Molded Cup Lid Outer Edge Shaping Method

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Solution Overview

Problem

Conventional plastic cup lids cause environmental pollution and fail to securely cover paper cups, leading to leakage due to their design limitations in manufacturing processes, particularly with the formation of an inverted-hook groove which is unstable and prone to separation when exposed to heat and force.

Innovation Solution

A manufacturing method for a molded cup lid using pulp-shaping and heat-pressure shaping processes, where a semi-finished product is compressed and deformed to form a protruding outer covering edge with an inverted-hook groove, ensuring a secure fit on paper cups by using an outer mold with slide blocks and a transversally movable shaping mold to create a stable outer covering edge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional plastic injection molding is used to manufacture cup lids, then the manufacturing process is simple and efficient, but the lid cannot securely cover the paper cup mouth and causes leakage due to limited demolding space

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidcovering security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cup lid structure is segmented into multiple functional portions: a top ring portion with cover portion, a peripheral portion, and an outer covering edge with inverted-hook groove. This segmentation allows each portion to perform its specific function - the inverted-hook groove engages with the paper cup rim to prevent leakage, while the cover portion provides the sealing surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from conventional 2D flat lid design to a 3D structured design with vertical depth variations. The inverted-hook groove extends downward from the peripheral portion, creating a negative angle structure that engages with the paper cup rim in the vertical dimension, thereby improving covering security beyond what flat lids can achieve.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Shape

If the inverted-hook groove is formed by compression and deformation of semi-finished product, then the outer covering edge can be shaped, but the groove structure becomes unstable and prone to separation when exposed to heat and force

Engineering Contradiction:
Improveouter covering edge profileVSAvoidinverted-hook groove stability
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The inverted-hook groove is pre-formed during the molding process rather than created by subsequent compression and deformation. The mold includes a shaping mold with shaping ridge that forms the groove structure in the semi-finished product before final setting, ensuring the groove maintains its intended shape and stability without requiring post-processing deformation that compromises structural integrity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention controls the physical and chemical parameters during the molding process to ensure proper formation of the inverted-hook groove. By controlling temperature, pressure, and material flow during molding, the groove structure is formed with optimal dimensions and material properties that maintain stability under heat and force conditions.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If pulp-shaping and heat-pressure shaping processes are used to create semi-finished product, then environmental protection requirements are met, but the moving space required for demolding is limited

Engineering Contradiction:
Improveenvironmental pollutionVSAvoiddemolding space
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The mold design incorporates movable components including slide blocks that can move horizontally and a shaping mold that can move transversally. These dynamic elements allow the mold to adapt its configuration during different stages of the molding process, enabling demolding of complex 3D structures without requiring excessive moving space that would compromise the environmental benefits of pulp-shaping processes.

Inventive Principle:
Principle #15Dynamics

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 produces a molded cup lid with a stable outer covering edge that securely fits paper cups, preventing leakage and separation even when exposed to heat, thus addressing the environmental and functional issues of conventional plastic cup lids.

Implementation Method 1

Push the shaping mold to move continuously forward by the external power, so that the surface of the semi-finished product is compressed by the shaping ridge and deformed to form the profile of the outer covering edge

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

the surface of the semi-finished product is compressed by the shaping ridge and deformed to form the profile of the outer covering edge

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

a semi-finished product of the molded cup lid made of a plant fiber material being manufactured by a pulp-shaping process and a heat-pressure shaping process

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP3133028B1Manufacturing method for outer covering edge of molded cup lid
Publication Date: 2018.11.28 DANDONG MINGCHENG ENVIRONMENTAL PROTECTION PROD CO LTD
  • EP3133028B1 patent drawingFigure 1~2
  • EP3133028B1 patent drawingFigure 3~6
  • EP3133028B1 patent drawingFigure 4~5

AI summary

A manufacturing method for the outer covering edge of a molded cup lid and product, in particular, the manufacturing method in which plant-fiber is used for material, pulp-shaping and heat-pressure shaping are applied to produce a semi-finished product of the molded cup lid, and further processing is performed to mold a ring of outer covering edge that protrudes from inside to the outside on the periphery of the semi-finished product; and the molded cup lid product manufactured using said method.