PVC low foaming profile
DATE：2022/6/8 8:41:56 / READ： / SOURCE：This station
PVC low foaming profile
PVC low foaming profile has the advantages of light weight, beautiful appearance, fire resistance and so on. It is mostly used to replace wood as decorative non structural material. It is generally used to produce window frames, furniture edging materials, fences, decorative parts, etc. it is a product with rapid development in recent years. In particular, China is quite short of forest resources, so it is imperative to replace wood with PVC low foaming profile, and PVC low foaming profile is an ideal substitute for wood. In addition, it is of great significance to save raw materials, reduce costs and improve economic benefits. Hollow plate production line www.handern com
UPVC low foaming profile was developed extensively in the 1970s. It is mostly used to replace wood as decorative non structural material, and has broad development prospects. Chemical foaming method and physical foaming method are widely used in the extrusion of PVC foamed profile, specifically belonging to the free expansion system. This kind of product can be controlled by "seluca" method. Unplasticized rigid PVC products are widely used in this field. Unplasticized PVC foamed profile products are the largest application field of commercial foamed profiles. Hollow plate production line www.handern com
Process flow of PVC low foaming profile:
(1) Kneading process kneading is a key process in PVC processing. Kneading quality directly affects the quality of extruded products. Two high-speed kneaders are used in series, and the high-speed hot kneaded materials are put into the cold kneader for cold kneading. In this way, the components in the material can be better dispersed, and the material can be prevented from overheating and decomposition
The process parameters are as follows. Hollow plate production line www.handern com
(2) High speed thermal kneading kneading time is 5~10min, kneading temperature is (95 ± 5) ℃. High speed cold kneading kneading time is 5~10min, kneading temperature is (35+5) ℃. (2) The extrusion process is very important for the extrusion temperature control of foamed profiles, especially the temperature control of the die and die. If the temperature is too low, the foaming is insufficient, and the product density is too high. In addition, the addition of ACR increases the elasticity of the foaming material melt, which intensifies with the decrease of temperature and is prone to melt breakage. Therefore, only by plasticizing at a higher temperature can the product be fully foamed. However, if the temperature of the machine head is too high, the foaming speed will become faster, the bubble will expand rapidly, resulting in the rupture of the bubble, the scar on the product surface, and a small amount of material decomposition. Therefore, PVC foaming extrusion requires strict temperature control, and large temperature fluctuation is not allowed. After the open die, it expands and foams under reduced pressure.
(3) 3. Rotation is beneficial to extrusion foaming. While increasing the screw speed, it should be matched with the cooling system to avoid flow. ④ for the twin-screw extruder, the screw speed should be controlled at 5~10r/min. Dynamic defect.
(4) ⑤ type 10~2.5m/min is suitable.
(5) The cooling water tank for 6-quality PVC foaming production is generally about 3~8m long, which can be calculated according to the cooling time of about one minute. The water temperature can be room temperature or 5~10 ℃. Select the length of cooling water tank and hollow plate production line www.handern com
(6) (3) outgoing equipment
(7) ① the single screw used for foaming of equipment B is a modified screw, with a length diameter ratio of 24~30 and a compression ratio of (21) ~ (31). The length of the screw metering section is determined by the total length of the screw and the die resistance. Generally, the length of the metering section is inversely proportional to the matching of the die resistance, and it is required that the length of the metering section shall not exceed 10 diameters.
(8) ② screw diameter. To determine the screw diameter is to select the size of the extrusion host. It is recommended to select according to the sectional area, output and traction speed of the profile. For example, for a single screw extruder with a diameter of 65mm, the cross-sectional area of the profile is 2~6cm, the traction speed is 6~12m/min, and the output is about 45~80kg/h. If there is a forced feeding system, the output can reach more than 100kg/h. For twin-screw extruder, the main machine size shall be selected according to the output of 65~86kg/h for profiles with the same section. The specific selection should also consider the influence of traction speed, foaming ratio, cooling speed and other factors.
(9) ③ high resistance nose. For high resistance die, the effect is best when the screw length is 20d and the compression ratio is 3:1. For low resistance die, the mixing capacity of the screw itself is high. The screw length used is (25~30) D and the compression ratio is 1.5~1.8. In this way, high-quality foam products can also be obtained
(10) ④ heating and cooling. Besides normal heating, it is better to have air cooling device for the cylinder. The screw can be internally circulated with hot oil for proper temperature adjustment.
(11) ⑤ screw head. The shape of screw head shall not adopt the form with dead point on the top. The flow cross-sectional area at the front end of the barrel shall not be too large to avoid pressure relief and foaming in advance. Similarly, excessive agitation caused by mixing elements on the screw shall be avoided, and sudden flow direction change shall not be allowed. ⑥ Mold sleeve is used for shaping. According to the traction speed of most profiles, the mold
(12) But the vacuum water tank or the vacuum water tank is cooled and shaped. The setting device is set at a position about 25~300mm away from the die lip outlet.
Hollow plate production line www.handern com
PVC low foaming profile has the advantages of light weight, beautiful appearance, fire resistance and so on. It is mostly used to replace wood as decorative non structural material. It is generally used to produce window frames, furniture edging materials, fences, decorative parts, etc. it is a product with rapid development in recent years. In particular, China is quite short of forest resources, so it is imperative to replace wood with PVC low foaming profile, and PVC low foaming profile is an ideal substitute for wood. In addition, it is of great significance to save raw materials, reduce costs and improve economic benefits. Hollow plate production line www.handern com
UPVC low foaming profile was developed extensively in the 1970s. It is mostly used to replace wood as decorative non structural material, and has broad development prospects. Chemical foaming method and physical foaming method are widely used in the extrusion of PVC foamed profile, specifically belonging to the free expansion system. This kind of product can be controlled by "seluca" method. Unplasticized rigid PVC products are widely used in this field. Unplasticized PVC foamed profile products are the largest application field of commercial foamed profiles. Hollow plate production line www.handern com
Process flow of PVC low foaming profile:
(1) Kneading process kneading is a key process in PVC processing. Kneading quality directly affects the quality of extruded products. Two high-speed kneaders are used in series, and the high-speed hot kneaded materials are put into the cold kneader for cold kneading. In this way, the components in the material can be better dispersed, and the material can be prevented from overheating and decomposition
The process parameters are as follows. Hollow plate production line www.handern com
(2) High speed thermal kneading kneading time is 5~10min, kneading temperature is (95 ± 5) ℃. High speed cold kneading kneading time is 5~10min, kneading temperature is (35+5) ℃. (2) The extrusion process is very important for the extrusion temperature control of foamed profiles, especially the temperature control of the die and die. If the temperature is too low, the foaming is insufficient, and the product density is too high. In addition, the addition of ACR increases the elasticity of the foaming material melt, which intensifies with the decrease of temperature and is prone to melt breakage. Therefore, only by plasticizing at a higher temperature can the product be fully foamed. However, if the temperature of the machine head is too high, the foaming speed will become faster, the bubble will expand rapidly, resulting in the rupture of the bubble, the scar on the product surface, and a small amount of material decomposition. Therefore, PVC foaming extrusion requires strict temperature control, and large temperature fluctuation is not allowed. After the open die, it expands and foams under reduced pressure.
(3) 3. Rotation is beneficial to extrusion foaming. While increasing the screw speed, it should be matched with the cooling system to avoid flow. ④ for the twin-screw extruder, the screw speed should be controlled at 5~10r/min. Dynamic defect.
(4) ⑤ type 10~2.5m/min is suitable.
(5) The cooling water tank for 6-quality PVC foaming production is generally about 3~8m long, which can be calculated according to the cooling time of about one minute. The water temperature can be room temperature or 5~10 ℃. Select the length of cooling water tank and hollow plate production line www.handern com
(6) (3) outgoing equipment
(7) ① the single screw used for foaming of equipment B is a modified screw, with a length diameter ratio of 24~30 and a compression ratio of (21) ~ (31). The length of the screw metering section is determined by the total length of the screw and the die resistance. Generally, the length of the metering section is inversely proportional to the matching of the die resistance, and it is required that the length of the metering section shall not exceed 10 diameters.
(8) ② screw diameter. To determine the screw diameter is to select the size of the extrusion host. It is recommended to select according to the sectional area, output and traction speed of the profile. For example, for a single screw extruder with a diameter of 65mm, the cross-sectional area of the profile is 2~6cm, the traction speed is 6~12m/min, and the output is about 45~80kg/h. If there is a forced feeding system, the output can reach more than 100kg/h. For twin-screw extruder, the main machine size shall be selected according to the output of 65~86kg/h for profiles with the same section. The specific selection should also consider the influence of traction speed, foaming ratio, cooling speed and other factors.
(9) ③ high resistance nose. For high resistance die, the effect is best when the screw length is 20d and the compression ratio is 3:1. For low resistance die, the mixing capacity of the screw itself is high. The screw length used is (25~30) D and the compression ratio is 1.5~1.8. In this way, high-quality foam products can also be obtained
(10) ④ heating and cooling. Besides normal heating, it is better to have air cooling device for the cylinder. The screw can be internally circulated with hot oil for proper temperature adjustment.
(11) ⑤ screw head. The shape of screw head shall not adopt the form with dead point on the top. The flow cross-sectional area at the front end of the barrel shall not be too large to avoid pressure relief and foaming in advance. Similarly, excessive agitation caused by mixing elements on the screw shall be avoided, and sudden flow direction change shall not be allowed. ⑥ Mold sleeve is used for shaping. According to the traction speed of most profiles, the mold
(12) But the vacuum water tank or the vacuum water tank is cooled and shaped. The setting device is set at a position about 25~300mm away from the die lip outlet.
Hollow plate production line www.handern com
Author：admin