Regulator Bag Controls Foam Deformation Rate in Vacuum Forming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vacuum forming processes for foam blanks are impractical and prone to variability, often resulting in cracking due to rapid forming and sensitivity to vacuum levels, making it difficult to achieve a standardized and repeatable method for thermoforming fiber-reinforced composite materials.
Innovation Solution
A vacuum-forming system that includes a regulator bag positioned inside the vacuum bag to support the foam blank, which slowly deflates to control the rate of deformation, allowing the foam to form around a tool in a controlled and repeatable manner, reducing the risk of cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If vacuum is applied rapidly to form the foam blank, then the forming speed is improved, but the foam blank cracks due to excessive deformation rate
Solution Approach 1:
A regulator bag is introduced as an intermediary element between the vacuum source and the foam blank. The regulator bag controls the rate at which vacuum is applied to the foam blank through its controlled deflation, preventing rapid deformation that causes cracking while still achieving efficient forming.
Solution Approach 2:
The system transitions from static vacuum application to dynamic control. The regulator bag's gradual deflation creates a time-dependent vacuum application process, allowing the deformation rate to be controlled and adjusted during the forming process to prevent cracking.
2Productivity
If vacuum level is increased to improve forming efficiency, then the forming rate is improved, but the process becomes highly sensitive and variable
Solution Approach 1:
The regulator bag provides inherent feedback control by responding to pressure differential. As vacuum is applied, the bag deflates at a controlled rate based on the pressure difference between inside and outside, automatically regulating the vacuum application to maintain consistent forming conditions.
Solution Approach 2:
The system changes the parameter of vacuum application from direct and immediate to gradual and controlled. The regulator bag modifies the pressure-time profile, transforming the vacuum application characteristics to achieve consistent forming results with reduced variability.
3Device complexity
If manual handling of hot foam is attempted, then the process simplicity is improved, but safety risks and handling difficulty increase
Solution Approach 1:
The regulator bag acts as a mediator that remains in contact with the hot foam throughout the forming process, eliminating the need for manual handling of hot materials. The bag can be safely manipulated while the foam is being formed, improving safety without significantly increasing process complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides a controlled and repeatable method for thermoforming foam blanks, reducing the incidence of damage during the forming process and ensuring consistent results by decoupling the deformation rate from the vacuum level, thereby improving the forming process's reliability and precision.
Implementation Method 1
the exterior of the sealed bag is at a determined reduced pressure
Implementation Method 2
the regulator bag has a rate of deflation wherein the sealed bag will deflate from the first volume to a second volume
Implementation Method 3
a vacuum membrane coupled to the tool, the membrane configured to form a vacuum space enclosing the forming blank and the at least one regulator bag
Implementation Method 4
The external air pressure applies a uniformly distributed force that forms the foam around the tool
Data Source
AI summary
A vacuum-forming system for deforming a forming blank is disclosed. The system includes a tool and at least one regulator bag disposed adjacent to the tool. The regulator bag includes a sealed bag having an exterior and an interior and a first volume and a defined passage from the interior to the exterior of the regulator bag. The passage is configured such that the regulator bag has a rate of deflation wherein the sealed bag will deflate from the first volume to a second volume over a determined period of time while the exterior of the sealed bag is at a determined reduced pressure. The system also includes a vacuum membrane coupled to the tool, the membrane configured to form a vacuum space enclosing the forming blank and the at least one regulator bag.