Polypropylene fibers (PPF) are a class of synthetic fibers that, due to a few characteristics, are an excellent addition to building supplies, particularly when concrete is required. PP fibers, either continuous or discontinuous, are often placed on a plastic matrix to create polypropylene fibers, which act as reinforcing agents. It is a practical method for producing high-strength concrete and other building materials. Roads, tunnels, high-performance concrete, and industrial pavements are a few places where polypropylene fibers have found application. It provides outstanding chemical resistance to several common solvents. Additionally, this substance resists freeze-thaw weathering. It is a fantastic option even for humid conditions due to its low moisture regain.
JAM Group Co. is a prominent polypropylene fibers manufacturer with high properties applicable to construction materials. This company operates two developed factories, one in Poland and the other in the middle east; it helps JAM Group, as a polypropylene fibers supplier, to present a product that meets the requirements of international markets. Every customer can rely on this powerful polypropylene fibers exporter to have their intended type of this material through a stress-free purchase. In this case, the customer can enjoy different logistics and shipping options available. For more information, please reach out to us.
What is Polypropylene Fiber?
The first stereoregular polymer to become significant in the industry is polypropylene (PP). In the 1970s, polypropylene fibers were introduced to the textile industry and have since come to play an essential role in the fast-expanding family of synthetic fibers. Polypropylene currently holds the fourth rank, with polyester, nylon, and acrylic as the “big three” fiber classifications. Contrary to other commodity fibers, its use in clothing and domestic textiles has been relatively limited; the majority of the manufactured fiber goes for industrial purposes.
Polypropylene (PP) is a thermoplastic material. Its linear structure relies on the monomer CnH2n. Polypropylene can be produced using propylene gas and a catalyst, like titanium chloride. Aside from that, PP is a by-product of oil refining activities. More specifically, it belongs to a group of synthetic fibers, called polypropylene, which have certain qualities that make them a perfect addition to building materials, particularly when concrete is required. Polypropylene fibers are typically composed of continuous or discontinuous PP fiber placed over a plastic matrix when employed as a reinforcement material. This multipurpose product is a crack control, coating, and reinforcing agent. It is vital to know that, contrary to amorphous thermoplastics like polystyrene, PVC, polyamide, etc., where radicals are distributed at random, the majority of polypropylene utilized is highly crystalline and geometrically regular.
You can read more about the properties of polypropylene fibers below.
The Structure of Fiber
There are crystalline and non-crystalline areas in polypropylene fibers. The size of the spherulites that form from a nucleus can range from fractions of a micrometer to centimeters. The chain axis lies uniformly in planes perpendicular to the radial direction in which the a-axis of the crystal unit cell faces. Non-crystalline material enfolds each crystal. Both crystalline and amorphous regions may align due to fiber spinning and drawing. Spherulites deform elastically and without structural disruption if the extension is less than 0.5%. Otherwise, they become highly orientated in the direction of the force and eventually become microfibrils. Anisotropic fiber qualities result from these extremely anisotropic microfibrillar structures.
Polypropylene Fiber Crystallinity
PP fiber typically has a crystallinity of between 50% to 65%, depending on the manufacturing conditions. Crystallization occurs between the equilibrium melting point (Tm) and the glass transition temperature (Tg). At low temperatures, the rate of polypropylene crystallization is quick. According to reports, the crystallization rate declines with rising crystallization temperatures and increasing molecular weight. Following a fast quenching, a paracrystalline structure with only 45% crystallinity may result. Further downstream quenching also leads to a much higher crystallinity of 62%. Although the drawing orients the crystallites, it may also reduce crystallinity.
Thermal Properties
The melting temperature of polypropylene is 165°C, and its softening point is around 140°C. PP fibers maintain their remarkable elasticity at -70°C or below. PP fibers’ mechanical properties remain unchanged at higher temperatures (but below 120°C). Of all commercial threads, PP fibers have the lowest heat conductivity. It is the warmest fiber of all in this regard.
Different Grades of Polypropylene Fiber
As a thermoplastic material, polypropylene fiber holds various properties resulting from its production process; It is one of the products of polypropylene, a crucial type of thermoplastics. Polypropylene fiber functions in many industries as a multipurpose product due to its chemical and physical properties. Therefore, it must be produced in several grades to suit every application; for instance, it should hold specific properties to be used as a reinforcing agent for concrete and crack control in concrete. Different kinds of additives can be added to liquid polypropylene throughout the production process of polypropylene fiber to alter the qualities of the finished product. It is helpful to know that there are primarily two types of polypropylene fibers, depending on the addition used:
Homopolymer Polypropylene:
Propylene monomer is present in the homopolymer polypropylene type of polypro plastic in a semi-crystalline solid form, meaning it is in its natural state with no additions.
Copolymer Polypropylene:
The majority of polypropylene fabrics are copolymers. Random copolymer polypropylene and block copolymer polypropylene are two further divisions of this type that hold specific properties and serve different roles in the industry.
Different Grades Based on Physical Properties
The polypropylene fiber used in the reinforcing and coating agent can fall into various categories based on its physical properties and size. Below, you can see the differences in detail.
- The tensile strength (GF/den): 3.5 to 5.5;
- Elongation: 40 to 100%;
- Moisture absorption: 0.0 to 0.05%;
- The Fiber thickness: 18 to 30 microns;
- Young’s modulus: 5500 to 7000 mp.
Knowing that every material has a fundamental property called Young’s modulus that cannot be altered is helpful. Young’s modulus, often known as elastic modulus, measures a material’s stiffness. To put it another way, it is how easily it can be bent or stretched. This factor varies by pressure and temperature, so that it can vary in different situations.
Polypropylene Fiber Production Process
It goes without saying that polypropylene fibers can be created using polypropylene chips. It is accomplished through traditional melt spinning, though the operating parameters must be adjusted depending on the final products. So, it is helpful to learn about polypropylene production stages that lead to the production of polypropylene fibers used in concrete reinforcement.
Polypropylene Production Method
In general, propene chain-growth polymerization produces polypropylene. Gas phase polymerization, bulk polymerization, and slurry polymerization can all be employed to create this material industrially. However, gas-phase or bulk reactor systems are common in all modern processes.
In gas-phase and slurry-reactors:
The polymer is created around heterogeneous catalyst particles using this technique. PP FB Manufacturers transfer propene over a bed containing the heterogeneous (solid) catalyst during the gas-phase polymerization process in a fluidized bed reactor. The resulting polymer is then separated as a fine powder and subsequently transformed into pellets. Recycled unreacted gas goes back into the reactor.
In bulk polymerization:
Using this technique, liquid propene functions as a solvent to stop the polymer from precipitating. Propene is kept in a liquid state during the polymerization process by applying 30 to 40 atm of pressure and operating at 60 to 80 °C. Loop reactors serve mainly for bulk polymerization. Due to the polymer’s low solubility in liquid propene, the bulk polymerization is limited at 5% ethene as a comonomer.
In the slurry polymerization:
In this process, the developing polymer particles are typically suspended using inert diluents such as C4-C6 alkanes (butane, pentane, or hexane). Gaseous propane has been added to the mixture.
It is also worth mentioning that the tactility of PP and the orientation of its methyl groups (CH3) to those of nearby monomer units significantly impact its characteristics. As a result, by selecting the suitable catalyst, one can control the tactility of this material.
Polypropylene Fiber Production Method
Now, we’ve learned enough to move on from polypropylene creation to producing vital products from it, like fibers used in concrete reinforcement.
Melt-spinning is used to create the continuous filaments or fibers of polypropylene. The polymer chips are heated above their melting point with hot air or another heating system. The molten polymer forms in this manner. With the assistance of a geared feeding pump, this molten polymer moves to the spinning technique, where it first undergoes homogenization before passing through a filter. The molten polymer flows directly to spinnerets after being purified. The filament is heated when the molten polymer emerges from the tiny spinneret holes.
These filaments need to be cooled. They cool in cold air at a rate of 3 cubic meters of cool air per minute, which prevents filament damage. They are rough filaments. They go through rollers used for drawing. The filaments are heated and stretched out many times longer than they were original. These filaments are now crimped to increase their bulkiness. These crimped filaments receive a heat-setting process. You can wind these filaments onto spools or bobbins. Additionally, the filaments can be divided into pieces based on the needs. The spun yarn consists of these chopped filaments.
Polypropylene Fiber Applications
In the previous sections, we focused on polypropylene fiber’s different properties that lead to its applications. It is a type of synthetic linear fiber made from propylene polymerization. Its advantages are its lightweight, high strength, toughness, and corrosion resistance. The PPF finds wide application in the building, apparel, energy, chemical, and energy-related industries. Glass wool manufacturers use this material as the main component, too. Because of its fatigue resistance, polypropylene makes most plastic living hinges, such as those used on flip-top bottles. It is crucial to ensure chain molecules are orientated across the hinge to maximize strength.
In Concrete Reinforcement
The usage of polypropylene as a reinforcing agent for concrete is among other applications due to various reasons. Numerous investigators have worked to understand how polypropylene fiber affects concrete’s durability. They examined how PPF affected characteristics, including sorptivity, salt penetration, and water absorption in terms of durability and crack control in concrete. The findings indicated that PPFs in concrete benefit the material’s durability regarding sorptivity and water absorption.
Concrete’s low tensile strength, poor deformation resistance, and weak crack resistance are drawbacks in the building sector. The permeability of the concrete increases by the ease with which the microcracks can be generated from the outside to the interior. Concrete’s interior is easily penetrated by water or other dangerous ions, which hastens the concrete’s degeneration. When PPF is added to concrete, a three-dimensional random distribution network structure can be created, effectively preventing the formation and growth of microcracks. The PPF can stop water and other hazardous ions from penetrating the concrete. PPF can be added to concrete to increase its tensile strength. It can be utilized in architectural, pavement, and hydraulic engineering because of its excellent qualities.
In architectural engineering:
Mass concrete must be poured once for high-rise structure foundation construction in architectural engineering. Early heat fracture production in bulk concrete is simple. PPF can effectively reduce concrete temperature cracks and act as a crack control agent. As a result of fewer through cracks in the concrete, introducing PPFs can also increase the concrete’s resist-permeability.
In pavement engineering:
In this field, pavement frequently carries the impact force of moving vehicles, necessitating exceptional toughness and crack resistance, particularly in the case of pavements with high traffic volumes or heavy loads. Compared to regular concrete, PPF-reinforced concrete is more durable. Pavement hardness can be significantly increased when PPF is used in concrete. Meanwhile, fewer creaks are observed when vehicles contact the pavement, demonstrating that incorporating PPFs in concrete increases the pavement’s longevity.
In hydraulic engineering:
Bridges, culverts, docks, and dams are examples of hydraulic engineering that frequently come into touch with water. Concrete needs to be impermeable to hazardous ions and running water in this application. The PPF may efficiently boost concrete’s resist-permeability and stop water and dangerous ions from entering through cracks, indicating that employing PPFs can improve concrete performance.
About JAM Group’s Polypropylene Fibers
JAM Group Co. ranks among the polypropylene fibers manufacturers due to several distinct advantages. This company tends to provide customers with a pure product and superior properties suitable to function as reinforcing and coating agents. In terms of reinforcement, this product offers a more cost-effective, quick, and simple alternative. Retraction and contraction cracks are less likely to form as a result. Using this product saves time because it may be used immediately after being combined with concrete during construction. It has Lower labor costs due to the building work’s execution needing fewer phases. Polypropylene fibers of the company are accessible to combine with concrete on-site and in the manufacturing plant.
As a well-known polypropylene fibers exporter, JAM Group offers every customer worldwide the accordance of products with international certificates; this merit ensures the material’s high performance in different applications. As a result, customers can enjoy this product as a reliable reinforcing agent for concrete. This company also presents various logistics plans and transportation options for each purchaser. These steps are planned based on international standards but can be customized as the customer desires. For more information on it, please get in touch with our team.
Conclusion
Polypropylene fibers (PPF) are a group of synthetic fibers that are particularly useful when it comes to concrete. Polypropylene fibers have properties that make them a perfect complement for achieving certain benefits when utilized in construction, specifically when added to concrete. Polypropylene is frequently included in the cement matrix to increase the resistance of concrete. Fiber-reinforced concrete has a substantially higher tensile strength and is less likely to crack than normal concrete. They mainly consist of continuous or broken polypropylene fibers organized in a plastic matrix. Manufacturers produce polypropylene fiber using different methods and technologies, such as gas-phase and slurry reactors, bulk polymerization, or slurry polymerization. Each of them leads to a distinct type with unique physical properties.
