Heavy Duty Sacks

Borealis has developed a line of bimodal films designed to address the heavy duty sacks industry. Shipping sack production is one of the largest segments for film converters. As increased global trading has meant more transportation of goods, the need to protect free-flowing materials in various types of sacks becomes evident.

Heavy duty shipping sacks (HDSS) are used for goods such as:

• plastic pellets,
• pigments,
• fertilizer,
• sand,
• food,
• pharmaceuticals,
• intermediate products.

LDPE and LDPE/LLDPE blends are still the most common resin compositions for HDSS, mainly because of cost and availability reasons. Many film converters use co-extrusion technology to manufacture these films, and incorporate higher density materials in core layers. This provides increased stiffness which facilitates down-gauging.

For heavy duty sacks, it is important that the film provides:

• rigidity/stiffness during packaging, storage and transport to avoid tearing, rupture or other damage to the film;
• optimal film thickness distribution and creep resistance to avoid tearing, rupture or other damage to the film;
• sufficient heat sealing range for trouble-free sealing and high packaging speed;
• low inside friction and blocking for easy opening;
• toughness to avoid bag failures and product spoilage during handling.

Solutions adapted to the needs of the market

Borstar® bimodal LLDPE film grades offer a combination of high impact and seal strength that reduces the risk of packages bursting during various stages of their lifetime - from filling, to transportation, to end-use.

Additional benefits of using Borstar® bimodal film grades are: 

• material savings, lower costs,
• shorter production time per bag for a lower unit cost,
• reduced transport costs,
• reduced environmental taxation.