Optimization of feed system of base mold for washing machine using CAE

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J. Korea Society of Die & Mold Engineering, Vol.15 No.1, 2021 ISSN 2092-9692 . 1,2)_. 1, : E-mail: srhan@kongju.ac.kr . . , , . (shrinkage) (shortshot) 3)_. . 1 2 1 2,

Optimization of feed system of base mold for washing machine using CAE

Min-ji Yoo

1

_{, Kyung-A Kim}

2

_{, Seong-Ryeol Han}

Department of Optical Engineering and Metal Mold, Kongju National University1 Department of Metalmold Design Engineering, Kongju National University2, (Received January 12, 2021 / Revised February 29, 2021 / Accepted March 31, 2021)

Abstract: The position of the gate is one of the important factors for optimal injection molding. This is because inappropriate gate positions cannot fill the cavity uniformly, which can lead to defects such as contraction. In this study, CAE was performed on hot runner injection molding of the washing machine base and plasticity was compared by changing gate position from existing gate position. A total of two alternatives have been applied to compare the plasticity of the washing machine base according to its optimal gate position. The gate position of the improved molds and the gate position of the current mold is analyzed by injection molding analysis. The results of the fill time, the pressure at V/P switchover, clamping force, and deflection were compared. In washing machine base injection molding, the deflection was reduced by about 3.76% in the improved mold 2. In improved mold 1, the fill time during injection molding was reduced by 3.32% to enable uniform charging, and the clamping force was reduced by 31.24%. We have confirmed that the position of the gate can change the charging pressure and the clamping force and affect the quality and cost savings of the molded product.

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. Lee , 4)_{. Kim} SUS316L 90˚ Elbow 5)_{. Park} _CAE GATE ( ) 6)_{. Cho} 7)_{. Oh} CAE 8)_. Base , , . . Base . , . Fig. 1 Base . 517.5 × 419.9 × 59.5mm , 2.5mm Basell

Pololefins Europe (Polypropylene)

EP640P . Table 1

.

Process conditions Unit Value

Elastic modulus MPa 1600

Poisson‘s ratio - 0.39

Shear modulus MPa 580

Conductivity W/m ˚C 0.16

Specific heat J/kg ˚C 2960

Melt Density g/cm³ 0.73

Mold temperature range

˚C

20 ~ 60 Melt temperature range 220 ~ 280

Ejection temperature 70

Base AUTODESK

Moldflow Insight 2018 9)_{. Fig. 2 Base}

. Dual Domain ,

68,834 . Table 2

(hot runner) .

Table 3 .

Type of runner and gate Hot runner system

Diameter of gate 4

Average diameter of hot runner 10.38 Diameter of manifold runner 12

Diameter of sprue 14 Diameter of nozzle 6 (Table 3) . Fig. 3 . Fig. 3(a) Fig. 3(b) (0, 0) .

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Process conditions Unit Value

Injection time sec 4

Holding pressure MPa 67.5

Holding time sec 6

Cooling time sec 20

Mold temperature ˚C 30 Melt temperature ˚C 240 Base 5.472mm . 0.2mm . Fig. 5 . 15MPa . . 1 2 . Fig. 6(a) 1 , Fig. 6(b) . 1 20mm . Fig. 7(a) 2 , Fig. 7(b)

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. 1 1 2 . Fig. 6 7 . Fig. 8 (a), (b), (c) 1, 2 . , (a) 4.756s, (b) 4.598s, (c) 4.481s 1 3.32%, 2 5.78% . , . . . . 1 2 . 1 . Fig. 9 (a), (b), (c) 1, 2 . . (a)

30.09MPa, (b) 23.75MPa, (c) 38.82MPa .

1 6.34MPa ( 21.07%) 2 8.73MPa( 29.01%) . 2 . Fig. 10

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. . 1 8.2MPa( 51.29%) , 2 2 . Fig. 11 2 . (a), (b), (c) , 1, 2 ,

(a) 224.7ton (b) 154.5ton (c) 296.1

. 1 70.2ton( 31.24%) 2 71.4ton( 31.77%) . 300ton 1 200ton . Fig. 12 2 . Fig. 12 (a), (b), (c) , 1, 2 . (a) 5.472mm, (b) 5.551mm, (c) 5.266mm 1 0.082mm ( 1.44%) , 2 0.206mm( 3.76%) . Fig. 10 1 , 1 , (Fig. 8 ), 2 1 . .

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. Base , . 1) 1, 2 . 2) , 1 . .

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and number of plastic products using CAE”, Domestic Master's Degree thesis Inha university School, 2004. 7) Cho, S. B., Park C. H., Pyo B. K., Lee B. O. and Choi, D. H., “Optimization of gate position of injection molding using microgenetic algorithm”, Spring Conference of the Korean Society of Automotive Engineers, pp. 1946-1949, 2011. 8) Oh, H. G., “A Study on the optimization of gate

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