Release Aids with Adjustable Cloud Points for Creping
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Solution Overview
Problem
The paper-making process for tissue and towel products faces challenges in achieving the right balance between adhesion and release of cellulosic fiber webs on the Yankee dryer, affecting crepe quality, softness, and uniformity, due to inadequate control over the adhesion/release balance.
Innovation Solution
The use of release aids containing a mixture of polyethers and hydrophilic polymers, which adjust the cloud point and glass transition temperature, enhancing adhesion, tack, rewetability, and release properties when mixed with an adhesive, allowing for improved control over the creping process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesives are used for creping, then the paper web can be adhered to the Yankee dryer, but the adhesion/release balance cannot be properly controlled, resulting in poor crepe quality
Solution Approach 1:
The invention modifies the adhesive composition by incorporating specific release aids with controlled cloud points and glass transition temperatures. This changes the physical-chemical parameters of the adhesive system, enabling precise control over adhesion and release characteristics during the creping process, thereby resolving the contradiction between reliable adhesion and manufacturing precision.
Solution Approach 2:
The invention creates a composite adhesive system combining base adhesive with specially formulated release aids containing polyethers and hydrophilic polymers. This composite material provides both the necessary adhesion to hold the web on the dryer and the controlled release properties needed for high-quality creping, simultaneously achieving reliable adhesion and manufacturing precision.
2Strength
If the adhesion between paper web and Yankee dryer is increased, then the web can be held firmly during drying, but the release becomes difficult causing poor sheet quality or sheet break
Solution Approach 1:
The invention introduces dynamic control of adhesion strength through temperature-responsive release aids. The adhesive system can maintain strong adhesion at dryer operating temperatures while automatically reducing adhesion strength during the creping phase, preventing sheet break and poor quality without sacrificing initial adhesion strength.
Solution Approach 2:
The release aids utilize phase transitions (cloud point and glass transition temperature changes) to dynamically adjust adhesion strength. As temperature and moisture conditions change during processing, the release aids undergo phase transitions that modulate the adhesive properties, enabling strong initial bonding followed by controlled release without damaging the sheet.
3Reliability
If the release aid cloud point is not properly adjusted, then the adhesion/release balance cannot be optimized, but adjusting it requires complex formulation changes
Solution Approach 1:
The invention systematically adjusts key parameters (cloud point and glass transition temperature) of the release aid formulation to optimize adhesion/release balance. By focusing on these specific controllable parameters rather than complex overall formulation changes, the invention achieves reliable adhesion/release control with manageable formulation adjustments.
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 solution provides improved control over the creping process, leading to enhanced crepe quality, softness, and uniformity of tissue and towel products by managing the adhesion and release balance effectively.
Implementation Method 1
The release aid, in an aqueous solution that includes water and about 3 vol % of the release aid based on the total volume of the release aid and water, can have a cloud point that is greater than the first temperature and less than the second temperature at a pressure of 100 kPa
Implementation Method 2
release aids containing one or more polyethers and one or more hydrophilic polymers, which adjust the cloud point and glass transition temperature, enhancing adhesion, tack, rewetability, and release properties
Implementation Method 3
conductive heat is transferred from the drum
Implementation Method 4
hydrogen bonds form between the fibers creating a flat and dense web morphology
Data Source
AI summary
Methods for making cellulosic fiber webs using release aids containing one or more polyethers and one or more hydrophilic polymers. In at least one specific embodiment, a release aid having a first temperature can be applied to a drying surface having a second temperature. The second temperature can be greater than the first temperature. The release aid, in an aqueous solution that includes water and about 3 vol % of the release aid based on the total volume of the release aid and water, can have a cloud point greater than the first temperature and less than the second temperature at a pressure of 100 kPa. The method can also include adhering a cellulosic fiber web to the drying surface by contacting the cellulosic fiber web to the drying surface. The method can also include dislodging the cellulosic fiber web from the drying surface.