• Technology | Weldless Molding


Weldless Molding

Improved glossy finish.
Superior molded parts without weld lines
offering better aesthetics and strength.

Weld lines impact the quality of the external appearance.
Our own technology that prevents weld lines produces superior products.
Improving the glossy finish eliminates the need for a coating process,
and it also has excellent strength.

Technology Overview

In standard injection molding, weld lines are generated where two melt fronts meet, leading to an unwanted appearance. However, this new technology makes the weld lines practically invisible, producing superior molded parts.

Conventional Method
  • Thin wall moldings crack easily. Therefore, metal (Mg) is used to compensate.
  • Uneven texturing on molded parts results in a partial gloss and haze on the surface. Thus, coating is required.
New Method
  • Even thin wall parts now have excellent strength. Glass filler and/or carbon filler are added instead of magnesium alloy.
  • With better melt transcription to the mold surface, fine details such as the grained structure are replicated better on the part surface. The coating process is not necessary because it has a better glossy finish and weld lines do not form.


  • Transparent and semi-transparent parts: Panels for car audio and navigation systems (trim plates)
  • Plated and vapor deposited parts: Small parts such as keycaps on audio systems
  • Thin walled parts: Memory cards and similar items
  • Parts that require high strength: Housing for home appliances such as digital cameras, computers and projectors
  • Non-coating parts: LCD panels and LCD frame panels for car audio and navigation systems