Polyvinyl Chloride PVC Resin Description
PVC resin, with the full name of polyvinyl chloride resin, is a kind of synthetic material that is popular and widely used in many industrial fields. Its main components is polyvinyl chloride, and other components are added to enhance its heat resistance, toughness and ductility. With the characteristics of good chemical stability, corrosion resistance and water resistance, polyvinyl chloride is the most widely used raw material in plastic production.
Polyvinyl chloride resin is a thermoplastic polymer compound formed by polymerization of vinyl chloride monomer(VCM) or dichloroethane(EDC) under the action of an initiator. It has the advantages of flame retardancy, wear resistance, chemical corrosion resistance, excellent electrical insulation, strong mechanical properties and low coat performance.
Technical Specifications of Polyvinyl Chloride Resin
|Viscosity No. ml/g||135-127||118-107||95-87||86-73|
|Number of impurity particles||16max||16max||20max||20max|
|Volatile Matter, %||0.3max||0.4max||0.4max||0.4max|
|Apparent Density, g/ml||0.45min||0.48min||0.50min||0.50min|
|Number of Fish Eye (/400 cm2)||20max||20max||30max||30max|
|Plasticizer absorption of 100g resin, g||26min||19min||12min||12min|
|VCM Residue, ppm||5max||5max||5max||5max|
SG3 is for hoses, leathers, wire cables, shoes and other general purpose soft products.
SG5 is for pipes, profile, fittings, panels, injection, moulding, sandals, etc.
SG7/SG8 is for bottles, sheets, calendaring, rigid injection and moulding pipes.
Technical Specifications of PVC Paste Resin
|Average polymerization degree||1450±200||1000±150|
|Number of impurity particles ≤||20||20|
|Brookfield viscosity 10-3Pa.S (50r/min, Resin : DOP=100:60) ≤||5000||7000|
|Sieving rate (greater 0.063μ m mesh) %≤||1.0||1.0|
|VCM Residue (μg/g) ≤||10||10|
Polyvinyl Chloride Resin Uses
PVC general soft products. Used for the production of hoses, cables, wires, etc. With various molds, it can be used to make plastic sandals, shoe soles, slippers, toys, auto parts, etc.
PVC films. After the PVC resin is mixed with additives and plasticized, it can be used to make a transparent or colored film with a specified thickness. It can also be used to process packaging bags, raincoats, tablecloths, curtains, inflated toys, etc. The wide transparent film can be used for greenhouses, mulching films. The biaxially stretched film has the characteristics of heat shrinkage and can be used for shrink packaging.
PVC coated products, such as artificial leather. Artificial leather with a backing is made by coating PVC paste resin on cloth or paper, and then plasticizing it at a temperature above 100℃. For artificial leather without a substrate, the PVC emulsion resin is directly rolled into a soft sheet with a certain thickness by a calender, and then pattern is pressed.
PVC foam products. When mixing flexible PVC, add an appropriate amount of foaming agent to make a sheet, and then foamed into foam plastic, which can be used to make foam slippers, sandals, insoles, shock-proof cushioning packaging materials, etc. It can also be used to make low-foam hard PVC boards and profiles, which can replace wood as a new type of construction material.
PVC transparent sheet. Adding impact modifier and organic stabilizer to polyvinyl chloride resin, and then mix, plasticize and calender them to make transparent sheet. The PVC transparent sheet can be made into thin-walled transparent containers or used for vacuum blister packaging, which is an excellent packaging material and decorative material.
PVC pipe and PVC hose. Adding stabilizers, lubricants and fillers to liquid PVC and mixing them. Then use extruder to extrude hard pipes, special-shaped pipes and corrugated pipes of various calibers, which can be used as sewer pipes, drinking water pipes, wire casings or staircase handrails. The calendered sheets can be overlapped and hot pressed to make hard plates of various thickness.
PVC profile. Be used to make hard profiled materials for doors and windows.
Know More About PVC Resin & PVC Paste Resin
According to the production method, it can be divided into general-purpose PVC resin, high polymerization PVC resin, cross bonding polyvinyl chloride resin. The general-purpose type is formed by the polymerization of vinyl chloride monomer under the action of an initiator. High polymerization type refers to a resin polymerized by adding a chain extender to the vinyl chloride monomer polymerization system. The cross bonding type is a resin polymerized by adding a cross-linking agent containing diene and polyene into the vinyl chloride monomer polymerization system. General-purpose type has a simple preparation method and a wide range of uses. But it has some shortcomings that it can’t be adapted to high-end and special processing applications. The high-polymerization polyvinyl chloride resin generally refers to PVC resin with an average degree of polymerization above 1700 or a slight cross-linked structure between the molecules. This type improves the processing performance of general-purpose polyvinyl chloride resin, and is more suitable for processing special soft products, high resilience, high toughness rubber products, as well as matte products. Make products have the characteristics of higher tensile strength, tear strength, elongation at break, abrasion resistance, high temperature and low temperature resistance, lower compression set, excellent plasticizer retention, etc.
According to the content of plasticizer, it can be divided into rigid PVC and flexible PVC. Without plasticizer, it is rigid PVC, and its glass transition temperature is as high as 80℃-85℃, which is not easy to process. But after adding plasticizer, the glass temperature will decreasse, plasticity and flexibility will in crease and mmake it easy to process even at low temperature.
The industry generally distinguishes the PVC resin according to the method of obtaining vinyl chloride monomer. Depends on the polymerization method, PVC suspension resin is currently the largest variety, followed it is the PVC paste resin made by emulsion method.
PVC suspension resin refers to the polyvinyl chloride resin produce by the suspension polymerization method. And then it is generally divided into SG1-SG8. Among them, SG1 has the largest molecular weight, SG8 has the smallest molecular weight. Choose PVC resin SG5 for rigid PVC pipes and profiles. PVC resin SG8 is generally for injection products, while PVC soft products generally choose SG type or below.
PVC paste resin, also known as PVC emulsion resin, with fine powder and immobility, is often prepared by emulsion and micro-suspension method. Polyvinyl chloride paste resin is mixed with the plasticizer and then stirred to form a stable suspension, which is then made into PVC paste, or PVC plastisol, PVC sol. Paste resin is named after its highly dispersible powder used for paste processing. Because of its excellent paste-forming properties and good dispersion properties, it is mainly used in the field of soft materials of PVC resin. Polyvinyl chloride paste resin is widely used in artificial leather, decorative materials, floor leather, wall paper, industrial conveyor belts, sports venues, coatings, adhesives, toys, disposable medical gloves, daily decorative materials, electrical instruments and tools, and many other fields.
Compared with PVC suspension resin, PVC paste resin has the following advantages: (1) The processing equipment is cheap. (2) The mold is simple and cheap. (3) It can be made into a special shape. (4) Easy to foam. (5) The products are heated less frequently, and can be produced in small quantities and with multiple varieties.
- From the physical state, polyvinyl chloride paste is in the form of white fine powder, while the PVC resin is in the form of white fine particles.
- In terms of usage method. PVC paste resin should be mixed with appropriate amount of plasticizer and be used in the form of liquid plastisol, which is generally used in the production of flexible plastic products. Polyvinyl chloride resin is used after granulation with an appropriate amount of plasticizer, and is generally used in the production of rigid plastic products.
The K value is an index indicating the polymerization degree and molecular weight of polyvinyl chloride. In addition, the viscosity number is also an indicator of the molecular weight of the polymer. This product is an amorphous linear polymer compound. The larger the relatively molecular weight, the higher the viscosity, the better the strength, stiffness, toughness, heat and low temperature resistance of the material, but the worse the molding processability. The difference in K value of polyvinyl chloride resin will have a certain impact on the processing technology and product performance, Therefore, when purchasing polyvinyl chloride resin, customers need to choose the suitable grade depends on the K value and applications.
K70-75 PVC resin with high K value and higher molecular weight has the best mechanical properties, but is more difficult to process.
PVC resin k65/k66, PVC resin k67/k68 with suitable K value have a good balance between mechanical properties and processability. They are the most popular and can meet the needs of the most PVC applications.
K58-60 polyvinyl chloride with low value has the lowest mechanical properties and the processing is easiest. However, it has many difficulties in the application process.