1. What difference between Internal and external heating system ? Which method is better ?
If fixed the radiators inside the chamber, which is internal heating system; if fixed the the radiator outside the chamber then it’s external heating system.
If used internal heating system, the energy will be save but not good for maintenance; if used external heating system then need insulate the radiator and blow ducts.
In hot area, external system is better due to convenient for maintenance; in cold area, should use internal system to save the energy cost.
2. How about the open-top chamber for coating line ?
The open-top chamber is convenient for substrates (film) applying and easy for cleaning.
Definitely the machine cost will increased and energy cost will be increased some.
3. How long we should change a Meyer bar ?
When the BOPP film always friction the Mayer bar in production, slowly the coating thickness will be changed, decreased and not uniform. How long need change ? After used for few months, and when found out the coating thickness then need change one.
4. What difference between 2 Mayer bar and 3 Mayer bar coating ?
Popularly we used 2 Mayer bar for coating; 1st bar is used for roughly scrap and decrease the glue quantity, 2nd bar is used for actual coating.
In 3 Mayer bar coating, the 3rd bar is used to replace the 2nd bar, when need cleaning the working bar but need not stop the production.
5. How to operate the “auto” join at unwind station ?
Why you would change a new film roll but don’t want to stop the production, then need “auto join”.
The step of auto join:
1)new film start running and do match the linear speed as old film roll.
2)Auto join – stick together by a wide tape (prepared on new roll before join)
3)To cut the tail of old roll
6. What difference between normal turret type rewinder and differential arm type rewinder ?
People used a differential arm rewinder, because this method can be avoid 30-40 meters wrinkle at ends of per jumbo before cutting and change to winding a new Jumbo Roll. It’s big wastage. By this method, the wastage will be about 5-10 meters.
However, new design of turret rewinder can be do the same – low wastage, also 5-10 meters, then need not spend high cost for a differential arm rewinder.
7. Can we do printing on BOPP coating line, in line ?
The answer is yes but not recommend.
We’re “no problem” to equip a printer on a BOPP tape coating line, however, when saved machine cost but not save production time.
In fact, do ink printing and do glue coating is 2 different kinds of job. In production, if problem happened in printing then whole the production must be stop and fix, thus no production for coating in this period; the same, when coating problem then can not do printing, due to whole production shut down again. Thus it’s not economic.
Secondly, printing has higher production speed, however to match the glue coating and drying time, the printing speed must be slow down. Thus it’s not economic again.
To equip a printer on a coating line, you may save few labor cost and machine cost for just 1 set of unwinder and rewinder. But will lose 30-50% production.
