Bacterial Cellulose Web Production via Continuous Pulling
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Solution Overview
Problem
Existing methods for producing bacterially synthesized cellulose often result in materials with non-uniform dimensions and structures, limited by reactor geometry, and lack consistent nutrient availability, making them unsuitable for large-scale production of homogeneous, flat cellulose products.
Innovation Solution
A method involving a trough-like culture vessel where bacterial cellulose is cultivated at the interface of a nutrient medium, with continuous supply and removal of the cellulose as a coherent band, allowing for defined thickness and variable length, and treated with a bacteria-killing medium to prevent further cultivation, enabling the production of homogeneous, flat cellulose materials independent of reactor geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If bacterial cellulose is cultivated in standing cultivation with nutrient medium in a cultivation vessel, then the cellulose can be obtained at the interface between air and nutrient medium, but the size and form of the cellulose material is limited by the cultivation vessel geometry
Solution Approach 1:
The cultivation process is segmented into multiple sequential stages where the cellulose band is progressively extended beyond the cultivation vessel. The band is divided into cultivated and uncultivated portions, allowing continuous production of lengths exceeding the vessel dimensions.
Solution Approach 2:
The product extends into a new spatial dimension by pulling the cellulose band outward from the cultivation vessel in a direction perpendicular to the vessel's main dimensions, allowing length to exceed the vessel's length constraint.
2Productivity
If bacterial cellulose is produced by continuous winding of filaments during cultivation, then the yield can be increased, but the inner structure becomes non-uniform and the material is not produced in flat form
Solution Approach 1:
The method produces a homogeneous flat band structure where cellulose is uniformly distributed throughout the thickness. The band is formed by continuous deposition at the air-nutrient interface, ensuring uniform composition and structure across the entire product cross-section.
3Productivity
If bacterial cellulose sheets are obtained from a gel film using linear bioreactor or rotary disk reactor, then continuous production is achieved, but the material is very inhomogeneous without defined dimensions
Solution Approach 1:
The flat band structure is formed by controlled deposition at the air-nutrient interface, ensuring uniform cellulose distribution and consistent thickness throughout the product. This maintains homogeneity while enabling continuous production.
Solution Approach 2:
The method controls key parameters including band thickness (0.1-10 mm), width (10 mm to several meters), and length (cm to km) through adjustable cultivation conditions and pulling speed, enabling precise dimensional control while maintaining continuous production.
4Ease of operation
If standing cultivation is used for bacterial cellulose production, then the process is simple to operate, but it takes up a lot of space and nutrient supply is not optimal
Solution Approach 1:
The method implements continuous nutrient supply to the cultivation interface and continuous removal of the cellulose band, maintaining optimal nutrient availability and preventing space limitations. The band is continuously extended beyond the vessel as it is formed, enabling unlimited length production.
5Shape
If mechanical force is applied to wind BC biofilms into thin foils, then flat BC can be obtained, but the structure is changed and aggregation into thin foils does not occur during biosynthesis
Solution Approach 1:
The flat band structure is formed naturally during biosynthesis through controlled deposition at the air-nutrient interface, preserving the homogeneous 3-dimensional network structure of bacterial cellulose without mechanical disruption. The flat form emerges spontaneously from the cultivation process itself.
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
Enables the production of cellulose materials with consistent, reproducible quality and variable dimensions, suitable for large-scale production, while maintaining a homogeneous structure and preventing inhomogeneous material formation.
Implementation Method 1
bacterially synthesized cellulose... cultivated in a culture vessel at the interface of a nutrient medium contained therein and inoculated with a bacterial culture to the air
Implementation Method 2
the part of the band with the finished cultivated cellulose or with the finished cultivated cellulose-containing material is each exposed to the bacteria-killing treatment medium after removal from the culture vessel, through which a further cultivation process of the cellulose or the cellulose-containing material of this part of the band is prevented
Data Source
Figure 1
AI summary
The invention relates to a method for producing bacterially synthesized cellulose and cellulose-containing material in a planar form. The aim of the invention is to devise a universally usable method that is suitable for large-scale production and allows homogeneous, planar bacterially synthesized cellulose and cellulose-containing materials to be efficiently produced at any defined length and thickness, regardless of the reactor geometry. Said aim is achieved by removing the bacterial cellulose (5) synthesized in the culture vessel (1) in a continuous fashion or step by step from the culture vessel (1) as an endless planar "cellulose web" comprising the completely cultivated cellulose. The part of the "web" containing the cellulose that has not been completely cultivated yet remains in the culture vessel until the cellulose has reached the desired thickness. After being removed from the culture vessel at the desired length, the endless "web" is cut into portions.