In Angular, we create libraries; which, follow the NPM architecture for creating packages. We simply build them using

  ng build --prod 

NPM Pack Creates the tarball

This zipped file is ready to integrate with the NPM System.

Import to Another Project

In another project, use

    npm i folderpath/custom-element-0.0.1.tgz

OtherProject/Node_Modules

JWP2020

Private NPM Packages,
NPM Packages Folder