Spraying-free polypropylene and processing method thereof

Abstract

The invention discloses spraying-free polypropylene, which comprises homopolymerized PP resin A, copolymerized PP resin B, a flexibilizer POE, a modified filler, pearlescent master batch and a processing aid bag. The invention further discloses a processing method of the spraying-free polypropylene. The processing method comprises the following steps: firstly, adding the homopolymerized PP resin A, the copolymerized PP resin B and the flexibilizer POE into a high-speed mixer for high-speed mixing; adding the modified filling agent and the processing aid bag, and mixing; extruding the mixed raw materials in a double-screw extruder, and adding the prepared pearlescent master batch into a side feeding weightlessness scale according to a proportion in a side feeding manner; before the pearlescent master batch is added, the rotating speed of a main machine is controlled to be 900-1000R / min. The pearlescent master batch is added into the raw materials, so that spraying-free effect can be realized, high gloss is realized by using the high-gloss PP resin, and weather resistance is realized by using the weather-resistant agent.

Description

Technical Field

[0001] The invention relates to spray-free polypropylene and a processing method thereof. Background Art

[0002] The existing fully automatic toilet lid and non-electrical direct contact parts are made of ABS, which is easy to yellow and needs to be sprayed (processing is not environmentally friendly and the cost is high). Patent publication number CN109456538B: A low-density, low-shrinkage, silver metallic polypropylene composite material and its preparation method, the polypropylene composite material includes the following components: high crystalline polypropylene, high melt index polypropylene, low shrinkage polypropylene, hollow glass microbeads, ultra-white ultra-fine talcum powder, toughening filler, metal pigment, nano zinc sulfide, hyperbranched resin, antioxidant, scratch-resistant agent. It can also be used directly to replace ABS in the fields of home appliance housings. While the material density is much lower than ABS, the overall performance can reach the level of ABS. Wu Jun's paper "Preparation and Mechanical Properties of Spray-free Modified Polypropylene Materials" published in "Shanghai Plastics" Vol. 50, No. 6, 2022 adopts the following preparation method: set the extrusion temperature of the twin-screw extruder to 210-230°C, add the material at the main feed port of the extruder, and add the aluminum powder effect pigment at the side feed port as needed, extrude, draw, water-cooled and pelletized, and the pellets are dried in a 90°C oven tray for 3 hours, and then injection molded. The molding conditions are 220-230°C, medium injection speed, and medium injection pressure. It adopts the method of side feeding the effect pigment. Ma Dandan's paper "Preparation and Characterization of High-rigidity Spray-free Polypropylene Composite Materials" published in "Plastics Industry" Vol. 48, No. S1, July 2020, is prepared in the following way: make a premix and set it aside. Start the twin-screw extruder, set the temperature of each zone according to the process requirements, and after reaching the set temperature, start the extruder and add materials to wash the machine. After adjusting the parameters, add the premix, extrude, pull, cool, dry, and granulate to finally obtain the spray-free polypropylene composite material. It can be seen that the existing technology is still insufficient in functionality and cannot achieve the functions of high gloss and weather resistance in the field of spray-free polypropylene, which are urgently needed for fully automatic toilet covers and non-electrical direct contact parts. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide a spray-free polypropylene. Since pearlescent masterbatch is added to the raw material, spray-free can be achieved, high gloss is achieved by using high-gloss PP resin, and weather resistance is achieved by using a weathering agent.

[0004] To achieve the above purpose, the technical solution of the present invention is to design a spray-free polypropylene, including homopolymer PP resin A, copolymer PP resin B, toughening agent POE, modified filler, pearlescent masterbatch, and processing aid package. Since pearlescent masterbatch is added to the raw material, spray-free can be achieved, high gloss is achieved by using high-gloss PP resin, and weather resistance is achieved by weathering agent.

[0005] A further technical solution is that the modified filler is 6000 mesh barium sulfate; the added amount of pearlescent masterbatch is 5-10%; the processing aid package includes antioxidant, weathering agent, nucleating agent, lubricant, release agent and dispersant.

[0006] A further technical solution is that the pearlescent masterbatch is prepared by the following preparation method: S1: 5000 mesh white mica or wollastonite powder is selected, polyacrylamide solution, polyacrylate emulsion, and cationic latex are added to prepare a suspension, sulfuric acid is added to adjust the pH to an acidic environment, a metal salt solution is added to the acidic mica / wollastonite suspension, and then sodium hydroxide is titrated into the mica suspension. As the pH of the solution increases in alkalinity, metal hydroxide particles are precipitated and deposited on the surface of the mica to form a hydroxide film, and then the pearlescent pigment is obtained by washing, drying, and baking;

[0007] S2: The pearlescent pigment prepared in the first step is mixed with homopolymer PP with high melt index and dispersant by a single screw machine for extrusion granulation to obtain a pearlescent masterbatch with a content of 5%. The mass percentages of the pearlescent pigment, homopolymer PP with high melt index and dispersant are: 5%:94%:1%; the temperature of the single screw machine is 180℃-200℃, and the rotation speed is 400-500r / min.

[0008] A further technical solution is that resin A is 10-50 parts, resin B is 30-70 parts, POE is 1-10 parts, barium sulfate is 10-30 parts, and pearlescent masterbatch is 5-10 parts; antioxidant is 0.1-1 part, weathering agent is 0.1-1 part, nucleating agent is 0.1-0.5 part, lubricant is 0.1-0.5 part, release agent is 0.1-0.5 part, and dispersant is 0.5-2 parts.

[0009] A further technical solution is that POE is a copolymer of ethylene-octene, with a brand name of poe6012FL and a melt index of 1.6 g / 10 min; and the brand name of barium sulfate is Yuanlei Powder 6000A.

[0010] A further technical solution is that the gloss of the spray-free polypropylene is 98-102, the weather resistance is 1000 hours of xenon lamp aging, the color difference is less than 3, the tensile strength is 30MPa, the elongation is 300%, the flexural strength is 45MPa, the flexural modulus is 1500MPa, and the temperature is 230℃ and 2.16kg / cm 2The melt index under pressure is (10-20) g / 10min and the impact strength is 5 kj / m 2 .

[0011] The present invention also relates to a technical solution for processing spray-free polypropylene, S1, adding homopolymer PP resin A, copolymer PP resin B and toughening agent POE in proportion to a high-speed mixer and mixing at high speed for 2 to 3 minutes;

[0012] S2, then add the modified filler and processing aid package into the high-speed mixer and mix at high speed for 2 to 3 minutes to fully mix the components;

[0013] S3. Extruding the mixed raw materials in a twin-screw extruder with a length-to-diameter ratio of 40:1. The extruder is provided with ten temperature zones, and the temperatures of the ten temperature zones are 180°C, 190°C, 200°C, 210°C, 210°C, 210°C, 210°C, 210°C, 205°C, and 200°C respectively; the vacuum degree in the temperature zones is controlled at -0.08MPA to ensure that VOC, low molecular weight substances, and decomposition products of the materials can be fully discharged during the processing;

[0014] S4. Add the prepared pearlescent masterbatch to the side-feed loss-in-weight scale in proportion by side-feeding; before adding the pearlescent masterbatch, the main engine speed is controlled at 900-1000R / min. The twin-screw equipment with a large aspect ratio can adapt to more components and higher filling; the side-feeding of the pearlescent masterbatch is mainly to prevent the pearlescent masterbatch from being broken by the twin-screw extruder and losing the pearlescent effect; if the main engine speed is too high, the pearlescent masterbatch will be broken, and the final pearlescent effect will be extremely poor; if the speed is too low, the dispersion is poor and the pearlescent effect is not ideal.

[0015] The advantages and beneficial effects of the present invention are as follows: the use of a twin-screw device with a large aspect ratio can accommodate more components and higher filling; the side feeding of the pearlescent masterbatch is mainly to prevent the pearlescent masterbatch from being broken by the twin-screw extruder and losing the pearlescent effect; if the main engine speed is too high, the pearlescent masterbatch will be broken and the final pearlescent effect will be extremely poor; if the speed is too low, the dispersion is poor and the pearlescent effect is not ideal.

[0016] Since pearlescent masterbatch is added to the raw materials, spraying is not required, high gloss is achieved by using high-gloss PP resin, and weather resistance is achieved by using weathering agents.

[0017] In the field of spray-free polypropylene, high gloss and weather resistance are realized, which are urgently needed for fully automatic toilet seats and non-electrical direct contact parts.

[0018] It can be used for fully automatic toilet seats and non-electrical direct contact parts to replace the existing ABS, solving the shortcomings of ABS that is easy to yellow and needs spraying (processing is not environmentally friendly and the cost is high).

[0019] Gloss 98-102, weather resistance 1000 hours xenon lamp aging, color difference less than 3, tensile strength 30, elongation 300, flexural strength 45, flexural modulus 1500, melt index 230℃ / 2.16KG / 10-20g / 10min, impact strength 5kj / m 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a twin-screw extruder involved in Example 2 of a spray-free polypropylene of the present invention;

[0021] Figure 2 yes Figure 1 Rear view of

[0022] Figure 3 is an exploded schematic diagram of a single screw extruder and a rubber plug in the second embodiment of the present invention;

[0023] Figure 4 yes Figure 3 Side view of the middle disc;

[0024] Figure 5 It is a schematic diagram of the rubber plug rod, stirring blade, and stirring shaft in the second embodiment;

[0025] Figure 6 yes Figure 5 a cross-sectional view of the middle collar;

[0026] Figure 7 It is an exploded schematic diagram of a single screw extruder and a rubber plug in the third embodiment of the present invention;

[0027] Figure 8 yes Figure 7 An enlarged schematic diagram of a local portion of the left end of the middle rectangular box;

[0028] Fig. 9 yes Figure 8 Side view of the middle bending channel, two stops and the rigid bending rod;

[0029] Fig.10 yes Figure 7 An enlarged schematic diagram of the rubber plug in the middle.

[0030] In the figure: 1. single-screw extruder; 2. twin-screw extruder; 3. screw; 4. disc; 5. rubber slot; 6. rubber plug rod; 7. flexible shaft; 8. stirring blade; 9. stirring shaft; 10. collar; 11. ring groove; 12. guide way; 13. gear lever; 14. block; 15. curved channel; 16. hard curved rod; 17. magnetic sheet. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0032] Embodiment 1: The present invention is a spray-free polypropylene, and its formula is as follows: 1. PP resin A

[0033] 2. PP resin B

[0034] 3. Toughening agent POE

[0035] 4. Modified filler barium sulfate 6000 mesh

[0036] 5. Pearlescent masterbatch (self-made addition amount 5-10%)

[0037] 6. Processing aid package (including antioxidants, weathering agents, nucleating agents, etc.);

[0038] Spray-free is achieved through pearlescent masterbatch, high gloss is achieved by using high-gloss PP resin, and weather resistance is achieved through weathering agent.

[0039] Resin A is recommended to be 10-50, resin B is recommended to be 30-70, POE is recommended to be 1-10, barium sulfate is recommended to be 10-30, pearlescent masterbatch is 5-10, antioxidant is 0.1-1, weathering agent is 0.1-1, nucleating agent is 0.1-0.5, lubricant is 0.1-0.5, release agent is 0.1-0.5, and dispersant is 0.5-2.

[0040] Homopolymer PP and copolymer PP are used in combination.

[0041] POE is a copolymer of ethylene-octene; the brand is poe 6012FL, and the MI is 1.6 g / 10min.

[0042] The modified filled barium sulfate is the barium sulfate model 6000A from Yuanlei Powder.

[0043] The homemade process of pearlescent masterbatch is:

[0044] Step 1: The materials for homemade pearlescent masterbatch include 5000 mesh white mica or wollastonite powder, adding polyacrylamide solution, polyacrylate emulsion, cationic latex, etc. to prepare a suspension, and then adding sulfuric acid to adjust the pH to an acidic environment. Metal salt solution is added to the acidic mica / silica gray suspension, and then sodium hydroxide is titrated into the mica suspension. As the pH of the solution increases with the alkalinity, metal hydroxide particles precipitate and settle on the surface of the mica to form a hydroxide film, which is then washed, dried and baked to obtain pearlescent pigments.

[0045] Step 2: Then, the pearlescent pigment prepared in the first step, 5% pearlescent pigment, 94% high melt index homopolymer PP, and 1% dispersant are blended and extruded into granules using a single screw machine at a temperature of 180℃-200℃ and a rotation speed of 400-500R / min to obtain a 5% pearlescent masterbatch.

[0046] Antioxidant 0.1-1, weathering agent 0.1-1, nucleating agent 0.1-0.5, lubricant 0.1-0.5, release agent 0.1-0.5, and dispersant may also be present.

[0047] The glossiness of the spray-free polypropylene is 98-102, the weather resistance is 1000 hours of xenon lamp aging, the color difference is less than 3, the tensile strength is 30, the elongation is 300, the bending strength is 45, the bending modulus is 1500, the melt index is 230℃ / 2.16KG / 10-20g / 10min, and the impact strength is 5kj / m 2

[0048] Spray-free high gloss polypropylene processing technology:

[0049] The preparation method of the composite material of the present invention:

[0050] The first step is to add PP resin A, PP resin B, and POE into a high-speed mixer according to the proportion and mix at high speed for 2 to 3 minutes;

[0051] The second step is to add the modified filler barium sulfate powder and the processing aid package into the high-speed mixer and mix at high speed for 2 to 3 minutes to make the components fully mixed;

[0052] The third step is to extrude the mixed raw materials through a twin-screw extruder with a length-to-diameter ratio of 40:1. Twin-screw equipment with a large length-to-diameter ratio can adapt to more components and higher filling. The processing temperature of the extruder is set to ten temperature zones, and the temperature of each temperature zone is 180℃, 190℃, 200℃, 210℃, 210℃, 210℃, 210℃, 210℃, 205℃, and 200℃ respectively; the vacuum degree in the temperature zone is controlled at -0.08MPA to ensure that the VOC, low molecular weight substances, and decomposition products of the materials can be fully discharged during the processing.

[0053] Step 4: Add the homemade pearlescent masterbatch to the side-feed loss-in-weight scale by side-feeding, and add it in proportion. The side-feeding method of pearlescent masterbatch is mainly to prevent the pearlescent masterbatch from being broken by the twin-screw extruder and losing the pearlescent effect. Before adding the pearlescent masterbatch, the main engine speed needs to be controlled at 900-1000R / min. If the speed is too high, the pearlescent masterbatch will be broken, and the final pearlescent effect will be extremely poor; if the speed is too low, the dispersion is poor and the pearlescent effect is not ideal.

[0054] Embodiment 2: The difference from Embodiment 1 is that Figures 1 to 6As shown (for the convenience of illustration, Figure 1 The disc and rubber slot are not shown). In step S1 of the pearlescent masterbatch preparation method, the screw 3 of the single-screw extruder 1 or the twin-screw extruder 2 is used to rotate and drive the stirring blade to stir to prepare the suspension and the stirring after the sodium hydroxide titration.

[0055] The screw 3 of the single-screw extruder and / or the twin-screw extruder extends out of one end of the body of the single-screw extruder or the twin-screw extruder, and the exposed end of the screw 3 is fixedly connected to a disc 4, and different positions of the disc are fixedly connected to a rubber slot 5, and a rubber plug rod 6 is adapted to the rubber slot, and the non-insertion end of the rubber plug rod is fixedly connected to a flexible shaft 7, and the end of the flexible shaft away from the rubber plug rod is fixedly connected to a stirring blade 8 (a preferred solution is: the end of the flexible shaft away from the rubber plug rod is fixedly connected to a stirring shaft made of a hard material, and the stirring blade 8 is rotatably arranged on the stirring shaft 9, and a sleeve 10 adapted to the cup mouth of the suspension container is fixedly connected to the stirring shaft, so that the stirring blade can be ensured to be in the middle position of the suspension container such as a cylindrical tank, so as to prevent the stirring blade from touching the tank wall, and an annular groove 11 is arranged on the sleeve 10 to facilitate the sleeve 10 to cover the tank mouth of the cylindrical tank);

[0056] During the process of preparing the suspension, the rubber rod 6 is inserted into the rubber slot 5 which is farther from the center of the disc; during the process of pH adjustment and sodium hydroxide titration, the rubber rod is inserted into the rubber slot which is closer to the center of the disc.

[0057] In the process of preparing pearlescent masterbatch, whether it is the preparation of suspension, the PH adjustment process, or the sodium hydroxide titration process, stirring is required, and the stirring speed is different, so a stirring device is required, which increases energy consumption and the number of equipment required (and cost), and the stirring speed needs to be adjusted in different processes, which increases labor. After the present embodiment is set up in this way, the power of the single-screw extruder or the twin-screw extruder itself is used, so the stirring mechanism is omitted, and the number of equipment and cost are not increased. In addition, the rubber plug rod, the flexible shaft and the stirring blade structure are matched with the rubber slots set at different positions of the exposed end of the screw to realize the automatic speed adjustment in different processes, reduce labor and reduce labor intensity (the operator does not need to take the initiative to adjust, and the rubber plug rod can be directly inserted into the rubber slots at different positions to meet the different speeds required for different processes). After such a setting, the suspension is prepared, the PH adjustment and the sodium hydroxide titration are performed when the pearlescent masterbatch required for the subsequent preparation of polypropylene is prepared while the spray-free polypropylene is extruded or the pearlescent masterbatch is extruded and granulated, so that each time the spray-free polypropylene is prepared, the pearlescent masterbatch required for the next polypropylene can be prepared at the same time.

[0058] There are two rubber slots on the disc, and identification stickers can be attached to the two rubber slots on the disc to remind the operator whether it is the stirring process of preparing the suspension or the pH adjustment process (or sodium hydroxide titration process). In this way, the position of the rubber slot on the disc can be set in advance according to the rotation speed required for pH adjustment and sodium hydroxide titration and the rotation speed required for preparing the suspension. Three rubber slots can also be set (if the stirring speed required for the pH adjustment and sodium hydroxide titration processes is different.

[0059] Embodiment 3: The difference from Embodiment 2 is that Figures 7 to 10 As shown (for ease of illustration, Figure 8 The curved channel is not shown), a rectangular box is arranged on the side of the disc 4 away from the body, and two curved guide channels 12 are arranged in the rectangular box. The two guide channels are respectively connected to the rubber slots 5, and a shift rod 13 hinged on the inner wall of the guide channel is arranged at the exit of the two guide channels 12. A torsion spring is arranged on the hinge shaft of the shift rod to ensure that the shift rod always has a tendency to rotate toward the inside of the guide channel, and a stopper 14 is arranged on the inner side of the shift rod (referring to the inner side of the shift rod relative to the guide channel), and a curved channel 15 is arranged between the two guide channels. The two stoppers 14 are fixedly connected by a hard curved rod 16 arranged in the curved channel 15. One of the two stoppers 14 extends out of the bottom wall of the guide channel (that is, it is located outside the curved channel, that is, it is located in the guide channel to form a function of blocking the shift rod), and the other is located in the curved channel 15. The shape of the block is larger at the top and smaller at the bottom, and the size of the larger end at the top is slightly larger than the channel opening of the curved channel 15 (so the block located in the curved channel is subjected to the squeezing force of the curved channel, and the block is made of elastic material), a magnetic sheet is arranged on the top of the block, and a magnetic sheet 17 adapted to the aforementioned magnetic sheet is arranged on the rubber plug 6 (a more preferred solution is to arrange the insertion end of the rubber plug into a cylindrical shape and to wrap a circle of flexible magnetic strip around the side of the cylindrical insertion end to ensure that no matter at what angle the rubber plug is inserted, it can form a magnetic attraction force with the magnetic sheet on the top of the block), and a steel wire can also be fixedly arranged on the soft shaft fixedly connected to the rubber plug so that the soft shaft maintains a certain hardness to facilitate insertion into the rubber slot through the guide channel.

[0060] After such setting, the operator does not need to consider which rubber slot the rubber rod is inserted into. Just insert it and it will automatically be realized that one time is the rubber slot corresponding to the large stirring speed, and the other time is the rubber slot corresponding to the small stirring speed. It is only necessary to make it clear that the first time is the large stirring speed. Before starting the machine, just insert the block on the guide path connected to the rubber slot farther from the center of the disc into the curved channel. In this way, after starting work, the soft shaft (and the rubber rod) is manually inserted along the guide path. Since a block is exposed outside the curved channel to form a block, the soft shaft is inserted into the guide path where the block inserted into the curved channel is located and finally inserted into the rubber slot at the far end of the guide path. When the pH is adjusted after the suspension is prepared and stirred, the soft shaft is pulled out to separate the rubber rod from the rubber slot. In the process of pulling out, the magnetic sheet is finally affected by the magnetic sheet (or magnetic strip) on the rubber rod, and the block originally inserted is sucked out, so that the block extends outward, and the block at the other end connected by the hard curved rod is pulled into the curved channel where it is located. Therefore, when the PH is adjusted, the flexible shaft and the rubber rod are inserted again. The process is opposite to the above process. Therefore, there is no need to consider which rubber slot to insert into manually. One insertion into this rubber slot and the other insertion into another rubber slot are automatically realized.

[0061] If the stirring speed during the pH adjustment process and the stirring speed during the sodium hydroxide titration process can be consistent, this structure can realize all three processes. It is only necessary to continue the sodium hydroxide titration without pulling out the flexible shaft (and rubber plug) after the pH adjustment.

[0062] If the stirring speed during the pH adjustment process is inconsistent with the stirring speed during the sodium hydroxide titration process, the improvement of this embodiment can still solve the two processes without manual supervision, and can be directly plugged and unplugged twice, which can also reduce labor intensity.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A spray-free polypropylene, characterized in that: Including homopolymer PP resin A, copolymer PP resin B, toughening agent POE, modified filler, pearlescent masterbatch, and processing aid package.

2. The spray-free polypropylene according to claim 1, characterized in that: The modified filler is 6000 mesh barium sulfate; the added amount of pearlescent masterbatch is 5-10%; the processing aid package includes antioxidant, weathering agent, nucleating agent, lubricant, release agent and dispersant.

3. The spray-free polypropylene according to claim 2, characterized in that: The pearlescent masterbatch is prepared by the following preparation method: S1: 5000 mesh white mica or wollastonite powder is selected, polyacrylamide solution, polyacrylate emulsion, and cationic latex are added to prepare a suspension, sulfuric acid is added to adjust the pH to an acidic environment, a metal salt solution is added to the acidic mica / wollastonite suspension, and then sodium hydroxide is titrated into the mica suspension. As the pH of the solution increases in alkalinity, metal hydroxide particles are precipitated and deposited on the surface of the mica to form a hydroxide film, and then the pearlescent pigment is obtained by washing, drying, and baking; S2: The pearlescent pigment prepared in the first step is mixed with homopolymer PP with high melt index and dispersant by a single screw machine for extrusion granulation to obtain a pearlescent masterbatch with a content of 5%. The mass percentages of the pearlescent pigment, homopolymer PP with high melt index and dispersant are: 5%:94%:1%; the temperature of the single screw machine is 180℃-200℃, and the rotation speed is 400-500r / min.

4. The spray-free polypropylene according to claim 3, characterized in that: The resin A is 10-50 parts, the resin B is 30-70 parts, the POE is 1-10 parts, the barium sulfate is 10-30 parts, the pearlescent masterbatch is 5-10 parts; the antioxidant is 0.1-1 parts, the weathering agent is 0.1-1 parts, the nucleating agent is 0.1-0.5 parts, the lubricant is 0.1-0.5 parts, the release agent is 0.1-0.5 parts, and the dispersant is 0.5-2 parts.

5. The spray-free polypropylene according to claim 4, characterized in that: The POE is a copolymer of ethylene-octene, with a brand name of poe 6012FL and a melt index of 1.6 g / 10 min; the brand name of barium sulfate is Yuanlei Powder 6000A.

6. The spray-free polypropylene according to claim 5, characterized in that: The spray-free polypropylene has a gloss of 98-102, a xenon lamp aging resistance of 1000 hours, a color difference of less than 3, a tensile strength of 30MPa, an elongation of 300%, a flexural strength of 45MPa, a flexural modulus of 1500MPa, and a strength of 230°C and 2.16kg / cm 2 The melt index under pressure is (10-20) g / 10min and the impact strength is 5 kj / m 2 .

7. The method for processing spray-free polypropylene according to any one of claims 1 to 6, characterized in that: S1. Add homopolymer PP resin A, copolymer PP resin B and toughening agent POE into a high-speed mixer in proportion and mix at high speed for 2 to 3 minutes; S2, then add the modified filler and processing aid package into the high-speed mixer and mix at high speed for 2 to 3 minutes to fully mix the components; S3. Extruding the mixed raw materials in a twin-screw extruder with a length-to-diameter ratio of 40:

1. The extruder is provided with ten temperature zones, and the temperatures of the ten temperature zones are 180°C, 190°C, 200°C, 210°C, 210°C, 210°C, 210°C, 210°C, 205°C, and 200°C respectively; the vacuum degree in the temperature zones is controlled at -0.08MPA to ensure that VOC, low molecular weight substances, and decomposition products of the materials can be fully discharged during the processing; S4. Add the prepared pearlescent masterbatch to the side-feed loss-in-weight scale in proportion by side-feeding; before adding the pearlescent masterbatch, the main engine speed is controlled at 900-1000R / min.

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