Calcium Filler for Woven Sacks & Raffia Tape

What Is It?

Woven sacks and raffia tape — used for cement, grain, fertilizer, and general bulk packaging — are made from PP tape extruded, stretched, and woven (or laminated) into sack fabric. Nexxa's calcium PP filler, carrying 80–82% CaCO₃ loading at an MFI of 25 ± 5, is compounded into the PP resin feed at the tape extrusion stage specifically to displace virgin PP resin cost on what is typically a high-volume, thin-margin product.

How It's Manufactured

The filler is compounded on twin-screw extruders inside a highly automated plant, with production capacity dedicated to this product line so tape-line converters get consistent loading and melt-flow characteristics lot after lot. Consistency matters more here than in many other applications because raffia tape is drawn down to a fine, thin cross-section during extrusion — any batch-to-batch drift in melt flow changes how the tape stretches and orients, which shows up directly as tape strength or width variance on the converter's line.

Manufacturing Process for This Application

On the tape line, filler-loaded PP resin is extruded through a flat die into a film, slit into narrow tapes, then stretched (drawn) at a controlled ratio to orient the polymer chains along the tape's length — this orientation step is what gives raffia tape its tensile strength. The oriented tape is wound onto bobbins and woven into sack fabric, or used directly as strapping and twine. Because the draw-down step relies on the melt behaving predictably, a filler with stable MFI lets the converter hold draw ratio and tape width without re-tuning line speed for every new batch of material.

Why Polymer Choice Matters Here

A woven sack has one job: hold its rated weight without tearing, through loading, transport, and stacking. Tape strength comes from how well the PP orients during stretching, and an inconsistent filler undermines that in two ways — loading variance changes melt viscosity enough to cause tape breaks during high-speed drawing, and poor CaCO₃ dispersion creates localized weak points that can snap under load or during weaving. Because sacks are a cost-driven, high-volume product, the filler also has to hold enough CaCO₃ loading to make the cost case work in the first place, without pushing loading so far that tape strength drops below what the sack's rated capacity requires.

Why This Compound Is Suited

Nexxa Compounds is a leading manufacturer of calcium PP filler for woven sack and raffia tape applications in India, with production dedicated to this line, in-house R&D oversight on loading and melt-flow consistency, and manufacturing entirely in India — removing the freight lead time and minimum-order constraints that come with imported filler for a product where margin is won or lost on material cost per kilogram.

Nexxa Compounds is a leading manufacturer of PP Filler compounds for woven sacks & raffia tape applications in India, supplying some of the largest manufacturers across India and internationally.

Related Posts