Winder with Variable Wrap Angle for Film Roll Quality

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Solution Overview

Problem

Existing winders face challenges in winding plastic films with varying formulations, leading to distortions and creases due to inconsistent web tension and air entrainment, which affects the quality and usability of the wound rolls.

Innovation Solution

The winder maintains a variable, predetermined angle of wrap for the material web over the contact roller, using a system of pendulum arms and auxiliary rollers to adjust the angle dynamically during winding, ensuring a reduced angle of wrap that minimizes air compression and subsequent creasing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the material web is wound with high tension to ensure compact rolls, then roll density improves, but distortions and creases increase

Engineering Contradiction:
Improveroll densityVSAvoidfilm distortion
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent applies dynamics by making the wrap angle variable rather than fixed. The wrap angle is dynamically adjusted based on winding conditions, allowing the system to optimize between roll density and film quality at different stages of the winding process. This resolves the contradiction by enabling adaptive tension control through angle modulation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the wrap angle to control winding characteristics. By varying this parameter, the system can optimize the balance between achieving compact rolls and preventing film distortions, directly addressing the technical contradiction between roll density and film shape integrity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the wrap angle is increased to improve winding stability, then winding control improves, but air compression and creasing increase

Engineering Contradiction:
Improvewinding controlVSAvoidair compression
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent makes the wrap angle dynamic rather than static, allowing it to be adjusted during the winding process. This enables the system to maintain optimal winding control while minimizing air compression effects by reducing the angle when necessary, thus resolving the contradiction between stability and harmful air compression.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary anti-action by proactively reducing the wrap angle to prevent excessive air compression before it causes harmful effects. This anticipatory adjustment prevents air entrapment and crease formation while maintaining adequate winding control.

Inventive Principle:
Principle #9Preliminary anti-action

3Device complexity

If a fixed wrap angle is used to simplify the winding system, then device complexity is reduced, but winding quality varies with formulation

Engineering Contradiction:
Improvewinding systemVSAvoidfilm formulation adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adjustability of the wrap angle, transforming a fixed-parameter system into a variable-parameter system. This enables the winder to adapt to different film formulations and winding conditions without requiring multiple fixed-angle mechanisms, thus improving versatility while maintaining reasonable system complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a universal winding system that can handle various film formulations through a single adjustable mechanism. The variable wrap angle serves multiple functions: controlling tension, preventing distortions, and adapting to different material properties, thereby achieving multi-functionality that resolves the contradiction between simplicity and adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Productivity

If winding speed is increased to improve productivity, then output increases, but web tension control becomes inconsistent

Engineering Contradiction:
Improvewinding speedVSAvoidweb tension consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the wrap angle speed-dependent. As winding speed increases, the wrap angle is adjusted accordingly to maintain consistent web tension control. This dynamic adaptation allows high-speed operation while preserving tension consistency, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2782858B1Winder for an endless material web
Publication Date: 2019.09.18 SWISS WINDING INVENTING
  • EP2782858B1 patent drawingFigure 1a
  • EP2782858B1 patent drawingFigure 1b~2a
  • EP2782858B1 patent drawingFigure 2b

AI summary

The present invention relates to a method and a device for producing a roll (18) made of a material web (5) of flexible material which is guided via a contact roller (19) of a winder and is wound in the said winder to form a roll (18), wherein the contact roller (19) maintains contact with the roll (18) during winding and the wrap angle (alpha) of the material web (5) passing over the contact roller (19), as the former is progressively wound, is maintained throughout at a variable reference value predetermined for each winding. In this way the wrap angle (alpha) for the winding can be adapted to the respective composition of the material web (5), which improves the quality of the winding.