The annual output of PVC resin is now the second largest in synthetic resin and has been widely used in various fields of daily life. Transparent products are an important application area, although in recent years the market share of PVC transparent products has decreased due to the use of other transparent materials. However, due to the wide range of PVC sources, simple processing technology, low equipment investment and low price; at the same time, the formula can be easily adjusted for different purposes and performance requirements to meet user requirements and the best performance-price ratio. Therefore, transparent articles made of polyvinyl chloride resin are still widely used.
PVC high impact transparent bottle granules, the most important indicator is the impact strength. Take half of the drop height (referring to the height of 750mL, 40g bottle weight drop), for example, the half drop height required for cosmetic bottle granules (MBS dosage 6-8 parts) is only 30cm, 3000mL oil bottle granules (MBS dosage) About 12-15 parts) The required half drop height is about 100cm, while the high impact transparent granules (about 18-20 parts of MBS) have a drop height of more than 300cm, which is 10 times that of ordinary cosmetics bottles. It is 3 times that of 3000mL oil bottle granules.

Increasing the impact strength of PVC usually involves adding an impact modifier such as MBS. However, increasing the amount of MBS on a large scale brings a series of problems, such as decreased transparency, increased melt viscosity, and internal friction as the amount of MBS increases. Increased, reduced thermal stability, shortened cycle time of the blow molding machine, etc. This topic is mainly to select a suitable heat stabilizer, internal and external lubrication system, to develop a reasonable formula, to solve the problem of reduced transparency due to improved impact resistance, a sharp shortening of the processing cycle, and a decrease in thermal stability.
PVC resin
PVC high-impact transparent granules are hard packaging materials. They should be made of PVC resin with high hygienic properties and a K value of 62 or less (average polymerization degree less than 720). Qilu Petrochemical Company's food grade S-700PVC resin has a K value of 57-59, an average polymerization degree of 650-750, and a VCM content of less than 1*10-6, which is suitable for the production of PVC odorless materials.
Impact modifier
In order to increase the impact resistance of the blow molded bottle, an appropriate amount of impact modifier is generally added to the formulation. The mechanism of action is that when the bottle is impacted, the added impact modifier absorbs the external impact energy by forming a plurality of fine cracks to ensure that the bottle does not rupture. The amount of impact agent added should be determined by the impact requirements of the blow molded bottle. In general, it is not advisable to simply pursue the impact resistance and the dosage is too large, otherwise the transparency of the bottle will decrease, the melt viscosity will be too high, and the heat stabilizer will be consumed too quickly due to excessive internal friction. The impact modifiers in transparent blow molding bottles generally use MBS with similar refractive index to PVC. In general, the higher the impact resistance of the same series of MBS, the lower the transparency. The imported MBS is selected for testing, which is suitable for blow molding, and its impact modification ability and transparency are excellent.
Heat stabilizers
There are two main types of excellent heat stabilizers for PVC products for food packaging. One is thiol organotins, such as the AD-VASTABTM series of Morton Corporation. These products are excellent in thermal stability, transparency and processability, but they are not suitable for PVC odorless materials because they contain thiol fat, which makes PVC products smelly and lasts for a long time. The second is a calcium-zinc (Ca-Zn) soap composite stabilizer in metal soap, which has low odor and no organic tin odor, and has a short evaporation time. The disadvantage is poor thermal stability.

Wuxi Jiahong Plastic Technology Co., Ltd. has nearly 30 years of experience in research and development and granulation of modified PVC granules. The professional technical service team can provide one-stop system solutions for customers. For more information about the product, please visit our official website: www.sdbzkt.cn, consult online customer service or call the hotline. Fixed line: 0510-68755207 Mobile: 15190220696, we will be happy to help you.

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