Plastic injection molding

Plastic injection molding

Injection molding is a manufacturing process, which is making semi-finished parts of certain shapes by pressurizing, injecting cooling and separating molten thermoplastic.

Validate and optimize your tool design


  • Challenges
  • Design phases
  • Simulation methods
  • Summary and question


Many factors and decisions for molded components

  • Continual change

Part geometry, process type, material design, mold design

  • Application criteria

Function, cosmetics, volume, economics, life cycle

  • Variations

Lot-2-material, machine ware, machine cloning, mold ware

Process and analysis types

  • Gate location analysis
  • Molding window
  • Filling
  • Runner balancing
  • Fiber orientation
  • Packing
  • Design of experiment
  • Venting analysis
  • Crystallization analysis
  • Core shift analysis
  • In-mold label
  • Wire sweep paddle shift
  • Cooling and heating analysis…………steady state, transient, multi cycle, conformal
  • ‘repaid heating and cooling…………water, steam electrical or induction
  • War page and shrinkage analysis
  • Thermoplastic injection molding
  • Two-shot molding sequential, insert molding, over-molding, IMD
  • Gas-assisted injection molding
  • Injection compression molding
  • Bi-injection molding
  • Microcellular injection molding
  • Birefringence
  • Structural reaction injection molding
  • Rubber, liquid silicone injection molding
  • Multiple-barrel reactive molding
  • Reaction injection molding
  • Microchip encapsulation and underfill encapsulation
  • Export as-manufactured properties to FEA
  • Defect visualization

The Best opportunity for the design process

  • Part design

Concept, select material, prototype, estimate cost…..

  • Mold design

Quoting, concept, initial layout, during fabrication…….

  • Process development

Develop a stable process, optimize quality criteria, and minimize cycle time

  • Production troubleshooting

Oops…….. I did it again

Product development cycle

  • Lower costs through upfront insight into the part and mold optimization
  • Reduce time to market and avoid warranty issues and recalls
  • Have confidence that the design is the right

Part design


Normal wall thickness

  • Thickness variation
  • Traffic-light display
  • Plastic design rule: thickness changes no more than 30% of nom. Wall thickness

Draft angle

  • Draft variations
  • The Draft is acceptable locations


  • Suitable undercuts

Molding window analysis

  • Take the guesswork out of your process window

Helps determine process window and optimum conditions

  • Full range of  plastic mold, melt temperature
  • Pressure limit
  • Temperature drop through part

Define the size of window by

  • Number and location of gates
  • Per geometry
  • Material – can compare several materials

Mold design

  • Runner system
  • Venting
  • Steel types
  • Cooling and heating

Cooling and heating

Revised design

  • Range 72 – 105 degree
  • Difference 33 degree
  • Average tem 89.1 degree

Original design

  • Range 55 – 119 degree
  • Difference 64 degree
  • Average tem 88.2 degree

Variable coolant inlet temperature and coolant during a cycle:

  • Heating phase
  • Air purge
  • Cooling phase
  • Air purge

Mold heated by:

  • Water, steam, electrical or induction

Heating and cooling phase:

  • Time or temperature (thermocouple) controlled


The design is the choice of your

  • Mold design
  • Part geometry
  • Process type
  • Material

Validate and optimize your design

  • Part simulation
  • Runner simulation
  • Venting simulation
  • Cooling and heating simulation
  • Design of experiment

United Grinding Technologies Announces Plans to Buy Ewag USA

At IMTS, the huge manufacturing trade fair held September 4–11 in Chicago, United Grinding Technologies (UGT) announced that it will acquire Ewag USA of North Kingstown, Rhode Island, and merge its operations into UGT. The merger is scheduled to be complete by January 1, 2003.

Ewag USA was founded in 1946 and now makes tool grinding machines and tool grinding centers for the production of rotary tools and high-quality indexable inserts of tungsten carbide, PCD and PCBN. Ewag will be a UGT product division specializing in tool and cutter grinding machines.

The company’s headquarters will continue to be in UGT’s facility at Miamisburg, Ohio

Plastic Industry news

IBM Confirms Intention to
Acquire EADS Matra Datavision

IBM has confirmed its intention to acquire EADS Matra Datavision, a major supplier of engineering applications and services that is a wholly owned subsidiary of the EADS Group. Once complete, the combination of IBM and EADS Matra Datavision will significantly enhance IBM’s product lifecycle management (PLM) offerings.

Product lifecycle management refers to solutions and methodologies that allow manufacturers to integrate product development processes and knowledge across an extended enterprise. PLM enables innovation, improved product development efficiencies, and e-collaboration by all contributors involved in a product rollout, including engineers, production teams, operations personnel, suppliers, and after-sales service specialists. The PLM services market is expected to grow from $1.9 billion in 2001 to $5.5 billion in 2006, for a combined annual growth rate of 23.4%.

EADS Matra Datavision has been IBM’s top producing PLM business partner since it entered an alliance with IBM in 1998. The transaction is expected to be completed by January 1, 2003, at which time EADS Matra Datavision will become part of IBM.

Trumpf Reports 2001-02 FY Results;
Laser, Medical Technologies Growing


The Trumpf Group reports that its 2001-02 fiscal year has ended with €1.17 billion ($1.04 billion) in consolidated sales, close to the the previous year’s level of €1.22 billion ($1.09 billion). Despite the recession that continued throughout the company’s entire fiscal year, group sales remained stable and total earnings high. Orders received totaled €1.14 billion ($1.02 billion), slightly less than sales.

While sales decreased in Europe and the United States, Trumpf grew in Asia. The overseas share of consolidated sales totaled 64%.

The company’s Laser Technology and Medical Technology divisions increased sales by 12% (to €319 million) and 27% (to €117 million), respectively. The Machine Tools division experienced a drop in sales of 9.2% (to €971 million), and sales were down by 8.3% in the Power Tools division (at €39 million).