Improvised Explosive devices are bombs made with available material. Bombs made by countries are not called IED's. Polypropylene, Polyethelene are derivatives of crude oil fracking that has plenty of industrial applications.
Exploding is not one of them!!! Finding five bags of Polypropylene tells me it was imported by some Pakistani company for one of its many final end use products. I am sure it was exported by Reliance to some Pakistani importer. If Pakistan does not want Indian industrial supplies, import them from Dubai (who will get it from India and charge a 50% markup, and put "made in Dubai" on the packaging). Either way you will get what you want and India will sell what it has.
By the way Polyethelene was used by Iran in the arms ship that Israel stopped heading for Hezbollah to hide weapons from the X-ray machines.
Report: U.S. stopped Israel from attacking 'Hezbollah arms ship' - Haaretz - Israel News
"Little knowledge is dangerous". I am not an expert but i am not stupid either.