A special material for polyethylene pipe color changing washing machine and its preparation method and application

Abstract

The present invention belongs to the field of polyethylene pipe and polyethylene composite pipe processing, and provides a polyethylene pipe color-changing washing machine special material, a preparation method and an application thereof. The polyethylene pipe color-changing washing machine special material is composed of the following raw materials in parts by weight: 40-80 parts of pipeline-grade polyethylene, 10-25 parts of polyether block copolymer elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 2-7 parts of ethylene-vinyl acetate copolymer modified by maleic anhydride grafting, 1-15 parts of inorganic filler, and 0.2-4 parts of functional additives; the polyethylene pipe color-changing washing machine special material is obtained by blending and twin-screw melt granulation. The polyethylene pipe color-changing washing machine special material of the present invention utilizes the principle of in-situ fiberization of polyether block copolymer elastomer in polyethylene, and the added inorganic filler accelerates the cleaning effect of colored materials in the polyethylene pipe equipment mold. The polyethylene pipe color-changing washing machine special material of the present invention has strong color-changing ability and fast color-changing speed, and the color-changing washing machine time is reduced from more than 6 hours to less than 2 hours.

Description

Technical Field

[0001] The present invention belongs to the field of polyethylene pipe and polyethylene composite pipe processing, and specifically relates to a polyethylene pipe color changing and washing machine special material and a preparation method and application thereof, and more specifically to a polyethylene pipe color changing and washing machine special material with the function of rapid color changing and washing, and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Due to the needs of pipeline function and identification, pipelines are often made into different colors. Polyethylene pipelines and composite pipelines are generally extruded by a single screw extruder or co-extruded by multiple single screw extruders. Polyethylene special materials are then molded through molds to obtain polyethylene pipelines and composite pipelines. In the production process of polyethylene pipelines of different colors, due to the complex configuration of the extruder screw and the various spiral structures of the mold cavity, the color change production of polyethylene pipes of different colors is extremely time-consuming, labor-intensive, and material-intensive. The mold is often disassembled and cleaned. This process is extremely time-consuming. After the mold is disassembled and installed, a large amount of polyethylene original color material is required to wash the machine to its original color. Taking the DN250 pipeline equipment as an example, it takes up to 20 hours to change the black raw material in the equipment to red, and the cost is about 4,000 yuan, which brings great inconvenience to the production of polyethylene pipelines.

[0004] Traditional processes often use three methods to clean twin-screw extruders or injection molding machines used for plastic modification: removing the screw, removing the mold for physical cleaning, using a large amount of raw materials to wash the machine, and preparing special materials for washing the machine. Physical cleaning is time-consuming and labor-intensive, and it is easy to damage the equipment; raw material cleaning is time-consuming and material-intensive, and has low efficiency. Developing special materials for washing machines has become a new trend for washing machines. The patent with application number 201510147511.0 discloses a universal polymer special material for washing machines, which is composed of 40-60% high-density polyethylene, 20-40% polymethyl methacrylate, 10-20% calcium carbonate filling, 100 parts of modified polymer alloy, 0.5-1 part of thermoplastic initiator, 0.5-1.5 parts of surfactant, 0.5-1.5 parts of cleaning agent, and 0.5-1.5 parts of silicone oil. The patent with application number 202110572047.5 discloses an amphiphilic cleaning material, which includes the following components by mass: 50-75 parts of PC resin, 10-20 parts of EMA-g-GMA resin, 15-30 parts of UHWPE resin, and 0.1-1 parts of antioxidant. The patent with application number 201710545622.6 discloses a special material for cleaning a plastic screw extruder, which uses a thermoplastic elastomer as a carrier, a multi-faceted microparticle stripping agent formed by composite ceramic microspheres and polytetrafluoroethylene-coated quartz sand, and an activator to achieve efficient stripping and cleaning of scale and residues in the screw extruder. Existing special materials for washing machines are not suitable for polyethylene pipe processing equipment because their base materials are all polymers incompatible with polyethylene. If they are used to clean polyethylene pipe equipment, the residual cleaning materials will affect the appearance and pressure-bearing performance of the polyethylene pipe. Summary of the invention

[0005] In order to solve the problems of physical disassembly and cleaning of screws and molds, long machine washing time and waste of polyethylene raw materials, and the lack of color-changing washing materials dedicated to polyethylene pipes, the present invention proposes a special material for polyethylene pipe color-changing washing machines and its preparation method and application. The special material for polyethylene pipe color-changing washing machines is prepared by blending and twin-screw melt granulation from pipeline-grade polyethylene, polyether block copolymer elastomer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer grafted with maleic anhydride, inorganic filler, and functional additives. The special material is obtained by blending and twin-screw melt granulation. The special material for polyethylene pipe color-changing washing machines of the present invention utilizes the principle of in-situ fiberization of polyether block copolymer elastomer in polyethylene, and the addition of inorganic fillers accelerates the cleaning of residual colored materials in polyethylene pipe extruders and molds.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a special material for a polyethylene pipe color-changing washing machine, which is composed of the following raw materials in parts by weight: 40-80 parts of pipeline-grade polyethylene, 10-25 parts of polyether block copolymer elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 2-7 parts of ethylene-vinyl acetate copolymer modified by maleic anhydride grafting, 1-15 parts of inorganic filler, and 0.2-4 parts of functional additives.

[0008] In some embodiments, the pipe-grade polyethylene is selected from at least one of PE80 grade, PE100 grade, and PERT polyethylene;

[0009] In some embodiments, the pipe-grade polyethylene has a melt mass flow rate of 0.2-1.4 g / 10 min at 190° C. and 5 kg weight.

[0010] In some embodiments, the polyether block copolymer elastomer is selected from a polyamide elastomer formed by a block containing a polyether soft segment and a polyamide hard segment, and a thermoplastic polyester elastomer formed by a block containing a polyester hard segment and a polyether soft segment;

[0011] In some embodiments, the polyether block copolymer elastomer has a melting point below 200°C.

[0012] In some embodiments, the vinyl acetate content of the ethylene-vinyl acetate copolymer is 8%-28%, and the melt mass flow rate is 0.5-8 g / 10 min at 190° C. and 2.16 kg weight.

[0013] In some embodiments, the maleic anhydride grafting rate of the maleic anhydride-grafted ethylene-vinyl acetate copolymer is 0.5%-1.5%.

[0014] In some embodiments, the inorganic filler is selected from at least one of needle-shaped wollastonite, alumina fiber, glass fiber, basalt fiber, and carbon fiber.

[0015] In some embodiments, the functional additive is selected from at least one of hindered phenol antioxidants, sulfur-containing hindered phenol antioxidants, phosphite antioxidants, hindered amine light stabilizers, pigments, and masterbatches.

[0016] The second aspect of the present invention provides a method for preparing a special material for a polyethylene pipe color changing washing machine, comprising:

[0017] The pipeline-grade polyethylene, polyether block copolymer elastomer, ethylene-vinyl acetate copolymer, maleic anhydride grafted modified ethylene-vinyl acetate copolymer, inorganic filler and functional additives are uniformly mixed, twin-screw extruded and granulated to obtain polyethylene pipeline color-changing washing machine special material.

[0018] The third aspect of the present invention provides the application of the above-mentioned special material for polyethylene pipe color changing and washing machine or the special material for polyethylene pipe color changing and washing machine prepared by the above-mentioned method in the production of color changing and washing machines for polyethylene pipes and polyethylene composite pipes.

[0019] In some embodiments, the above-mentioned polyethylene pipe color-changing washing machine special material or the polyethylene pipe color-changing washing machine special material prepared by the above method is first used for washing for 20-40 minutes, and then the original color polyethylene pipe material is used for washing for 30-80 minutes.

[0020] Beneficial Effects of the Invention

[0021] (1) The present invention combines pipeline-grade polyethylene, polyether block copolymer elastomer, ethylene-vinyl acetate copolymer, maleic anhydride grafted ethylene-vinyl acetate copolymer, inorganic filler, and functional additives, and the special material for polyethylene pipe color-changing and washing machine has the functions of high color-changing and washing efficiency. Traditional pipeline production color-changing and washing machines generally use physical cleaning such as removing screws and molds, and then use natural polyethylene for continuous cleaning, which is laborious and time-consuming, and generally takes 6-24 hours to complete; while the special material for polyethylene pipe color-changing and washing machine of the present invention can be used to wash the machine for 20-40 minutes, and then the natural polyethylene pipe material can be used to wash the machine for 30-80 minutes to complete the color-changing and washing work, which greatly improves the efficiency of the color-changing and washing machine.

[0022] (2) The polyethylene color-changing washing machine special material of the present invention utilizes the incompatibility and in-situ fiberization principle in the blending modification to improve the cleaning of the extruder and the dead corner of the mold. The inventor found that pipeline-grade polyethylene and polyether block copolymer elastomer are two incompatible polymer materials. Pipeline-grade polyethylene has poor fluidity and is a non-polar plastic, while polyether block copolymer elastomer is a polar polymer material. The polyether block copolymer elastomer is dispersed in polyethylene. The two are incompatible, but adding 10-20 parts of ethylene-vinyl acetate copolymer and 2-7 parts of ethylene-vinyl acetate copolymer modified by maleic anhydride grafting can improve the dispersion of polyether block copolymer elastomer in polyethylene. After extrusion through a cylindrical mold, a fibrous structure is formed. This is mainly because ethylene-vinyl acetate copolymer and ethylene-vinyl acetate copolymer modified by maleic anhydride grafting play the role of compatibilizers, improving the compatibility of pipeline-grade polyethylene and polyether block copolymer elastomer. After blending modification, the polyether block copolymer elastomer forms a fibrous structure in polyethylene. After fiberization, the special material can strengthen and improve the cleaning ability of the screw and the dead corner of the mold, thereby achieving rapid color change and machine washing.

[0023] (3) The polyethylene color-changing and washing machine special material of the present invention further improves the cleaning ability of the polyethylene color-changing and washing machine special material by adding fibrous fillers. The fibrous fillers can clean the screws of the complex extruders and various strange cavities in the molds. The inorganic fillers are dispersed in the polyethylene color-changing and washing machine material, and the fibers with high aspect ratios are dispersed in the polyethylene. The fibers have a pulling effect and can effectively pull away the materials in the dead corners of the screws and molds, thereby further improving the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 This is a picture of the special material for color-changing washing machines in Example 1 of the present invention being used to change black polyethylene pipes to green.

[0026] Figure 2 This is a picture of the in-situ fiber forming process of the extrusion process of the special material for the color-changing washing machine in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0029] Example 1

[0030] The special materials for polyethylene pipe color changing washing machine are composed as shown in Table 1:

[0031] Table 1 Formula of special material for polyethylene pipe color changing washing machine in Example 1

[0032]

[0033] The information of the raw materials used in Example 1 is as follows:

[0034] Polyethylene: PN049-030-122, SABIC (Tianjin) Petrochemical Co., Ltd.

[0035] Polyether block copolymer: polyether polyamide block copolymer, MH1657, Arkema;

[0036] Ethylene-vinyl acetate copolymer: EVA18J3, vinyl acetate content 18%, melt mass flow plastic 2.8g / 10min, Sinopec Yanshan Petrochemical Company;

[0037] Maleic anhydride grafted modified ethylene-vinyl acetate copolymer (EVA-g-MAH): EN115, maleic anhydride grafting rate 0.8%, Shandong Donghong Pipe Industry Co., Ltd.;

[0038] Inorganic filler: wollastonite mineral fiber for rubber and plastic, particle size D50 is 10μm, aspect ratio 10:1-15:1, Jiangxi Aote Technology Co., Ltd.;

[0039] Functional additives: Hindered phenol antioxidant 3114, BASF.

[0040] The specific steps for preparing the special material for polyethylene pipe color changing washing machine are as follows:

[0041] The components were mixed evenly by a mixer according to the proportions in Table 1, added to a twin-screw extruder, melt-blended at 210° C. and 400 rpm, and granulated to obtain a special material for polyethylene pipe color-changing washing machines.

[0042] Polyethylene pipe color changing washing machine special material is used to change black polyethylene pipes to green applications:

[0043] The DN250 polyethylene pipe production line that has produced black pipes was used. The temperature of the equipment was set to 195°C. The polyethylene pipe color-changing washing machine special material of the present invention was used to wash the machine at an extrusion rate of 30 kg / h for 30 minutes. Then, a mixture of 96% polyethylene (PN049-030-122) and 4% green masterbatch was switched to wash the machine at an extrusion rate of 30 kg / h until the color of the pipe extruded by the mold was pure green. The time and material consumption used for washing the machine were recorded, as shown in Table 5.

[0044] Example 2

[0045] 3PE anti-corrosion special materials are composed according to Table 2:

[0046] Table 2 Formula of special material for polyethylene pipe color changing washing machine in Example 2

[0047]

[0048] The information of the raw materials used in Example 2 is as follows:

[0049] Pipe grade polyethylene: DGDB2480, Qilu Petrochemical;

[0050] Polyether block copolymer: thermoplastic polyester elastomer (polyether polyester block copolymer), Keyflex3140D, LG Chemical, South Korea;

[0051] Ethylene-vinyl acetate copolymer: UL00428, vinyl acetate content 28%, melt mass flow plastic 4g / 10min, Levima Advanced Materials Technology Co., Ltd.;

[0052] Maleic anhydride grafted modified ethylene-vinyl acetate copolymer (EVA-g-MAH): EN115, maleic anhydride grafting rate 0.8%, Shandong Donghong Pipe Industry Co., Ltd.;

[0053] Inorganic filler: chopped glass fiber, T438G, length 3 mm, Taishan Glass Fiber Co., Ltd.;

[0054] Functional additives: It is composed of 20% hindered phenol antioxidant 1010 (Jiyi Holding Group) and 80% blue masterbatch.

[0055] The specific steps for preparing the special material for polyethylene pipe color changing washing machine are as follows:

[0056] The components were mixed evenly by a mixer according to the proportions in Table 2, added to a twin-screw extruder, melt-blended at 200° C. and 450 rpm, and granulated to obtain a special material for polyethylene pipe color-changing washing machines.

[0057] Polyethylene pipe color changing washing machine special material is used to change black polyethylene pipes to blue:

[0058] Taking the DN250 polyethylene pipe production line that has produced black pipes, the temperature of the equipment is set to 205°C, and the polyethylene pipe color-changing washing machine special material of the present invention is used to wash the machine at an extrusion rate of 30kg / h for 20 minutes, and then switched to a mixture of 96% pipeline-grade polyethylene (DGDB2480) and 4% blue masterbatch for washing, and the washing is carried out at an extrusion rate of 30kg / h until the color of the pipe extruded by the mold is pure blue. The time and material consumption used for washing the machine are recorded, as shown in Table 5.

[0059] Comparative Example 1

[0060] The raw materials used are the same as those in Example 1.

[0061] The special material for polyethylene pipe color changing washing machine in Comparative Example 1 is composed according to Table 3:

[0062] Table 3 Formula of special material for polyethylene pipe color changing washing machine in comparative example 1

[0063]

[0064]

[0065] The components were mixed evenly by a mixer according to the proportions in Table 3, added to a twin-screw extruder, melt-blended at 210° C. and 400 rpm, and granulated to obtain a special material for polyethylene pipe color-changing washing machines.

[0066] Polyethylene pipe color changing washing machine special material is used to change black polyethylene pipes to green applications:

[0067] The DN250 polyethylene pipe production line that has produced black pipes was used. The temperature of the equipment was set to 195°C. The polyethylene pipe color-changing washing machine special material of the present invention was used to wash the machine at an extrusion rate of 30 kg / h for 30 minutes. Then, a mixture of 96% polyethylene (PN049-030-122) and 4% green masterbatch was switched to wash the machine at an extrusion rate of 30 kg / h until the color of the pipe extruded by the mold was pure green. The time and material consumption used for washing the machine were recorded, as shown in Table 5.

[0068] Comparative Example 2

[0069] The raw materials used are the same as those in Example 2.

[0070] The special material for polyethylene pipe color changing washing machine in Comparative Example 2 is composed as shown in Table 4:

[0071] Table 4 Formula of special material for polyethylene pipe color changing washing machine in comparative example 2

[0072]

[0073] The specific steps for preparing the special material for polyethylene pipe color changing washing machine are as follows:

[0074] The components were mixed evenly by a mixer according to the proportions in Table 2, added to a twin-screw extruder, melt-blended at 200° C. and 450 rpm, and granulated to obtain a special material for polyethylene pipe color-changing washing machines.

[0075] Polyethylene pipe color changing washing machine special material is used to change black polyethylene pipes to blue:

[0076] Taking the DN250 polyethylene pipe production line that has produced black pipes, the temperature of the equipment is set to 205°C, and the polyethylene pipe color-changing washing machine special material of the present invention is used to wash the machine at an extrusion rate of 30kg / h for 20 minutes, and then switched to a mixture of 96% pipeline-grade polyethylene (DGDB2480) and 4% blue masterbatch for washing, and the washing is carried out at an extrusion rate of 30kg / h until the color of the pipe extruded by the mold is pure blue. The time and material consumption used for washing the machine are recorded, as shown in Table 5.

[0077] Table 5 Color changing washing machine of the embodiment and the comparative example

[0078]

[0079]

[0080]

[0081] It can be seen from Examples 1 and 2 that the special material for the polyethylene pipe color-changing washing machine prepared by the present invention has a strong cleaning ability. The special material for the polyethylene pipe color-changing washing machine of the present invention is first used to wash the machine for 20-30 minutes, and then the original color polyethylene pipe material is used to wash the machine for 30-80 minutes. The color change and washing of the pipe can be completed within 2 hours.

[0082] By comparing 1A, 1B, 1C, 1D of Example 1 with Comparative Examples 3A and 3B, it can be seen that the polyether block copolymer elastomer is not added to the special material for the polyethylene pipe color-changing washing machine, and the washing machine effect is extremely poor. By comparing 1A of Example 1 with Comparative Examples 3B and 3C, it can be seen that the addition ratio of the polyether block copolymer elastomer added to the special material for the polyethylene pipe color-changing washing machine is less than 10 parts, and the color-changing washing machine time is prolonged. By comparing 1D of Example 1 with Comparative Examples 3D and 3E, it can be seen that the addition ratio of the polyether block copolymer elastomer added to the special material for the polyethylene pipe color-changing washing machine is higher than 25 parts, resulting in the deterioration of the compatibility of the polyether block copolymer elastomer in the special material for the washing machine, which remains in the equipment, and it takes a long time to clean the polyether block copolymer elastomer, otherwise pits or elastomers are likely to appear when the pipe is extruded, which is caused by the polyether block copolymer elastomer incompatible with polyethylene not being thoroughly washed out. It can be seen that the optimal addition ratio of the polyether block copolymer elastomer is 10-25 parts. When it is too low, it cannot effectively form a fibrous network to improve the cleaning effect; when it is too high, the polyether block copolymer elastomer is easy to remain in the pipe equipment and is difficult to remove.

[0083] By comparing 2A, 2B, 2C of Example 2 with 4A of Comparative Example 2, it can be seen that adding 1-15 parts of inorganic filler to the special material for polyethylene pipe color-changing washing machine can improve the effect of the special material for polyethylene pipe color-changing washing machine to a certain extent. By comparing 2C with 4B of Comparative Example 2, it can be seen that the special material for polyethylene pipe color-changing washing machine does not have a polyether block copolymer elastomer, and the washing effect is extremely poor. By comparing 2A, 2B, 2C of Example 2 with 4A, 4B, 4C of Comparative Example 2, it can be seen that 1-15 parts of inorganic filler should be added to the special material for polyethylene pipe color-changing washing machine. If the added inorganic filler is too high, the inorganic filler will wear the inner and outer surfaces of the extruder screw and the mold during long-term washing, causing the extruded surface of the pipe to be uneven. From the comparison between 2A of Example 2 and 4D, 4E and 4F of Comparative Example 2, it can be seen that EVA and EVA-g-MAH are the key to improving the compatibility of polyethylene and polyether block copolymer elastomers. The compatibility of polyethylene and polyether block copolymer elastomers is poor. The special material for polyethylene pipe color changing and washing machine cannot effectively form a fibrous structure during the extrusion process, and the washing machine material cannot improve the cleaning effect of the extruder screw and the pipe extrusion die through the fibrous structure.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A special material for polyethylene pipe color changing washing machine, characterized in that: The invention is composed of the following raw materials in parts by weight: 40-80 parts of pipeline-grade polyethylene, 10-25 parts of polyether block copolymer elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 2-7 parts of ethylene-vinyl acetate copolymer modified by maleic anhydride grafting, 1-15 parts of inorganic filler and 0.2-4 parts of functional additive.

2. The polyethylene pipe color-changing washing machine special material as claimed in claim 1, characterized in that: The pipeline-grade polyethylene is selected from at least one of PE80, PE100, and PERT polyethylene; Alternatively, the pipe-grade polyethylene has a melt mass flow rate of 0.2-1.4 g / 10 min at 190° C. and a 5 kg weight.

3. The polyethylene pipe color-changing washing machine special material according to claim 1, characterized in that: The polyether block copolymer elastomer is selected from a polyamide elastomer formed by a block containing a polyether soft segment and a polyamide hard segment, and a thermoplastic polyester elastomer formed by a block containing a polyester hard segment and a polyether soft segment; Alternatively, the polyether block copolymer elastomer has a melting point lower than 200°C.

4. The polyethylene pipe color-changing washing machine special material according to claim 1, characterized in that: The vinyl acetate content of the ethylene-vinyl acetate copolymer is 8%-28%, and the melt mass flow rate is 0.5-8g / 10min at 190°C and 2.16kg weight.

5. The polyethylene pipe color-changing washing machine special material as claimed in claim 1, characterized in that: The maleic anhydride grafting rate of the maleic anhydride-grafted ethylene-vinyl acetate copolymer is 0.5%-1.5%.

6. The polyethylene pipe color-changing washing machine special material as claimed in claim 1, characterized in that: The inorganic filler is selected from at least one of needle-shaped wollastonite, alumina fiber, glass fiber, basalt fiber and carbon fiber.

7. The polyethylene pipe color-changing washing machine special material as claimed in claim 1, characterized in that: The functional auxiliary agent is selected from at least one of hindered phenol antioxidants, sulfur-containing hindered phenol antioxidants, phosphite antioxidants, hindered amine light stabilizers, pigments, and masterbatches.

8. A method for preparing a special material for polyethylene pipe color changing washing machine, characterized in that: include: The pipeline-grade polyethylene, polyether block copolymer elastomer, ethylene-vinyl acetate copolymer, maleic anhydride grafted modified ethylene-vinyl acetate copolymer, inorganic filler and functional additives are uniformly mixed, twin-screw extruded and granulated to obtain polyethylene pipeline color-changing washing machine special material.

9. The special material for color changing and washing of polyethylene pipes as described in any one of claims 1 to 7 or the special material for color changing and washing of polyethylene pipes prepared by the method described in claim 8 is used in the color changing and washing of polyethylene pipes and polyethylene composite pipes.

10. The use according to claim 9, characterized in that First, use the polyethylene pipe color-changing washing machine special material described in any one of claims 1 to 7 or the polyethylene pipe color-changing washing machine special material prepared by the method described in claim 8 to wash the machine for 20 to 40 minutes, and then use the original color polyethylene pipe material to wash the machine for 30 to 80 minutes to obtain the product.

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