Plastic yarn, also known as packaging yarn, is made from polyethylene, polypropylene, or recycled polyethylene/polypropylene materials that are turned into granules and used for packaging purposes.
Plastic yarns are versatile and used in various fields such as gift wrapping, agriculture, fishing, and packaging. Their application depends largely on their thickness. For instance, low-thickness and low-strength packaging yarns are primarily used for lightweight packaging like vegetables and pastry boxes, while thicker yarns are used for bundling publications.
Some yarns are made from a combination of natural and synthetic fibers, referred to as blended yarns—such as polyester-cotton or polyester-wool yarns.
Yarns such as effect yarns, Kadika, and spandex fall under the category of fancy yarns.
Types of Plastic Yarn
Twisted Yarn:
Twisted yarn is strong and durable, resistant to acidic and alkaline chemicals, abrasion, and tension. It is unaffected by moisture, making it easy to clean. It is lighter in weight compared to nylon and polyester yarns, which gives it a length advantage under similar weight conditions. It is widely used in the packaging industry, particularly for securing cartons during moving. Twisted yarns are commonly found in red, white, and smoky colors, with white being of higher quality, ideal for heavier cartons.
Baler Twine (Harvest Yarn):
Also known as baling twine or harvester yarn, this type is heavily used in agriculture. High-quality baler twine does not shed lint and shows good resistance to water and sunlight, helping preserve the packaged crop. It usually comes in red and varies in quality. It is commonly used for pressing forage, collecting straw, and hay.
Gift Packaging Yarn:
Compared to the previous two, gift yarn is thinner and lighter, designed for lightweight packaging. It is produced in various colors and patterns and is selected based on customer preference and usage. Often sold by weight (kilogram) in bulk, it’s widely used in vegetable shops and confectioneries.
Gift yarn comes in two styles: plain and fancy. The plain type is used for tying vegetables and pastry boxes, while the fancy type is ideal for wrapping gifts, available in diverse colors and designs to enhance visual appeal.
Production Method
Yarns are generally divided into two categories based on production method and structure: spun yarns and filament yarns.
Spun Yarns:
Spun yarns are made by twisting together many parallel fibers. Their production process differs from filament yarns, and key factors include fiber diameter, length, and crimp, which influence spinning technique.
Filament Yarns:
These are commonly used in the carpet industry and fall under synthetic fibers. Filament yarns are either monofilament (single continuous strand) or multifilament (multiple continuous strands).
Plastic yarn is produced using the melt-spinning method. Raw materials, along with masterbatch or color granules, are placed into an extruder. The material is melted by heaters and mixed by the screw system.
After extrusion, two methods are used:
Method 1: The molten plastic is shaped into a continuous hollow tube, cooled with air, and stretched, then cut by blades and wound into bobbins.
Method 2: The melted material is extruded through cone-shaped nozzles (ranging from 2 to 20 mm), then passed through a cold or warm water tank. The shaped strands are collected onto bobbins.
Characteristics of High-Quality Plastic Yarn
– High tensile strength
– No fraying or linting
– Smooth, uniform, knot-free, with strong structure and consistent color
– Should not break easily or feel hollow; such yarns are problematic and unreliable during use