BCTMP SCK Paper Composition for Low-Basis-Weight Release Liners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in producing release liners for adhesive labels is maintaining the quality characteristics such as transparency, density, and mechanical strength while reducing the basis weight to meet the demands of high-speed labeling processes, particularly when using bleached chemithermomechanical pulp (BCTMP), which complicates controlling paper properties at higher production speeds.
Innovation Solution
A method for manufacturing supercalendered kraft paper using an optimal combination of bleached softwood kraft pulp and BCTMP, with specific ratios to adjust fiber furnish, ensuring a basis weight of 50-70 g/m², transparency above 40%, and density of 1040-1140 kg/m³, achieved through controlled supercalendering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the basis weight of the paper is reduced to meet high-speed labeling demands, then productivity is improved, but the mechanical strength and quality characteristics deteriorate
Solution Approach 1:
The patent uses a composite fiber furnish combining BCTMP (5-50 wt%) with BKP (10-40 wt%) and NBKP (50-85 wt%), creating a multi-component paper structure that achieves both reduced basis weight (50-70 g/m²) and maintained mechanical strength through synergistic fiber interactions
Solution Approach 2:
The patent applies controlled supercalendering with specific parameters (temperature 80-120°C, pressure 10-50 bar, speed 1-10 m/min) to transform the physical properties of the paper, achieving the required density (1040-1140 kg/m³) and surface smoothness while maintaining low basis weight
2Ease of manufacture
If BCTMP is used to increase bulk and maintain basis weight to thickness ratio, then ease of manufacture is improved, but manufacturing precision deteriorates due to complex control requirements at higher production speeds
Solution Approach 1:
The patent specifies precise parameter ranges for supercalendering (temperature 80-120°C, pressure 10-50 bar, speed 1-10 m/min) and fiber furnish composition (BCTMP 5-50 wt%, BKP 10-40 wt%, NBKP 50-85 wt%) to achieve consistent paper properties (density 1040-1140 kg/m³, transparency >40%) even at high production speeds
Solution Approach 2:
The patent implements quality control mechanisms that monitor and adjust paper properties during production, ensuring that density, transparency, and mechanical strength remain within specified ranges despite variations in production speed and fiber furnish composition
3Reliability
If highly refined bleached chemical pulp is used to meet quality expectations, then reliability is improved, but loss of substance increases due to high hardwood content requirement
Solution Approach 1:
The patent creates a composite pulp system combining BCTMP (5-50 wt%) with BKP (10-40 wt%) and NBKP (50-85 wt%), replacing some hardwood kraft pulp with chemithermomechanical pulp to reduce overall pulp consumption while maintaining required paper quality through the synergistic effects of different fiber types
Solution Approach 2:
The patent modifies the traditional high hardwood content formulation by introducing BCTMP and adjusting the pulp mix ratios, achieving quality characteristics (transparency >40%, density 1040-1140 kg/m³) with reduced total pulp consumption and lower environmental impact
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 supercalendered kraft paper suitable for release liners with maintained quality characteristics, allowing for reduced basis weight without adverse effects, facilitating high-speed labeling processes and recyclability.
Implementation Method 1
The paper web is dried in a drying section, thereby forming paper, and calendering the paper
Data Source
AI summary
The invention relates to a method for manufacturing SCK paper having a basis weight in the range of 50 to 70 g/m2, wherein an optimal combination of BSKP and BCTMP is used to adjust the properties of the fiber furnish. In SCK papers with low basis weight the bulk of the formed paper web upon paper manufacturing may be controlled by means of the fiber furnish, without downgauging and without adverse effects to other paper properties, which would prevent the use of the SCK paper as substrate layer in a release liner. Thus SCK paper with exceptionally high share of BCTMP in the fiber furnish may be produced into the same thickness as was possible before for a conventional supercalendered kraft paper having a higher basis weight, while maintaining other quality characteristics of the paper sufficient for use as a substrate layer of an industrial release liner.