Lipstick Cup Centering in Elastic Mould Casting

Solution Overview

Problem

Existing lipstick manufacturing methods face challenges in accurately centering the stick within the device, leading to smudges and high production costs due to discards, especially in high-end products.

Innovation Solution

A method and machine that center the cup within the mould before casting, ensuring precise alignment of the cup and stick, using elastic moulds and actuators to position the cup accurately, and integrating projections for enhanced adhesion and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the stick is made in elastic moulds for convenience, then the manufacturing process is simplified, but centring precision between the stick and device deteriorates

Engineering Contradiction:

Improveease of manufactureVSAvoidcentring precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The cup is positioned and centred in the mould cavity before the melting and injection of the cosmetic product. This preliminary positioning action ensures that when the stick solidifies, the cup is already correctly aligned with the mould axes, eliminating the need for complex post-solidification centring operations and ensuring precise stick-device alignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mould cavity acts as an intermediary structure that defines the precise spatial relationship between the cup and the stick. By designing the mould cavity with specific geometric constraints and using it as a fixed reference frame during the melting and injection process, the system achieves precise centring without requiring the elastic mould to maintain perfect shape throughout the entire process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the cup is fitted onto the stick after solidification, then the assembly process is simplified, but the risk of smudges and misalignment increases

Engineering Contradiction:

Improveease of assemblyVSAvoidquality reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The cup is positioned and centred in the mould cavity before the melting and injection of the cosmetic product. This preliminary positioning action ensures that when the stick solidifies, the cup is already correctly aligned with the mould axes, eliminating the need for complex post-solidification centring operations and ensuring precise stick-device alignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The cup and stick formation processes are merged into a single integrated operation within the mould. The cup is positioned in the mould cavity, then the cosmetic product is melted and injected directly onto the cup, forming the stick and cup assembly simultaneously. This merging eliminates separate assembly steps and ensures perfect alignment.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If imperfect centring occurs during stick-device coupling, then production speed is maintained, but product quality deteriorates due to smudges

Engineering Contradiction:

Improveproduction speedVSAvoidcentring precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The cup is positioned and centred in the mould cavity before the melting and injection of the cosmetic product. This preliminary positioning action ensures that when the stick solidifies, the cup is already correctly aligned with the mould axes, eliminating the need for complex post-solidification centring operations and ensuring precise stick-device alignment.

Inventive Principle:

Principle #10Preliminary action

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

Minimizes smudges and misalignments, reduces production waste, and enhances customization options by allowing in-store coupling of devices with customized sticks, while improving seal resistance and reducing reject rates.

Implementation Method 1

arranging a mould (2) made of elastic material, preferably silicone

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

pouring a melted cosmetic product through the cup (3) and into the casting cavity (4)

Methodology Applied

Scientific EffectSolidification: Freezing

Data Source

PatentUS12575659B2Method for forming a stick for lips, a machine for forming sticks for lips, and a product for lips made using this method

Publication Date: 2026.03.17 CHROMAVIS SPA

AI summary

A method for forming a stick for lips includes positioning a mould (2) made of an elastic material, such as silicone, on a first support (11), the said mould comprising a casting cavity (4) endowed with an opening (5). The method further includes centring a cup (3) in the casting cavity (4) opening (5), pouring a melted cosmetic product through the cup (3) and into the casting cavity (4), waiting for the solidification of the melted cosmetic product in the casting cavity (4) so as to form the stick, and extracting the stick (7) from the cavity by gripping the cup (3).