Slit Coating Volume Compensation via Equalization Channel

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Slit coating devices experience issues with fluid dispensing when varying the effective length of the slit, leading to unwanted adhesive discharge or incomplete coating due to volume changes in the distribution channel, resulting in poor coating results and soiling.

Innovation Solution

A device with an equalization channel connected to the distribution channel, allowing for volume compensation by adjusting the internal volume of the equalization channel to maintain a constant fluid-filled volume, preventing air from entering and adhesive from being forced out during changes in slit length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the effective length of the slit is varied by shifting the closure element, then the application width is adjustable, but the volume of the distribution channel changes causing adhesive to be pressed out or air to be drawn in

Engineering Contradiction:

Improveapplication width adjustmentVSAvoidcoating quality consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The distribution channel is segmented into a variable portion (adjusted by closure element) and a fixed portion, with the fixed portion maintaining a constant minimum volume to prevent air ingress and adhesive overflow during adjustment

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the parameter of distribution channel volume from variable to constant by introducing a fixed portion, thereby eliminating the harmful effects of volume changes while preserving the ability to adjust application width through closure element movement

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If the distribution channel volume is increased, then more adhesive can be stored, but air may flow into the slit and delay adhesive flow

Engineering Contradiction:

Improveadhesive storage volumeVSAvoidcoating delay

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The fixed portion of the distribution channel is pre-filled with adhesive to maintain a constant minimum volume, ensuring that adhesive is always available at the discharge opening and preventing air from entering the system during length adjustment

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the distribution channel length is reduced, then the application width is decreased, but adhesive may be pressed out of the discharge opening

Engineering Contradiction:

Improveapplication width variationVSAvoidadhesive wastage

Core Design Contradiction:

Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The fixed portion of the distribution channel acts as a cushion that maintains constant volume, preventing pressure buildup that would force adhesive out of the discharge opening when the variable portion is shortened

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8800476B2Volume compensation for application heads with application width adjustment

Publication Date: 2014.08.12 NORDSON CORP

AI summary

A device for dispensing fluid onto a substrate includes a basic body, a fluid supply channel connectible to a fluid source for supplying the fluid, and a nozzle assembly which has a distribution channel that communicates with the fluid supply channel and which has an essentially elongated slit that communicates with the distribution channel. The slit includes at least one discharge opening for dispensing the fluid. The effective length of the distribution channel is variable by means of a closure element that is movable in the distribution channel. An equalization channel is connected with the distribution channel, and the volume of the equalization channel is adjustable.