WO2020186830A1

WO2020186830A1 - Double-wall corrugated pipe for use in summer and preparation method for double-wall corrugated pipe

Info

Publication number: WO2020186830A1
Application number: PCT/CN2019/123109
Authority: WO
Inventors: 张波; 周峰
Original assignee: 惠升管业有限公司
Priority date: 2019-03-15
Filing date: 2019-12-04
Publication date: 2020-09-24
Also published as: CN109940929A

Abstract

The present invention relates to a double-wall corrugated pipe for use in summer and a preparation method for the double-wall corrugated pipe. The double-wall corrugated pipe comprises an inner layer and an outer layer which are sequentially provided from inside to outside. The outer layer comprises the following raw material components in parts by weight: 26-30 parts of PPH, 25-32 parts of HDPE, 3-8 parts of mPE, 30-40 parts of an inorganic filler, 2.5-3 parts of a lubricant, 1.5-2.5 parts of a color master batch, 2-2.5 parts of a coupling agent mixture, 0.2-0.5 part of an antioxidant, 0.2-0.25 part of an auxiliary antioxidant, 0.5-0.8 part of a light stabilizer, and 0.2-0.25 part of an ultraviolet light absorber. The materials are uniformly mixed to interact with each other so as to generate comprehensive synergistic effects: obtaining physical and chemical properties such as excellent tensile strength, ring-stiffness, and Charpy impact; moreover, construction requirements of strong ultraviolet light and high temperature in summer are satisfied.

Description

Double-wall corrugated pipe for summer and preparation method thereof

Cross references to related applications

This application claims the priority of the Chinese patent application with the application number 201910198051.2 and the title "A double-wall corrugated pipe for summer use and its preparation method" submitted to the China Patent Office on March 15, 2019, the entire content of which is incorporated by reference In this application.

Technical field

The present disclosure belongs to the field of pipelines, and relates to a water supply pipe, in particular to a double-wall corrugated pipe for summer and a preparation method thereof.

Background technique

Double-wall corrugated pipe (the main component is usually high-density polyethylene, namely HDPE) is a new type of pipe with a ring-shaped outer wall and a smooth inner wall. It was first developed in Germany in the early 1980s. After more than ten years of development and improvement, it has developed from a single variety to a complete product series. The double-wall corrugated water supply pipe quickly occupied the market due to its advantages of light weight, smooth inner and outer walls, corrosion resistance, and good sealing. However, it is not resistant to high temperatures and exposure to sunlight, and the longitudinal elongation of the pipeline is relatively large at high temperatures. In summer, under ultraviolet and high temperature conditions, the above problems are more prominent.

Summary of the invention

The purpose of the present disclosure includes, for example, to provide a double-wall corrugated pipe for summer in order to overcome the shortcomings of the prior art.

The present disclosure provides a double-wall corrugated pipe for summer, which includes an inner layer and an outer layer sequentially arranged from the inside to the outside, and the outer layer includes the following raw material components in parts by weight:

The inorganic filler is a mixture of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 10:2:3; the coupling agent mixture is a titanate coupling agent and a silane coupling agent. A mixture composed of a mass ratio of 1:1; the lubricant is a mixture of stearic acid and PE wax in a mass ratio of 1:1.

In one or more embodiments, the weight parts of PPH in the outer layer is 27-29 parts; preferably 26-28 parts; more preferably 26.5-27.5 parts.

In one or more embodiments, the parts by weight of HDPE in the outer layer are 26 to 31.5 parts; preferably 27 to 31 parts; more preferably 28 to 30.5 parts.

In one or more embodiments, the parts by weight of mPE in the outer layer are 3.5-7 parts; preferably 4-6.5 parts; more preferably 4.5-6 parts.

In one or more embodiments, the weight parts of the inorganic filler in the outer layer is 30-37 parts; preferably 30-25 parts; more preferably 30-32 parts.

In one or more embodiments, the inorganic filler in the outer layer is at least one selected from the group consisting of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber.

In one or more embodiments, the inorganic filler in the outer layer is composed of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 8-12:1-3:2-4 mixture.

In one or more embodiments, the inorganic filler in the outer layer is a mixture of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 10:2:3.

In one or more embodiments, the weight parts of the lubricant in the outer layer is 2.6 to 2.9 parts; preferably 2.65 to 2.85 parts; more preferably 2.7 to 2.85 parts.

In one or more embodiments, the lubricant in the outer layer is a mixture of stearic acid and PE wax.

In one or more embodiments, the lubricant in the outer layer is a mixture of stearic acid and PE wax in a mass ratio of 1-10:1-10.

In one or more embodiments, the lubricant in the outer layer is a mixture of stearic acid and PE wax in a mass ratio of 1:1.

In one or more embodiments, the weight parts of the color masterbatch in the outer layer is 1.6 to 2.4 parts; preferably 1.7 to 2.3 parts; more preferably 1.8 to 2.2 parts.

In one or more embodiments, the weight parts of the coupling agent mixture in the outer layer is 2 to 2.4 parts; preferably 2 to 2.3 parts; more preferably 2 to 2.2 parts.

In one or more embodiments, the coupling agent mixture in the outer layer is a mixture of a titanate coupling agent and a silane coupling agent.

In one or more embodiments, the coupling agent mixture in the outer layer is a mixture of titanate coupling agent and silane coupling agent in a mass ratio of 1-10:1-10.

In one or more embodiments, the coupling agent mixture in the outer layer is a mixture composed of a titanate coupling agent and a silane coupling agent at a mass ratio of 1:1.

In one or more embodiments, the weight part of the antioxidant in the outer layer is 0.25 to 0.45 parts; preferably 0.27 to 0.4 parts; more preferably 0.28 to 0.35 parts.

In one or more embodiments, the weight part of the auxiliary antioxidant in the outer layer is 0.2 to 0.24 parts; preferably 0.2 to 0.23 parts; more preferably 0.2 to 0.22 parts.

In one or more embodiments, the weight parts of the light stabilizer in the outer layer is 0.5 to 0.7 parts; preferably 0.5 to 0.65 parts; more preferably 0.5 to 0.6 parts.

In one or more embodiments, the weight parts of the ultraviolet absorber in the outer layer are 0.2 to 0.24 parts; preferably 0.2 to 0.23 parts; more preferably 0.2 to 0.22 parts.

In one or more embodiments, the outer layer includes the following raw material components in parts by weight:

In one or more embodiments, the weight parts of HDPE in the inner layer is 31-38 parts; preferably 32-36 parts; more preferably 33-35 parts.

In one or more embodiments, the weight parts of the PPR in the inner layer is 31-38 parts; preferably 32-36 parts; more preferably 33-35 parts.

In one or more embodiments, the parts by weight of LLDPE in the inner layer is 3.5-7 parts; preferably 4-6.5 parts; more preferably 4.5-6 parts.

In one or more embodiments, the weight parts of the heavy calcium carbonate powder in the inner layer is 17 to 23 parts; preferably 18 to 22 parts; more preferably 19 to 21 parts.

In one or more embodiments, the weight parts of the color masterbatch in the inner layer is 1.7 to 2.3 parts; preferably 1.8 to 2.2 parts; more preferably 1.9 to 2.1 parts.

In one or more embodiments, the weight parts of the lubricant in the inner layer is 1.2 to 2.8 parts; preferably 1.5 to 2.5 parts; more preferably 1.8 to 2.2 parts.

In one or more embodiments, the weight parts of the titanate coupling agent in the inner layer is 0.6 to 1.4 parts; preferably 0.7 to 1.3 parts; more preferably 0.8 to 1.2 parts.

In one or more embodiments, the inner layer includes the following raw material components in parts by weight:

Another object of the present disclosure is to provide a method for preparing the above-mentioned double-wall corrugated pipe for summer, which includes the following steps:

(a) Weigh the ingredients of the inner layer and the outer layer of the formula, and then add them to two mixers for mixing;

(b) Heating the inner layer raw material and outer layer raw material separately, and extruding through a double-layer composite die;

(c) The corrugated tube is pulled out and shaped by the forming machine, and the finished product is cut after cooling.

In one or more embodiments, in step (a), the mixing of the outer layer raw materials is specifically: using a silane coupling agent to perform surface treatment on the alkali-free glass fiber, and then performing melt extrusion granulation with PPH; Weigh the formulated amount of stearic acid, PE wax, wollastonite powder and heavy calcium carbonate powder, stir and activate in the mixer at 70～90℃; add the remaining outer layer materials, and stir at 70～90℃ , Dehumidification, put the material for use.

In one or more embodiments, in step (a), the mixing of the inner layer raw materials is specifically: stearic acid, PE wax, and heavy calcium carbonate are weighed in a formula amount, and placed in a mixer at 70 Stir and activate at ~90°C; add the remaining outer layer materials, stir at 70~90°C, dehumidify, and put the material for use.

Due to the application of the above technical solutions, the present disclosure has at least the following advantages compared with the prior art: The double-walled corrugated pipe used in summer of the present disclosure uses specific content of raw material components to be mixed separately to form an inner and outer layer structure, so that the materials are mixed Uniformity and interaction produce a comprehensive synergistic effect: to obtain excellent tensile strength, ring stiffness, simple beam impact and other physical and chemical properties; at the same time, it can meet the construction requirements of strong ultraviolet rays and high temperature in summer.

detailed description

In order to make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below. If the specific conditions are not specified in the implementation, it shall be carried out in accordance with the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used without the manufacturer's indication are all conventional products that can be purchased commercially.

Unless otherwise defined herein, scientific and technical terms used in connection with the present disclosure shall have the meanings commonly understood by those of ordinary skill in the art. Exemplary methods and materials are described below, but methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure.

As used herein, the term "double-wall corrugated pipe for summer" refers to a double-wall corrugated pipe that is relatively more suitable for use in summer, but is not intended to limit the use season of the double-wall corrugated pipe. That is, in one or more embodiments, the "double-wall corrugated pipe for summer" described herein can also be used in spring, autumn, and/or winter.

The term PPH as used herein is an abbreviation for polypropylene-homo.

As used herein, the term HDPE is an abbreviation for high-density polyethylene. Generally speaking, the density of high-density polyethylene in this field is 0.915-0.935 g/cm ³ .

As used herein, the term mPE is an abbreviation of Metallocene Polyethylene.

The term PPR as used herein is an abbreviation for polypropylene-random.

The term LLDPE as used herein is an abbreviation for linear low-density polyethylene. Generally speaking, the density of linear low-density polyethylene in this field is 0.910 to 0.940 g/cm ³ .

The double-wall corrugated pipe for summer of the present disclosure includes an inner layer and an outer layer arranged in order from the inside to the outside, and the outer layer includes the following raw material components in parts by weight: PPH 26-30 parts; HDPE 25-32 parts; mPE 3-8 Parts; 30～40 parts of inorganic fillers; 2.5～3 parts of lubricants; 1.5～2.5 parts of color masterbatch; 2～2.5 parts of coupling agent mixture; 0.2～0.5 parts of antioxidants; 0.2～0.25 parts of auxiliary antioxidants; light stabilizers 0.5 to 0.8 parts; 0.2 to 0.25 parts of ultraviolet absorber; The inner layer includes the following raw material components by weight: 30-40 parts of HDPE; 30-40 parts of PPR; 3-8 parts of LLDPE; 15-25 parts of heavy calcium carbonate powder Parts; color masterbatch 1.5～2.5 parts; lubricant 1～3 parts; titanate coupling agent 0.5～1.5 parts; the inorganic filler is heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 10 : A mixture of 2:3; the coupling agent mixture is a mixture of titanate coupling agent and silane coupling agent in a mass ratio of 1:1; the lubricant is stearic acid and PE wax in a mass ratio 1:1 mixture. By using specific content of raw material components to be mixed separately to form an inner and outer layer structure, the materials are evenly mixed and interact, resulting in a comprehensive synergistic effect: excellent tensile strength, ring stiffness, and simply supported beam impact are obtained. ;Meanwhile, it meets the construction requirements of strong ultraviolet rays and high temperature in summer.

The outer layer preferably includes the following raw material components in parts by weight: 27 parts of PPH; 30 parts of HDPE; 5 parts of mPE; 30 parts of inorganic fillers; 2.8 parts of lubricants; 2 parts of color masterbatch; 2 parts of coupling agent mixture; 0.3 parts of antioxidants; auxiliary 0.2 part of antioxidant; 0.5 part of light stabilizer; 0.2 part of ultraviolet absorber. The inner layer preferably includes the following raw material components in parts by weight: 34 parts of HDPE; 34 parts of PPR; 5 parts of LLDPE; 20 parts of heavy calcium carbonate powder; 2 parts of color masterbatch; 2 parts of lubricant; 1 part of titanate coupling agent .

The above-mentioned preparation method of double-wall corrugated pipe for summer includes the following steps: (a) Weigh the inner and outer raw materials of the formula, and then add them to two mixers for mixing; (b) The inner layer raw material and the outer layer raw material are heated separately and extruded through a double-layer composite die; (c) the corrugated tube is pulled out and shaped by a forming machine, and the finished product is cut after cooling. In step (a), the mixing of the outer layer raw materials is specifically: surface treatment of the alkali-free glass fiber with a silane coupling agent, followed by melt extrusion granulation with PPH; weighing the formulated amount of stearic acid and PE Wax, wollastonite powder and heavy calcium carbonate powder are stirred and activated in the mixer at 70-90°C; the remaining outer layer materials are added, stirred and dehumidified at 70-90°C, and the material is placed for use; step ( In a), the mixing of the inner layer raw materials is specifically as follows: Weigh the formulated amount of stearic acid, PE wax, and heavy calcium carbonate, stir and activate it in the mixer at 70-90°C; add the remaining outer layer The raw materials are stirred and dehumidified at 70-90°C, and the materials are released for use; the above process steps are conducive to the full mixing of the raw materials and can improve the overall performance of the product.

The present disclosure will be further described below in conjunction with embodiments.

Example 1-3, Comparative Example 1-2

Examples 1-3 and Comparative Examples 1-2 respectively provide a double-wall corrugated pipe for summer. They respectively include an inner layer and an outer layer arranged in order from the inside to the outside (see Table 1 for the specific raw material formula). The specific preparation process can be Adopt the conventional method: put the ingredients of the inner layer of the formula into a mixer for mixing, the mixing temperature is 80℃, and the stirring time is 25min; put the ingredients of the outer layer of the formula into the mixer in turn for mixing, and the mixing temperature is 80℃, the mixing time is 25min; the inner layer raw materials and outer layer raw materials are added to two extruders respectively, and the temperature of the first, second, third, fourth and fifth sections of the barrel are 50℃, 180℃, 200℃, 210℃ and 220℃, the temperature of the die is divided into four sections. The temperature of the first, second, third and fourth sections of the die is 220℃, 220℃, 220℃ and 225℃ respectively. After being pulled out, it is cut to length by a cutting machine (disclosed in the application number 201610697945.2).

Table 1 Formulation table of double-wall corrugated pipe for summer in Examples 1-3 and Comparative Example 1-2 (unit: kg)

The outer layer formula of the double-wall corrugated pipe for summer use in Example 1-3 and Comparative Example 1-2 was blended according to step (a) above, and then melt-extruded at 190-210°C using a twin-screw extruder After cooling, cut into pellets. The prepared pellets were prepared into standard samples conforming to GB/T1040.1-2006 and GB/T1043.1-2008 using an injection molding machine at 190-210°C and then subjected to performance testing. The results are shown in Table 2.

Table 2 Table 2 Example 1-3, Comparative Example 1-2, double-wall corrugated pipe outer layer formulation material performance table for summer

The summer double-wall corrugated pipes prepared in Examples 1-3 and Comparative Examples 1-2 were tested for performance, and the results are shown in Table 3.

Table 3 Table 3 Example 1-3, Comparative Example 1-2, double-wall corrugated pipe outer layer formulation material performance table for summer

Example 4

This embodiment provides a double-wall corrugated pipe for summer. Its raw material formula is the same as that in Example 1. The difference is that the preparation method is slightly different, specifically:

(a) Surface treatment of alkali-free glass fiber with silane coupling agent, followed by melt extrusion granulation with PPH; weigh the above-mentioned pellets, stearic acid, PE wax, wollastonite powder and heavy carbonic acid in the formula Calcium powder, stir and activate in the mixer at 70～90℃; add the rest of the outer raw materials, stir at 70～90℃, dehumidify, and put the material for use; weigh the formulated amount of stearic acid and PE wax 、Heavy calcium carbonate, stir and activate in the mixer at 70～90℃; add the remaining outer layer materials, stir at 70～90℃, dehumidify, and put the material for use; after the same blending treatment, Use a twin-screw extruder to melt and extrude at 190～210℃, and then cut into pellets after cooling; use an injection molding machine at 190～210℃ to prepare the pellets to meet GB/T1040.1-2006, GB /T1043.1-2008 standard sample after the performance test, the result is better than that in Example 1;

(b) Heating the inner layer raw material and the outer layer raw material separately, and extrude them through a double-layer composite die (the heating and extrusion parameters are the same as those in Example 1);

The above-mentioned embodiments are only to illustrate the technical ideas and features of the present disclosure, and their purpose is to enable those familiar with the technology to understand the content of the present disclosure and implement them accordingly, and cannot limit the scope of protection of the present disclosure. All equivalent changes or modifications made to the spirit and substance should be covered by the protection scope of the present disclosure.

The above are only the preferred embodiments of the present disclosure and are not used to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Industrial applicability

The double-wall corrugated pipe used in summer of the present disclosure uses specific content of raw material components to be mixed separately to form an inner and outer layer structure, so that the materials are evenly mixed and interact, resulting in a comprehensive synergistic effect: excellent tensile strength, ring Physical and chemical properties such as stiffness and impact of simply supported beams; at the same time, it meets the construction requirements of strong ultraviolet rays and high temperature in summer

Claims

A double-wall corrugated pipe for summer. The double-wall corrugated pipe for summer includes an inner layer and an outer layer sequentially arranged from the inside to the outside, and is characterized in that:

The outer layer includes the following raw material components in parts by weight:

The inner layer includes the following raw material components in parts by weight:

The inorganic filler is a mixture of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 10:2:3; the coupling agent mixture is a titanate coupling agent and a silane coupling agent. A mixture composed of a mass ratio of 1:1; the lubricant is a mixture of stearic acid and PE wax in a mass ratio of 1:1.
The double-wall corrugated pipe for summer use according to claim 1, wherein the weight parts of PPH in the outer layer is 27-29 parts; preferably 26-28 parts; more preferably 26.5-27.5 parts.
The double-wall corrugated pipe for summer use according to claim 1 or 2, wherein the weight parts of HDPE in the outer layer is 26 to 31.5 parts; preferably 27 to 31 parts; more preferably 28 to 30.5 parts .
The double-wall corrugated pipe for summer use according to any one of claims 1 to 3, wherein the weight parts of mPE in the outer layer is 3.5-7 parts; preferably 4-6.5 parts; more preferably 4.5 to 6 copies.
The double-wall corrugated pipe for summer use according to any one of claims 1 to 4, wherein the weight parts of the inorganic filler in the outer layer is 30-37 parts; preferably 30-25 parts; Preferably 30-32 parts;

Preferably, the inorganic filler in the outer layer is at least one selected from the group consisting of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber;

Preferably, the inorganic filler in the outer layer is a mixture composed of heavy calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 8-12:1-3:2-4, preferably composed of heavy A mixture of calcium carbonate powder, wollastonite powder and alkali-free glass fiber in a mass ratio of 10:2:3.
The summer double-wall corrugated pipe according to any one of claims 1 to 5, wherein the weight parts of the lubricant in the outer layer is 2.6 to 2.9 parts; preferably 2.65 to 2.85 parts; Preferably 2.7～2.85 parts;

Preferably, the lubricant in the outer layer is a mixture of stearic acid and PE wax;

Preferably, the lubricant in the outer layer is a mixture of stearic acid and PE wax in a mass ratio of 1:1.
The double-wall corrugated pipe for summer use according to any one of claims 1-6, wherein the weight parts of the color masterbatch in the outer layer is 1.6 to 2.4 parts; preferably 1.7 to 2.3 parts; Preferably it is 1.8 to 2.2 parts.
The double-wall corrugated pipe for summer use according to any one of claims 1-7, wherein the weight parts of the coupling agent mixture in the outer layer is 2 to 2.4 parts; preferably 2 to 2.3 parts ；More preferably 2～2.2 parts;

Preferably, the coupling agent mixture in the outer layer is a mixture of titanate coupling agent and silane coupling agent;

Preferably, the coupling agent mixture in the outer layer is a mixture of titanate coupling agent and silane coupling agent in a mass ratio of 1-10:1-10;

Preferably, the coupling agent mixture in the outer layer is a mixture of titanate coupling agent and silane coupling agent in a mass ratio of 1:1.
The double-wall corrugated pipe for summer use according to any one of claims 1-8, wherein the weight parts of the antioxidant in the outer layer is 0.25 to 0.45 parts; preferably 0.27 to 0.4 parts; Preferably, it is 0.28 to 0.35 parts.
The double-wall corrugated pipe for summer use according to any one of claims 1-9, wherein the weight part of the auxiliary antioxidant in the outer layer is 0.2 to 0.24 parts; preferably 0.2 to 0.23 parts; It is more preferably 0.2 to 0.22 parts.
The double-wall corrugated pipe for summer use according to any one of claims 1-10, wherein the light stabilizer in the outer layer has 0.5 to 0.7 parts by weight; preferably 0.5 to 0.65 parts; More preferably, it is 0.5 to 0.6 parts.
The double-wall corrugated pipe for summer use according to any one of claims 1-11, wherein the weight parts of the ultraviolet absorber in the outer layer are 0.2 to 0.24 parts; preferably 0.2 to 0.23 parts; It is more preferably 0.2 to 0.22 parts.
The double-wall corrugated pipe for summer use according to any one of claims 1-12, wherein the outer layer comprises the following raw material components in parts by weight:
The summer double-wall corrugated pipe according to any one of claims 1-13, wherein the weight parts of HDPE in the inner layer is 31-38 parts; preferably 32-36 parts; more preferably 33 to 35 servings.
The double-wall corrugated pipe for summer use according to any one of claims 1-14, wherein the weight parts of PPR in the inner layer is 31 to 38 parts; preferably 32 to 36 parts; more preferably 33 to 35 servings.
The double-wall corrugated pipe for summer use according to any one of claims 1-15, wherein the parts by weight of LLDPE in the inner layer is 3.5-7 parts; preferably 4-6.5 parts; more preferably 4.5 to 6 copies.
The double-wall corrugated pipe for summer use according to any one of claims 1-16, wherein the inner layer comprises the following raw material components in parts by weight:
The method for preparing a double-wall corrugated pipe for summer use according to any one of claims 1 to 17, characterized in that it comprises the following steps:

(a) Weigh the ingredients of the inner layer and the outer layer of the formula, and then add them to two mixers for mixing;

(b) Heating the inner layer raw material and outer layer raw material separately, and extruding through a double-layer composite die;

(c) The corrugated tube is pulled out and shaped by the forming machine, and the finished product is cut after cooling.
The method for preparing a double-wall corrugated pipe for summer use according to claim 18, characterized in that, in step (a), the mixing of the outer layer raw materials is specifically: using a silane coupling agent to perform surface treatment on the alkali-free glass fiber, Then it was melted and extruded with PPH for granulation; the formulated amount of stearic acid, PE wax, wollastonite powder and heavy calcium carbonate powder were weighed, and stirred and activated in the mixer at 70～90℃; added the rest Layer raw materials, stir and dehumidify at 70-90°C, and release the materials for later use.
The method for preparing a double-wall corrugated pipe for summer use according to claim 18 or 19, characterized in that, in step (a), the mixing of the inner layer raw materials is specifically: weighing the formula amount of stearic acid, PE wax, Heavy calcium carbonate is stirred and activated in the mixer at 70-90°C; the rest of the outer layer materials are added, stirred at 70-90°C, dehumidified, and the material is placed for use.