Multi-layer liner web with bleached printing layer
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Solution Overview
Problem
Current methods for producing printable packaging papers struggle to achieve high print quality with high color density and contrast while being cost-effective and sustainable, as they often require bleached cellulose fibers which are resource-intensive and costly, and recycled fibers result in lower strength and print quality issues due to contamination from unbleached carrier layers.
Innovation Solution
A multi-layer liner web production method involving a bleached pulp for the printing layer and an unbleached pulp for the carrier layer, with specific dewatering and drying processes to prevent contamination, using a hybrid former and gap former arrangement, and surface sizing agents to enhance strength and printability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If bleached virgin pulp is used for the printing layer, then print quality and strength are improved, but production costs and resource consumption increase
Solution Approach 1:
The packaging paper is divided into multiple layers with different functions: the printing layer uses bleached pulp for quality, while the carrier layer uses unbleached recycled pulp for sustainability. This segmentation allows each layer to be optimized independently for its specific purpose.
Solution Approach 2:
Different layers of the packaging paper have different quality characteristics tailored to their functions. The printing layer has high whiteness and smoothness for print quality, while the carrier layer has structural strength from recycled fibers, creating local quality differentiation throughout the product.
2Ease of manufacture
If unbleached recycled pulp is used for the carrier layer, then sustainability is improved, but contamination of the printing layer occurs reducing print quality
Solution Approach 1:
The harmful factor (contamination from unbleached pulp) is extracted and isolated by placing the unbleached carrier layer below the printing layer. The dewatering and drying processes further extract and remove any potential contaminants before they can affect the printing layer.
Solution Approach 2:
The dewatering and drying processes act as intermediary steps between the carrier layer and printing layer, preventing direct contact and potential contamination while still allowing the multi-layer structure to function as an integrated product.
3Device complexity
If multiple Fourdrinier wires are used in the paper machine, then multi-layer paper formation is enabled, but production speed is limited increasing costs
Solution Approach 1:
The formation of multiple layers is merged into a single integrated process where the printing layer and carrier layer are formed simultaneously in one pass through the paper machine, eliminating the need for separate formation steps and increasing production efficiency.
4Manufacturing precision
If smoothing rollers are applied to improve printability, then surface properties are enhanced, but machine speed is limited and operating costs increase
Solution Approach 1:
The surface properties suitable for printing are prepared in advance during the dewatering and drying processes, before the paper reaches the printing stage. This preliminary preparation eliminates the need for additional smoothing operations that would slow down production.
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 method produces a paper with high print quality, mechanical strength, and sustainability, reducing production costs by minimizing bleached cellulose use and preventing contamination, resulting in a cost-effective and eco-friendly packaging solution.
Implementation Method 1
multi-stage dewatering/drying of the multi-layer paper web
Implementation Method 2
multi-stage dewatering/drying of the multi-layer paper web
Data Source
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AI summary
The invention relates to a method for producing a printable, multi-layer liner web (1) for packaging. In the method, a first paper layer (4) is produced from a first pulp (2) comprising a bleached first pulp (3) containing cellulose fibers. A second paper layer (7) is then produced from a second pulp (5) comprising an unbleached second pulp (6) containing cellulose fibers. The first paper layer (4) and the second paper layer (7) are bonded together to form a multi-layer paper web (8) and processed into a multi-layer liner web (1) in a multi-stage dewatering/drying process. The first paper layer (4) forms a printing layer (9), and the second paper layer (7) forms a support layer (10) directly bonded to this printing layer (9).It is provided that the first paper layer (4) is formed from the first pulp (2) by means of a first forming arrangement (18) directly on a Fourdrinier (19) of the first forming arrangement (18), and that the second paper layer (7) is formed from the second pulp (5) by means of a second forming arrangement (20) directly on the first paper layer (4), so that the first paper layer (4) and the second paper layer (7) are joined to form the multilayer paper web (8).