how to download a zip file
I think you're setting the responseType in the wrong place, instead of this:
$http.post('/api/apiZipPipeLine/', model)
Try this:
$http.post('/api/apiZipPipeLine/', model, {responseType:'arraybuffer'})
Take a look at this answer for more details.
At a matter of fact you are rigth adding responseType:'arraybuffer'
. That added to the following code when received the response from ajax will prompt a file to download:
var a = document.createElement('a');
var blob = new Blob([responseData], {'type':"application/octet-stream"});
a.href = URL.createObjectURL(blob);
a.download = "filename.zip";
a.click();