Molded Paper Body Wrinkle Prevention via Localized Pressing

Solution Overview

Problem

Conventional molded paper bodies used in containers often develop wrinkles during deep drawing, leading to incomplete sterilization and leakage issues due to gaps or pockets near the joint between the side wall and body member, especially in long-life food and drink containers.

Innovation Solution

A method involving deep drawing with a wrinkle pressing mechanism that sets the pressure based on the characteristic relation between wrinkle pressing force and blank tensile strength, using a die with a rounded distal end and controlled pressure application to prevent wrinkling, resulting in a smooth surface and good adhesion between the bottom and body members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If deep drawing is performed to form molded paper bodies, then the container shape is achieved, but wrinkles occur in the upright portions along the periphery

Engineering Contradiction:

Improvecontainer shapeVSAvoidsurface smoothness

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pressing the outer peripheral portion of the blank before deep drawing to prevent wrinkles from forming during the forming process. This preliminary pressing action stabilizes the paper structure and prevents the development of wrinkles in the upright portions along the periphery.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by applying pressure specifically to the outer peripheral portion of the blank rather than uniformly across the entire surface. This localized pressing action targets the specific area prone to wrinkling during deep drawing, while leaving the rest of the blank unaffected.

Inventive Principle:

Principle #3Local quality

2Shape

If wrinkles are formed in the side wall of the bottom member, then the container structure is created, but gaps or pockets occur near the joint between side wall and body member

Engineering Contradiction:

Improvecontainer structureVSAvoidjoint alignment

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pressing the outer peripheral portion of the blank before deep drawing to prevent wrinkles from forming during the forming process. This preliminary pressing action stabilizes the paper structure and prevents the development of wrinkles in the upright portions along the periphery.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by applying pressure specifically to the outer peripheral portion of the blank rather than uniformly across the entire surface. This localized pressing action targets the specific area prone to wrinkling during deep drawing, while leaving the rest of the blank unaffected.

Inventive Principle:

Principle #3Local quality

3Shape

If gaps or pockets are present near the joint between side wall and body member, then the container is formed, but sterilization becomes incomplete

Engineering Contradiction:

Improvecontainer formationVSAvoidsterilization completeness

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The patent applies preliminary action by pressing the outer peripheral portion of the blank before deep drawing to prevent wrinkles from forming during the forming process. This preliminary pressing action stabilizes the paper structure and prevents the development of wrinkles in the upright portions along the periphery.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by applying pressure specifically to the outer peripheral portion of the blank rather than uniformly across the entire surface. This localized pressing action targets the specific area prone to wrinkling during deep drawing, while leaving the rest of the blank unaffected.

Inventive Principle:

Principle #3Local quality

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 method effectively eliminates visible wrinkles, ensuring a smooth surface and reliable adhesion, preventing leakage and ensuring complete sterilization, making the paper containers suitable for long-life applications.

Implementation Method 1

a mechanism for holding by pressing an outer peripheral portion of the blank with a wrinkle pressing member and a die top surface, wherein a pressure is applied by the wrinkle pressing member

Methodology Applied

Scientific EffectMechanical compression: Compression

Implementation Method 2

The die that engages with the punch has a rounded distal end shape, with a radius of curvature R being 2.5 t to 6 t

Methodology Applied

Scientific EffectPressure distribution: Compression

Data Source

PatentUS10518925B2Molded paper body with minimal wrinkling and forming method thereof

Publication Date: 2019.12.31 TOYO SEIKAN GRP HLDG LTD

AI summary

The objective of the present invention is to provide a molded paper body in which the outer peripheral portion of a blank primarily of paper is formed in a raised shape using draw processing, wherein the molded paper body eliminates the occurrence of wrinkles causing leaking or instability of adhesion when used as the bottom member of a paper cup or similar paper container and a forming method thereof. The method for manufacturing this molded paper body is to draw-process, with a punch and die, a single blank primarily of paper, and is characterized by use of a holding mechanism to press the outer peripheral portion of the blank between a wrinkle pressing member and the die upper surface, and setting the force applied by the wrinkle pressing member within an appropriate range.