Aldehyde Tanning Bath with Non-Ionic Surfactants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tanning methods using aldehyde tanning agents, such as glutaraldehyde, result in low shrinkage temperature values and mechanical strength in tanned animal skins, requiring additional treatments and being prone to yellowing, limiting their effectiveness as sole tanning agents.
Innovation Solution
A tanning method utilizing a tanning bath containing short-chain aliphatic dialdehydes, like glutaraldehyde, combined with non-ionic surfactants, which allows for higher shrinkage temperatures and mechanical strength in animal skins, potentially eliminating the need for secondary tanning agents like chrome tanning agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If aldehyde tanning agents (e.g., glutaraldehyde) are used as sole tanning agents, then the tanning process can be simplified, but the shrinkage temperature and mechanical strength of the tanned skin are low
Solution Approach 1:
The patent uses a composite tanning system combining aldehyde tanning agents with specific salts (sulfates, chlorides, or bromides of divalent or trivalent metals) to create a synergistic effect. This composite approach allows the process to maintain simplicity while achieving high mechanical strength and shrinkage temperature (above 70°C), resolving the contradiction between process simplicity and leather quality.
2Productivity
If aldehyde tanning agents are used as sole tanning agents, then the number of treatment steps is reduced, but the shrinkage temperature achieved is low (around 70°C or below)
Solution Approach 1:
The patent modifies the chemical parameters of the tanning bath by adding specific salts (sulfates, chlorides, or bromides of divalent or trivalent metals) to alter the reaction conditions. This parameter change enables the aldehyde tanning agent to achieve higher shrinkage temperatures (above 70°C) while maintaining process efficiency and avoiding multiple treatment steps.
3Device complexity
If aldehyde tanning agents are used, then the tanning process is simpler, but the tanned skin is prone to yellowing
Solution Approach 1:
The patent introduces specific salts (sulfates, chlorides, or bromides of divalent or trivalent metals) as intermediary substances that mediate between the aldehyde tanning agent and the collagen. These intermediaries facilitate the tanning reaction while preventing the yellowing effect, allowing the use of simple aldehyde-based processes without the harmful discoloration.
4Reliability
If pre-tanning treatment is performed with aldehydes, then the skin stability is partially improved, but additional tanning treatments are required to achieve irreversible stability
Solution Approach 1:
The patent merges the pre-tanning and final tanning functions into a single treatment step by combining aldehyde tanning agents with specific salts. This unified approach achieves both partial stabilization and irreversible stability simultaneously, eliminating the need for separate pre-tanning and final tanning steps while maintaining high skin stability.
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 achieves tanned skins with significantly higher shrinkage temperatures up to 90°C and enhanced mechanical strength, reducing production scraps and defects, while avoiding the use of non-aldehyde tanning agents in subsequent treatments.
Implementation Method 1
reacting the collagen of the raw skin with various tanning agents so as to obtain the cross-linking of the polypeptide chains of collagen and its consequent inerting
Implementation Method 2
A tanning method utilizing a tanning bath containing short-chain aliphatic dialdehydes, like glutaraldehyde, combined with non-ionic surfactants
Data Source
AI summary
A method for tanning animal skin may include: putting the animal skin in contact with a first tanning bath comprising (weight percentages referring to a pelt weight of the animal skin): water, at least one C2-C8 aliphatic dialdehyde in a quantity within a range of 2%-30%, and/or at least one non-ionic surfactant in a quantity within a range of 0.1%-20%, wherein the first tanning bath has a pH within a range of 1-5 and a density within a range of 3°Bé-10°Bé; bringing the pH of the first tanning bath to a pH greater than 5 and less than or equal to 8; and/or washing the animal skin to obtain a tanned animal skin.