Sequential Gaseous Amine Catalysts for Foundry Core Curing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cold box process for forming foundry shapes using gaseous catalysts, particularly tertiary amines, faces challenges in optimizing the use of these catalysts, especially in combinations, due to issues like boiling point, molecular weight, and odor, which affect diffusion and handling, and there is a lack of understanding on the sequential use of different catalysts for efficient curing.
Innovation Solution
The process involves using a first vaporous catalyst less active than a second vaporous catalyst, both being tertiary amines, in a sequential manner, with the first catalyst being triethyl amine and the second catalyst being dimethylisopropylamine or dimethyl ethyl amine, to effectively cure the foundry mix, and an apparatus is provided to manage the sequential delivery of these catalysts with a carrier gas, allowing for recovery and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single gaseous catalyst is used for curing the binder, then the process is simple, but the curing efficiency is insufficient and requires larger amounts of catalyst
Solution Approach 1:
The curing process is segmented into two distinct stages: a first curing stage using a first gaseous catalyst (such as triethylamine) followed by a second curing stage using a second gaseous catalyst (such as dimethylisopropylamine or dimethyl ethyl amine). This segmentation allows each catalyst to perform its function optimally, with the first catalyst initiating curing and the second catalyst completing it, thereby improving overall curing efficiency while maintaining manageable process complexity through sequential rather than simultaneous application.
2Speed
If lower molecular weight amines are used, then diffusion through foundry mix is improved, but odor becomes stronger and handling becomes unpleasant
Solution Approach 1:
The invention changes the parameter of molecular weight by using a combination of two different gaseous catalysts with different molecular weights and properties. The first catalyst (e.g., triethylamine, Mw 101) has higher molecular weight and less odor, while the second catalyst (e.g., dimethylisopropylamine, Mw 87) has lower molecular weight for better diffusion. By sequencing their application, the process achieves both adequate diffusion speed and acceptable odor levels, as the less odorous first catalyst is applied first when the foundry mix is more accessible.
3Ease of operation
If higher boiling point amines are used, then handling is easier, but condensation occurs in the mold
Solution Approach 1:
The invention optimizes the boiling point parameter by selecting two catalysts with different boiling points. The first catalyst (triethylamine, bp 89°C) has a higher boiling point for easier handling, while the second catalyst (dimethylisopropylamine, bp 64-67°C or dimethyl ethyl amine, bp 44-46°C) has a lower boiling point that prevents condensation. The sequential application ensures that the higher boiling point catalyst is used first when temperatures are more favorable, avoiding condensation issues while maintaining handling ease.
4Reliability
If more catalyst is used, then curing is more complete, but the total amount of amine required increases
Solution Approach 1:
The invention changes the chemical composition parameter by using two different amine catalysts with different curing mechanisms and efficiencies. The first catalyst initiates the curing reaction, and the second catalyst completes it more efficiently. This compositional change allows achieving complete curing with a reduced total volume of catalyst, as each catalyst is used at optimized concentrations for its specific function rather than using excessive amounts of a single catalyst.
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
This approach results in a more efficient curing process requiring less total amine volume, with the second catalyst being more active than when used alone, demonstrating improved curing efficacy and reduced amine usage compared to single-catalyst methods.
Implementation Method 1
a carrier gas, preferably one that is catalytically inert, moves the curing catalyst through the core box in which the foundry shape is contained
Implementation Method 2
The formed foundry shape is contacted in a sequential manner with a first vaporous curing catalyst and then with at least a second vaporous curing catalyst. Each of the vaporous curing catalysts is capable of curing the formed foundry shape.
Implementation Method 3
The use of gaseous catalysts, and especially tertiary amines, as curing agents in the cold box process of curing phenol formaldehyde and poly-isocyanate resins
Implementation Method 4
The apparatus has an apparatus for providing a first and a second curing catalyst in a vaporous state
Data Source
Figure 1~4
AI summary
A "cold box" process for forming a foundry shape by curing a binder in a foundry mix operates by sequentially introducing a first vaporous curing catalyst to a pattern containing the formed foundry mix, followed by introducing at least a second vaporous curing catalyst. By arranging the amounts of the respective vaporous curing catalysts and the contact times, as well as by using the less active vaporous curing catalyst first, the total amount of curing catalyst used to effect the cure is reduced. Carrier gas may be used with the respective vaporous curing catalysts. Typically, the vaporous curing catalysts are tertiary amines having between three and six carbon atoms.