cae - cheric * †** , 402-751 253 ... as a result, the optimum condition based on the above...

8
577 HWAHAK KONGHAK Vol. 41, No. 5, October, 2003, pp. 577-584 CAE * ** , 402-751 253 * 343-856 ! "#$ %&’ 1233 ** ( 540-742 ) ( *+ 315 (2001 , 9 - 7 . /0, 2003 , 8 - 4 . 12) Application of CAE in Injection Molding Process Beomho Kim*, Woojin Jang, Junghoon Kim, Junghwan Cho, Yung-Hoon Park** and Soonja Choe Department of Chemical Engineering, Institute of Polymer Science and Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751, Korea *Hyundai Engineering Plastics Co., Ltd., 1233 Tongjung-li, Seokmun-myun, Tangjin-gun, Chungnam 343-856, Korea **Dept. of Polymer Science and Technology, Sunchon National University, 315 Maegok-dong, Sunchon, Chonnam 540-742, Korea (Received 7 September 2001; accepted 4 August 2003) ! "#$%, A 29” TV backcover & ’( ) *+, - .$ /0 12 3 ) 45& 67 89: Mold Flow CAE software(S/W) & ;9< =>(? @A9B. C D) E FGH 0IJG K(local database) LM DN OP- QRS K(standard database) @AT& UV WX9B. Y T 29” TV backcover - .$ => Z[? @\9 ]9<, => ^_ ‘a9b 67 45b 4cd 9: => e 67 45 b fd9< (, .$ =>gh? i9B. DE local database H j standard database @A T& UV9<, DE FG_ \ k:, lG 7m no_ p qrsG Zi9:, 4 _$ database @A Tb U t 9B. Abstract - Injection molding process is influenced by the injection conditions such as various thermal history and deforma- tion processes that affect mechanical properties of the fabricated product. The design of the 29-inch TV backcover modified with the alteration of the thickness of special parts. Then the flow analysis was performed using the CAE S/W of the Mold Flow Company. In addition, the analysis was performed using the measured viscosity(local database) at various shear rates and the results were compared with those using the standard database. In order to reduce the unbalanced flow of the molten resin, the thickness of the part, where the flow speed was slow, increased, while that of the part, where the flow speed was fast, reduced. As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in terms of idealized flow pattern. In addition, the analyses based on the local database and the standard database showed no dis- tinctive difference, although the measured viscosity was slightly higher and the temperature distribution was broader than by the standard database. Keywords: Injection Molding, CAE (Computer Aided Engineering), Filling Phase Analysis, Packing Phase Analysis 1. !"# $ %& ’()#, *+,- !. / 012 34 (567 8 9:; < => ? @ ABC 9:; D E !"# ’F. 1872 G Hyatt H2 celluloid 7 IJK ’L, 1923 G # Eichengrun Eckert M NO PQR P7 IJ"S T, 1950 GU V Willert W XY ,Z[R P IJ )\ ]^K _‘ abF. ’‘ 6Q’ c2 W de 2"f g !"\ hi_ jk lmno p "f "f qr FsK *+,- tu , YvK To whom correspondence should be addressed. E-mail: [email protected]

Upload: vukhuong

Post on 01-Apr-2018

214 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

HWAHAK KONGHAK Vol. 41, No. 5, October, 2003, pp. 577-584

CAE� ��� ���� ��

���*������������ **����†

����� �����, ���� �402-751 ��� � ��� 253

*�� ���� �����343-856 �� � ! "#$ %&' 1233

**(���� ����540-742 )� (�� *+� 315

(2001, 9- 7. /0, 2003, 8- 4. 12)

Application of CAE in Injection Molding Process

Beomho Kim*, Woojin Jang, Junghoon Kim, Junghwan Cho, Yung-Hoon Park** and Soonja Choe†

Department of Chemical Engineering, Institute of Polymer Science and Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751, Korea

*Hyundai Engineering Plastics Co., Ltd., 1233 Tongjung-li, Seokmun-myun, Tangjin-gun, Chungnam 343-856, Korea**Dept. of Polymer Science and Technology, Sunchon National University, 315 Maegok-dong, Sunchon, Chonnam 540-742, Korea

(Received 7 September 2001; accepted 4 August 2003)

� �

���� ���� � � � ��� �� �� ���� �� ���� ��� ��� � ! "#$%�, A��

29” TV backcover& '(�� )�� *+, ��- .$� /0 12� 3 )�� 45& 67��� �89: Mold

Flow�� CAE software(S/W)& �;9< =>�(? @A9B�. C� D)� E�� FGH 0IJG K(local database)�

LM DN OP- QRS K(standard database) �� @AT�& UV WX9B�. Y T� 29” TV backcover ����

- .$� => Z[�? @\9� ]9<, => �^_ `a9b 67� 45b 4cd 9: =>� e� 67� 45

b fd9< �(�, .$� =>gh? i�9B�. DE� local databaseH �j� standard database �� @A T�&

UV9<, DE FG_ �\ k:, lG 7m� no_ �p qrsG Zi9:, 4 _$ database �� @A T�b U

t 9B�.

Abstract − Injection molding process is influenced by the injection conditions such as various thermal history and deforma-

tion processes that affect mechanical properties of the fabricated product. The design of the 29-inch TV backcover modifiedwith the alteration of the thickness of special parts. Then the flow analysis was performed using the CAE S/W of the Mold

Flow Company. In addition, the analysis was performed using the measured viscosity(local database) at various shear rates and

the results were compared with those using the standard database. In order to reduce the unbalanced flow of the molten resin,the thickness of the part, where the flow speed was slow, increased, while that of the part, where the flow speed was fast,

reduced. As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

terms of idealized flow pattern. In addition, the analyses based on the local database and the standard database showed no dis-tinctive difference, although the measured viscosity was slightly higher and the temperature distribution was broader than by

the standard database.

Keywords: Injection Molding, CAE (Computer Aided Engineering), Filling Phase Analysis, Packing Phase Analysis

1. � �

����� ���� � �� � ��� ���� ���� �

�� ����� !"# $� %& '()#, *+,- !.� �/

01�2 ���� �34 (567 8�� 9:;� <� =>�� ?

@ AB��C 9:; �D� E� ��� !"# ��'F. ���

�� 1872G� Hyatt ��� ��H2 celluloid7 IJK 'L, 1923G

�# Eichengrun� Eckert M� NO PQR ����P7 IJ"S�

T, 1950GU V Willert� �W XY ,Z[R ����P� IJ )\

� ]^K _`� abF. '`� ����� 6Q�'� �c�2 '

W de�� 2"f g� !"\� hi_ jk� lmno� �p

"f �"f q�r� FsK *+,- tu� ��, YvK ���†To whom correspondence should be addressed.E-mail: [email protected]

577

Page 2: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

578 ��������������� ����

el,

� �D w ��xy� z{ M� UK |}� U~� de�F. ��

� �U !.��� ��"# ��� ���, PQ� ��, ���� w

�P ��� �K !� �D� ���� �� �� 0i�# H&�

�D� ��� l��'�� �K '�� W��� W�"� )�F.

' W�P ' CAE (computer aided engineering)2$, ����� �

�Q� UK l��'�� �"f !�� �U{ l�#$ � ��

' �F.

CAE� �()# �` W�� (5 � ��8�  �� ¡}"

# ��� W�"# ����C ¢Qxy� ��xy, £ ¡}"# (

5� H� z{7 �¤o# 9:;  � =>, ̀ �¥>, ¦� M�

§�� ¨©ªF. �&"f �`l J « �# ¬­+2(weld line),

�`de(short shot), air trap M� �� ®¯ �D� °& ±²KF.

Spencer³ Gilmore[1, 2]# 8�  � ¡}D´7 µk"f W�

"S�T, Kamal M[3, 4]� ��� 9:;��� 2¶� ¡} W�� µ

l"SF. Ballman M[5]� ·�� power law ̧ ¹� �("f ���

9:;�� 1¶�� ¡}� W�"SF. Harry³ Parrot[6]# 1¶� º

�D D´R� � »�R� �¼"f ��� 9:;�� ¡}W�� J

`l½�T, Load³ Williams[7], Tadmor³ Gogos[8]# ¾¿��� ¦

�, => w À�3Á7 1¶� :M¦ D´7 ��"f W�"SF.

Kamal M[9]� ��� 9:;�� 2¶� ¡}�D�, hele-shaw flow ̧

¹� W�"f �'Â� Ã� Ä+ ¡} `_"# ÅÆ Ç�� ¸s�

±²"SF. Wang M[10]� ¡K �� (finite element method)� ¡K

¶3 (finite difference method)�� �� 2¶� ¡}� ÈO É�� W

�"SF. Tadmor M[11]� M¦� ÅÆ� ��"� M� ÊË ·

�(equivalent Newtonian viscosity)7 �(K FAN(flow analysis

network) W� É � IJ"S�T, Kamal� Kenig[3, 4]# a= ��

� =�� ¡6� :M¦ ¡}�� ��"� Powerlaw ̧ ¹� Spencer-

Gilmore D´É�R� �("f 9:;  � =>3Á�d� ¡¯�

� »Ì��7 �"SF. ÍK Friedl� McCaffrey[12]# �` W��

�"f ���� �'� ��{7 ±²"� ��{� ���� PQ�

��� °Î# §�� �Ï"SF. Bakerdjian� Kamal[13], White³

Dee[14]� f� ��xy� UK µk� �"f �`��' ����

PQ� ��� ÐÑ ÒFÓ §�� °Î� �B� JÔ"SF.

Chiang[15]� º 3¶�� UK a=�� W�� �|"� "S�, a=

���# ·� ¸¹� � =��' Õ�����# ¦�³ Õ�Ö

� Ä× H�Ø' ��N� �x"S�T, Sherbelis³ Friedl[16]

� �`� a= �Q�� `�Ù� ¦� �p�� Ú�"SF.

Malguarnera M[17]� ¬­+2� �� ��xy' PQ� ���

°Î# §�� �Ï"S�, Chung� Ryan[18], Sanschagrin[19]� 9:

; =>� ±²� �� �i7 Ú�"\� �Û{K ¸¹� W�' µ

� ��� 0Î"�Ü l�"SF. Kamal� Lafluer[20]# :M¦ ·Ý

� ¡}� Ä× a= ��� W�"S�T, Wang M[21, 22]� a= w

Õ��� ¸¹� �l"� `�Ù, ¦�, =>' ·�� °Î# §��

Ú�"S�T, Þß a= ���� => �à� á�>� °Î# §��

�"SF. â³ E� Ú� ��7 ãU� GIL, ASAHI CHEMICAL,

CADMOULD, CINPRESS, MOLDFLOW M ��# W�( ä��å

� IJ"S�, �Û{æ ¸¹� W�"f µ� ����� ¡�K x

y� df"f W�"# Ú�7 QÀ _m"� �F.

ÑK H�� ç# ���� �� z�'>� Úáæ °è�x� z

{³ éê ¥>� ë�{"P â"f, � ��`'� °�� M�

±É"# ¡}W�, �� `6� Ì0K Õ�� µ�lì Õ�À��

¶'� �K éê¥>� ±É"# Õ�W�, �� Õ�l 8� í��

� �� �K �� z�� É"� �� ®¯ �2� î'# a

=W� M' �F. â� W�� �"f �ïð ��7 ¼> Ø�� �

("f z�W�� "\ ñ� ò �� ���� z�¯� �´7 ±²

ó �F.

ª Ú���# A�� 29” TV backcover ¢Q�\� �("f �'

Â� âγ , ��lô, 8�� ¦� M ����� §�� °Î#

z�� ��"�, ¸¹� d3�2 ÈO z{� �K � ¡}�

z� ¢�"� ë�� ��xy� õbF. '7 âK W��#

MOLDFLOW�� CAE S/W7 �("S�T, Pª ¢Q7 �"# É

� ¸ö"SF. ÍK µ�� `�À�� Ä+ ²�æ ·�(local

database)³ .6�� Þ�� dfK ·�Ø(standard database)

� �K W�� :÷ øã"SF. MOLDFLOW software# Fig. 1� ¡

}W�� Fig. 2� a=W� flow chart� ùô� È�F.

2. �� ��

2-1. �� ��

CAE ¼> $'�# �34� �� Þ�2$, �`��, :�, (5

��, ÅÆ � ¦�, ñ� ¦� M'F. ª Ú��� �(æ ä��å

2 MOLDFLOW��# �34 (56� �� �� ���� �`ú�

áûæ Pª�2 � 3!R� �`��, :�, (5 ��7 �"f �"

#$, 01�2 �34 (56� �ü!Q# 10−7 m2/sec ��'F.

(5# â�� ¡}(pseudoplastic flow)6'T, ¡}W�� â"

f ·�# ¦�³ `�Ù N� Ôl"SF. ÍK �� ��� '()

� �# ·�� N�# Powerlaw model, Carreau model, Cross mod

Ellis model �&� Second order model[16, 23] M� �("SF. �3

4 tu� �� z{# �` �Q 'ò� ¡}� ý §�� °Î� )

#$, �� z{7 Q!ó þ# ÿD� �D� ̧ È �(ó �# Tait

Fig. 1. Flow charts for computation of filling phase analysis.

���� �41� �5� 2003� 10�

Page 3: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

CAE� ��� ����� ��� 579

D´ É�R (1)� '("SF.

(1)

C# 0.0894'�, v0(T)# =>' 00 þ :6�'F. ÿD� �D�

UK �� FB� E' gi_F.

if, T>Tt (2)

if, T<Tt (3)

if, T>Tt (4)

if, T<Tt (5)

if, T>Tt (6)

if, T<Tt (7)

��� ̀ '¦� Tt� =>� 0¶ Ç�N+� ��"\ FB R (8)

� EF.

(8)

2-2. ���� ���

�`��(filling phase)� a=��(packing phase)��# � 8�

  �}� ¦� z{� �K 6� �� ��KF. � �� �`�Q

��# 8�� 9:; í�� 7 ��"�, È �� a=�Q��

# �� �K 6� ��7 aD"P â"f =>� �"T, è ��

Õ��Q��# (5�d� 8��� �� É�N��C (5D´

� 7 �{l�F. ·Ý�62 � jÑ �` �Q�� :=�

�, :M¦¡}� "# :Êã�í(non-newtonian) ¡6� Þ�� �

T, a=� Õ��Q��# :�D D´� =��, :M¦ ¡}� "T

ÿ6�� �6� D' z{KF.

' þ �()# à É�R[24]� FB� EF.

Equation of Continuity: (9)

Equation of Momentum: (10)

Equation of Energy:

(11)

�&�, ' W�� '(æ Pª ��� FB� EF.

- incompressible fluid: =0 (12)

- generalized Newtonian fluid: τ = η( ) (13)

- constant thermal conductivity: κ (14)

' R�� ρ# (5��, # :6�, # �>�À�, τ# `�¥

>, P# pressure, Cp# :�, β# tu� ü/Q, κ# �`��, η#aP ·�, # `�Ù'�, τ=η 'F.

2-3. � ���

� �� �, F× d3��d� 8�' �"# � ̄w 8�'

UP�'� �� ��P� � P# �¯' �F� ��"f �â lô

� �d� 8��� '}"# �¯� Q!"S�T, ÈO� F× d

3� Õ�lô� ©L R� ù�"f ëU � ÈO7 Pº�� Q!"SF.

9:; ��d3' Õ�)#$ ��)# lô tc# FB� E' �ï

� �#$,

(15)

Õ� lô� ³ ���� �ÈO(h)� ��� :�KF.

fP�, TX# 9:; ��� ¦�, TM� 8�¦�, TP# (5¦

� �&� α# � ü!Q'F.

2-4. Local Database ��

ª Ú�� �(K MOLDFLOW�� CAE S/W# � µ² Ø�

���� "f 2nd order ·� É�R� Ai ��i_ master curve��

h� data³ 'D xy�� Ôº µk /Î7 �("f hi� 4u

(standard database)7 Pª�� ��i��T, ���� ÐÑ �i�F. �

�� µ�� ��� !"# �/ �j��# data7 ²�ó þ 'D�

�j�� ¶'� o¶� �� ��r�, � KQ7 :÷"P â"f 0

1� �j�� ̀ �À�7 ²�"f local database� "SF. µ� ·�#

Rosand�� Advanced Capillary Extrusion Rheometer� ²�"SF.

2-5. Filling Balance

Filling balance# flow balance³ runner balance� ��F. Flow balance

# �� K �`'� ��`��  d éê¥>' Ò¤� !P)#

��� z�'� PQ� H� ""7 ÉKF. 1\� ò4# ���

gate�d� ��)# � s� ÌM"� x�"f sprue �� J

)# gas7 #�"�, �� $�� °��� #�KF.

3. ��� ��

ª Ú���# ���� ��� ë�{7 µ�"P â"f MOLDFLOW

�� ̀ ò ~&P2 MF/VIEW7 �("S�T, Solver�# MF/FLOW,

v T p,( ) v0 T( ) 1 C ln 1p

B T( )------------+

=

v0 T( ) b1 1, b2 1, T+=

v0 T( ) b1 s, b2 s, T+=

B T( ) b3 1, exp b– 4 1, T( )=

B T( ) b3 s, exp b– 4 s, T( )=

v T p,( ) 0=

v T p,( ) b7exp b8 Tb9p–( )=

Tt p( ) b5 b6p+=

∂ρ∂t------ ∇ ρv⋅( ) 0=+

∂∂t---- ρv( ) ρg ∇ τ⋅[ ] ∇ ρvv⋅[ ]–+=

ρCp∂T∂t------ v ∇T⋅+

βT ∂P∂t------ v ∇P⋅+

ηr·2 κ∇2T+ +=

∇ v⋅r· r·

v g

r· r·

tch2

π2α---------

TX TM–

TP TM–------------------

ln=

TX TM–

TP TM–------------------

ln

Fig. 2. Flow charts for computation of packing phase analysis.

HWAHAK KONGHAK Vol. 41, No. 5, October, 2003

Page 4: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

580 ��������������� ����

MF/COOL, MF/WARPM� �("SF.

ª Ú��� CAE W�� ¡K�� 7 Pª�� c� Q!� �

Ù��� 3ó"P â"f 01� ���� W�� �()# %�� �

� �´� shell mesh7 �("SF.

W�� ���# ��� ZP³ aspect ratio(%�� ���� %��

� '[# �/ & z� UK ' <'� :� �W (Ñ)#$, ��

)4� *�"\ aspect ratio# +©� W� lô' P"]��

� *�"r� W� ��� Ä+ ��"� ��"SF. � ±�, ¡}

w Õ� W�� jÑ# 1.5, z� w �xW� jÑ# 1.3 �'� ,â

�� ¢�"SF. �&"f â� xy� -� ��K surface� ,ä[, ¾

¿, �' M� ¸¹.K ò �(ó � $'�, ����P� �s

w ���� ��xy� �("f W�"SF. ��� ô/ß �0"\,

` ~& ��2 ¸¹.(modelling)� ��3ó(meshing), W� ��2

��É�R ¡�(derivation of element equations), ��É�R x1

(assembly of element equations), jQxy� ¢�(application of boundary

conditions) w l,2R� W�(solution of system equations)� ��

~&"f 3,*�'Ø(display results)� h�F[23].

�'Â7 �W 4� �i�# � ¡}'>(melt flow history)�

§�� g# 242 5ê, �' âÎ w , ����� P"c

� �´, ·� w ¡} Ç�� âÎ M��, ª Ú���# �'Â

âγ , ��lô, 8� ¦� M ����� §�� °Î# z��

��"�, ¸¹� d3� ÈO z{� �K � ¡}� z� ¢�

"f ë� ��xy� õbF.

ÍK, CAE +.� 6�K �34� �� Þ�(�`��, :�, (5

��, ÅÆ�¦�, ñ�¦� M)� áûæ ¼>$'� ���, ª Ú

�� �(æ ä��å2 MOLDFLOW��# �34 (56� Pª�

� 3!R� �`��, :�, (5��7 '("f �"�, 01�2 �

34 (56� � 3!��# 10−7 m2/sec7 �("SF. Shear stress,

τzx=η(dvx/dz)��, :� D η# aP·�(apparent viscosity), À�

�à2 dvx/dz# `�Ù'F.

ÍK (5# â�� ¡}�� ��"S�r� ¡}W�� â"

f ·�# ¦�³ `�Ù� N� Ôl"SF.

4. � ��

4-1. ��� �� � ��

�(æ ̧ ¹2 A�� 29” TV backcover� ̧ ¹ �D w ��� Fig. 3�

Table 1� �l"SF. ��� ZP# �� 651.6 mm è� 573.3 mm <

' 325.6 mm'T, ' ��� 7d8³ 7�¯� �� 2212.3 cm3³

2.1 kg'F. 89:°;� �¡} HIPS(high impact polystyrene)7

�("S�, Fig. 3� <�ö�� �ï� 3 hot runner system� �("

f 7 g¼"SF. Fig. 3� ö=� �ï� �³ E' � d3� Ä

+ ÈO7 ú&"S�T, � d3> ÈO# Table 1� �iÈ�F.

4-2. �� ��� ��� �� �! ��"#

�'Â�d� ��æ # ¡}"?' @� A�� 4� BCd §

D�� ë5 �`' '[i� )#$ �` lô> � ¡}EF

� Fig. 4� �l"SF. � G`ß �`"#$(Fig. 4(d)) HI l

ô� 3.455V'T Fig. 4(a), (b)³ E' `1��� ��� D�d� :

"f "�d� J� �`)T, Þß Fig. 4(c)��# ÌM"� �`)

"# ®ÌM ¡}� K �F.

¡}' â��~L 9:;� $�dM ÌM"� �`)

"\ N�� �`)# d3��# ��` �D' 0i�  d éê¥

>' *�)� ��� PQ� H�' "")# }l� � Õ�«

þ z�' J KF. Ä+� 7 9:;� $�dM ÌM"� �

`l��, ��� PQ� H�� ¡l�# ,â�� FB� 3� É

�� ÈO7 z{lì ¸¹� ¡}EF� Ä× ®Ì�� W�"��

"SF.

• CASE 1: Ppí� UK ¡}W�

• CASE 2: � ¡}' DU��� �� d3� ÈO7 *�

• CASE 2: ÈO *�: 2.8 mm→3.3 mm: D� ( ·Ñ², O\ "� ��)

• CASE 3: � ¡}' DU��� N× d3� ÈO7 ��

• CASE 2: (ÈO ��: 2.8 mm→2.5 mm: D� ��, ( ·Ñ ²\ ��)

Fig. 3. Shape of the model used in this study.

Table 1. Characteristics of the 29” TV monitor backcover

Dimensions Length 651.0 mmWidth 573.3 mm Height 325.6 mm

Thickness (by color) Green 3.0 mm Cyan 2.0 mmBlue 2.8 mm Purple 3.5 mmYellow 1.5 mm Gray 2.25 mm

Volume & weight Gross Volume: 2212.28 [cm3]Gross Weight: 2.06 [kg]

Used resin Kumho chemicals: High flowing HIPSApplication gate 3 SIDE-GATE system (red)

Fig. 4. Flow pattern of the molten resin.

���� �41� �5� 2003� 10�

Page 5: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

CAE� ��� ����� ��� 581

• CASE 4: CASE 2³ CASE 3� P1�´� ¡}� Q¾, ��

• CASE 2: (ÈO *�: 2.8 mm→3.3 mm: D� ( ·Ñ², O\ "� ��)

• CASE 2: (ÈO ��: 2.8 mm→2.5 mm: D� ��, ( ·Ñ ²\ ��)

R � :÷S� UK W���7 Fig. 5³ Table 2� �l"S#$,

ªL� ¸¹2 CASE 1� :"f ¸¹ ÈO� z{7 º CASE 2, 3

w 4� ¡}EF' �D)�B� afg� �F. � ���� CASE 4

� ¡}' �/ Ñ"f '7 ë5 í�� ?T"SF. l�� �` ¶

'7 4èß �UaP â"f Fig. 6� CASE 1� CASE 4� lô>

¡}EF� :÷V�l"S#$, 3V j� )�� þ� ¡} EF' D

�ß í���� �D)�B� ü2 ó �F.

4-3. $% & '! "#

4-3-1. ¦�3Á

¡}W��� Q!K � ̀��� � ̀'ò� ¦�3Á7 �� Fig. 7

� Fig. 8� �ï �F. ' ¸¹�� Q!K ¦� 3Á# 216.9oC��

231.1oC �'� � ¶� 0 14.2oC� �i� :÷� s9"SF. 01

��� �` � ¦�3Á# 8�� � ¡¼)# Ûô � âÎ� �

ï�# ¦�3Á2$ � ¶'# U/ 20oC '"'i! KF. ¦� ¶

'� Z\, ¡}"?� W¶� *�N� H�, ��� Xá� §�

� °Î# weld line� ��� PQ� H�' ú+_F. (5� ¡

}�� tu� ·�� �p"#$ ·�# ¦�� N'r� 8�� i

Fig. 5. Flow pattern in each CASE.

Fig. 6. Flow pattern upon injection time.

Table 2. Comparison of the flow analysis in each CASE

CASE 1 CASE 2 CASE 3 CASE 4

used resin HIPS HIPS HIPS HIPSmold temperature 50 oC 50oC 50oC 50oCresin temperature 230oC 230oC 230oC 230oCinjection time 3.426s 3.359s 3.414s 3.365smolding pressure (MPa) 59.85 64.62 62.01 65.84temperature distribution (during filling) 217.5oC-231.2oC 217.3oC-231.1oC 218.4oC-231.2oC 216.9oC-231oCtemperature distribution (after filling) 174.9oC-239oC 184.9oC-239.7oC 182.5oC-239.3oC 204.3oC-235.9oCShear stress (MPa) 0.26-0.53 0.35-0.53 0.24-0.47 0.31-0.39Shear rate (1/s) 12883-75036 379075 19996-77902 239913.23clamp force (tonne) 1678.3 1661.9 1723.4 1705.6

HWAHAK KONGHAK Vol. 41, No. 5, October, 2003

Page 6: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

582 ��������������� ����

Y âÎ�� � ¦�� @©_F\ ' ·� ¡}"?' Ò¤� �

�=>�  d¥>' *�"f ���� H� �� H�� §�� ºF.

�` 'ò� ¦�3Á# �`' Zð 'ò, Õ�' l+)P `M

� ¦�z{�C Õ�+2 ¢Q� ��K 4u'F. ¦�� <� d3

� @� d3' �p"# jÑ�# ¦�� <� [� Õ��Ù� *�

lì ¦�3Á7 x�W! KF. ¦� ¶'� Z\ � ��� ú+�

éê¥>� �W ��� Z\(crack)' J « �F. ��� ���

Fig. 7. Temperature distribution before injection.

Fig. 8. Temperature distribution after injection.

Fig. 9. Air trap.

Fig. 10. Experimental local and standard database (shear rates vs. vis-cosity at 220oC).

Fig. 11. Comparison of flow pattern by the standard and local database.

���� �41� �5� 2003� 10�

Page 7: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

CAE� ��� ����� ��� 583

jec-

ly-

s.

n

-

ing,

-

ter-

.

rk

,”

in

�x� F× '¡� 2W ¦� ¶'7 î' ó jÑ�# Rib M�

a�"# �x� É �� '7 aGKF.

4-3-2. Air Trap

Fig. 9# �� ��l �,� J "# âÎ7 afg� ��T, ' $

'�7 ãU� ]Â(vent)7 ¢Î"#$, ]Â� ^^� ÈO� 0.02mm-

0.03 mm'T ¿:# 0 10 mm ��'F.

¸_ # �� ��l �,7 J "r� 8� í�� ¡¼)# �

,7 ��W g `�\ �,� J "# ·�� °��'� �� =

�� �W ��' ï# �D Í# �,4a(burning, burn mark) M' b©

Ô\' �c� a'# M �� ®¯' &F. �,7 ��"P âK É

�� � J âÎ7 8�� BCÇ(parting line)[�� deg�� � d3

� ñ�f(ejector pin)� ¢Î"f ��"#$, 'g' ®�3K jÑ �,

� J "# âÎ� ]Â7 ¢Î"f ��"P� KF.

4-4. Local database �! "#

Standard³ local database� �K master curve� ��i_ ¦� w ̀

�À�� UK ·� Ø� Fig. 10� �l"S#$, `4� :"f ò4

� µ² Ø' F� <� �ïhF.

â� È � database7 �� 29” TV backcover ����� UK

¡} W�� ��7 Fig. 11� �l"S#$, È � jÑ�� �� ¡

�K ¡} EF� a'� �F. �` � ¦� 3Á� UK :÷�� local

database7 �(K jÑ(Fig. 12)# 209.6oC-231.4oC�C standard

database� �K ¦� 3Á 216.9oC-231.1oC� :"f W¶� 7.6oC

�� i Ò��, ' Dl ¦� j(,â ' 'r�, È database ̧

È ý k�� �# g�� �ïhF.

5. �

���� ��� ���� xy� Ä+ FsK �´� � '>� z

� '>� l� )� � �� ë5 ���� PQ� H�' �"ß ú

+r�, ª Ú���# A�� 29” TV backcover model� 342 ���

� � �`� §�' ý d3� ÈO7 x�"\� MOLDFLOW

�� CAE S/W7 '("f ¡} ��� W�"SF. � ��� 29” TV

backcover� ������ � ¡} ®Ì�' W�)�Ü ¡}� �

6� J "# d3� ÈO# *�l��, ¡}' N× d3� ÈO#

��ß ��lm��C 'D�2 � ¡}EF� ��ó ��F.

�&� µ�� ��� ¦�> ·�³ `�À�7 ²�K Ø2 local

database³ standard database� �K W� ��, `4� ò4� :W ·

�� F� <� ²�)� W�� ���� ¦� W¶ Dl �à *�"

S�, È � W� �� �'� ý o¶� �# 0áæ ��� ��

)�F.

����

1. Spencer, R. S. and Gilmore, G. D., “Flow Phenomena in the In

tion Molding of Polystyrene,”J. Collid. Sci., 6, 118(1950).

2. Spencer, R. S. and Gilmore, G. D., “Equation of State for High Po

mers,”J. Appl. Phys., 21, 523(1950).

3. Kamal, M. R. and Kenig, S., “Injection Molding of Thermoplastics.

I. Theoretical Model,”Polym. Eng. Sci., 12, 294-301(1972).

4. Kamal, M. R. and Kenig, S., “Injection Molding of Thermoplastic

II. Experimental Test of the Model,” Polym. Eng. Sci., 12, 302(1972).

5. Ballman, R. L., Shusman, T. and Toor, H. L., “Injection Molding,”

Ind. & Eng. Chem., 51, 847(1959).

6. Harry, D. H. and Parrot, R. G., “Numerical Simulation of Injectio

mold Filling,” Polym. Eng. Sci., 10, 209(1970).

7. Lord, H. A. and Williams, G., “Mold-Filling Studies for the Injec-

tion Molding of Thermoplastic Materials. II. Transient Flow of Plas

tic Materials in the Cavities of Injection-Molding Dies,”Polym. Eng.

Sci., 15, 569(1975).

8. Tadmor, Z. and Gogos, C. G., Principles of Polymer Process

John Wiley & Sons, New York(1979).

9. Kamal, M. R., Kuo, Y. and Doan, P. H., “Injection Molding Behav

ior of Thermoplastics in Thin Rectangular Cavities,”Polym. Eng.

Sci., 15, 863(1975).

10. Wang, K. K., S. F., Stevenson, J. F. and Hieber, C. A., “Compu

Aided Injection Molding Syster,” CIMP progress Report, Mo. 4, 9(1977)

11. Tadmor, Z., Broyer, E. and Gutfinger, C., “Flow Analysis Netwo

(FAN). Method for Solving Flow Problems in Polymer Processing

Polym. Eng. Sci., 14, 660(1974).

12. Friedl, C. F. and McCaffrey, N. J., “Crystallization Prediction

Fig. 12. Comparison of temperature distribution during filling by thestandard database and local database.

HWAHAK KONGHAK Vol. 41, No. 5, October, 2003

Page 8: CAE - CHERIC * †** , 402-751 253 ... As a result, the optimum condition based on the above modification of the special part of TV backcover is selected in

584 ��������������� ����

.

C.,

-

6).

ion

s

.

l-

ed

Injection Molding,” SPE ANTEC Technical Papers, 50, 330(1991).

13. Bakerdjian, Z. and Kamal, M. R., “Distribution of Some Physical

Properties in Injection-Molded Thermoplastic Parts,”Polym. Eng.

Sci., 17, 96-100(1977).

14. White, J. L. and Dee, H. B., “Flow Visualization for Injection Mold-

ing of Polyethylene and Polystyrene Melts,”Polym. Eng. Sci., 14,

211(1974).

15. Chinag, H. H., “Simulation and Verification of Filling and Post-Fill-

ing Stages of the Injection-Molding Process,” Ph.D. Thesis, Univer-

sity of Cornell, Ithaca, New York(1989).

16. Sherbelis, G. and Friedl, C., “The Importance of Low Temperature

Viscosity to CAE Injection Molding Simulation,”SPE ANTEC, 954

(1992).

17. Dietz, W., White, J. L. and Clark, E. S., “Orientation Development

and Relaxation in Injection Molding of Amorphous Polymers,” Polym.

Eng. Sci., 18, 277(1978).

18. Chung, T. S. and Ryan, M. E., “Analysis of the Packing Stage in

Injection Molding,”Polym. Eng. Sci., 21, 271(1981).

19. Sanschagrin, B., “Process Control of Injection Molding,”Polym. Eng.

Sci., 23, 431(1983).

20. Kamal, M. R. and Lafleur, P. G., “A Structure-Oriented Computer Simu-

lation of the Injection Molding of Viscoelastic Crystalline Polymers

Part II: Model Predictions and Experimental Results,”Polym. Eng.

Sci., 26, 103(1986).

21. Wang, K. K., Shen, S. F., Cohen, C., Hieber, C. A., Ricketson, R.

Wang, V. W. and Emerman. S., “Integration of CAD/CAM for Injec

tion Molded plastic Parts, CIMP Progress Report,” No. 12, 12(198

22. Wang, K. K., Shen, S. F., Cohen, C. and Hieber, C. A., “Integrat

of CAD/CAM for Injection Molded Plastic Parts, CIMP Progres

Report,” No. 13, 13(1987).

23. Austin, C. and Kennedy, P., “Moldflow Data Theory,” Moldflow Pty

Ltd(1992).

24. Min, N., Kim, S. W., Park, C. S., Lee, M. H. and Lee, K.-J., “Ana

ysis of Warpage Phenomena of Fiber-Reinforced Injection Mold

Parts,”HWAHAK KWNGHAK, 35(4), 468(1997).

���� �41� �5� 2003� 10�