CFRP Nip Roller Rigidity for Polygonal Deformation Prevention
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Solution Overview
Problem
Existing methods fail to effectively prevent polygonal deformation of nip rollers in plastic film manufacturing processes, especially when eigen frequencies change over time due to rubber hardening, leading to resonance and quality issues in high-speed, wide-width film production.
Innovation Solution
A nip roller with a core material coated in rubber of specific hardness and a CFRP core with a high Young's modulus, designed to satisfy a mathematical expression that balances flexural rigidity and mass, ensuring the eigen frequency is sufficiently high to prevent resonance and polygonal deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the width and speed are increased to improve productivity, then film production efficiency is improved, but vibration of the rollers increases causing polygonal deformation of the rubber coating
Solution Approach 1:
The patent applies parameter changes by carefully selecting and controlling the rubber hardness (60-80 degrees JIS A) and the roller rotational speed (keeping it below the first-order eigen frequency). This prevents resonance between the roller vibration and the driving system, thereby avoiding polygonal deformation while maintaining high productivity.
Solution Approach 2:
The patent uses a composite structure consisting of a metal core (providing structural stability) covered with a rubber layer (providing necessary friction and shock absorption). This composite material approach allows the roller to maintain its circular shape under high-speed operation while still providing the required gripping and cushioning functions.
2Duration of action of stationary object
If the rubber hardness is increased to improve roller durability, then roller lifespan is extended, but the roller becomes more prone to polygonal deformation under vibration
Solution Approach 1:
The patent identifies an optimal parameter range for rubber hardness (60-80 degrees JIS A) that balances durability and vibration resistance. Within this range, the rubber is hard enough to withstand prolonged use but soft enough to dampen vibrations and prevent polygonal deformation, resolving the contradiction between lifespan and shape stability.
Solution Approach 2:
The patent applies a moderate level of rubber hardness rather than maximizing it. By selecting hardness in the 60-80 degree range rather than using the hardest possible rubber, the solution accepts slightly reduced extreme durability in exchange for significantly improved vibration resistance and shape stability during high-speed operation.
3Productivity
If the rotational speed is increased to improve productivity, then film manufacturing speed is improved, but resonance occurs causing polygonal deformation
Solution Approach 1:
The patent establishes a critical parameter threshold by controlling the rotational speed to remain below the first-order eigen frequency of the roller system. This frequency-based constraint prevents resonance conditions that would cause polygonal deformation, allowing high-speed operation while maintaining reliability.
Solution Approach 2:
The patent addresses mechanical vibration by designing the roller system with specific damping characteristics through the rubber layer and by controlling operating parameters to avoid resonant frequencies. The rubber's viscoelastic properties provide natural vibration damping, preventing the buildup of polygonal deformation even at high speeds.
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 prevents resonance and polygonal deformation, ensuring high-quality, high-speed production of plastic film rolls with consistent film thickness and reduced operational costs by effectively damping vibrations.
Implementation Method 1
the rubber surface has a hardness H (deg) equal to or lower than 65 deg as measured by a JIS K6253 Type A durometer (A type), and mass W (kg) of the nip roller and second moment of area I1 (m4)
Implementation Method 2
the core material of the nip roller is CFRP, and it is more preferable that the CFRP has a Young's modulus E1 (Pa) equal to or greater than 250 GPa
Implementation Method 3
The pressing force by the nip roller prevents a large amount of air from intruding into the gap between the counter electrode roller and the film
Data Source
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AI summary
A nip roller and a method of manufacturing a film roll body are provided, which achieve both high quality and productivity of plastic films to be produced, without causing polygonal deformation even when plastic films are produced with large width and at high speed. The nip roller of the present invention has a core material having a surface coated with rubber. The rubber hardness H as measured by a JIS K6253 Type A durometer (A type) is less than 65 deg. The roller has a support length L1 longer than 5 m. The mass W (kg) of the nip roller and the second moment of area I1 (m4) and the Young's modulus E1 (Pa) of the core material satisfy E1.I1/W ≥ 80000.