Filling modification of PVC multifunctional PVC heat sealing embossing machine
DATE：2021/6/28 8:44:32 / READ： / SOURCE：This station
Filling modification of PVC multifunctional PVC heat sealing embossing machine
Filling modification is one of the important means of plastic modification. Adding various fillers (calcium carbonate, talc, wollastonite, mica and fiber) into PVC can reduce the cost, improve the rigidity, hardness and heat resistance of the material, improve the dimensional stability and creep resistance of the product, and give the material special functions. However, the polarity difference between PVC and filler is large, the compatibility is poor, the filler is not easy to disperse uniformly in the resin, and the interfacial adhesion is low, which reduces the tensile strength, impact strength and elongation at break of the material. Since the 1980s, the emergence and development of the toughening theory of inorganic rigid particles and the interface induction theory have changed the traditional concept that only adding elastomer can improve the toughness of materials, which makes the toughening of PVC by inorganic rigid particles get great development. Multifunctional PVC heat sealing embossing machine www.handern.comCalcium carbonate is the most widely used filler in PVC. Calcium carbonate has the advantages of low price, non-toxic, non irritating, odorless, white color, low refractive index, easy coloring, softness (Mohs hardness is 3), sufficient supply of raw materials and so on. It is also an acid acceptor in the secondary stabilization of PVC and can reduce the shrinkage of products. Therefore, there are many researches on calcium carbonate filled PVC. There are many kinds of calcium carbonate used in PVC plastics. Generally speaking, it is divided into light calcium carbonate and heavy calcium carbonate; In terms of surfactants, there are stearic acid activated calcium carbonate and titanate coupling agent activated calcium carbonate. Compared with calcium carbonate without surface treatment, its tensile strength, bending strength and impact strength are significantly higher than those of unactivated calcium carbonate. Multifunctional PVC heat sealing embossing machine www.handern.com
UPVC profiles were filled with nano CaCO: powder and nano CaCO masterbatch (nano CaCO: dispersed in a small amount of CPE) to prepare high performance UPVC profiles. The results show that when CaCO; When the filling amount of powder or masterbatch is about 5 parts by mass, the impact strength and tensile strength of UPVC are improved to a certain extent, and the modification effect is better than that of light calcium carbonate (as shown in table 3-5); When the content of nano CaCO was more than 8 phr, the properties of the material decreased, and nano CaCO was directly filled; The effect of powder is better than that of nano CaCO; Filling masterbatch. The performance of HDVC is superior to that of PVC. Multifunctional PVC heat sealing embossing machine www.handern.com
The properties of plastics filled with rigid particles mainly depend on two factors: one is the average particle size of inorganic particles; The second is the surface activity of inorganic particles. Light CaCO was compared（ The toughening effects of CaCO: particles treated with titanate coupling agent were studied. It is found that when the particle size of CaCO: is larger, the impact strength of the blend decreases with the increase of CaCO 3 content; The impact property of modified CaCOs is better than that of untreated caco. Modification system; For example, when the amount of 5000 mesh CaCO: 10 phr, the impact strength of the system increases from 15 kJ / m to 27 kJ / m. When the content of nano CaCO is 10%, the impact strength of the system is 3 times higher than that of PVC matrix resin, and the tensile strength reaches the maximum value (58 MPa), which is 11 MPa higher than that of the matrix resin. However, the tensile strength of micron CaCO particle system has no obvious change although the impact property is improved to a certain extent. The dispersion of inorganic nanoparticles has a great influence on the properties of the blends. When the number of nanoparticles increases, it is difficult to disperse in the system, and it is easy to produce the phenomenon of particle aggregation, which is easy to cause the stress concentration of the system. At the same time, when the system is subjected to external force, the agglomerated particles are easy to slip each other, which makes the performance of the system worse. There is no obvious gap between the particles and the matrix interface, and the matrix has a certain mesh structure in the impact direction. When the amount of nano particles increases, the impact fracture surface is agglomerated, which indicates that the adhesion between nano particles and matrix is poor, but the toughening effect becomes worse. Multifunctional PVC heat sealing embossing machine www.handern.com
Therefore, the finer the particle size of calcium carbonate, the better the mechanical properties of PVC; After surface treatment, calcium carbonate can reduce the whitening phenomenon when the products are bent and folded, and give the products better luster and smooth surface. Multifunctional PVC heat sealing embossing machine www.handern.com
PVC plastics filled with talc powder can improve its rigidity, dimensional stability, prevent its creep at high temperature, make it lubricious, and reduce the wear of molding machine and mould. Because the refractive index of talc is 1.577, which is similar to PVC, talc can be used in translucent PVC products. The tensile strength and impact strength of 20 ~ 30 phr talc with proper fineness added in the suspension polymerization of PVC are higher than those of rigid PVC with conventional filling (talc added in plastic processing), which has great practical value. Multifunctional PVC heat sealing embossing machine www.handern.com
Talc coated with PMMA and talc coated with PMMA copba have better filling effect on PVC. The tensile strength and impact strength of PVC modified with talc composite particles coated with polymer are obviously higher than those of ordinary talc filling system, which is a better treatment method. Multifunctional PVC heat sealing embossing machine www.handern.com
Author：admin