Print Arrangement With Lateral Stretch And Roll Segments
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Solution Overview
Problem
In large format printing, irregularities in the substrate surface such as undulations, wrinkles, and folds can cause damage to the substrate and disrupt the printing process, due to non-homogeneous materials, misbalanced drive systems, poor winding, handling, or surface damage, necessitating the prevention of these irregularities for even printing.
Innovation Solution
A print arrangement featuring a first pressure roll and lateral stretch members that engage the substrate to apply transverse tension, adjust its angle, and control the nip width between rolls, ensuring even substrate tension and orientation, comprising coaxially aligned roll segments of varying diameters and actuators to manage substrate tension and orientation dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If substrate is transported through nips formed by opposite rolls, then substrate can be conveyed through the printing system, but irregularities such as undulations, wrinkles and folds may form causing substrate damage and printing disruption
Solution Approach 1:
The substrate is pre-stretched in the transverse direction before entering the printing nip by lateral stretch members. This preliminary stretching action removes undulations and wrinkles before the substrate reaches the printing area, preventing damage and ensuring continuous printing operation.
Solution Approach 2:
The system dynamically adjusts the transverse stretch force applied to the substrate by controlling the lateral stretch members. By changing the tension parameter in the transverse direction, the substrate surface is smoothed to eliminate irregularities that would otherwise cause printing disruptions.
2Manufacturing precision
If conventional print arrangement design is used, then mechanical accuracy requirements must be high to prevent substrate irregularities, but this increases device complexity and manufacturing difficulty
Solution Approach 1:
Instead of relying on high-precision mechanical alignment and rigid substrate handling, the system uses a flexible stretching mechanism with lateral stretch members. This substitutes complex precision mechanical design with a more adaptable tensioning system that actively compensates for substrate irregularities.
Solution Approach 2:
The print arrangement incorporates dynamically adjustable stretch forces through lateral stretch members that can be controlled during operation. This dynamic adjustment capability allows the system to adapt to different substrate conditions without requiring fixed high-precision mechanical tolerances.
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 effectively prevents substrate damage and ensures even printing by smoothing undulations and maintaining substrate alignment, simplifying print arrangement design and reducing mechanical accuracy requirements.
Implementation Method 1
The first roll (2) may comprise a pressure roll for pressurizing a substrate (27) against the transport surface (3) to counter wrinkles and undulations in the substrate (27)
Implementation Method 2
The first roll (2) may comprise two coaxially aligned roll segments (33) of similar diameters for rolling over a substrate (27) with a distance in between, for inducing a stretch in the substrate (27), at least between the two roll segments (33), in a direction (L) transverse with respect to a substrate moving direction (V)
Implementation Method 3
a lateral stretch member (7) arranged to engage the substrate (27) and arranged to apply a transverse stretch force (F) to the substrate (27)
Data Source
AI summary
Print arrangement, comprising a first roll, a transport surface, a nip between the first roll and the transport surface through which, at least during printing, a substrate is threaded, a drive system arranged to change a width of the nip, and a lateral stretch member arranged to engage a side of the substrate. The first roll comprises a two coaxially aligned roll segments of similar diameters for rolling over the substrate, with a distance in between.