Coating Die Confluence Passage for Accurate Two-Layer Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional coating dies for two-layer coating in lithium-ion secondary battery manufacturing face challenges in accurately forming coating films due to limitations in discharge port spacing, leading to insufficient discharge pressure and potential foreign matter entrapment, which affects the accuracy and quality of the coating process.

Innovation Solution

A coating die design featuring a single discharge port with a confluence passage where two coating materials are joined before discharge, utilizing shims with specific arm configurations to control flow passages and prevent leakage, allowing for improved coating gap management and material distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the discharge port for the upper-layer coating material is spaced away from the material to be coated by the thickness of the lower-layer coating film, then the coating materials can be discharged separately, but the discharge pressure becomes insufficient and coating accuracy deteriorates

Engineering Contradiction:
Improvecoating film formation accuracyVSAvoiddischarge pressure
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The patent merges the discharge ports for both coating materials into a single common discharge port. This allows both coating materials to be discharged through the same location, maintaining adequate discharge pressure while enabling the formation of multi-layer coating films. The merging of discharge functions resolves the contradiction by eliminating the need to space discharge ports apart, thus preserving discharge pressure while achieving accurate coating film formation.

Inventive Principle:
Principle #5Merging (Combining)

2Stress or pressure

If the discharge port for the upper-layer coating material is located closer to the material to be coated, then discharge pressure is sufficient, but the coating gap becomes excessively narrow causing foreign matter entrapment and cutting

Engineering Contradiction:
Improvedischarge pressureVSAvoidforeign matter entrapment and cutting
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

By combining the discharge ports into a single common discharge port, the invention maintains an optimal coating gap distance from the material to be coated. This single discharge port is positioned at a distance that prevents foreign matter entrapment and cutting while still delivering sufficient discharge pressure. The merging approach eliminates the need for closely spaced separate discharge ports, thus avoiding the harmful effects of narrow coating gaps.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If separate discharge ports are used for different coating materials, then each material can be discharged independently, but the discharge port spacing creates limitations on coating gap and discharge pressure

Engineering Contradiction:
Improveindependent material dischargeVSAvoidcoating film formation accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the flow passages for different coating materials while merging the discharge port. Each coating material has its own dedicated flow passage (first flow passage and second flow passage) that leads to the common discharge port. This segmentation allows independent control and delivery of each coating material, while the merged discharge port ensures accurate coating film formation by maintaining optimal discharge pressure and coating gap. The segmentation of flow paths preserves material independence while the unified discharge resolves the spacing limitation.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4104937B1Coating die and coating device
Publication Date: 2024.11.13 PANASONIC HOLDINGS CORP
  • EP4104937B1 patent drawingFigure 1
  • EP4104937B1 patent drawingFigure 2A~2B
  • EP4104937B1 patent drawingFigure 3

AI summary

This coating die is provided with: a first body; a second body; a discharge port; an intermediate member sandwiched between the first body and the second body; a first shim that is sandwiched between the first body and the intermediate member so as to demarcate a first flow path; a second shim that is sandwiched between the second body and the intermediate member so as to demarcate a second flow path; and a merged flow path at which the first flow path and the second flow path are merged and which is connected to the discharge port. The first shim has a pair of first arm parts, and the second shim has a pair of second arm parts. The first arm parts each have, at a tip thereof, a first female section at least a portion of which is cut out in the thickness direction of the first shim and a first male section that is thicker than the first female section. The second arm parts each have, at a tip thereof, a second female section at least a portion of which is cut out in the thickness direction of the second shim and a second male section that is thicker than the second female section. Each of the first female section and the second male section and a corresponding one of the first male section and the second female section are engaged with each other.