Multilayer Plastic Preform Seamless Color Transition

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Solution Overview

Problem

Existing methods for producing containers with multiple colors result in heterogeneity, complexity, and fragility due to limited continuity and placement options for secondary materials, leading to unsatisfactory color effects and increased production costs.

Innovation Solution

A multilayer preform structure where primary and secondary materials solidify simultaneously, creating a continuous welding joint that extends along the thickness of the preform, with the secondary material being opaque or translucent, and optionally fluorescent, to achieve a seamless color transition and enhanced color effects without visible seams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If secondary material is injected through different injection points to create multi-color containers, then color variety is improved, but bonding joints become visible and homogeneity is lost

Engineering Contradiction:
Improvecolor varietyVSAvoidhomogeneity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The injection system is segmented into multiple independent injection points, each capable of injecting different colored materials. This segmentation allows different colors to be introduced at different locations and times, achieving color variety while maintaining control over the injection process to preserve homogeneity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mold cavity is prepared with multiple injection points and channels in advance, allowing different colored materials to be injected sequentially or simultaneously through predetermined paths. This preliminary setup ensures that color transitions are controlled and homogeneous, avoiding visible bonding joints.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If secondary material is applied on top of primary material, then color placement flexibility is improved, but bonding joint visibility increases and structural strength decreases

Engineering Contradiction:
Improvecolor placement flexibilityVSAvoidbonding joint strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

Multiple colored materials are nested within each other through sequential injection, with each color layer contained within the structure of the previous layer. This nesting approach allows flexible color placement while maintaining strong bonding joints, as each material is injected into a confined space that ensures intimate contact and adhesion.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Different regions of the container are assigned different color qualities through localized injection at specific points. Each injection point introduces material with specific color properties to specific locations, achieving color placement flexibility while maintaining uniform bonding quality throughout the structure.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If multiple successive injection operations are used to achieve multi-color effects, then color variety is improved, but process complexity and production time increase

Engineering Contradiction:
Improvecolor varietyVSAvoidinjection process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Multiple injection operations are merged into a single integrated injection system with multiple injection points. This combining of operations allows different colored materials to be injected through a unified system, reducing overall process complexity and production time while maintaining the ability to achieve multi-color effects.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The injection process is made continuous through the use of multiple injection points that can operate simultaneously or in rapid succession. This continuity eliminates idle time between injection operations, maintaining steady production flow and reducing overall process complexity while achieving diverse color effects.

Inventive Principle:
Principle #20Continuity of useful action

4Manufacturing precision

If discrete color deposition is used in predetermined areas, then color placement control is improved, but structural weakness increases at empty spaces

Engineering Contradiction:
Improvecolor placement controlVSAvoidstructural integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The injection system uses asymmetric distribution of injection points and material flow paths to achieve precise color placement control. By strategically positioning injection points and controlling material flow asymmetrically, the system deposits colors in predetermined areas while ensuring that no empty spaces remain, thereby maintaining structural integrity throughout the container.

Inventive Principle:
Principle #4Asymmetry

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 solution provides a high-quality, continuous color effect with reduced visibility of joints, increased strength, and cost-effectiveness by allowing for flexible color placement and reduced pigment usage, while maintaining formability and providing a light barrier for sensitive products.

Implementation Method 1

primary and secondary materials solidify simultaneously, creating a continuous welding joint

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 2

the secondary material being opaque or translucent, and optionally fluorescent, to achieve a seamless color transition and enhanced color effects while maintaining formability and providing a light barrier for sensitive products

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

the secondary material being opaque or translucent, and optionally fluorescent, to achieve a seamless color transition and enhanced color effects

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP2318194B1Plastic preform and process for the manufacturing thereof to a container and the use thereof
Publication Date: 2013.01.09 RESILUX NV
  • EP2318194B1 patent drawingFigure 1~2
  • EP2318194B1 patent drawingFigure 3~6
  • EP2318194B1 patent drawingFigure 7~10

AI summary

Preform for the blow moulding of a container comprising a neck section (1) including a pouring opening (20), an adjacent wall section (2) and a bottom section (3). It consists of a primary plastic raw material in a primary area (A1, A2, A3) and at least one secondary material in at least a secondary area (B1, B2, B3) both having a mutually different coloration. Said preform is remarkable in that said bottom section (3) is composed of a multi-layer structure with primary layers composed of said primary plastic material, and additional secondary layers (6, 7, 8, 9, 10). The latter are composed of said secondary material, two surface secondary layers the one of which (6) is directed outwardly respective the preform, whereas the other one (10) is directed inwardly, and an intermediate secondary layer between them (7, 8, 9), which constitutes a core layer, which is located between two said primary layers. Said preform is in one single piece, the transition (Z1, Z2) from said primary to said secondary material being seamless and uninterrupted. The invention further relates to a manufacturing method of said preform.