Inside PVDC Manufacturing: How a Rigid Film Becomes a Moisture Barrier
PVDC-coated rigid film is the workhorse of pharmaceutical blister packaging. A look at how it is coated, controlled, and qualified — and why Bangladesh now makes it at scale.
Alu-Alu gets the attention, but PVDC-coated rigid film is the material most Bangladeshi tablets and capsules actually meet first. It is thermoformable, transparent, cost-efficient, and — when coated correctly — a genuinely capable moisture barrier. Rifat Aluminum holds roughly 50 percent of the domestic PVDC market, and that position was built on process control rather than price.
What the film is made of.
The base is a rigid PVC web, typically 250 microns, which provides the stiffness needed for forming deep pockets. On top of it sits a PVDC dispersion applied in successive passes, each pass followed by a controlled drying zone. The finished structure is defined not by thickness but by coating weight in grams per square metre — the number that determines barrier performance.
Where quality is won or lost.
Three control points decide the outcome. Coating uniformity across the web width, because a light edge becomes a failed stability study. Drying profile, because trapped solvent shows up later as odour or delamination. And winding tension, because a roll that is wound tight in a warm plant will not run clean on a customer's forming machine six weeks later.
"In pharmaceutical packaging, consistency is the product. A good roll and a bad roll look identical — the difference only appears eighteen months into a shelf-life study."
Every batch is checked for coating weight, water vapour transmission rate, forming behaviour, and seal integrity before release. Retained samples stay with us so that a question raised a year later can still be answered against the original roll.
Why local matters.
An imported roll arrives with a four to eight week lead time and no practical route back if it misforms. A locally produced roll arrives in about ten days, and a technician can be on the customer's floor the same week to look at the forming station with them. That proximity, more than any specification sheet, is what has moved PVDC volume onto domestic lines.