Injection Molding MFG 355. 15 Ton Injection Molding Machine Click on frame to start video.

Injection Molding

MFG 355

15 Ton Injection Molding Machine

Click on frame to start video

77 Ton Injection Molding Machine

Click on frame to start video

Click on frame to start video

150 Ton Injection Molding Machine

Equipment

• Injection Unit

Screw drive arrangement

Feed hopper

Barrel heaters Nozzle

Tool

Screw Check valve Screw tip

Equipment

• Injection Unit

Injection

• Parts of the injection screw– Screw– Head and check ring

Equipment

• Molds

Molds

Mold Materials

• Aluminum filled epoxy

• Aluminum

• Tool steel

• Stainless steel

• Hotwork die steel

• Beryllium-copper

Mold Materials

• Choice based on critical properties– Machinability– Coefficient of thermal expansion– Specific heat capacity– Thermal conductivity– Density– Hardness (abrasion resistance)– Yield strength– Weldability

Mold Parts

• Bases– Standard sizes– Hold mold inserts– Can decrease overall mold costs

Mold Parts

• Guide pins– Align mold cavities

Guide pins

Mold Parts

• Sprue Bushing– Hot sprue– Cold sprue

Mold Parts

• Sprue Bushing– Hot sprue

Mold Parts

• Sprue Bushing– Cold sprue– Sprue puller

Mold Parts

• Sprue Bushing– Cold sprue– Sprue puller

Mold Parts

• Runner

Mold Parts

• Runner– Layout

Conventional Improved Balanced “H” Circular

Mold Parts

• Runner– Layout

Conventional Improved Balanced “H” Circular

Mold Parts

• Runner– Cold well

Mold Parts

• Runner

Mold Parts

• Gates

Submarine Gate

Pinpoint Gate

Fan or Edge Gate

Mold Parts

• Gates

Sprue Gate

Tab Gate

Flash Gate

Mold Parts

• Gates

Internal Ring GateExternal Ring Gate

Mold Parts

• Gate

Mold Parts

• Gate

Mold Parts

• Gate

Mold Parts

• Cavity– Where the part is made– Layout is critical to material flow

Mold Parts

• Cavity– Knit/weld lines

This shows where the weld lines (shown in red) will most likely occur withthe part gated in the center (yellow cone).

Mold Parts

• Cooling– Reduce cycle time– Control formation of crystalline areas – Freeze part

Mold cavity

Cooling lines

Mold Parts

• Ejector system

Ejector Plate

Ejector pins

Return Springs

Equipment

• Clamping Unit

Equipment

• Clamping Unit– Toggle clamping– Hydraulic clamping– Hybrid hydraulic-toggle clamping

Equipment

• Clamping Unit

Equipment

• Clamping Unit– Toggle system

Click on frame to start video

Plant Concepts

Safety

• High clamping forces

• High pressure lines

• High voltage

• High temperatures

Safety

• Position switches– Mechanical, hydraulic and electrical

• Shields

• Lock out/tag out

Material and Product Considerations

• Shapes– Possible to do very complex shapes

• Structural features– Pins, ribs, bosses, threads, holes

– Deep parts are possible– Internal or external threads– Undercuts require sliding mold sections

Sliding Mechanism

Material and Product Considerations

• Part design– Uniform wall thickness

• Helps reduce dimples, shrink marks and distortion

– Ribs• Save weight at given strength

– No sharp bends• Helps to fill the mold cavity easier

– Oversize the mold• Shrinkage amount is dependant on material and

additives/fillers

Operations and Control

• Temperature of melt

• Temperature of mold

• Pressure of injection and hold

• Injection or fill rate and time

• Dwell time

• Freeze time

• Ejection (dead time)

Special Injection Molding Processes

• Coinjection molding– Two separate screws– Two different material selections

• Color, strength, flexibility

Special Injection Molding Processes

• Coinjection molding

1 2 3

Special Injection Molding Processes

• Coinjection molding

Part 1

Part 2

Special Injection Molding Processes

• Flow-controlled injection processes– Sometimes called Scorim

Special Injection Molding Processes

• Flow-controlled injection processes– Sometimes called Scorim

Special Injection Molding Processes

• Gas injection molding– Employs gas to create hollow parts

Special Injection Molding Processes

• Injection-compression molding

Injection-CompressionMolding

Injection Molding

Parts were made with the same mold. The only difference between the two parts is the use of the compression cycle

Modeling and Computer-Aided Mold-Flow Analysis

• Used to help identify potential problems with the mold/part design

• Models based on the CAD part

• Adjusted by resin

Thank You