BCTMP Release Liner Paper Bulk-to-Grammage Ratio
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Solution Overview
Problem
The challenge is to develop a method for producing low-weight, high-quality paper suitable for use as a release liner that reduces raw material usage and transportation costs while maintaining mechanical properties such as surface smoothness, tearing resistance, and transparency, without compromising the paper's functionality in high-speed labeling processes.
Innovation Solution
The use of bleached chemithermomechanical pulp, manufactured through a hybrid process involving chemical pretreatment and mechanical refining, which increases the cellulose fiber content in a specific volume without increasing grammage, allowing for a lighter mass per unit area while maintaining paper quality. This pulp is blended with bleached chemical pulp to optimize paper manufacturing conditions, including internal bond strength and reduced brittleness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the grammage of the paper is reduced to decrease the weight of the release liner, then the transportation costs are reduced, but the mechanical strength and surface smoothness deteriorate
Solution Approach 1:
The patent changes the fundamental parameter of pulp selection from conventional bleached chemical pulp to bleached chemithermomechanical pulp (BCTMP). This pulp type has inherently different properties including higher bulk, lower density, and superior surface smoothness. By changing this material parameter, the paper achieves reduced grammage while maintaining or improving mechanical properties and surface quality, thus resolving the contradiction between weight reduction and strength maintenance.
Solution Approach 2:
The patent employs a composite pulp system by blending BCTMP with conventional bleached chemical pulp or bleached kraft pulp. This composite approach allows optimization of both bulk/surface properties (from BCTMP) and strength properties (from chemical pulp), enabling the production of lightweight paper with adequate mechanical strength for high-speed labeling applications.
2Weight of moving object
If the grammage of the paper is reduced to decrease the weight of the release liner, then the transportation costs are reduced, but the surface smoothness deteriorates
Solution Approach 1:
The patent changes the pulp type parameter to BCTMP, which naturally provides superior surface smoothness due to its manufacturing process (chemithermomechanical treatment). This eliminates the need for excessive calendering while maintaining smoothness even at reduced grammage, thus resolving the contradiction between weight reduction and surface quality maintenance.
Solution Approach 2:
The patent extracts and eliminates the need for intensive calendering operations by selecting BCTMP as the base material. The inherent surface smoothness of BCTMP allows the paper to achieve required surface quality without additional mechanical compression, thereby maintaining smoothness while reducing grammage and weight.
3Weight of moving object
If the paper thickness is reduced to decrease the weight of the release liner, then the transportation costs are reduced, but the paper becomes more brittle and less suitable for high-speed labeling
Solution Approach 1:
The patent changes the pulp type to BCTMP, which has different physical properties including higher elasticity and flexibility compared to conventional pulps. These inherent property changes allow the paper to maintain reliability and suitability for high-speed labeling applications even at reduced thickness and grammage, thus resolving the contradiction between weight reduction and functional reliability.
Solution Approach 2:
The patent uses a composite pulp system blending BCTMP with bleached chemical pulp or bleached kraft pulp. This combination provides both the bulk and flexibility from BCTMP and the strength and reliability from chemical pulp, enabling thin, lightweight paper that remains suitable for demanding high-speed labeling applications.
4Weight of moving object
If conventional paper is used with reduced grammage, then the weight is reduced, but the bulk-to-grammage ratio deteriorates
Solution Approach 1:
The patent changes the fundamental material parameter from conventional pulp to BCTMP, which has inherently higher bulk and lower density. This material parameter change directly improves the bulk-to-grammage ratio, allowing the paper to achieve reduced weight while maintaining or increasing bulk, thus resolving the contradiction between weight reduction and bulk maintenance.
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 approach results in paper with improved bulk-to-grammage ratio, enabling reduced raw material usage and extended paper machine runnability, while maintaining sufficient density and transparency for release coating, thus addressing the need for lighter, high-quality release liners.
Implementation Method 1
manufactured through a hybrid process involving chemical pretreatment and mechanical refining
Implementation Method 2
manufactured through a hybrid process involving chemical pretreatment and mechanical refining
Implementation Method 3
use of bleached chemithermomechanical pulp
Data Source
Figure 1a
Figure 1b
Figure 2a~2b
AI summary
The invention relates to paper and method for manufacturing paper suitable for use as a layer of a release liner, the paper having density equal to or less than 1200 kg/m3, the paper having a ratio of grammage to thickness of the paper in micrometres equal to or higher than 1.0, wherein the grammage refers to the weight of the paper in grams per square meter, the paper comprising cellulose fibres from - bleached chemical pulp and - bleached chemithermomechanical pulp, wherein the bleached chemithermomechanical pulp comprises cellulose fibres from hardwood and softwood.