Forming method

Abstract

A molding method is provided that can efficiently mold high-quality molded products using recycled resin materials. [Solution] A molding method using recycled resin material, in which the type and content of foreign matter contained in the recycled resin material is determined, a correction coefficient is calculated based on the type and content of foreign matter, and pre-set molding conditions are corrected using the correction coefficient.

Description

[Technical Field]

[0001] The present invention relates to a molding method. [Background technology]

[0002] As shown in Figure 4, in injection molding, in which a resin material is melted in an injection machine and injected into a mold to form a resin product, molding conditions C1 to C5, such as the temperature C1 of the heating barrel and mold, the amount of resin material C2, the injection speed C3, the holding pressure C4 when clamping the mold, and the injection time C5, are set, and molding M is performed under these molding conditions C1 to C5.

[0003] Meanwhile, in order to achieve circular economy (CE) and carbon neutrality (CN), there is a demand to replace petroleum-derived resins used in injection molding with recycled resins derived from scrapped cars and other industries.However, when replacing resins with recycled resins, foreign matter contained in the recycled resins frequently causes quality defects such as off-size or poor appearance in injection-molded products.

[0004] Patent Document 1 describes that injection molding conditions are generated using a predetermined relational expression based on data that links and accumulates material property values ​​of resin materials, injection molding conditions, and molding quality parameters. Examples of the generated injection molding conditions include injection speed, temperature, and dwell pressure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-141495 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned predetermined relational expressions are to be created for each delivery of recycled resin material supplied by a material supplier, for example. Therefore, if various data are linked and accumulated, and relational expressions are created and molding conditions are generated for each delivery of recycled resin material, a considerable number of trials are required for each delivery, resulting in a problem of low production efficiency.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide a molding method that can efficiently mold high-quality molded products using recycled resin materials. [Means for solving the problem]

[0008] In order to achieve the above object, the molding method of the present invention comprises: A molding method using recycled resin material, The type and amount of foreign matter contained in the recycled resin material are identified, calculating a correction coefficient based on the type and content of the foreign matter; The preset molding conditions are corrected by the correction coefficient.

[0009] According to this molding method, by correcting the molding conditions that have been set in advance under specified conditions based on a correction coefficient calculated from the type and amount of foreign matter contained in the recycled resin material, it is possible to efficiently mold high-quality molded products under appropriate molding conditions without having to try molding each recycled resin material. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a molding method that can efficiently mold high-quality molded products using recycled resin materials. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram illustrating the molding method according to this embodiment. [Figure 2] FIG. 2 is a diagram showing the types of foreign matter, the amounts contained, and correction coefficients for each type of foreign matter. [Figure 3] FIG. 3 is a diagram showing correction coefficients for various foreign substances and their contents. [Figure 4] FIG. 4 is an explanatory diagram illustrating a general molding method. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram illustrating the molding method according to this embodiment. As shown in Fig. 1, the molding method according to this embodiment is a method for molding a resin molded product using an injection molding machine. In injection molding, in which a resin material is melted in the injection machine and injected into a mold to form a resin product, predetermined molding conditions C1 to C5 are set in advance, and molding M is performed under these molding conditions C1 to C5.

[0013] As mentioned above, when replacing resin materials with recycled resin materials, foreign matter contained in the recycled resin materials frequently causes quality defects such as off-size or poor appearance in molded products.

[0014] For this reason, in this embodiment, molding conditions C1 to C5 are adjusted depending on the foreign matter contained in the recycled resin material used. This allows molding under appropriate molding conditions using recycled resin material. Therefore, quality defects such as dimensional errors and poor appearance can be reduced, and molded products of the same high quality as those molded from petroleum-derived resin materials can be molded.

[0015] The molding method according to this embodiment will be described below. (Molding condition setting) First, molding conditions C1 to C5 for injection molding are set. The molding conditions C1 to C5 include, for example, the temperature C1 of the heating barrel and the mold, the amount of resin material C2, the injection speed C3, the dwell pressure when clamping the mold C4, and the injection time C5.

[0016] (Analysis of recycled resin materials) Next, the recycled resin material to be used undergoes a foreign matter analysis process P1. Recycled resin materials from scrapped cars and other industrial sources may contain foreign matter such as iron (Fe), copper (Cu), sodium (Na), chlorine (Cl), and zinc (Zn). In this foreign matter analysis process P1, the type and amount of foreign matter contained in the recycled resin material are identified and determined, and the physical properties of the foreign matter (thermal conductivity, melting point, hardness, chemical reactivity, etc.) are confirmed in order to understand the impact that the foreign matter contained in the recycled resin material has on molding.

[0017] Figure 2 shows the types of foreign matter, their content, and the correction coefficients for each type of foreign matter. As shown in Figure 2, in the foreign matter analysis process P1, the types of foreign matter (iron, copper, sodium, chlorine, zinc) contained in the recycled resin material and the content A, B, C, D, and E of each foreign matter are calculated.

[0018] (Calculation of correction coefficient) Next, a correction coefficient calculation process P2 is performed to calculate correction coefficients. In this correction coefficient calculation process P2, correction coefficients Z, Y, X, W, and V for each foreign particle are calculated based on the type and content A, B, C, D, and E of the foreign particles identified in the analysis process P1 (see FIG. 2).

[0019] (injection molding) As described above, the molding conditions C1 to C5 are corrected based on the correction coefficients Z, Y, X, W, and V calculated based on the type and content of each foreign matter, and molding M is performed under these corrected molding conditions C1 to C5 (see Figure 1). This reduces the impact of foreign matter contained in the recycled resin material on injection molding.

[0020] Next, specific correction coefficients for each type of foreign matter contained in recycled resin materials will be described. FIG. 3 is a diagram showing correction coefficients for various foreign substances and their contents. The correction coefficients Z, Y, X, W, and V are a temperature correction coefficient (°C) for the molding condition C1 (temperature), a weighing correction coefficient (g) for the molding condition C2 (weighting), a speed correction coefficient (%) for the molding condition C3 (speed), a holding pressure correction coefficient (%) for the molding condition C4 (holding pressure), and a time correction coefficient (seconds) for the molding condition C5 (time). These temperature correction coefficients (°C), weighing correction coefficient (g), speed correction coefficient (%), holding pressure correction coefficient (%), and time correction coefficient (seconds) were determined by conducting molding tests based on the molding conditions C1 to C5 that were actually set.

[0021] That is, as shown in FIG. 3, the correction coefficients Z, Y, X, W, and V are configured as follows for each type of foreign matter: The iron correction coefficient Z has a temperature correction coefficient Z1, a weighing correction coefficient Z2, a speed correction coefficient Z3, a pressure holding correction coefficient Z4, and a time correction coefficient Z5. The correction coefficient Y for copper includes a temperature correction coefficient Y1, a weighing correction coefficient Y2, a speed correction coefficient Y3, a pressure holding correction coefficient Y4, and a time correction coefficient Y5. The correction coefficient X for sodium includes a temperature correction coefficient X1, a weighing correction coefficient X2, a speed correction coefficient X3, a pressure holding correction coefficient X4, and a time correction coefficient X5. The correction coefficient W for chlorine includes a temperature correction coefficient W1, a weighing correction coefficient W2, a speed correction coefficient W3, a pressure holding correction coefficient W4, and a time correction coefficient W5. The correction coefficient V for zinc includes a temperature correction coefficient V1, a weighing correction coefficient V2, a speed correction coefficient V3, a pressure holding correction coefficient V4, and a time correction coefficient V5.

[0022] These iron correction coefficients Z1 to Z5, copper correction coefficients Y1 to Y5, sodium correction coefficients X1 to X5, chlorine correction coefficients W1 to W5, and zinc correction coefficients V1 to V5 are coefficients for adjusting each molding condition C1 to C5 according to the content of each foreign matter, and are calculated based on the reference value for each molding condition C1 to C5. This reference value is the value when each foreign matter is contained at 1%, and is the reference temperature, reference weight, reference speed, reference dwell pressure, and reference time corresponding to molding conditions C1 to C5.

[0023] Next, the reasons for correction and the formulas for calculating the correction coefficients for each of the foreign substances iron, copper, sodium, chlorine, and zinc will be described.

[0024] (1) Iron (Fe) (temperature) Reason for correction: Because iron has high thermal conductivity, the molding temperature needs to be lowered slightly. Temperature correction coefficient (℃): Z1 = Reference temperature - A% x 0.5 (weighing) Reason for correction: Iron is heavy, so it is necessary to improve the accuracy of weighing the material. Measurement correction coefficient (g): Z2 = reference measurement + A% x 0.1 (speed) Reason for correction: The hardness of the iron reduces the fluidity of the material, so the injection speed is reduced. Speed ​​correction coefficient (%): Z3 = Reference speed - A% x 0.2 (holding pressure) Reason for correction: Dimensional stability is ensured by increasing the holding pressure appropriately. Holding pressure correction coefficient (%): Z4 = Reference holding pressure + A% x 0.3 (time) Reason for correction: Extend cooling time. Time correction coefficient (seconds): Z5 = Reference time + A% x 0.2

[0025] (2) Copper (Cu) (temperature) Reason for correction: Copper has high thermal conductivity, so the molding temperature needs to be lowered. Temperature correction coefficient (℃): Y1 = Reference temperature - B% x 0.4 (weighing) Reason for correction: It is necessary to improve the weighing accuracy by taking into account the weight of copper. Measurement correction coefficient (g): Y2 = reference measurement + B% x 0.1 (speed) Reason for correction: Considering the effect of fluidity, reduce the injection speed. Speed ​​correction coefficient (%): Y3 = Reference speed - B% x 0.15 (holding pressure) Reason for correction: Dimensional stability is ensured by increasing the holding pressure appropriately. Holding pressure correction coefficient (%): Y4 = Reference holding pressure + B% x 0.25 (time) Reason for correction: Extend cooling time. Time correction coefficient (seconds): Y5 = Reference time + B% x 0.15

[0026] (3) Sodium (Na) (temperature) Reason for correction: Since sodium has a low melting point, the molding temperature needs to be lowered slightly. Temperature correction coefficient (℃): X1 = Reference temperature - C% x 0.2 (weighing) Reason for correction: It is necessary to take into account the weight of sodium and improve the measurement accuracy. Weighing correction coefficient (g):X2=Reference weighing+C%×0.05 (speed) Reason for correction: Correct the injection speed since it affects the flowability. Speed ​​correction coefficient (%): X3 = Reference speed - C% x 0.1 (holding pressure) Reason for correction: Correct the holding pressure appropriately. Holding pressure correction coefficient (%): X4 = Reference holding pressure + C% x 0.2 (time) Reason for correction: Corrects cooling time. Time correction coefficient (seconds): X5 = Reference time + C% x 0.1

[0027] (4) Chlorine (Cl) (temperature) Reason for correction: The molding temperature is corrected taking into account the chemical reactivity of chlorine. Temperature correction coefficient (℃): W1 = Reference temperature - D% x 0.3 (weighing) Reason for correction: Correct weighing accuracy. Weighing correction coefficient (g): W2 = Reference weight + D% x 0.05 (speed) Reason for correction: Correct the injection speed. Speed ​​correction coefficient (%): W3 = Reference speed - D% x 0.1 (holding pressure) Reason for correction: Correct the holding pressure. Holding pressure correction coefficient (%): W4 = Reference holding pressure + D% x 0.2 (time) Reason for correction: Corrects cooling time. Time correction coefficient (seconds): W5 = Reference time + D% x 0.1

[0028] (5) Zinc (Zn) (temperature) Reason for correction: The molding temperature is corrected to take into account the effect of zinc. Temperature correction coefficient (℃): V1 = Reference temperature - E% x 0.4 (weighing) Reason for correction: Correct weighing accuracy. Measurement correction coefficient (g): V2 = reference measurement + E% x 0.1 (speed) Reason for correction: Correct the injection speed. Speed ​​correction coefficient (%): V3 = Reference speed - E% x 0.15 (holding pressure) Reason for correction: Correct the holding pressure. Holding pressure correction coefficient (%): V4 = Reference holding pressure + E% x 0.25 (time) Reason for correction: Corrects cooling time. Time correction coefficient (seconds): V5 = Reference time + E% x 0.15

[0029] The correction coefficients thus obtained can be used to finely correct the molding conditions C1 to C5 in accordance with various foreign matters (iron, copper, sodium, chlorine, zinc).

[0030] As explained above, according to the molding method of this embodiment, by correcting the molding conditions C1 to C5 based on the correction coefficient calculated from the type and content of foreign matter contained in the recycled resin material, molding can be performed under appropriate molding conditions without trying to mold each recycled resin material, and high-quality molded products with reduced dimensional deviations and poor appearance can be efficiently molded. [Explanation of symbols]

[0031] A,B,C,D,E content C1,C2,C3,C4,C5 Molding conditions P1 Foreign matter analysis process P2 Correction coefficient calculation process Z, Y, X, W, V correction coefficients

Claims

[Claim 1] A molding method using recycled resin material, The type and amount of foreign matter contained in the recycled resin material are identified, calculating a correction coefficient based on the type and content of the foreign matter; Correcting the preset molding conditions using the correction coefficient. Molding method.

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