Stepped sonotrode and anvil energy director grids for narrow/complex ultrasonic welds of improved durability

摘要

A specially designed sonotrode and anvil are adapted to be used in combination for ultrasonic welding of work pieces, to produce a narrower weld region, but one exhibiting greater durability, thereby permitting use of less packaging material. The contact surfaces comprise a surface of the anvil having a plurality of energy directors, where the plurality of energy directors are arranged into a three-dimensional grid pattern to be capable of distributed vibration-transmissive contact. The energy directors may comprise a series of plateau surfaces being regularly spaced apart from each other in a first direction, and in a second direction that is orthogonal to the first direction, to form the grid pattern. The rectangular-shaped plateaus may be spaced apart by valleys. Engagement of the energy directors of the anvil with the corresponding surface of the sonotrode may cause minor elastic deformation of work pieces positioned therebetween prior to ultrasonic welding.

主权项

1. A horn and anvil combination, said horn and anvil combination configured for use in ultrasonic welding of thin work pieces, for improved integrity in the packaging of solids and liquids with narrow welds to reduce per-package material usage and costs:
said horn comprising:
a plurality of energy directors, said plurality of energy directors being spaced in a first direction and in a second direction to form a pattern, each of said plurality of energy directors comprising a rectangular-shaped plateau surface with each side of said rectangular-shaped plateau surfaces configured to transition into an angled side surface to create a first, a second, a third, and a fourth angled side surface for each said plateau surface; each of said angled side surfaces of each said plateau surface being connected with another side surface of an adjacent plateau surface, except at an outer periphery of said horn; said anvil comprising:
a plurality of energy directors being spaced in a first direction and in a second direction to form a pattern, each of said plurality of energy directors comprising a rectangular-shaped plateau surface with each side of said rectangular-shaped plateau surfaces configured to transition into an angled side surface to create a first, a second, a third, and a fourth angled side surface for each said plateau surface; each of said angled side surfaces of each said plateau surface being connected with another side surface of an adjacent plateau surface, except at an outer periphery of said anvil;and wherein said energy directors of said horn and said energy directors of said anvil are configured for alignment, whereby said side surfaces of said horn plateaus interlock with said side surfaces of said anvil plateaus in a pattern, in both said first direction and said second direction.