Membrane Preparation: Process, Pain Points, and Equipment Optimization

At present, the preparation of proton exchange membranes/anion exchange membranes for domestic electrolytic cells is not only achieved through the use ofHomogeneous membraneBeyond the route, we are exploring the direction of enhancing the membrane. Its preparation process is based on "solution coating+Reinforced layer composite”Main: Prepare the membrane material solution first and perform the process on the base membraneCoating, followed by composite reinforcement layer, a second coating, and finally drying and heat treatment to obtain the finished film. withPEMFor example, the thickness of the reinforcement layer is usually controlled at about80Microns.

In the actual production/mass production process, common problems with ion exchange membranes mainly focus on three categories:

1. Appearance defect: The target is a transparent film, but the finished product is prone to yellowing; Spots or impurities appear on the surface of the membrane, affecting its transparency and consistency;

2. Uneven size: The membrane thickness fluctuates greatly, making it difficult to meet the assembly accuracy requirements of the electrolytic cell;

3. Structural hazards: Local coating cracking or loose interlayer bonding can shorten the service life of the membrane.

Four key optimizations are proposed from the perspective of device system design to address the above issues:

1. Stable pressure control: Stabilize the pressure throughout the entire process from pulping to die discharge, and collaborate with die suppliers to optimize cavity design to reduce coating unevenness caused by pressure fluctuations;

2. Precise micro tension control: For flexible reinforcement layers such as titanium, a micro tension system is used to avoid tensile deformation during transmission and ensure composite flatness;

3. Wide width temperature uniformity control: For films with a width of more than 1 meter, the horizontal temperature difference of the oven should be controlled within ± 2 ℃ to avoid deformation or yellowing caused by local drying too fast;

4. Clean environment guarantee: The oven is placed in a clean laboratory and uses high-efficiency filters that are resistant to high temperatures and low shedding to reduce spot defects caused by dust and foreign objects.

For proton/anion exchange membranes without reinforcement layers, the solution viscosity needs to be adjusted in the process (usually requiring higher viscosity), and the process is simplified as "base film coating leveling+heat treatment".