Blow Molding Moving Plug for Recessed Closure Integration

Solution Overview

Problem

The challenge in blow molding articles with recesses proximal to the opening portion is the formation of undercuts, which hinders the unmolding process and restricts design integration with the closure, leading to inefficiencies and damage during traditional straight-pull mold opening.

Innovation Solution

A process involving the translation of a moving plug relative to the article's base to form recesses near the neck portion, allowing for the integration of the closure with the article and enabling the article to wrap around the closure, while maintaining a flush surface and minimizing material flow against the natural molding direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a recess is formed proximal to the opening portion of the article, then closure integration and design flexibility are improved, but undercuts are generated that prevent unmolding with traditional straight-pull processes

Engineering Contradiction:

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The mold plug is made movable rather than fixed, allowing it to translate relative to the article during the molding process. This dynamic element enables the formation of complex recess geometries with undercuts while maintaining the ability to unmold the article by reversing the plug's motion, thus resolving the contradiction between design flexibility and manufacturability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Instead of pulling the mold straight out as in traditional processes, the invention inverts the approach by using a movable plug that can translate into and out of the article. The unmolding action is reversed from a simple extraction to a controlled translation motion, allowing complex geometries to be formed and then released without damage

Inventive Principle:

Principle #13The other way round (Inversion)

2Shape

If material is moved against the natural flow direction to form shoulders above the neck, then recess geometry is improved, but material flow control becomes more difficult

Engineering Contradiction:

Core Design Contradiction:

ShapeVSDevice complexity

Solution Approach 1:

The parison or preform is carefully designed and prepared before the blow molding process to anticipate the material flow requirements. By pre-configuring the material distribution and flow paths in the parison, the process enables complex recess geometries to be formed without requiring complex real-time control during molding, as the material flow has been predetermined

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If trimming operations are used to finish recess geometry, then manufacturing precision is improved, but production cost and time increase

Engineering Contradiction:

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The movable plug system is designed to form the final recess geometry directly during the blow molding process itself, without requiring subsequent trimming operations. The plug's translation motion and geometry are configured to create the precise final shape in one step, making the process self-sufficient and eliminating the need for additional finishing operations that would reduce productivity

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS9205592B2Process for the manufacture of an article comprimising a recess

Publication Date: 2015.12.08

AI summary

The present invention relates to a process for blowing an article with at least one recess.