Longterm has extensive experience of designing molds of European and American standard.

Special attention is paid to the mold construction, cooling channels and moving mechanisms to ensure the highest quality parts are delivered from its mold at the minimum cycle. All molds are carefully designed to maximize its service life and to ease maintenance.

Most of engineer tool making software is available in our systems, such as Solid work, UG Pro/E, AutoCAD, E-drawing, alias/studio tools.

During construction, making changes or modifications early in the design process, rather than, after cutting the steel, is highly recommended. In fact, certain changes are very costly after the mold-maker has begun his work. For this reason, Longterm has purchased advanced computer software that can simulate potential defects or flaws in the mold design prior to design approval.

Flow analysis is the first stage of the molding simulation process. Flow calculates the melt front advancement that grows through the part from the injection location, and continues until the switch-over point to packing. Flow analysis provides the ability to simulate, identify, and optimize the process to avoid molding uncertainty or resolve an existing injection molding problem.

Packing analysis builds on the results of the filling analysis by extending the first stage of the injection molding process into the packing phase. This second stage fills the non-filled portion of the mold with additional material to compensate for the loss in volume as the material shrinks. The part is then held under pressure while it solidifies.

Flow analysis evaluates or determines the following:

  • Uniformity of fill
  • Number of gates
  • Gate size and location
  • Weld line location
  • Air entrapment
  • Pressure & temperature
  • Shear rate, shear stress
  • Part designs
  • Processing conditions
  • Hot runner sizing
  • Sequential valve gating
  • Runner balancing

Packing analysis evaluates or determines the following:

  • Gate freeze time
  • Packing pressure profile
  • Volumetric shrinkage
  • Sink location
  • Clamp tonnage/machine sizing

The importance of sound plastic parts design cannot be overstated.  There are numerous considerations that affect the cost, quality and performance of a plastic part – and those considerations need to be carefully thought-through at the design phase of a new product, before investing substantial sums in tooling, pilot production and assembly.

Most importantly, material selection impacts thermal performance, dimensional stability, cost, structural strength and molding cycle time.  Mechanical design has an affect on the productivity and ease of subsequent assembly operations.  How the part is designed has a great impact on the part’s cosmetic appeal.  Finally, sound design discipline improves the product’s time-to-market by avoiding the delays associated with time-and-money wasting tooling adjustments common with poor designs.

Longterm’s highly experienced engineering team has been assisting clients in assuring that all of these design considerations are optimized before tooling is committed.  This collaborative design effort assures the optimal combination of part performance, cosmetic appearance, part quality, functionality and cost for the part