Lightweight Crown Cap with Grooved Panel and Hard Steel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional crown caps are heavy and have not significantly changed in design since the 1890s, lacking improvements in weight reduction and efficiency for both twist-off and pry-off types, particularly for recycled bottles.
Innovation Solution
A lightweight crimp-type crown cap with a steel shell of increased hardness, featuring a panel with structural features like grooves, stars, and dimples, and a thermoformed liner for improved sealing and reduced metal usage, allowing for crimping onto glass bottles with a crimping tool that contacts the flutes at the outer edge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If conventional crown cap design is used, then structural strength and sealing performance are maintained, but weight and material usage remain high
Solution Approach 1:
The patent changes the material parameters by using higher hardness steel (greater than 62 on the 30T scale) and adjusting the gauge thickness to achieve weight reduction while maintaining strength. The increased hardness allows for thinner material usage while preserving structural integrity during crimping and sealing operations.
Solution Approach 2:
The patent employs a composite structure combining a steel shell with a thermoformed liner. The steel shell provides structural strength and sealing, while the liner (made of materials like PVC, PE, or PP) provides additional sealing and protects the bottle. This composite approach allows optimization of each material for its specific function, reducing overall weight.
2Quantity of substance
If increased steel hardness is used, then weight and material usage are reduced, but manufacturing complexity increases
Solution Approach 1:
The patent specifies precise hardness parameters (greater than 62 on the 30T scale, with preferred ranges of 65-73) to optimize the balance between material usage and manufacturability. These parameter specifications allow existing manufacturing equipment to produce the harder steel without significant modifications, as the hardness is achieved through material selection and heat treatment processes already present in the industry.
3Reliability
If structural features like grooves and dimples are added to the panel, then sealing performance is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by adding structural features (grooves, dimples, or a combination) specifically to the panel portion of the crown cap where sealing contact occurs. These localized modifications concentrate the sealing function in specific areas without requiring complexity throughout the entire crown cap structure. The features are strategically positioned to contact the bottle rim and enhance sealing where needed.
Solution Approach 2:
The panel structure is segmented into functional zones: areas with grooves or dimples for sealing contact, and smooth areas for structural integrity and crimping. This segmentation allows each region to perform its specific function efficiently, improving overall sealing reliability without uniformly increasing complexity across the entire component.
4Productivity
If crimping tool contacts flutes at the outer edge, then crimping effectiveness is improved, but risk of bottle damage increases
Solution Approach 1:
The flange is segmented into flutes and lands, with the crimping action concentrated on the flutes at the outer edge. This segmentation allows the crimping tool to apply force to specific locations (flutes) that are designed to deform and affix the cap, while the lands provide distribution zones that reduce concentrated stress on the bottle. The flutes are positioned to engage with the bottle finish beads or threads without directly contacting the glass.
Solution Approach 2:
The flutes act as an intermediary element between the crimping tool and the bottle. Instead of the crimping tool directly contacting the bottle (which would cause damage), the flutes deform to affix the cap while distributing the crimping force. The flutes serve as a mechanical intermediary that transfers the crimping action to the bottle finish features without transmitting excessive force to the glass.
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 solution results in a crown cap that is up to 25% lighter, using less steel, reducing carbon emissions, and maintaining performance comparable to conventional caps, with the increased hardness enabling effective sealing and crimping without significant changes to existing manufacturing equipment.
Implementation Method 1
a thermoformed liner on the underside of the cap is pressed against the bottle's rim to enhance sealing
Implementation Method 2
the flutes are deformed to affix the cap to a bead or threads on the bottle's finish
Data Source
AI summary
A crown cap that may use less steel than a conventional crown cap is disclosed. A crown cap comprises a shell formed of an increased hardness, including a peripheral skirt, a round panel integrally formed with the skirt, the panel including one to three radially symmetric grooves formed therein, each groove spaced apart from a contact portion of the panel that is adapted for contacting the rim of a bottle upon application of the crown cap onto the bottle, and a liner located on the underside of the panel. The radially symmetric grooves may be circular.