Paper Machine Compression and Sizing Unit for Flexible Kraft Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The market for sack kraft paper is subject to fluctuations, leading to overcapacity or reduced production, necessitating improved capacity utilization of paper machines while maintaining high quality and minimizing investment and operating costs.
Innovation Solution
A paper machine design that includes a forming section, press section, dryer section with pre- and post-dryer sections, and a reel, equipped with a compression device and a sizing device arranged after the pre-dryer section, allowing for the production of both sack kraft paper and low-strength paper webs by adjusting the dry content and using a transfer device to selectively route the paper web through either the compression or sizing device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the paper machine is equipped with additional devices (sizing device, transfer device) to enable production of both sack kraft paper and low-strength paper, then capacity utilization and productivity improve, but device complexity and investment costs increase
Solution Approach 1:
The paper machine is designed with a sizing device and transfer device that enable it to perform multiple functions - producing both sack kraft paper and low-strength paper on the same machine. The sizing device can be selectively engaged or bypassed depending on the desired product type, allowing one machine to serve multiple product lines and improve capacity utilization
Solution Approach 2:
The paper machine incorporates a transfer device with movable components that can dynamically route the paper web through different processing paths. The transfer device can switch between directing the web to the sizing device or bypassing it, enabling flexible adaptation to different production requirements without requiring separate dedicated machines
2Quantity of substance
If the paper web is dewatered to higher dry content in the press section, then the dry content at the entrance to the post-dryer section increases, but the porosity of the sack kraft paper web decreases
Solution Approach 1:
The process optimizes the dry content parameter at different stages of production. For sack kraft paper, the press section is configured to achieve a specific dry content range (38-44%) that balances dewatering efficiency with porosity preservation. The compression device then adjusts the web properties without excessive dewatering, maintaining the required porosity for sack kraft paper while achieving the necessary dry content for subsequent processing
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
Enhances capacity utilization and economic operation by enabling the production of both high-strength sack kraft paper and low-strength paper webs, improving porosity and strength properties through controlled dry content and drying processes, and allowing for flexible production adjustments.
Implementation Method 1
a dryer section with a pre-dryer section and a post-dryer section for further dewatering of the paper web
Implementation Method 2
a compression device for compressing the fibrous web
Implementation Method 3
After the compression device, the sack kraft paper web is completely dried in the after-dryer section, preferably to a dry content of between 92% and 98%
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a paper machine (1) suitable for producing a sack kraft paper web (2) and a low-strength paper web (2.1), comprising a forming section (3) for forming and dewatering the paper web (2, 2.1), a press section (4), and a drying section (5) with a pre-drying section (5.1) and a post-drying section (5.2) for further dewatering the paper web (2, 2.1), as well as a winding unit (9), wherein a compression unit (10) for compressing the paper web (2, 2.1) is arranged downstream of the pre-drying section (5.1). According to the invention, a sizing unit (11) is additionally arranged downstream of the pre-drying section (5.1).