Dual Slot Die Coater Gap Adjustment for Uniform Wide Coating

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Solution Overview

Problem

Conventional dual slot die coaters face challenges in adjusting the coating gap and controlling widthwise deviation, leading to non-uniform coating of active material layers, especially when using different types of active material slurries, which affects the quality and productivity of secondary battery electrodes.

Innovation Solution

A dual slot die coater design featuring a plate member with adjustable upper and lower slots, controlled by first and second bolts, allowing precise manipulation of the coating gap without disassembly, ensuring uniformity and stability even under high pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the dual slot die coater increases in width to use a wide current collector in order to increase the production amount, then the productivity is improved, but it becomes more difficult to achieve uniform coating in the widthwise direction

Engineering Contradiction:
Improveproduction amountVSAvoidcoating uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The die coater is divided into multiple independent die blocks (first die block, second die block, third die block) that can be adjusted separately. Each die block has its own coating gap control mechanism, allowing independent adjustment of coating parameters across the width of the current collector. This segmentation enables uniform coating across wide substrates by treating different width sections as separate controllable units.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the coating gap is not uniformly controlled in the widthwise direction, then the device can handle wide current collectors, but the coating quality and stability deteriorate

Engineering Contradiction:
Improvecurrent collector width handlingVSAvoidcoating stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

Each die block is equipped with local adjustment mechanisms (adjustment screws, adjustment knobs) that enable independent control of the coating gap at specific width positions. This local quality control allows the system to adapt to wide current collectors while maintaining uniform coating quality across the entire width, as each section can be precisely controlled according to its specific requirements.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If different types of active material slurries are used to manufacture various types of products, then the adaptability is improved, but the coating gap control becomes more difficult

Engineering Contradiction:
Improveproduct varietyVSAvoidcoating gap control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The die blocks are designed with dynamic adjustment capabilities, allowing the coating gap to be modified during operation or between different coating tasks. The adjustment mechanisms enable quick reconfiguration of the coating gap for different slurry types and product requirements, providing operational flexibility while maintaining precise control for each specific coating application.

Inventive Principle:
Principle #15Dynamics

4Quantity of substance

If the thickness of the active material layer is increased to achieve high energy density, then the energy density is improved, but the coating uniformity and quality deteriorate due to severe migration during drying

Engineering Contradiction:
Improveactive material layer thicknessVSAvoidcoating uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The system enables precise preliminary control of the coating gap before the coating and drying process begins. By establishing uniform coating parameters in advance through the adjustable die blocks, the coating is applied with consistent thickness and uniformity from the start, preventing the migration and quality issues that occur during the drying phase of thick coatings.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4147791B1Dual slot die coater
Publication Date: 2026.04.01 LG ENERGY SOLUTION LTD
  • EP4147791B1 patent drawingFigure 1
  • EP4147791B1 patent drawingFigure 2
  • EP4147791B1 patent drawingFigure 3

AI summary

There is provided a dual slot die coater that is easy to adjust a coating gap and can control a widthwise deviation of coating gap. The dual slot die coater of the present disclosure includes a plate member including a lower plate, an intermediate plate positioned on the lower plate and an upper plate positioned on the intermediate plate, wherein a lower slot is formed between the intermediate plate and the lower plate, and an upper slot is formed between the upper plate and the intermediate plate; a block provided on a rear surface of the plate member, wherein the block can be separated from or coupled to the plate member, or integrally formed with at least one plate of the plate member; a first bolt to push at least one plate of the plate member from the block as the first bolt passes through the block; and a second bolt to pull the at least one plate of the plate member toward the block as the second bolt passes through the block.