment to grab the test injection molded parts, and determine the basic process parameters of the plasma processing equipment according to the burr treatment effect of the test injection molded parts and the required coating adhesion test quality requirements; S202: Using the control variable method, start the plasma processing equipment to test, perform plasma treatment on the test injection molded parts, and set different distances between the plasma and the test injection molded parts during the test. and different plasma processing speeds , using laser displacement sensors to collect data, and measuring the surface tension of the test injection molded parts after each parameter adjustment test ; S203: Measure the surface tension based on the parameters adjusted each time and the measured surface tension The distance between the plasma and the test injection molded part , plasma processing speed The changing relationship.

2. The method for plasma treatment of injection molded parts according to claim 1, characterized in that: In step S1, the resin raw material is modified polypropylene.

3. The method for plasma treatment of injection molded parts according to claim 2, characterized in that: In step S1, the thickness of the automobile injection molded part is 2.0 mm to 3.4 mm.

4. The method for plasma treatment of injection molded parts according to claim 3, characterized in that: In step S3, the parameters of the plasma processing equipment include: plasma flame width of 5mm~15mm, plasma flame height of 30mm~40mm, plasma power of 100W~1000W, input gas pressure of not less than 0.6MPa, input voltage of 220V, and input voltage frequency of 50Hz.

5. The method for plasma treatment of injection molded parts according to claim 4, characterized in that: In step S3, the distance between the plasma and the automobile injection molded part allowed by the plasma processing equipment is 10mm~24mm.

6. The method for plasma treatment of injection molded parts according to claim 5, characterized in that: In step S3, the plasma processing speed allowed by the plasma processing equipment is It is 275mm / s~625mm / s.

7. The method for plasma treatment of injection molded parts according to claim 6, characterized in that: In step S3, the plasma power is 900W.

8. The method for plasma treatment of injection molded parts according to claim 7, characterized in that: The value is -0.475, The value is 18.27, The average value is 11.87.

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