Package Formed with a Stepped Sonotrode/Anvil Combination having Energy Director Grids for Narrow Ultrasonic Welds of Improved Durability

摘要

A sonotrode and anvil are adapted for ultrasonic welding of work pieces, to produce a narrower weld region that exhibits greater durability, permitting use of less material per package. The horn-to-anvil contact is through a plurality of energy directors arranged into a three-dimensional grid pattern to be capable of distributed vibration-transmissive contact. The energy directors include a series of plateau surfaces regularly spaced apart in a first direction, and in a second direction that is orthogonal to the first direction, to form the grid pattern. The energy directors of the horn are configured to interlock with the energy directors of the anvil. The rectangular-shaped plateaus are spaced apart by angled side-surfaces that form valleys. A stepped transition to a corresponding region of reduced height for the energy directors of the sonotrode and anvil may form a cosmetic seal region with a lesser integrity, in addition to the main barrier seal.

主权项

1. A package formed using an ultrasonic sealing process on a form-fill-seal machine to produce a narrow weld region that exhibits greater durability, to permit use of less material per package, said package comprising:
a thin film, said thin film folded to have one or more sets of overlapped edges at a seam; and a weld at each of said one or more overlapped edges to form and seal said seam to create a sealed cavity; each said weld at said one or more overlapped edges comprising a selective three-dimensional grid pattern, said selective three-dimensional grid pattern formed by a coordinated plurality of energy directors on each of a sonotrode and an anvil of the form-fil-seal machine, the energy directors having a rectangular plateau surface and four angled side surfaces configured to selectively deform and increase a total surface area of the thin film at the weld when sandwiched between the energy directors the sonotrode and anvil, and subjected to vibration-transmissive contact during a welding process, to form said three-dimensional grid pattern in said thin film, and weld said overlapped edges.