What is PVC Compound
Polyvinyl chloride is made by polymerizing vinyl chloride monomer (VCM).
PVC cannot be processed alone due to its very poor thermal stability and high melt viscosity. Therefore, a large number of suitable additives must be combined with the polymer to give it a wide variety of properties suitable for many different end uses. It is this flexibility that allows the right formulation to produce a wide range of properties, giving PVC a wide range of applications unmatched by any other thermoplastic. PVC compounds are based on a combination of polymers and additives to give the end user the formulation they need. The rules for recording additive concentrations are based on parts per hundred (phr) of PVC resin. A compound is created by the intimate mixing of the ingredients, which under the influence of heat (and shear) transforms into a gelled product. Depending on the PVC type and additives, the
pre-gelling mass can be a free-flowing powder (known as a dry blend) or a liquid in paste or solution form.
PVC compounds can be compounded into flexible materials using a plasticizer commonly referred to as P-PVC. Compounds without plasticizers for rigid applications are called U-PVC.
How do you make a PVC compound?
PVC (polyvinyl chloride) is used in thousands of different applications. If you ask someone how PVC is made, you may be blinded. A blank face frowns when I explain that the main ingredients in PVC are salt and oil. actually!
PVC compounds are found in every aspect of our daily lives. It is a versatile workhorse that can be used to manufacture everything from medical tubing to decking to power cable jackets. If you look now, you will find countless items containing PVC ingredients.
Want to know how PVC compound is made?
The first step is the separation of ethylene from petroleum feedstock.
Ethylene, a derivative of natural gas, is supplied by the petrochemical industry. It is trapped during a process called pyrolysis. Liquid oil is heated in a steam oven and placed under extreme pressure. This changes the molecular weight of the chemicals in the petroleum feedstock. By altering its molecular weight, ethylene can be identified, segmented, and trapped. It is then cooled to return to a liquid state.
Another step is to extract chlorine from sea salt.
Chlorine contained in salt extracted from seawater gains extra electrons during the electrolysis process. Chlorine is separated and extracted from the mixture by passing a strong electric current through the seawater solution, strong enough to change the molecular structure.Ethylene dichloride (EDC) is formed when ethylene and chlorine react. It undergoes another pyrolysis process to produce a vinyl chloride monomer (VCM).The VCM is passed through a catalyst-containing reactor where polymerization occurs. Simply put, the chemicals are allowed to react until the VCM molecules bind.PVC resin is created by combining VCM molecules. This is the start line for all vinyl compounds.
Ways in which PVC Resin is Transformed into PVC Compound
PVC compounds are used in many applications. It can be said that it is a thermoplastic resin. That is, it changes shape when heated. That means you can turn it into all kinds of exciting things. Depending on its thickness and composition, it can be rigid or flexible. Remember the plastic wrap we used to wrap leftover lettuce in the fridge? Plastic wrap is also made from a specific chemical compound. Speaking of manufacturing, dozens of companies around the world use PVC counter-rotating twin-screw extruders to make products ranging from footwear, plastic wrap, automotive, and even medical. So when most companies like yours are looking for raw materials, it’s usually because they’re looking for something called PVC compounds or vinyl compounds..
General information about PVC formulations
PVC resin is simply in powder shape and can’t be used alone. Generally fixed.
PVC compound (polyvinyl chloride compound) is a powder of polyvinyl chloride. In practical use, additives such as stabilizers, lubricants, processing aids, pigments, and anti-vibration agents are added.
Granulation is not usually required in the extrusion process. Particles of PVC blends are more effective as they are thoroughly mixed during the granulation process and both homogeneity and plasticizing performance are optimal. Particles are commonly used in the molding process. There are requirements for non-combustibility, high strength, good weather resistance, geometric stability, and special requirements for resistance to oxidants, reducing agents, and strong acids. The resulting PVC blend should be compatible with the particulate matter and PVC particle blends listed above.
PVC compound extruders are divided into two categories: flexible PVC composites (soft polyvinyl chloride blends) and rigid PVC composites (rigid polyvinyl chloride blends). The main difference between the two is the different use and amount of emollients. Soft PVC, compounds need to cause the use of particles, and the corresponding processing temperature is relatively low. Rigid polyvinyl chloride (PVC) is a widely used engineering plastic. Those that do not use rigid polyvinyl chloride compounds at all are called “UPVC”.
How PVC resin becomes PVC compound
The definition of a compound is a substance shaped with the aid of using the chemical aggregate of or greater elements. But how is PVC Resin converted to a vinyl compound?
Develop new blend formulations to meet application needs and processing constraints. Chemists and formulation engineers create custom compounds by blending various additives, modifiers, and stabilizers with PVC resins to achieve specific properties.
In a nutshell, the difference between rigid PVC and soft PVC compounds is the plasticizer. Rigid PVC compounds are sometimes classified as rPVC or uPVC (unplasticized). It has high hardness, good mechanical properties, and a high melting point. These materials are suitable for specific applications such as Decks and handrails or pipe fittings, but there are other uses that are less rigid and require the use of more plastic materials.
Flexible PVC compound extruders are formulated to meet performance requirements in applications such as medical tubing, wire, body-side moldings, and garden hoses. We also formulated the customer’s processability requirements. Flexible PVC compounds contain plasticizers and plasticizers that help give them “rubber-like” properties. Market demands, scientific advances, regulatory guidelines, and raw material economics are pushing R&D engineers and formulation engineers to find more versatile and cost-effective materials for custom compound formulations. You have to make an effort. Due to their inherent versatility, vinyl compounds have proven to be very cost-effective materials in many markets and applications.
What is the difference between PVC resin and PVC compound?
Consider the material “PVC”. Close your eyes for 5 seconds and write down the first object that comes to mind. Maybe it’s a garden hose, school shoes, or cling film! These are just a few examples of PVC compound products that we use in our daily life. PVC compounds are all around us and come in many different shapes and sizes. Of course, the hardness also varies.
But what is the difference between flexible PVC compounds and rigid PVC compounds? Besides being able to call one “soft” and the other “hard,” there are a few other characteristics that set them apart.
1. Amount of plasticizer contained in various PVC compounds
The most notable differences are: Flexible PVC compounds have added plasticizers, while rigid PVC compounds have little or no added plasticizer. This plasticizer makes PVC resin more flexible, making it relatively soft and pliable. For example, these “gummy” properties are found in garden hoses. Rigid PVC compounds contain minimal amounts of plasticizers and thus retain their hardness.
2. Physical properties of compounds
Its physical properties depend on the amount of plasticizer added to the PVC compound. In general, rigid PVC compounds are usually denser and stiffer, giving them greater strength and durability. Flexible, on the other hand, is versatile. Each type has its own strengths and weaknesses. Rigid PVC is stronger and more durable, while flexible PVC can be more resistant to chemical and liquid damage.
3. Use of soft and hard PVC compounds
The application of PVC compound suggests certain qualities and advantages it should have, which can be adjusted and maintained during the PVC compound manufacturing process. Hard compounds are better suited for exterior protection applications such as wall cladding, fascia boards, and drainage pipes. Flexible compounds can serve a variety of uses. B. As a material for medical blood bags, rubber boots, and even coasters for summer drinks.
PVC is a valuable manufacturing material primarily due to its versatility. From coasters to school shoes, flexible and rigid PVC compounds play a vital role in human progress. Polystox is a reliable supplier and pioneer in this field. Contact us now.
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