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Design and manufacturing ofplastic injection mould

08 Runner system

Dr. Mik Balzsmiko.balazs@bgk.bmf.hu

BAGIM1ENNB

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Content

Identification of injection location Cold sprue

Runner system

Type of gates

Hot drop

Hot runner

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Aim of injection system

Drive the meltedplastic to thecavities

Parts

Sprue

Runners

Gate

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Type of injection system

Cold injection system

Hot injection system (heated)

Combinated system

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Identify the gate location

Equal filling up of the cavities

Minimal welding line

Minimal distance

Parting line geometry

Esthetic viewpoint

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Computer aided analysis

Best gate location

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Fill time

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Injection pressure

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Melt front temperature

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Quality prediction

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Welding line

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Air bubble / trap

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Sprue bushing

R 0 / 15,5 / 40

0,5/ 1

R0,5 / R2

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Sprue bushing

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Role of radii

Rs > Rm 16

Catalogue components

With radius 0 / 15.5 / 40

Angle 0.5/ 1Diameter d2

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Size of the sprue diameter

0,4 mm

0,7 mm

0,9 mm

0,55 mm

1in3=16,4cm

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2624

2460

2296

2132

1968

1804

1640

1476

1312

1148

984

820

656

492

328

164

0

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Runner system

Short length

Balancing

Optimal cross section

Simple manufacturing

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Balancing

Aim: same fill up time

Naturally balancing: equalrunner length

Artificial balancing: adjustrunner cross section

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Natural balancing

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Artificial balancing

A

A/2A/2 * 2/3

A/2 * 2/3 * 1/2

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Combined balancing

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Runner cross section

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Cold slug well

Collect the not too good quality material of the melt front.

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Runner diameter

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Runner size

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Runner diameter

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Runner diameter

12 mm

11 mm

10 mm

8 mm

6 mm

4,5 mm

3 mm

12 mm

11 mm

10 mm

8 mm

6 mm

4,5 mm

3 mm

cm

3/s

cm

3/s

82

65,6

49,2

32,8

16,4

0

82

65,6

49,2

32,8

16,4

0

0 76 ,2 152 ,4 2 28 ,6 304, 8 0 76 ,2 152 ,4 2 28, 6 304, 8

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Maximum runner length

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Gate type

Sprue gate

Edge gate / Side gate / Fan gate

Pin gate / Drop gate

Tab gate

Diafragm gate

Internal ring gate

External ring gate

Flash gate / Film gate

Submarine gate / Tunel gate

Curved tunel gate / Banana gate

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Sprue gate

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Edge gate / Side gate / Fan gate

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Edge gate / Side gate

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Examples

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Pin gate / Drop gate

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Pin gate / Drop gate

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Tab gate

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Diaphragm gate

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Internal ring gate

40

External ring gate

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Flash gate / Film gate

Thickness of the gate

Flow

length(mm)

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Submarine gate / Tunnel gate

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Submarine gate / Tunnel gate

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Submarine gate / Tunnel gate

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Submarine gate / Tunnel gate

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Insert for family mould

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Curved tunnel gate / Banana gate

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Curved tunnel gate / Banana gate

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Hot runner system

Less material cost (no waste) Shorter cycle time

More expensive mould

Nozzle min. 650

Manifold min. 1200

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System elements

Hot drop

Manifold Electric

connector

Temperaturecontrol

system

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Parts of manifold

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Nozzle types

Open gateGeneralSimple

Valve gateSpecialComplexThe order of opening is programmablePneumatic of electro magnetic actuatorTypical use: long parts

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System elements

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Type of gates

Material

Weight

Cycle time

ASK HELPFROM THEDISTRIBUTOR!

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Combined single nozzle system

More waste

Cheaper mould

Typical use: Deep cavity and high A plate

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New trends

Adjustable manifoldwith valve gate

Complete injection sizeas catalogue part