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New ground calcium carbonate-based product supports raffia bag producers

New ground calcium carbonate-based product supports raffia bag producers
8 June 2021

Performance Minerals APAC develops new generation GCC product to break into India’s largest plastic market.

Imerys is using its expertise in ground calcium carbonate (GCC) to resolve inconsistencies facing master batch manufacturers who supply to raffia bag manufacturers.

Raffia – or woven sacks – uses plastic tapes woven into fabric, and can be made with polypropylene (PP) or high-density polyethylene (HDPE). It includes a huge range of products, such as the fabric used in tarpaulins and geotextiles and bags for items such as food (salt, sugar, rice), cement, fertilizer and sand. 

Its strength, lightness, longevity - and with lamination, good moisture barrier properties - make it a more practical packaging material than jute bags.

The market in India alone is significant – the calcium carbonate demand from the Raffia segment is estimated at 500,000 MT per year.

The Performance Minerals (PM) APAC team has been working with key players in the industry to resolve issues where the process speed has increased significantly and has become a challenge for dispersion with existing products in the market. With input from key stakeholders, PM APAC has improved processes and developed two new products, which are key components for making a compound in combination with PP or HDPE before using it to manufacture woven bags.

ImerCarb® Ultra and ImerCarb® Ultra Plus have been developed with raffia-related master batches in mind. They are compounded with polymers and additives at predetermined ratios and formulations to suit specific requirements, such as the tenacity of tapes, lower friction, lower water carriage and unhindered processing – both for the master batch manufacturer and raffia bag manufacturer. High brightness marble ore is used and top cut is tightly controlled to meet the stringent requirements of the customer.

"The tricky thing", says Sudheer Narasipur, Sales Manager, APAC India, "is to get these properties right". “Coated GCC used in raffia-related compounds is a challenging product,” says Sudheer. “It involves making a dispersion-centric compound that is mixed in varying formulations with base polymer and extruded into sheets, which are further split into tapes. These tapes are rolled on bobbins, which are used on weaving machines to make fabrics. A GCC, like ImerCarb® Ultra or ImerCarb® Ultra Plus, makes up at least 80% of the whole compound. This needs to be of finely controlled particle size. These compounds are mixed into polymers based on a fixed ratio needed for the final product. Another key element is the fatty acid coating on the GCC. A variation in this could result in improper mixing and cause tape breakage during sheet extrusion, so the customer would have to start the whole process from scratch with huge loss of material and time. Our predetermined level of coating used has been fine-tuned based on customer feedback.”

Having analyzed the inconsistencies and faults of its own previous generation products and those available in the market, the Imerys team developed the Ultra range, and made trials for customers and finalized the specs to ensure the process was repeatable and consistent. Key parameters like PSD distribution, coating level control and residue checks were introduced to offer a better controlled product.

These products are produced at Imerys' Ipoh plant in Malaysia. ImerCarb® Ultra is specifically designed to be used in high-speed raffia applications. ImerCarb® Ultra Plus can be used at high-end end applications, and is being tried in more challenging applications, such as UPVC profiles and PVC wire and cable compounds, and is showing promise. 

Launched last year, these products are gaining popularity among key manufacturers in India who make the master batches or compounds and supply them to Raffia bag and fabric manufacturers. These raffia manufacturers then mix or dilute the master batch/compound with base polymers like PP or HDPE and make the fabric and bags and sell on to end user industries.

 “India was in lockdown, so we couldn’t hold face-to-face meetings, however the product development was so good and the pricing so competitive that it has been selling well,” says Sudheer, “Currently, we are moving more than 1,000 tons a month, but the market is huge – we are slowly but steadily building up.

“We are looking forward to reaching more customers and working with them on site to test and refine the products,” says Sudheer. “Each customer has a different challenge, so we want to make sure that the products work effectively for all of them.”


For more information on our ImerCarb® Ultra and ImerCarb® Ultra Plus grades, please contact our technical experts or sales representatives at enquiry.prpa.india@imerys.com