Torque Control for Laminated Cardboard Flatness
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Solution Overview
Problem
Existing methods for manufacturing laminated cardboard face issues with concaveness or convexness during the manufacturing process, leading to adverse side effects such as band breakage and loss of grip, which are not effectively addressed by controlling band tensions or adhesive application.
Innovation Solution
A method involving torque difference control for upper and lower rollers to maintain equal total torque, adjusting the torques of the rollers to counteract concaveness or convexness by applying a predetermined torque sum and difference, ensuring a taut running of the intermediate layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If band tensions of the laminating papers are controlled by means of brakes at the unrolling of the laminating papers, then concaveness or convexness in the conveying direction is prevented, but adhesive application instructions change and band breakage or loss of grip occurs
Solution Approach 1:
The patent replaces the mechanical brake system with a torque difference control system that acts on the adhesive applicator itself. By controlling the torque difference between the first and second adhesive applicators, the system achieves flatness control without relying on mechanical brakes that cause band tension instability and breakage
Solution Approach 2:
The patent changes the control parameter from band tension (which causes instability) to torque difference between adhesive applicators (which provides stable control). This parameter substitution allows flatness control while maintaining reliable band running and preventing breakage
2Manufacturing precision
If band tensions are increased to prevent concaveness or convexness, then flatness control is improved, but the risk of band breakage of wet outer paper layers increases
Solution Approach 1:
The patent replaces the mechanical brake system with a torque difference control system that acts on the adhesive applicator itself. By controlling the torque difference between the first and second adhesive applicators, the system achieves flatness control without relying on mechanical brakes that cause band tension instability and breakage
Solution Approach 2:
The patent introduces torque difference control as an intermediary mechanism between the adhesive applicators and the laminating process. This intermediary control method achieves flatness correction without directly increasing band tension, thereby preventing band breakage of wet outer paper layers
3Reliability
If band tension is decreased to reduce band breakage risk, then band stability is improved, but loss of grip at the spreader roll occurs resulting in pleats
Solution Approach 1:
The patent replaces the mechanical brake system with a torque difference control system that acts on the adhesive applicator itself. By controlling the torque difference between the first and second adhesive applicators, the system achieves flatness control without relying on mechanical brakes that cause band tension instability and breakage
Solution Approach 2:
The patent changes the control parameter from band tension (which causes instability) to torque difference between adhesive applicators (which provides stable control). This parameter substitution allows flatness control while maintaining reliable band running and preventing breakage
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
This approach effectively corrects flatness issues without affecting band running or tension, minimizing pleat and breakage risks of the glued layers, providing a stable manufacturing process.
Implementation Method 1
a measuring roller measures a measured band tension, in the conveying direction, of the intermediate layer being conveyed
Implementation Method 2
the first outer layer is glued together with the upper side of the intermediate layer by means of a rotating upper roller under exertion of a first torque, and the second outer layer is glued together with the lower side of the intermediate layer by means of a rotating lower roller under exertion of a second torque
Implementation Method 3
the first outer layer is glued together with the upper side of the intermediate layer by means of a rotating upper roller under exertion of a first torque
Implementation Method 4
a torque addition sum of the first torque and the second torque is controlled towards a pre-determined constant value of said torque addition sum, said pre-determined constant value being obtained from experience; and a torque difference between the first torque and the second torque is controlled towards a pre-determined value of said torque difference
Data Source
Figure 1
AI summary
In manufacturing two-sided laminated cardboard (1) in a laminating apparatus (10), by controlling band tensions of a first outer layer (11) and a second outer layer (12), a torque difference between an exerted first torque (Q1) in an upper roller (21) and an exerted second torque (Q2) in a lower roller (22) is controlled towards a pre-determined value (ΔQ) of said torque difference, while at the same time a torque addition sum of the first torque and the second torque is controlled towards a pre-determined constant value (Q) of said torque addition sum. Thus the invention provides an effective and reliable solution for counteracting concaveness or convexness, in the conveying direction (MD), of the two-sided laminated cardboard (1) to be manufactured.