Christian @ 2CT Media
Active Member
You should introduce your client to a banner track system.
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Ribbed trailer nightmare
- Thread starter TeamOutlaw
- Start date
printhog
New Member
Anytime your vinyl is going to be heated to conform, you need to use a cast film. Period.
Here's what happened.. you installed and heated calendered film into place.. you may have even heat set the vinyl if you're a properly trained wrapper. Probably looked great, and likely stayed that way for a bit.. but over time the calendered vinyl was slowly reset to its original flat shape by heating and cooling combined with its own stored energy. The design's dark image helped this by heating up in the sun. A dark surface can easily reach 130+ degrees in the day, and guess what... that's the thermal setpoint for vinyl wraps and the adhesives.
Knowing why it failed will make you feel better -
Calendered films are made by melting vinyl pellets to a low "glass transition" temperature of about 350 degrees, then extruding the soft vinyl and squishing repeatedly between multiple calender rollers making it thinner at each pass.. that's why its called "calendered". Each pass squishes the film and causes the polymer chains to spread apart a bit side to side.. and that stores up spring like energy along the direction of the stretching deformation. The calendering machines are fairly small, and cheap, and the process is reliable. But the vinyl polymer has been thermally and physically forced to be flat and will always try to return to its natural low energy state.
Cast vinyl, on the other hand, is made by melting pvc to a higher molten state (likely over 450F) and flowing the hot liquid out to be a flat sheet, and cooling it uniformly over long conveyors. Big, expensive process but best product and a stable unstressed film since it was cast flat from molten liquid (thus "cast vinyl").
Because the thermoformed calendered vinyls never reach the molten point, they have a lot of stored energy between the polymer chains, enough to shear the adhesive/vinyl bond if given the chance. As such the vinyl ALWAYS wants to return to its original shape. That's why calendered vinyls shrink and when they do they leave glue behind. And thats why your vinyl pulled away, it returned to its natural shape helped y the dark image and time.
Good luck on the repair, and sorry about the glue removal that's likely in your future..
Here's what happened.. you installed and heated calendered film into place.. you may have even heat set the vinyl if you're a properly trained wrapper. Probably looked great, and likely stayed that way for a bit.. but over time the calendered vinyl was slowly reset to its original flat shape by heating and cooling combined with its own stored energy. The design's dark image helped this by heating up in the sun. A dark surface can easily reach 130+ degrees in the day, and guess what... that's the thermal setpoint for vinyl wraps and the adhesives.
Knowing why it failed will make you feel better -
Calendered films are made by melting vinyl pellets to a low "glass transition" temperature of about 350 degrees, then extruding the soft vinyl and squishing repeatedly between multiple calender rollers making it thinner at each pass.. that's why its called "calendered". Each pass squishes the film and causes the polymer chains to spread apart a bit side to side.. and that stores up spring like energy along the direction of the stretching deformation. The calendering machines are fairly small, and cheap, and the process is reliable. But the vinyl polymer has been thermally and physically forced to be flat and will always try to return to its natural low energy state.
Cast vinyl, on the other hand, is made by melting pvc to a higher molten state (likely over 450F) and flowing the hot liquid out to be a flat sheet, and cooling it uniformly over long conveyors. Big, expensive process but best product and a stable unstressed film since it was cast flat from molten liquid (thus "cast vinyl").
Because the thermoformed calendered vinyls never reach the molten point, they have a lot of stored energy between the polymer chains, enough to shear the adhesive/vinyl bond if given the chance. As such the vinyl ALWAYS wants to return to its original shape. That's why calendered vinyls shrink and when they do they leave glue behind. And thats why your vinyl pulled away, it returned to its natural shape helped y the dark image and time.
Good luck on the repair, and sorry about the glue removal that's likely in your future..