Plastic Processing Machinery Forging
Injection moulding machines clamp with hundreds of tonnes of force, cycling every few seconds. Tie bars carry that load in pure tension, millions of times.
Forged plastic machinery components include tie bars carrying full clamping force in pure tension every cycle, platen hardware and extruder screw blanks. Tie bars are ultrasonically tested because high-cycle fatigue failure at thread roots is both dangerous and production-stopping.
- Components
- Tie bars, platen parts, screw blanks
- Materials
- EN19, EN24, 42CrMo4
- Tie bar length
- Up to 2,000 mm
- Threads
- Rolled where possible
- NDT
- UT on tie bars
Plastic Processing Machinery Forging at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Tie bars up to 2,000 mm length
- Ultrasonic testing on tie bars standard
- Rolled threads for fatigue resistance
- EN19, EN24 and 42CrMo4 grades
Tie Bars in Pure Tension
Four tie bars carry the entire clamping force, cycling from zero to full load every shot. This is textbook high-cycle fatigue, and tie bar failure is both dangerous and immediately production-stopping.
- Full clamp load every cycle
- Millions of cycles per year
- High-cycle fatigue design
- Thread roots are critical
Screw and Barrel Components
Extruder and injection screws work abrasive filled polymers at temperature. Screw blanks are forged for soundness through the section, then machined and often surface treated for wear resistance against glass-filled compounds.
People also ask
How many cycles do tie bars see?
Millions per year on a machine cycling every few seconds, which places them firmly in high-cycle fatigue design territory.
Why are tie bar threads rolled?
Rolling work hardens the thread root and leaves compressive residual stress, substantially raising fatigue life at the location where tie bars actually fail.
What material is used for screw blanks?
EN19 or 42CrMo4 forged for soundness, then machined and surface treated for wear resistance against filled and abrasive compounds.
Topics covered on this page
- injection moulding
- tie bar
- platen
- extruder screw
- high-cycle fatigue
- clamping force
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
Why do tie bars fail?
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High-cycle fatigue, usually initiating at thread roots, since they carry full clamp load from zero to maximum every shot.
Do you supply screw blanks?
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Yes, forged screw blanks for extruders and injection units, sound through the section for subsequent machining.
Are tie bars ultrasonically tested?
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Yes, because a tie bar failure is dangerous and internal soundness cannot be verified any other way.