Injection-Molded Drink-Through Lid With Durable Lock-Back Flap

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Solution Overview

Problem

Existing drink-through plastic lids face issues with scrap generation during thermoforming, require additional die cutting for lid release, and lack a durable, smooth finish, as well as limited durability in repeated open/close operations.

Innovation Solution

A one-piece drink-through plastic lid with an integral hinged flap that seals and latches back, manufactured via injection molding, eliminating scrap and providing a glossy finish, with a design allowing multiple open/close cycles and nesting for stacking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thermoforming is used to manufacture the lid, then the lid can be produced with a drink-through opening, but a substantial web of scrap is generated and additional die cutting is required

Engineering Contradiction:

Improvelid manufacturing processVSAvoidscrap material

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent changes the manufacturing method from thermoforming to injection molding. This parameter change eliminates the need for a substantial web of scrap material, as injection molding allows for near-net-shape production of the lid with the drink-through opening already formed during the molding process

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention segments the manufacturing process by integrating the drink-through opening formation directly into the injection molding process itself, rather than requiring a separate die cutting step after thermoforming. The lid is molded as a one-piece structure with the opening already present

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If thermoforming is used to manufacture the lid, then the lid can be produced, but the finish is not smooth and glossy

Engineering Contradiction:

Improvelid manufacturing processVSAvoidsurface finish quality

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the manufacturing method from thermoforming to injection molding. This parameter change produces a smooth, glossy finish on the lid surface as the injection molding process inherently creates higher surface quality compared to thermoforming

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the flap structure is designed for sealing, then the opening can be sealed, but the structure lacks durability for repeated open/close operations

Engineering Contradiction:

Improvesealing functionVSAvoiddurability for repeated operations

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies local quality by designing different structural features at different locations of the flap. The sealing surface is designed with specific properties for effective sealing, while the hinge area and latch engagement points are designed with reinforced structures to withstand repeated open/close operations. This differentiation of local structural qualities allows the flap to perform both sealing and durability functions

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8544677B2One-piece lock-back lid

Publication Date: 2013.10.01 LETICA CORP

AI summary

A drink-through plastic lid is injection molded in one piece to define a rim structure which snaps onto the rim of a cup and an asymmetric crown having a drink-through opening formed at the high point of an outer deck. An integral hinged flap with a C-shaped seal lip on the inside surface can lock by means of said lip into the drink-through opening when in one condition. The flexible outer edges of the flap latch into a lock-back recess which interrupts an intermediate inner deck formed between the outer crown deck and the floor of a well in the interior area of the lid.