PVC replacement is not as simple as finding a polymer which passes the “duck” test at a lower price. PVC substitutes require workarounds because PVC has unique characteristics.
PVC is not inert. It reacts with solvents found in inks and adhesives more than simpler inert commodity polymers. Inks and adhesives which have evolved to be compatible with vinyl will not have the same results when a different plastic film is dropped in. If we’ve heard it once, we’ve heard it literally dozens of times – ” your PVC substitute is no good; it doesn’t act exactly like our heirloom vinyl.” Nobody wants to have to bring in different inks, different adhesives, change the line speeds, drying conditions and embosser settings because they love mother gaya.
If there’s a volume buyer who is willing to pay a green premium, we have yet to meet them.
Billboard printers process truckloads of PVC film daily. Nobody ever asks where the used billboards end up ( answer: in the landfill where they degrade into chemicals we don’t like to talk about ).
RF welding is the same script. PVC is what is known as a “polar” molecule. It responds to radio frequency waves, hence the name RF for short. The radio waves induce the molecules to start spinning. This creates friction and welds from the inside out – the complete opposite of heat sealing which is done by heating from the outside. Other polymers such as urethane react similarly, but not anywhere near as much as PVC. Non – polar plastic films are anathema to established RF welding shops who are not about to make capital investments until their hand is forced.
The scrpt is always the same. The play has three acts with a run time of about 120 days.
ACT I
Purchasing searches for a PVC replacement because a major customer who has been forced to eliminate PVC might be lost. Specs for PVC are proferred to potential vendors along with promise to make minor tweaks to manufacturing process if necessary and to pay a green premium.
ACT II
Suppliers submit candidates for evaluation. Performance properties mimic PVC as closely as possible.Minor tweaks turn out to be major capex requirements, line personnel are hostile and reluctant to make adjustments. After the third iteration, all parties are frustrated. New suppliers are dismissed as incompetent.
ACT III
Once enthusiastic new suppliers are thanked either for succeeding in cracking the code or for their time and efforts if they have failed. In over 90 % of cases, they are told the information will be held in abeyance if there is a real impetus to find a PVC substitute.
