Unreeling Assembly Tension Control for Labeling Film
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Solution Overview
Problem
Existing unreeling assemblies for labeling devices face challenges with extensible continuous films, particularly those of reduced thickness and low density, leading to excessive stress and reduced productivity due to inadequate tension control and inefficient connection processes.
Innovation Solution
An unreeling assembly with a motorized traction drum and a movable tensioning element, controlled by servomotors, which adjusts its position along a defined path to apply preset tensions and accumulate film length, optimizing film tension and reducing stress during the connection step without slowing the traction drum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the speed of the traction drum is reduced during the connection step to adequately connect film ends, then the connection quality is improved, but the productivity of the labeling device is reduced
Solution Approach 1:
The system accumulates a length of film in advance between the reel and traction drum before the connection step. This preliminary accumulation allows the connection to be made without reducing the traction drum speed, as the accumulated film provides a buffer that maintains tension and enables high-speed operation during the connection process.
2Stability of the object's composition
If a pneumatic motor is combined with the braking device to minimize film tension during initial unreeling, then the longitudinal extension of the film is reduced, but compressed air consumption increases and noise is generated
Solution Approach 1:
The patent replaces the pneumatic motor with a servomotor that provides precise electronic control of the reel support. This substitution eliminates the need for compressed air while achieving the same goal of minimizing film tension and longitudinal extension during initial unreeling, along with reducing noise and maintenance requirements.
3Measurement precision
If a second servomotor is added to control the position of the tensioning dandy roll, then the control precision is improved, but the device complexity increases
Solution Approach 1:
The servomotor already present for controlling the reel support is made multi-functional. It simultaneously controls both the reel support position and the tensioning dandy roll position through a unified control system. This eliminates the need for a second dedicated servomotor while maintaining precise control over the tensioning element's position throughout the unreeling process.
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 solution allows for high-speed operation of the traction drum during film connection, reduces film stress, and enables processing of a wider range of film grammages, enhancing the unreeling assembly's performance and productivity.
Implementation Method 1
a respective reel support (4), which can be actuated to rotate about an unreeling axis (100) of the reel by a respective servomotor (13a, 13b)
Implementation Method 2
the unreeling assembly (1), in addition to feeding the continuous film (10) to the cutting assembly (21) to be cut, also has the function of correctly tensioning the film (10), longitudinally, by means of the action of the tensioning dandy roll (6a)
Data Source
Figure 1
Figure 1a
Figure 2~3
AI summary
The present invention relates to an unreeling assembly (1), particularly for labeling devices, comprising a supporting frame (2) for at least two reels (3) of continuous film (10) which are supported by a respective reel support (4), which can be actuated to rotate about an unreeling axis (100) of the reel (3) by a respective servomotor (13a, 13b), and a motorized traction drum (5), which is designed to unreel the continuous film (10) from one of the at least two reels (3) of continuous film (10), between the reel (3a) of film being unreeled and the traction drum (5) there being at least one element (6) for tensioning the continuous film (10), the tensioning element (6) being movable, with respect to the supporting frame (2), along a respective movement path (200), characterized in that it comprises control means (11) which operate on the servomotor (13a, 13b) and are adapted to control the position of the tensioning element (6) along the respective movement path (200).