Spun Polyester Bag Closing Thread

High-strength, smooth-running threads built for heavy-duty bag closing and bulk packaging operations.

Product overview

Spun polyester bag closing thread from Mahalaxmi is purpose-built for high-volume industrial packaging applications such as FIBC, woven sacks, feed bags and fertilizer bags. The thread combines very low elongation with high modulus to deliver clean and consistent seams that withstand heavy load, rough handling and exposure during transport and storage.

Made from 100% continuous filament polyester with a spun surface, these threads provide excellent stitch formation even on coarse and abrasive fabrics. The micro-lubrication ensures smooth running through high-speed bag stitching machines, reducing breakage and friction and ultimately improving productivity and machine life.

With excellent resistance to ultraviolet rays, stain-free performance and colorfastness, the thread maintains its strength and seam integrity in storage yards, warehouses and open environments. It is available in multiple deniers and cone/reel formats to match customer requirements for FIBC stitching, bag mouth closing, bag hemming and reinforced seams.

Technical specification

Tkt Tex No. Construction (Ply/Ne) Breaking Strength (Kg) Elongation Range (%) Recommended Needles (NM)
180 16 150*1 0.60 20 – 34 70 – 80
110 24 198*1 0.90 25 – 30 80 – 90
90 35 300*1 1.20 20 – 34 90 – 110
50 50 150*3 1.80 25 – 30 80 – 110
35 60 150*4 2.40 25 – 30 110 – 130

Key Features & Benefits

Very low elongation for neat seams

The high modulus structure ensures tight, uniform stitching with minimal seam distortion, even on high-tension bag closing machines.

High UV and weather resistance

Ensures durability of seams during transportation and outdoor storage, protecting the integrity of feed bags, FIBCs and fertilizer sacks even under prolonged sun exposure.

Smooth machine performance

Micro-molecular lubrication helps the thread glide through guide eyes, needles and existing stitch lines with minimal wear on machine parts — allowing long, continuous production runs.

Abrasion and friction resistant

Designed to handle coarse woven polypropylene, jute and geo-textile fabrics without fluffing, fuzzing or breaking, delivering reliable seam strength in high-friction environments.

Packaging and denier flexibility

Available in multiple ticket sizes and spool formats to suit different bag-closing and overedge machines, including reels for automated systems and cone formats for conventional sewing heads.

Colorfast and stain free

Resists fading and dye bleeding when in contact with contents or exposed to moisture, maintaining a clean, professional look on end products.

Typical applications

Our spun polyester bag closing threads are engineered for high-duty industrial use across the full range of bulk packaging and sack closing operations.

Sewing operations

Overlock

Coverstitch

Flatlock

Serger machines

Multi-needle industrial stitching

FIBC / Jumbo bags

Secure seams on top and bottom panels, edge reinforcement and lifting loop attachment.

Woven PP & HDPE sacks

Effective for closing rice, sugar, grain and fertilizer bags at high production speeds.

Feed & seed bags

Provides clean and reliable seams for animal feed, poultry feed and seed packaging that face repeated handling.

Cement & mineral bags

High tensile strength threads help maintain seam integrity under high load conditions.

Geo-textile and agricultural bags

UV- and abrasion-resistant stitching for heavy-duty outdoor applications.

Bag hemming and inner seam reinforcement

Used in edge finishing to improve strength and prevent fraying in large packaging applications.

Product Properties

Property Details
Composition 100% Spun Polyester
Elongation Very low – for high-tension stitch control
Lubrication Micro-molecular finish for smooth machine performance
UV Resistance High – suitable for outdoor storage and transport
Tensile Strength High – ideal for heavy-duty and bulk-load applications
Packaging Cones, reels and custom industrial-size formats
Colour Options Standard white and select industrial shades (custom shades on request)

Manufacturing Excellence

Mahalaxmi Threads leverages advanced manufacturing capabilities to ensure our textured polyester sewing threads meet the highest industrial standards:

Precision twisting and texturizing

deliver consistent thread diameter and bulk.

Finishing treatments

like lubrication reduce friction and extend needle life.

Standardized production protocols

maintain uniformity in tensile strength, elongation, and seam performance.

ISO 9001:2015 certified systems

ensure consistency, safety, and compliance for industrial-grade usage.

Why Leading Packaging & FIBC Manufacturers Choose Mahalaxmi