Multilayer Plastic Bottle Forming Without Mold Fixture Collisions

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Solution Overview

Problem

Current single-layer molding processes for plastic bottles result in low efficiency, material wastage, and equipment instability due to the need for a head mold fixture with a minimum thickness of 12 mm, leading to inefficient production and potential mold collisions.

Innovation Solution

A continuous multilayer molding process with independent driving devices for the head and main mold fixtures, allowing for synchronized movement without crossing over the mold, reduced head mold fixture thickness (0.5-3 mm), and secondary cooling via profiling mold cavities to enhance production efficiency and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If single-layer molding process is used with head mold fixture, then continuous production of plastic bottles is achieved, but production efficiency is low because only one row of bottles can be formed at a time

Engineering Contradiction:
Improveproduction efficiencyVSAvoidmolding process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the single molding system into multiple independent mold layers (first mold layer and second mold layer), each capable of forming bottles simultaneously. This segmentation allows parallel production across multiple layers, dramatically increasing productivity while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from single-layer (2D) molding to multi-layer (3D) molding by stacking mold layers vertically. This dimensional expansion enables simultaneous bottle formation in multiple rows across different layers, transforming the production capacity without proportionally increasing system complexity

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

2Loss of substance

If head mold fixture is used to tension parison downward, then parison stability is maintained, but material utilization is low due to required minimum wall thickness of 12 mm

Engineering Contradiction:
Improvematerial utilizationVSAvoidfixture wall thickness
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The patent extracts and eliminates the head mold fixture from the system by implementing a multi-layer mold design where the first mold layer directly forms the bottle neck and body. This removal eliminates the need for the thick-walled fixture, thereby improving material utilization without compromising parison stability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the structural parameters of the molding system by transitioning from a fixture-based tensioning system to a multi-layer mold system. This parameter change allows reduction of the required wall thickness from 12 mm to thinner dimensions, improving material efficiency while maintaining structural integrity through the layered mold design

Inventive Principle:
Principle #35Parameter changes

3Reliability

If head mold fixture crosses over the mold during operation, then positioning is achieved, but equipment stability is compromised due to risk of collision with the mold

Engineering Contradiction:
Improveequipment stabilityVSAvoidfixture positioning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes the head mold fixture that caused collision risks and replaces it with a multi-layer mold system where positioning is achieved through the coordinated movement and positioning of multiple mold layers. This extraction eliminates the harmful collision effect while maintaining positioning capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary positioning mechanism through the multi-layer mold coordination system. Instead of the head mold fixture directly crossing over the mold, the positioning is mediated through the synchronized movement and spatial arrangement of the first and second mold layers, eliminating direct collision while achieving precise positioning

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If single-row bottle formation is used, then equipment simplicity is maintained, but productivity is low resulting in waste area on product chain

Engineering Contradiction:
Improveproduction outputVSAvoidwaste area
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent segments the production system into multiple mold layers (first mold layer and second mold layer), each forming bottles in parallel. This segmentation enables multi-row simultaneous production, increasing output while reducing waste area per bottle through more efficient use of the product chain

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from single-row (1D linear arrangement) to multi-row (2D grid arrangement) bottle formation by stacking mold layers vertically. This dimensional change increases production output significantly while reducing waste area through better space utilization on the product chain

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

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

Improves production efficiency by forming multiple bottles simultaneously, reduces material wastage, and enhances equipment stability by avoiding collisions and ensuring thorough cooling, enabling production of bottles with varying specifications.

Implementation Method 1

A hot-melt parison is extruded by an extrusion device

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

A hot-melt parison is extruded by an extrusion device

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

The mold, the main mold fixture, and the head mold fixture move downward together to a mold opening position

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

secondary cooling via profiling mold cavities

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4656359A1Multi-layer continuous forming process for plastic bottles
Publication Date: 2025.12.03 SHINVA MEDICAL INSTR CO LTD
  • EP4656359A1 patent drawingFigure 1
  • EP4656359A1 patent drawingFigure 2
  • EP4656359A1 patent drawingFigure 3

AI summary

Disclosed is a continuous multilayer molding process for plastic bottles, including the following steps: (1) discharging of a parison; (2) initial sealing of the parison; (3) molding and filling of a bottle body; (4) sealing of a first bottle body; (5) sealing of the parison; (6) forming of a product chain; (7) positioning before mold closing; repeating the step (3) when a main mold fixture clamps and moves the product chain downward to a position corresponding to a mold closing position, opening the main mold fixture and moving up to a position corresponding to a previous product chain, and closing the main mold fixture; and repeating the steps (4) to (7) to form a cycle to realize continuous production of the plastic bottles. According to the present application, the production efficiency and productivity are improved.