Method for rapidly evaluating weld mark improvement effect of injection molding raw material

Abstract

The invention discloses a method for rapidly evaluating the improvement effect of injection molding raw materials on weld marks. The method comprises the steps that S1, a color plate injection mold is constructed; s2, injection molding of a color plate; and S3, comparing the degrees of the weld marks. According to the method, different polyolefin raw materials are subjected to injection molding by adopting a small and simple injection mold to form different color plates with weld marks, the improvement effects of the different polyolefin raw materials on the weld marks are evaluated according to the degrees of the weld marks on the different color plates, and according to the improvement effects of the weld marks, the quality of the color plates is improved. And screening out the polyolefin raw material with the weld mark with the minimum formation degree. The method is simple, efficient and rapid, time and labor consumed by a traditional mold testing method are greatly saved, meanwhile, polyolefin raw materials are saved, and the evaluation cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of polyolefin plastic injection molding, and in particular to a method for quickly evaluating the improvement effect of injection molding raw materials on weld marks. Background Art

[0002] In the polyolefin injection molding process, when multiple gates are used or there are holes, inserts in the cavity, and the thickness of the product varies greatly, the plastic melt will flow in more than two directions in the mold. When the two melts meet, weld marks (weld lines) will be formed in the polyolefin product. Although weld marks (weld lines) are formed during the mold filling process, their structure, shape and properties are related to the entire injection molding process.

[0003] The existence of weld marks (weld lines) not only affects the appearance quality of polyolefin products, but also has a great impact on the mechanical properties of polyolefin products, which often causes headaches for countless engineering and technical personnel. There are many ways to solve or improve the weld mark (weld line) problem, such as from the molding process, raw materials, mold processing, product structure optimization, etc., but there is currently no simulation method for raw materials, and the improvement effect can only be evaluated through repeated mold trials, which is time-consuming, labor-intensive and material-intensive. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for quickly evaluating the improvement effect of injection molding materials on weld marks. The present invention can evaluate the effect of polyolefin injection molding materials on improving weld marks. The method is simple and can quickly evaluate the improvement effect, and screen out the best polyolefin injection molding materials for improving weld marks, with high efficiency and accuracy.

[0005] The technical solution adopted to achieve the above-mentioned purpose of the present invention is:

[0006] A method for quickly evaluating the improvement effect of injection molding raw materials on weld marks comprises the following steps:

[0007] S1. Build the color plate injection mold:

[0008] The color plate injection mold comprises a mold body, a cavity for injection molding the color plate is provided in the mold body, the cavity is flat, an injection port is provided on the mold body, and one or more blocks are provided in the cavity for blocking and diverting the molten material entering from the injection port;

[0009] S2, injection color plate:

[0010] Assume there are n kinds of injection molding materials, n ≥ 2, and the injection molding material A i The molten material A is then heated and melted. iInject it into the mold cavity through the injection port, injection mold, cool it, open the mold, and obtain the color plate A i , where i is any integer from 1 to n;

[0011] S3. Compare the degree of weld marks;

[0012] Color plate A i There is a gate A formed by injection molding on the top i , color plate A i There is at least one hole A formed by injection molding due to the stopper i , in each hole A i Back gate A i A weld mark A is formed on one side of i ;

[0013] Compare the weld marks on color plate A1 A1...Color plate A i Weld mark A i ...Color Plate A n Weld mark A n By measuring the degree of improvement of the weld mark by the above n types of injection molding materials, we can know the improvement effect of the weld mark by the above n types of injection molding materials.

[0014] Furthermore, the cavity is square.

[0015] Furthermore, the blocks are arranged in straight lines, and all the blocks and the injection port are located on the same straight line.

[0016] Furthermore, the injection port is located at the center of the side wall in the width direction of the cavity.

[0017] Furthermore, the stopper is square.

[0018] Furthermore, the degree of the weld mark includes color depth and roughness.

[0019] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0020] 1. The present invention uses a small and simple injection mold to perform injection molding on different polyolefin raw materials to form different color plates with weld marks. According to the degree of weld marks on different color plates, the improvement effect of different polyolefin raw materials on weld marks is evaluated. According to the improvement effect of weld marks, the polyolefin raw material with the smallest degree of weld marks is screened out. The method is simple, efficient and fast, greatly saving the time and manpower consumed by the traditional mold trial method, while also saving polyolefin raw materials and evaluation costs.

[0021] 2. Compared with the traditional mold trial method, the method of the present invention is simple, fast and efficient, saving time, labor and materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the mold body.

[0023] Figure 2 For color plate A i Schematic diagram of the structure.

[0024] Among them, 1- cavity, 2- injection port, 3- stopper, 4- gate A i , 5-hole A i , 6-Weld mark. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to specific embodiments, but these embodiments are not to be interpreted as limiting the protection scope of the present invention in any sense.

[0026] Example 1

[0027] 1. Construct an injection mold for an injection color plate, wherein the injection mold includes a mold body, such as Figure 1 As shown, a cavity 1 for injection molding a color plate is provided in the mold body, and the cavity 1 is square and flat. An injection port 2 is provided in the center of the side wall in the width direction of the cavity 1, which is used to inject molten material into the cavity. Two blocks 3 are provided in the cavity 1 for blocking and diverting the molten material entering from the injection port. The block 3 is square, and the square block 3 facilitates the better presentation of the weld mark (weld line). The two blocks 3 and the injection port 2 are distributed on the same straight line, and this arrangement is also for faster and better presentation of the weld mark (weld line).

[0028] 2. Assume that the effect of improving weld marks on n types of polyolefin injection molding materials needs to be evaluated, n ≥ 2, and n is a natural number. Each polyolefin injection molding material is injection molded into a corresponding color plate using the injection mold constructed in step 1. The specific method is as follows:

[0029] The injection molding raw material Ai is heated and melted, and then the obtained molten material A i Inject it into the mold cavity through the injection port, injection mold, cool it, open the mold, and obtain the color plate A i , where i is any integer from 1 to n.

[0030] 3. Color plate A formed by injection molding in step 2 i like Figure 2 As shown, color plate A i A gate A formed by injection molding due to an injection port i 4. Color Swatch A i There are two holes A formed by injection molding due to the block i 5. Hole A i 5 is square. i 5 Back gate A iA weld mark A is formed on one side of 4 i 6. According to the weld mark A i 6 can be used to quickly evaluate the effect of injection molding raw material Ai on improving weld marks (weld lines) by color depth, roughness, etc., so as to screen out polyolefin raw materials with the smallest weld marks.

[0031] In order to compare the effects of different pigments on weld lines during polyolefin injection molding, two groups of polypropylene pipe formulations were evaluated using the above method. The two groups of polypropylene pipe formulations are shown in Table 1 below:

[0032] A Polypropylene resin 80 parts Maleic anhydride grafted polypropylene 3 parts 0.5 parts calcium zinc stabilizer Phthalocyanine blue 12 parts B Polypropylene resin 80 parts Maleic anhydride grafted polypropylene 3 parts 0.5 parts calcium zinc stabilizer Permanent Yellow 12 parts

[0033] The results showed that the weld lines in the color plate formed by formula B were darker and rougher.

Claims

1. A method for quickly evaluating the effect of injection molding raw materials on improving weld marks, characterized in that The steps include: S1. Build the color plate injection mold: The color plate injection mold comprises a mold body, a cavity for injection molding the color plate is provided in the mold body, the cavity is flat, an injection port is provided on the mold body, and one or more blocks are provided in the cavity for blocking and diverting the molten material entering from the injection port; S2, injection color plate: Assume there are n kinds of injection molding materials, n ≥ 2, and the injection molding material A i The molten material A is then heated and melted. i Inject it into the mold cavity through the injection port, injection mold, cool it, open the mold, and obtain the color plate A i , where i is any integer from 1 to n; S3. Compare the degree of weld marks; Color plate A i There is a gate A formed by injection molding on the top i , color plate A i There is at least one hole A formed by injection molding due to the stopper i , in each hole A i Back gate A i A weld mark A is formed on one side of i ; Compare the weld marks on color plate A1 A1...Color plate A i Weld mark A i ...Color Plate A n Weld mark A n By measuring the degree of improvement of the weld mark by the above n types of injection molding materials, we can know the improvement effect of the weld mark by the above n types of injection molding materials.

2. The method for rapidly evaluating the improvement effect of injection molding materials on weld marks according to claim 1, characterized in that: The cavity is square.

3. The method for rapidly evaluating the improvement effect of injection molding raw materials on weld marks according to claim 1, characterized in that: The stoppers are arranged in straight lines, and all the stoppers and the injection port are located on the same straight line.

4. The method for rapidly evaluating the improvement effect of injection molding raw materials on weld marks according to claim 3, characterized in that: The injection port is located at the center of the side wall in the width direction of the cavity.

5. The method for rapidly evaluating the improvement effect of injection molding materials on weld marks according to claim 1, characterized in that: The stopper is square.

6. The method for rapidly evaluating the improvement effect of injection molding materials on weld marks according to claim 1, characterized in that: The degree of the weld mark includes color depth and roughness.

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