Word Application scope closes all the word files open while exiting


Hi All,
I am working on an automation project to create pdf letters from word templates by adding data wherever needed. For converting the word file to pdf I have to use “ExportToPDF” activity which can be used inside word application scope. But when the code exits word application scope , it closes all the word files open on the system even though they are not related to the execution.
Does anyone know what can be done to avoid this?
Thanks in advance.