HS-1300 PVC resin is a general-purpose polymer with high molecular weight. It has large and uniform pores, narrow particle size distribution and fast absorption of plasticizer. It is widely used in calendering or extrusion to produce soft film, artificial leather, cable, pipe, soft. Quality profiles, etc., can also be used to produce injection molded products.
Chlorinated polyethylene (CPE) is a random chlorinated polymer obtained by chlorination of polyethylene (PE). It has excellent weather resistance, heat aging resistance, oil resistance, chemical resistance, cold resistance, flame retardancy and resistance to bending cracking. Other characteristics, widely used in impact modification of PVC products, production of roofing waterproofing membranes, mining flame retardant conveyor belts, magnetic rubber, wire and cable, oil and acid hoses, etc. With the continuous application of CPE modified PVC products Development, the use of CPE will be more and more extensive.
In the extrusion processing of PVC soft sheets, some processes require CPE to be added in a certain ratio to improve the tensile strength and elongation at break of the product, thereby producing the desired product. Under the same basic formula, the effect of different ratios of PVC and CPE on the properties of dry mix produced.
1 Test purpose
By changing the ratio of PVC to CPE, the tensile test of non-vulcanized sheet was carried out, and the variation of tensile strength and elongation at break was observed.
2 test formula
2. 1 Formulation
On the basis of the same formula, the amount of PVC and CPE is adjusted. There are 8 test formulas. The test formula is shown in Table 1 (parts by mass).
2. 2 recipe description
PVC and CPE are produced by Qingdao Haijing Chemical Group Co., Ltd., PVC grade is HS-1300, CPE grade is CPE135A; CaCO is colloidal CaCO produced by Zibo Zhangdian Lilong Chemical Plant;
The DOP is analytically pure; the stabilizer is a rare earth stabilizer produced by a plant in Lushan, Qingdao. With the increase of the formula number, the amount of PVC is gradually reduced, and the amount of CPE is gradually increased, but the total amount of the two is still 100 parts.
3 test equipment
SHR-10A high-speed mixer, Zhangjiagang Happy Machinery Factory; SK-160B open plastic mixer, Shanghai Machinery Manufacturing Plant; CMT-302 electronic universal testing machine, Zhuhai Sansi Measuring Instrument Co., Ltd.; Shaw LX-A rubber hardness tester , Jiangdu Experimental Machinery Factory; thickness gauge, accuracy of 0.01 mm, range of 0 ~ 10 mm, Shanghai Light Industry Bureau Standard Metrology Management Institute test plant.
4 test process
4. 1 Mixture
First, weigh the raw materials according to the formula, add the weighed powder into the mixing chamber of the high-speed mixer, and mix the mixture at high speed. After 3~5rain, the powder in the mixing chamber is basically evenly mixed; At the same time, add DOP from the small feeding port. When the material temperature reaches 100 °C, it can be discharged, and cooled for standby.
4. 2 Preparation of test strips
4.2.1 Refining
Raise the temperature of the twin-roll mill roll to 150 oC, keep the temperature constant for 30 min. Adjust the roll distance of the roll to the minimum, then pour 400 g of dry mix between the two rolls and start timing. After the tapping and the triangle package, the mixture is evenly mixed. After mixing for 3 minutes, the triangle bag is used for feeding. The remaining 7 samples are mixed according to this method.
4.2.2 Next film
The roll gap between the adjustment rolls is slightly smaller than the thickness of the lower piece to be obtained. The triangular package of the blank is placed between the two rolls for pressing, and the thickness is uniform and the lower piece is reserved.
4.2.3 Cutting
Place the film for more than 2 h. After the film is homogenized, cut the piece. Use a piece cutter with a cutter width of 6 mm and a length of 25 mm to cut the piece in the direction of the lower piece.
4. 3 test standards
Hardness, according to GB/T 531—1999~ Rubber Pocket Hardness Tester for hardness test method; tensile strength, tested according to GB/T528-1998 {Measurement of tensile stress and strain properties of vulcanized rubber or thermoplastic rubber; Elongation is calculated from the tensile strength by an instrument that measures tensile strength.
4. 4 Test results
First measure the Shore A hardness and thickness of the test piece, and then cut out three standard test pieces for each test piece for parallel tensile test. The test results are shown in Table 2, Figure 1~ Figure 3.
4. 5 test data analysis
4.5.1 Hardness
As the amount of CPE increases, the hardness tends to decrease. When the amount of CPE is more than 40, the hardness decreases sharply.
4.5.2 Elongation at break
With the increase of CPE dosage, the elongation at break increased sharply, from 32.19% of 0 parts to 700.86% of 100 parts.
4.5.3 Tensile strength
When the amount of CPE is less than 60 parts, the tensile strength drops sharply; when the amount of CPE is equal to 6 parts, the tensile strength is minimized; when the amount of CPE is 60-80 parts, the tensile strength index is almost unchanged; When the amount of CPE is more than 80 parts, the tensile strength increases slightly. It can be seen that when M(PVC): M(CPE)< 1：1时，增加CPE的用量，对拉伸强度的影响不大。
4.5.4 Plasticizing performance
During the test, the author found that the performance of the package roller of the 1 and 2 formulas was poor, and the performance of the 3~8 formula package rolls gradually improved. This indicates that the plasticizing performance of the formulation system increases with the increase of the CPE dosage.
5 Conclusion
It can be seen from the test results that with the gradual increase of the amount of CPE, the plasticizing performance of the dry blend is improved, the hardness is decreased, the elongation at break is increased, and the tensile strength is generally decreased. Increasing the amount of CPE can On the basis of plastic properties, the product has certain rubber properties, which can greatly improve the toughness of the product. Through testing, PVC processing enterprises can find suitable cutting results from the influence of PVC and CPE dosage ratio on performance. Point, thus producing PVC products that meet the needs.