Can Cap Sealing Member With Variable Sliding Layer Thickness

Solution Overview

Problem

Conventional caps for can containers face issues with high opening torque and instability due to thick hard sliding layers, which can be mitigated by making the sliding layer thinner, but this compromises moldability.

Innovation Solution

A cap design featuring a disk-shaped top plate and cylindrical skirt with a sliding layer that has a thin portion thinner than the center, positioned to face the base point of deformation during corner drawing, and a sealing layer that provides good sealability, along with knurl portions on the skirt for secure attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness of the hard sliding layer is increased, then the slidability with respect to the top plate portion is improved, but the load required for drawing the corner portion of the cap body increases

Engineering Contradiction:

ImproveslidabilityVSAvoidload for drawing corner portion

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The sliding layer is designed with non-uniform thickness, being thinner at the outer peripheral edge side and thicker at the center side. This local variation in thickness allows the sliding layer to provide adequate slidability at the contact area with the top plate portion while reducing the overall load during corner drawing operations, as the thinner outer region requires less force to deform during the drawing process.

Inventive Principle:

Principle #3Local quality

2Force

If the thickness of the hard sliding layer is decreased, then the load for drawing the corner portion is reduced, but the moldability of the sliding layer deteriorates

Engineering Contradiction:

Improveload for drawing corner portionVSAvoidmoldability

Core Design Contradiction:

ForceVSEase of manufacture

Solution Approach 1:

The sliding layer is designed with non-uniform thickness, being thinner at the outer peripheral edge side and thicker at the center side. This local variation in thickness allows the sliding layer to provide adequate slidability at the contact area with the top plate portion while reducing the overall load during corner drawing operations, as the thinner outer region requires less force to deform during the drawing process.

Inventive Principle:

Principle #3Local quality

3Force

If the sliding layer is made thinner, then the load for drawing the corner portion is reduced, but the stability during capping may be compromised

Engineering Contradiction:

Improveload for drawing corner portionVSAvoidstability during capping

Core Design Contradiction:

ForceVSStability of the object's composition

Solution Approach 1:

The sliding layer is designed with non-uniform thickness, being thinner at the outer peripheral edge side and thicker at the center side. This local variation in thickness allows the sliding layer to provide adequate slidability at the contact area with the top plate portion while reducing the overall load during corner drawing operations, as the thinner outer region requires less force to deform during the drawing process.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3875391B1cap

Publication Date: 2024.05.22 DAIWA CAN

Figure 1
Figure 2
Figure 3

AI summary

A cap (1) includes a cap body (11) including a disk-shaped top plate portion (21) and a cylindrical skirt portion (22) provided at a peripheral edge portion of the top plate portion (21); and a disk-shaped sealing member (12) including a sliding layer (41) and a sealing layer (42), the sliding layer (41) disposed on the top plate portion (21) side and having a thin portion (41d) thinner than at least a center side provided on an outer peripheral edge side, and the sealing layer (42) provided on a main surface opposite to the top plate portion (21) side of the sliding layer (41) and sealing a mouth portion (110) of a can container (100).