I have imported those attributes with csv export import plugin.
At the csv there was header for example “attribute:pa_Input voltage (Vac)”.
If i go to product page in back end, and remove mark “show attribute in product page” it removes all those empty values from front end and it works like that if i want to remove. But problem is that there are over 1000 product like this. And maybe those empty values shouldnt even be displayed in default but stil those are? Maybe i have done something wrong when importing csv?