Polypropylene spunbond nonwoven fabric is a new type of material made from molten polypropylene through processes such as spinning, mesh forming, felting, and shaping. Polypropylene spunbond nonwoven fabric has excellent physical and mechanical properties, and is widely used in fields such as construction, healthcare, hygiene, home furnishings, and automobiles.
Process flow for making non-woven fabrics from polypropylene: polymer feeding – melt extrusion – fiber formation – fiber cooling – web formation – reinforcement into fabric.
Detailed introduction of the process flow for producing non-woven fabrics from polypropylene:
Mix polypropylene and additives evenly in a mixer, and add the resulting mixture to the feeder in an extruder (such as a twin-screw extruder). The material enters the twin-screw through the feeder, is melted and mixed evenly by the screw, extruded, granulated, and dried to obtain non-woven fabric raw material pellets; Then, the non-woven fabric raw material pellets are added to a single screw extruder for melting and mixing, extrusion, airflow stretching, cooling and solidification, mesh laying, and reinforcement.
Raw material preparation
Polypropylene is a type of polyolefin family, and its molding principle is based on the melt flowability of polymers. The main raw material for preparing polypropylene spunbond nonwoven fabric is polypropylene particles, generally with a particle size between 1-3 millimeters. In addition, additives such as cellulose and glass fiber need to be added, and special production processes are used to melt the particles into a viscous paste.During production, attention should be paid to keeping the raw materials dry and avoiding the mixing of impurities.
Melt spinning
Melt spinning is one of the core processes for preparing polypropylene spunbond nonwoven fabrics. Place the polypropylene particles into the feeding hopper, feed them into the melting furnace through a screw conveyor, heat them to the appropriate temperature, and then enter the spinning machine. The spinning machine extrudes molten polypropylene into fine pores to form fibers. During this process, attention should be paid to adjusting parameters such as heating temperature, extrusion pressure, and cooling rate to ensure the uniformity and fineness of the fibers.
Net forming
After melt spinning, polypropylene has formed continuous fibers, and it is necessary to shape the fibers into a mesh. Mesh forming adopts the method of spray forming, where fibers are sprayed onto a drum and then treated with processes such as heating, cooling, and rolling to interweave the fibers and form a non-woven fabric like structure. During this process, parameters such as nozzle density, adhesive dosage, and speed should be reasonably controlled to ensure the uniformity and quality of the finished product.
Shrink velvet
Shrinking is the process of reducing the finished spunbond nonwoven fabric to the target size. There are two types of felting: dry felting and wet felting. Dry shrinkage is treated with high temperature and high humidity, while wet shrinkage requires the addition of a wetting agent during the shrinking process. During the shrinking process, attention should be paid to controlling parameters such as shrinkage rate, heat treatment time, and temperature to ensure the stability of the finished product size.
Fixed shape
Forming is the process of heating the shrunk spunbond nonwoven fabric to maintain its desired shape and size. The shaping process is carried out using hot rollers, airflow, and other methods, while paying attention to controlling parameters such as temperature, speed, and pressure to ensure stable quality of shaping.
The shaping process of spunbond nonwoven fabric involves hot pressing and fusion with high-temperature hot air after molding. In this process, the non-woven fabric enters the hot air chamber, and under the action of high-speed hot air, the gaps between the fibers are melted, causing the fibers to bond to each other, increasing their fastness and appearance, and finally forming a spunbond non-woven fabric that has been shaped and hot pressed.
Winding up
The winding process is to roll non-woven fabric with a certain width and length for subsequent processing and transportation. The winding machine usually uses a liquid crystal display screen and a programming controller for operation, which can adjust parameters such as size and speed according to needs.
Processing
Spunbond non-woven fabric is a multifunctional composite material that can be used to make various types of fabrics, clothing, masks, filter media, etc. During the processing, various treatment methods such as cleaning and purification, printing and dyeing, film coating, and lamination are also required to achieve product diversification and differentiation.
Summary
The process flow of polypropylene spunbond nonwoven fabric mainly includes: raw material preparation, melt spinning, mesh forming, felting, and shaping. Among them, the three key processes of melt spinning, mesh forming, and shaping have the greatest impact on the physical and mechanical properties of the finished product, and the control of their process parameters is crucial. Polypropylene spunbond nonwoven fabric has the advantages of light weight, high strength, and good breathability, and has broad development prospects in future applications.
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Post time: Aug-07-2024