DESIGN OF PLASTIC MOULDDESIGN OF PLASTIC MOULD

PRESENTED BY PRESENTED BY AMIT S. GOSAVIAMIT S. GOSAVI

A) COMPONENT DRAWINGA) COMPONENT DRAWING

2D DRAWING OF COMPONENT 3D DRAWING OF COMPONENT

COMPONENT DETAILSCOMPONENT DETAILS MATERIAL - POLY PROPYLENEMATERIAL - POLY PROPYLENE DENSITY - 0.96 gm/cmDENSITY - 0.96 gm/cm33

SHRINKAGE - 1%SHRINKAGE - 1% QUANTITY - XQUANTITY - X SURFACE AREA - 1000mmSURFACE AREA - 1000mm22

VOLUME - 2069.82 mmVOLUME - 2069.82 mm33

MASS - 1.98 gmMASS - 1.98 gm

NOTE THAT DESIGNER SHOULD GET IT CLEARE NOTE THAT DESIGNER SHOULD GET IT CLEARE FROM CUSTOMER THAT ON WHICH FACES FROM CUSTOMER THAT ON WHICH FACES PARTING LINE & GATE MARK ARE ALLOWED.PARTING LINE & GATE MARK ARE ALLOWED.

B) INJECTION MOULDING M/CB) INJECTION MOULDING M/C

MACHINE DETAILSMACHINE DETAILS

MACHINE - SP30MACHINE - SP30SHOT CAPACITY – 44gmSHOT CAPACITY – 44gmSTOKE VOLUME -49gmSTOKE VOLUME -49gm

CORE CAVITY CORE CAVITY & SHRINKAGE ALLOWANCE& SHRINKAGE ALLOWANCE

CORE & CAVITYCORE & CAVITY

CORECORE:-:- IT IS A PORTION OF THE MOULD PROJECTING OUTSIDE, IT IS A PORTION OF THE MOULD PROJECTING OUTSIDE,

WHICH FORMS INTERNAL SHAPES OF THE MOULDING. WHICH FORMS INTERNAL SHAPES OF THE MOULDING.

CAVITYCAVITY:- :- IT IS A PORTION OF THE MOULD PROJICTING IT IS A PORTION OF THE MOULD PROJICTING INSIDE, WHICH WHICH FORMS EXTERNAL SHAPES OF THE INSIDE, WHICH WHICH FORMS EXTERNAL SHAPES OF THE MOULDING.MOULDING.

THE SPACE FORMED IN BETWEEN CORE & CAVITY IS KNOWN AS THE SPACE FORMED IN BETWEEN CORE & CAVITY IS KNOWN AS IMPRESSIONIMPRESSION. AND MOLTEN PLASTIC IS INJECTED IN THE . AND MOLTEN PLASTIC IS INJECTED IN THE IMPRESSION. AFTER INJECTION THE CORE & CAVITY INSERTS IMPRESSION. AFTER INJECTION THE CORE & CAVITY INSERTS ARE EXPOSED TO COOLING MEDIA TO SOLIDIFY IT. PLASTIC ARE EXPOSED TO COOLING MEDIA TO SOLIDIFY IT. PLASTIC GETS GETS SHRINKSHRINK OVER THE CORE & THEREFORE IT NEED OVER THE CORE & THEREFORE IT NEED DRAFT ANGLEDRAFT ANGLE ON EXPOSED FACES, ON EXPOSED FACES, EJECTION SYSTEMEJECTION SYSTEM TO TO SEPARATE IT FROM CORE & GET EJECTED OUT OF THE TOOL.SEPARATE IT FROM CORE & GET EJECTED OUT OF THE TOOL.

SHRINKAGE-: vSHRINKAGE-: volumetric change of molten olumetric change of molten plastic at the time of mould cooling.plastic at the time of mould cooling.

SHRINKAGE ALLOWANCE IS PROPORTIONAL TO…..SHRINKAGE ALLOWANCE IS PROPORTIONAL TO…..

Plasticizing temperature.Plasticizing temperature. Mould temperature.Mould temperature. Component section thickness.Component section thickness. Cavity pressure (injection press.)Cavity pressure (injection press.) Injection cycle time.Injection cycle time.

SHRINKAGE ALLOWANCE DECREASE WITHSHRINKAGE ALLOWANCE DECREASE WITH Presence of filler Presence of filler

The actual dimension of The actual dimension of impression will be based impression will be based on the original on the original dimension plus the dimension plus the shrinkage allowanceshrinkage allowance

D = [ d*(1+S) ]D = [ d*(1+S) ] S = Shrinkage S = Shrinkage

allowance (mm. Per allowance (mm. Per mm.)mm.) d = Component d = Component dimension (mm.)dimension (mm.) D = Final tool D = Final tool dimension (mm.)dimension (mm.)

STAGES INVOLVED IN STAGES INVOLVED IN INJECTION MOULD DESIGNINJECTION MOULD DESIGN

1.1. STUDY THE COMPONENT DRAWINGSTUDY THE COMPONENT DRAWING1.1. SHAPE & SIZE SHAPE & SIZE 2.2. TYPE OF MATERIALTYPE OF MATERIAL3.3. RATE OF PRODUCTIONRATE OF PRODUCTION4.4. QUANTITY OF PRODUCTIONQUANTITY OF PRODUCTION

2.2. DETERMINATION OF MOULDING WEIGHTDETERMINATION OF MOULDING WEIGHT MOULDING WEIGHT = VOLUME *DENSITYMOULDING WEIGHT = VOLUME *DENSITY

=(2069.82/1000)*0.96=(2069.82/1000)*0.96 = 1.98gm= 1.98gm MOULDING WEIGHT PER CAVITY WITH LOSSES(W) MOULDING WEIGHT PER CAVITY WITH LOSSES(W) = 1.98*1.01= 1.98*1.01 = 1.9998 = 1.9998

= 2gm= 2gm

3. SELECTION OF INJECTION MOULDING MACHINE -3. SELECTION OF INJECTION MOULDING MACHINE - FOR THE FOR THE CURRENT COMPONENT,WE ARE GOING TO USE SP 30 MACHINECURRENT COMPONENT,WE ARE GOING TO USE SP 30 MACHINE

4.4. SELECTION OF TYPE OF MOULD - SELECTION OF TYPE OF MOULD - FOR THE CURRENT COMPONENT WE ARE GOING TO DESIGN FOR THE CURRENT COMPONENT WE ARE GOING TO DESIGN

SPLIT CAVITY MOULDSPLIT CAVITY MOULD 5. DETRMINITION OF NO. CAVITY -5. DETRMINITION OF NO. CAVITY -

1) 1) DETERMINED BY SHOT CAPACITY DETERMINED BY SHOT CAPACITY

SHOT CAPACITY IS THE WEIGHT OF PLASTIC INJECTED IN ONE SHOT CAPACITY IS THE WEIGHT OF PLASTIC INJECTED IN ONE STROKE OF PLUNGER. STROKE OF PLUNGER.

SHOT CAPACITY = SWEPT VOL. x DENSITY x 0.35SHOT CAPACITY = SWEPT VOL. x DENSITY x 0.35

= 49 x 0.96 x 0.35= 49 x 0.96 x 0.35

= 16.464 gm= 16.464 gm

NS = 0.85 * W/MNS = 0.85 * W/M

= 0.85*16.464/1.98= 0.85*16.464/1.98

= 7.067= 7.067

= 7= 7

DETERMINED BY PLASTICISING CAPACITYDETERMINED BY PLASTICISING CAPACITY PLASTICISING CAPACITY OF A MACHINE IS THE WEIGHT OF PLASTICISING CAPACITY OF A MACHINE IS THE WEIGHT OF

PLASTIC PROCESSED PER HOURPLASTIC PROCESSED PER HOUR P.C.= P.C.= P.C. FOR PP x Sp. HEAT OF PP x MOLDING TEMP OF PPP.C. FOR PP x Sp. HEAT OF PP x MOLDING TEMP OF PP Sp. HEAT OF PLASTIC x MOLDING TEMP OF PLASTICSp. HEAT OF PLASTIC x MOLDING TEMP OF PLASTIC

NP = (0.85*PC*TNP = (0.85*PC*TCC)) /3600*M/3600*M = [0.85*2.06*(1000/3600)*15]/1.98= [0.85*2.06*(1000/3600)*15]/1.98 = 3.68= 3.68 = 3= 3

6. SELECTION OF PARTING SURFACE (S) –6. SELECTION OF PARTING SURFACE (S) – FOR THE CURRENT COMPONENT IT IS FOUND FLATE FOR THE CURRENT COMPONENT IT IS FOUND FLATE

PARTING IS BESTPARTING IS BEST

7. PLACEMENT OF CAVITY7. PLACEMENT OF CAVITY

8. DESIGN OF CAVITY & CORE PLATE –8. DESIGN OF CAVITY & CORE PLATE – MINIMUM CAVITY WALL THICKNESS (t) =[ C *P * DMINIMUM CAVITY WALL THICKNESS (t) =[ C *P * D4 4 / (E*Y) ] / (E*Y) ] 1/31/3

=[0.084*720*(4.5)=[0.084*720*(4.5)44/2.1*10/2.1*1066 *0.003]*0.003]1/31/3

=1.578cm=1.578cm

=16mm=16mm Y= MAXIMUM DEFLECTION OF SIDE WALL (cm)Y= MAXIMUM DEFLECTION OF SIDE WALL (cm)

C= CONSTANTC= CONSTANT

P= MAX INJECTION PRESSURE (Kg/cmP= MAX INJECTION PRESSURE (Kg/cm2.2.))

E= MODULUSE OF ELASTICITY FOR STEEL (2.1*10E= MODULUSE OF ELASTICITY FOR STEEL (2.1*1066 Kg/cm Kg/cm22))

D = THICKNESS OF IMPRESSION (cm)D = THICKNESS OF IMPRESSION (cm)

9.DESIGN OF FEED SYSTEM9.DESIGN OF FEED SYSTEM

RUNNER DIA.(D) = WRUNNER DIA.(D) = W1/21/2*L*L1/41/4/3.7/3.7 = 1.98= 1.981/21/2*27.5*27.51/41/4/3.7/3.7 = 0.87mm= 0.87mm = 1mm= 1mm D = DIA OF RUNNER (mm)D = DIA OF RUNNER (mm) W = WEIGHT OF MOULDING (gm)W = WEIGHT OF MOULDING (gm) L = LENGTH OF RUNNER (mm)L = LENGTH OF RUNNER (mm) 10.DESIGN OF GATE-10.DESIGN OF GATE-

GATE WIDTH = n*AGATE WIDTH = n*A1/21/2/30/30 = 0.7*2000= 0.7*20001/21/2/30/30 = 1.043mm= 1.043mm GATE DEPTH = n*TGATE DEPTH = n*T = 0.7*2.5= 0.7*2.5 = 1.75mm= 1.75mm LENGTH OF GATE = 1.75LENGTH OF GATE = 1.75

n=MATERIAL CONST.=0.7n=MATERIAL CONST.=0.7A=SURFACE AREAA=SURFACE AREA

11.GUIDE PILLAR DIA11.GUIDE PILLAR DIA.. Q=2/3*DQ=2/3*DCC*H*P*H*PFF

D=(4Q/3.14*N*FD=(4Q/3.14*N*FSS))1/21/2

=(4=(4 *14.112/4*3.14*16)*14.112/4*3.14*16) =5mm=5mm Q=2/3*1.2*2.45*0.4*1800Q=2/3*1.2*2.45*0.4*1800 =1411.2kgf=1411.2kgf DDCC = MAX.DIA. OF CORE (cm) = MAX.DIA. OF CORE (cm) H = HEIGHT OF CORE (cm)H = HEIGHT OF CORE (cm) PPF F = CAVITY PRESSURE (Kg/cm 2)= CAVITY PRESSURE (Kg/cm 2) Q = SIDE THRUST (Kg)Q = SIDE THRUST (Kg) N = NO OF PILLARN = NO OF PILLAR FFSS = PILLAR MATERIAL = PILLAR MATERIAL

12. SELECTION OF EJECTOR SYSTEM12. SELECTION OF EJECTOR SYSTEM AS THE MOULDING IS CIRCULAR & FLATE SURFACE AS THE MOULDING IS CIRCULAR & FLATE SURFACE SLEEVE EJECTION IS SELECTEDSLEEVE EJECTION IS SELECTED13. SIDE ACTUAITNG CAVITY IS REQUIRED13. SIDE ACTUAITNG CAVITY IS REQUIRED (AS PER COMPO. (AS PER COMPO.

DRG & CAVITY LAYOUT)DRG & CAVITY LAYOUT)

• METHODS OF ACTUATION SPLITMETHODS OF ACTUATION SPLIT

SLIDING SPLITSSLIDING SPLITS CAM 1-:FINGER CAMCAM 1-:FINGER CAM 2-: DOG LEG CAM2-: DOG LEG CAM 3-:CAM TRACK 3-:CAM TRACK

SPRINGSPRING HYDRAULICHYDRAULIC

ANGLE LIFT SPLITANGLE LIFT SPLIT ANGLED GUIDED DOWELANGLED GUIDED DOWEL CAM TRACKCAM TRACK SPRINGSPRING

•FINGER CAM ACTUATION SPLIT FINGER CAM ACTUATION SPLIT MOVEMENT CALCULATIONMOVEMENT CALCULATION

•The distance traversed by each split across the face of the mould plate is determine by the length and angle of the finger cam

L=(M /sin Φ) + (2c /sin 2Φ) L=splits movement, Φ=angle of finger cam , c=clearance. The operating angle varies from 100 to 250.

• SPLIT LOCKING ARRANGEMENTSPLIT LOCKING ARRANGEMENT(go to (go to 2D ASSEMBLY2D ASSEMBLY))

•SPLIT SAFETY ARRANGEMENTSSPLIT SAFETY ARRANGEMENTS

Safety feature are Safety feature are necessary in moulds with necessary in moulds with can actuationcan actuation

Split may move out of Split may move out of alignment by shock, alignment by shock, vibration, gravityvibration, gravity

Spring detent methodSpring detent method

M=distance between the M=distance between the plunger and the plunger and the

depression is equaldepression is equal To split movementTo split movement

• DESIGNSDESIGNS OFOF SLIDING SLIDING SPLITSSPLITS

•NECCESARY ARRANGMENT WHILE SPLIT DESIGN 1-:Guiding split in desired direction.

2-:Actuating splits.

3-: Locking the split in position.

PART LISTPART LIST TOP PLATE TOP PLATE BOTTOM PLATE BOTTOM PLATE BOTTOM BACK PLATEBOTTOM BACK PLATE EJECTOR PLATEEJECTOR PLATE EJECTOR BACK PLATEEJECTOR BACK PLATE EJECTION SLEEVEEJECTION SLEEVE PUSH BACK PINPUSH BACK PIN CORE PLATECORE PLATE CORE BACK PLATECORE BACK PLATE SPLITSSPLITS GUIDE BLOCKGUIDE BLOCK HEEL BLOCKHEEL BLOCK

WEARE PLATEWEARE PLATE FINGER CAMFINGER CAM CORE INSERTCORE INSERT REST PADREST PAD GUIDE PILLARGUIDE PILLAR GUIDE BUSHGUIDE BUSH SACER BLOCKSACER BLOCK HOLLOW DOWELHOLLOW DOWEL SPRUE BUSH SPRUE BUSH LOCATING RINGLOCATING RING ALLEN BOLTALLEN BOLT

2D SPLITS2D SPLITS

3D SPLITS 3D SPLITS go to go to 2D ASSEMBLY2D ASSEMBLY go to go to 3D ASSEMBLY3D ASSEMBLYgo to go to LINKSLINKS

2D HEEL BLOCK2D HEEL BLOCK

3D HEEL BLOCK3D HEEL BLOCKgo to go to 2D ASSEMBLY2D ASSEMBLY go to go to 3D ASSEMBLY3D ASSEMBLYgo to go to LINKSLINKS

2D OF FINGER CAM2D OF FINGER CAM

3D OF FINGER CAM3D OF FINGER CAMgo to go to 2D ASSEMBLY2D ASSEMBLY go to go to 3D ASSEMBLY3D ASSEMBLYgo to go to LINKSLINKS

2D OF CORE INSERT2D OF CORE INSERT

3D OF CORE INSERT3D OF CORE INSERTgo to go to 2D ASSEMBLY2D ASSEMBLY go to 3D ASSEMBLYgo to 3D ASSEMBLYgo to LINKSgo to LINKS

2D OF BOTTOM PLATE2D OF BOTTOM PLATE

3D OF BOTTOM PLATE3D OF BOTTOM PLATEgo to 2D ASSEMBLY go to 2D ASSEMBLY go to 3D ASSEMBLYgo to 3D ASSEMBLYgo to LINKSgo to LINKS

2D OF GUIDE PILLLAR2D OF GUIDE PILLLAR

3D OF GUIDE PILLLAR3D OF GUIDE PILLLARgo to 2D ASSEMBLY go to 2D ASSEMBLY go to 3D ASSEMBLYgo to 3D ASSEMBLYgo to LINKSgo to LINKS

2D OF BOTTOM BACK PLATE2D OF BOTTOM BACK PLATE

3D OF BOTTOM BACK PLATE3D OF BOTTOM BACK PLATEgo to 2D ASSEMBLY go to 2D ASSEMBLY go to 3D ASSEMBLYgo to 3D ASSEMBLYgo to LINKSgo to LINKS

3D OF TOP PLATE 3D OF TOP PLATE go to 2D ASSEMBLY go to 2D ASSEMBLY go to 3D ASSEMBLYgo to 3D ASSEMBLYgo to LINKSgo to LINKS

3D ASSEMBLY3D ASSEMBLY

3D SPLITS3D SPLITS

3D HEEL BLOCK3D HEEL BLOCK

3D OF FINGER CAM3D OF FINGER CAM

3D OF CORE INSERT3D OF CORE INSERT

3D OF BOTTOM PLATE3D OF BOTTOM PLATE

3D OF GUIDE PILLLAR3D OF GUIDE PILLLAR

3D OF BOTTOM BACK PLATE3D OF BOTTOM BACK PLATE

3D OF TOP PLATE3D OF TOP PLATE

SPLIT LOCKSPLIT LOCK

finger camfinger camfinger cam with sensorfinger cam with sensorsplit coresplit coreassembly sequencingassembly sequencing2D assembly2D assembly

THANK YOU…..THANK YOU…..