The process of Monofilament Fiber Extrusion is highly useful for the development of products that are used in almost all walks of life. In fact, monofilaments are an essential part of our everyday work, making our work simpler along with making our leisure more enjoyable. For instance, monofilament finds usage for fishing line and to make strings for squash, tennis, racketball rackets and badminton. It is also used for making synthetic monoyarn which is used in the weaving process as well as in synthetic rope which finds usage in fences, construction, greenhouses, orchards, fastening, and many others.
Various products that are developed using Monofilament Fiber Extrusion process are as follows:
- Decorative tapes
- Webbing in lawn chairs
- Bristles for toothbrushes
- Grass trimmer lines
- Tire reinforcements
- Sewing thread for industrial textiles, apparel, home furnishings and floor coverings
Common Polymers Used For Producing Monofilaments
- Polyamide (nylon 6, nylon 6,6, and nylon 6,10)
- Polyphenylene sulfide
- Polyvinyilidene fluoride
Process Of Monofilament Fiber Extrusion
In the monofilament extrusion process, smaller extruders and longer lines are used. The products developed from this process have a very small diameter and many number of ends. Smaller diameter allows very swift cooling that too in a small space. On the cooling of filaments, they are drawn and wound onto the packages. The drawing process is done using comparatively large ovens having godet rolls on its every side. These rolls are used for drawing the filaments to the accurate denier (grams/9000 meters). After this process, the product is wound onto bobbins, wherein these can be utilized directly or by combination for producing some other products like rope etc.
Steps Followed In A Monofilament Line
- In general, 2.5 – 3.5 inch single screw extruder is used in most monofilament processes.
- A gear pump placed between the die and extruder provides consistent polymer flow & pressure.
- Filaments are extruded vertically by circular dies into the cooling bath. Here, the filaments are separated so that every filament runs separately via the line, where their wrapping process takes place. The wrapping is done on a bobbin or spool.
- After quitting the water bath, filaments are dried & further and passed via godet rolls, which are controlling the speed as well as draw from the die.
A large oven placed between two godet roll stands heat the filaments for facilitating the filament drawing. Second godet roll stand operates at a much higher speed than the first and is responsible for the determination of the draw inside the oven. The number of godet rolls and ovens completely depends on the sophistication of line and the draw required. After the filaments exist the last godet roll, they may be passed through a laser micrometer for monitoring individual filament diameters. Lastly, every monofilament is wrapped on separate package for being used in subsequent operations.
The products created by the process of Monofilament Fiber Extrusion are tested on the parameters of water shrinkage, hot air shrinkage, diameter uniformity, denier, color and filament smoothness.