阅读说明：本技术 一种煤矿井下用聚乙烯管及其制备工艺 (Polyethylene pipe for underground coal mine and preparation process thereof ) 是由 虞敏 朱加荣 于 2019-09-23 设计创作，主要内容包括：本发明公开一种煤矿井下用聚乙烯管及其制备工艺,该聚乙烯管由内到外依次包括内衬层、作为主体的聚乙烯支撑层和无卤保护层。所述钢衬层内衬层由分子量为150～650万的超高分子量聚乙烯合成的钢衬,提高管壁耐磨度,拓宽聚乙烯管的使用范围。所述聚乙烯支撑层按重量份计包括的组分如下：聚乙烯100～120份、抗氧化剂1～3份、抗静电剂1～3份、阻燃剂3～8份、润滑剂2～5份、分散剂10～12份、稳定剂1～2份；强度高,起到主要的支撑作用。所述无卤保护层按重量份计包括的组分如下：聚乙烯50～60份、无卤阻燃剂15～40份、抗静电剂5～15份、助剂5～10份,不仅保护管材,而且耐燃性好,提高管体在煤矿中使用的安全性。(The invention discloses a polyethylene pipe for underground coal mine and a preparation process thereof. The steel lining layer is a steel lining which is synthesized by ultra-high molecular weight polyethylene with the molecular weight of 150-650 ten thousand, so that the wear resistance of the pipe wall is improved, and the application range of the polyethylene pipe is widened. The polyethylene support layer comprises the following components in parts by weight: 100-120 parts of polyethylene, 1-3 parts of antioxidant, 1-3 parts of antistatic agent, 3-8 parts of flame retardant, 2-5 parts of lubricant, 10-12 parts of dispersant and 1-2 parts of stabilizer; the strength is high, and the main supporting function is achieved. The halogen-free protective layer comprises the following components in parts by weight: 50-60 parts of polyethylene, 15-40 parts of halogen-free flame retardant, 5-15 parts of antistatic agent and 5-10 parts of auxiliary agent, so that the pipe is protected, the flame resistance is good, and the safety of the pipe body in coal mine is improved.)

1. A polyethylene pipe for underground coal mine is characterized in that: the halogen-free protective layer comprises an inner liner, a polyethylene supporting layer as a main body and a halogen-free protective layer from inside to outside in sequence; the steel lining layer is a steel lining synthesized by ultra-high molecular weight polyethylene; the polyethylene support layer comprises the following components in parts by weight: 100-120 parts of polyethylene, 1-3 parts of antioxidant, 1-3 parts of antistatic agent, 3-8 parts of flame retardant, 2-5 parts of lubricant, 10-12 parts of dispersant and 1-2 parts of stabilizer; the halogen-free protective layer comprises the following components in parts by weight: 50-60 parts of polyethylene, 15-40 parts of halogen-free flame retardant, 5-15 parts of antistatic agent and 5-10 parts of auxiliary agent.

2. The polyethylene pipe for underground coal mine according to claim 1, wherein: the molecular weight of the polyethylene of the inner lining layer is 150-650 ten thousand.

3. The polyethylene pipe for underground coal mine according to claim 1, wherein: the antioxidant used by the polyethylene supporting layer is antioxidant CA, the antistatic agent is acetylene black, and the flame retardant is ammonium polyphosphate coated by epoxy resin; the lubricant is a composition of stearic acid and paraffin; the dispersing agent is stearic acid or polyacetate, and the stabilizing agent is hydroxyl-containing aryl phosphite or monophenyl diisooctyl phosphite.

4. The polyethylene pipe for coal mine underground according to claim 2, characterized in that: the weight ratio of the stearic acid to the paraffin wax in the lubricant is 4: 1.

5. The polyethylene pipe for underground coal mine according to claim 1, wherein: the halogen-free flame retardant of the halogen-free protective layer comprises the following components in parts by weight: 3-10 parts of epoxy resin coated ammonium polyphosphate, 1-5 parts of hyperbranched macromolecular flame-retardant char forming agent, 1-2 parts of melamine polyphosphate and 0.5-1 part of inorganic hypophosphite; the antistatic agent of the halogen-free protective layer is fatty alcohol-polyoxyethylene ether; the auxiliary agent of the halogen-free protective layer comprises a cross-linking agent, a coupling agent, a heat stabilizer and a defoaming agent.

6. The polyethylene pipe for underground coal mine according to claim 4, wherein: the cross-linking agent, the coupling agent, the heat stabilizer and the defoaming agent are prepared in parts by weight: 1:1:0.5:0.1.

7. The polyethylene pipe for underground coal mine according to claim 4 or 5, wherein: the cross-linking agent is aluminum chloride or aluminum sulfate or a mixture of the aluminum chloride and the aluminum sulfate; the coupling agent is epoxy silane; the heat stabilizer is composed of sodium stearate and metal salts of higher fatty acid in a ratio of 1: 1.

8. The polyethylene pipe for underground coal mine according to claim 1, wherein: the thickness of the lining layer is 2mm, the thickness of the polyethylene supporting layer is 15mm, and the thickness of the halogen-free protective layer is 3 mm.

9. The polyethylene pipe for underground coal mine according to claim 1, wherein: the preparation method comprises the following steps:

s1: material preparation and hot melting: preparing raw materials of the inner liner, the polyethylene supporting layer and the halogen-free protective layer respectively, dehumidifying and drying, and then adding the raw materials of each layer into an open mill respectively for hot melt mixing;

s2: and (3) extrusion molding: extruding the raw materials subjected to hot melting in the step S1 in an extruder at the same time, wherein the extrusion process parameters are as follows: the head pressure is 9 MPa; the machine barrel is divided into four sections, and the temperature is 185 ℃, 190 ℃, 195 ℃ and 200 ℃ in sequence; the die head zone is divided into 4 sections, the temperature is 210 ℃, 215 ℃, 220 ℃ and 225 ℃, the rotating speed of the extruder is 30rad/min, and the traction speed is 100 cm/min;

s3: cooling and cutting: and (4) carrying out spray cooling on the pipe extruded in the step S2 under the condition that the vacuum degree is 0.3Mpa, and then cutting to obtain the polyethylene pipe for the coal mine.

Technical Field

The invention relates to a polyethylene pipe for underground coal mine and a preparation process thereof.

Technical Field

Polyethylene pipe (PE pipe for short) is polymerized by monomer ethylene. Since resins having different densities can be obtained depending on polymerization conditions such as pressure and temperature during polymerization, they are classified into high-density polyethylene, medium-density polyethylene and low-density polyethylene. The requirements for PE pipes are different according to different application conditions, for example, materials for gas pipes and water supply pipes are required to bear certain pressure, and PE80 and PE100 can be selected; however, because of the high hygienic requirement of drinking water, LDPE (low density polyethylene), especially LLDPE (linear low density polyethylene) resin has become a common material for producing drinking water pipe, and the pressure bearing performance, air tightness and flame retardant performance of gas pipe are emphasized.

The underground coal mine pipelines comprise mine mortar conveying pipelines, gas discharge ventilation pipes and the like, and are required to be antistatic, flame retardant, impact resistant, corrosion resistant, wear resistant, scaling free and aging resistant. The mine mortar conveying pipeline is generally used for extracting the residual mortar, tailings and ore pulp from ores in the mine industry or an ore plant through one-pass process for secondary utilization after the ores are discharged into a tailing pond for waiting. The granularity of the refined mortar is generally fine and is generally between 50 and 200 meshes, the granularity of the refined mortar is not different from that of sand, and the mortar contains water and belongs to a medium such as slurry particles. The first factor to be considered in the selection of the pipe is wear resistance. Various pipelines with good wear resistance are used in mines, including ultrahigh molecular weight polyethylene pipes, ceramic composite pipes, wear-resistant rubber-lined pipelines and the like. The wear-resistant rubber lining pipeline is the most wear-resistant and is generally used in the second stage of mineral separation under the condition of large ore granularity; the ceramic composite pipe has strong wear resistance and is used in the third stage; the ultra-high molecular weight polyethylene pipe is mainly used in the last procedure and is mainly used for conveying media such as mortar, tailings and slurry particles. The gas discharge ventilation pipe is used for ensuring the safety of underground production, and underground ventilation is required to be ensured when coal is excavated so as to avoid serious accidents such as gas, coal dust accumulation, explosion and the like. Common pipe materials for the gas discharge ventilation pipe comprise a metal pipe, a glass reinforced plastic pipe, a polyvinyl chloride pipe, a polyethylene pipe and the like. At present, many laws and standards are developed in China to standardize the development of the industry, but the pipeline used under the coal mine as a dangerous operation pipe needs to be improved along with the improvement of the production requirement of the coal mine and the environmental protection requirement of the society.

The invention mainly aims to improve the existing mountain mortar conveying pipeline used under the coal mine. The mine mortar conveying pipeline is used for mortar left after ore extraction, the wear resistance is considered as the primary factor, the existing polyethylene pipe is often used for the last procedure for conveying mortar, tailings, slurry particles and the like due to insufficient wear resistance, other procedures need to use wear-resistant rubber lining pipelines and ceramic composite pipes, the use range of the polyethylene pipe in a mine is greatly limited, and therefore improvement is needed to widen the use range of the polyethylene pipe.

Disclosure of Invention

Aiming at the problems of the existing ultra-high molecular weight polyethylene pipe, the invention provides the polyethylene pipe for the underground coal mine and the preparation process thereof, and the material components and the preparation process of the pipe are improved, so that the purpose of producing the wear-resistant polyethylene pipe is achieved, and the application range of the polyethylene pipe under the mine is widened. The specific technical scheme is as follows:

a polyethylene pipe for underground coal mine sequentially comprises an inner liner, a polyethylene supporting layer as a main body and a halogen-free protective layer from inside to outside.

According to the preferable technical scheme, the steel lining layer is a steel lining which is synthesized by ultra-high molecular weight polyethylene with the molecular weight of 150-650 ten thousand.

According to a preferable technical scheme, the polyethylene support layer comprises the following components in parts by weight: 100-120 parts of polyethylene, 1-3 parts of antioxidant, 1-3 parts of antistatic agent, 3-8 parts of flame retardant, 2-5 parts of lubricant, 10-12 parts of dispersant and 1-2 parts of stabilizer; the antioxidant is preferably an antioxidant CA, the antistatic agent is preferably acetylene black, and the flame retardant is preferably ammonium polyphosphate coated by epoxy resin; the lubricant is preferably a combination of stearic acid and paraffin wax, and the weight ratio of the combination of the stearic acid and the paraffin wax is further preferably 4: 1; the dispersant is stearic acid or polyacetate, and the stabilizer is hydroxyl-containing aryl phosphite or monophenyl diisooctyl phosphite.

According to a preferable technical scheme, the halogen-free protective layer comprises the following components in parts by weight: 50-60 parts of polyethylene, 15-40 parts of halogen-free flame retardant, 5-15 parts of antistatic agent and 5-10 parts of auxiliary agent.

As a further preferable technical scheme, the halogen-free flame retardant of the halogen-free protective layer comprises the following components in parts by weight: 3-10 parts of epoxy resin coated ammonium polyphosphate, 1-5 parts of hyperbranched macromolecular flame-retardant char forming agent, 1-2 parts of melamine polyphosphate and 0.5-1 part of inorganic hypophosphite;

according to the preferable technical scheme, the antistatic agent of the halogen-free protective layer is fatty alcohol-polyoxyethylene ether; the auxiliary agent of the halogen-free protective layer comprises a cross-linking agent, a coupling agent, a heat stabilizer and a defoaming agent.

As a further preferable technical scheme, the weight parts of the cross-linking agent, the coupling agent, the heat stabilizer and the defoaming agent are as follows: 1:1:0.5:0.1. The cross-linking agent is preferably aluminum chloride or aluminum sulfate or a mixture of the aluminum chloride and the aluminum sulfate; the coupling agent is preferably an epoxy silane; the heat stabilizer is preferably composed of sodium stearate and metal salts of higher fatty acids in a ratio of 1: 1.

According to a preferable technical scheme, the thickness of the lining layer is 2mm, the thickness of the polyethylene supporting layer is 15mm, and the thickness of the halogen-free protective layer is 3 mm.

The preparation method of the polyethylene pipe for the underground coal mine comprises the following steps:

s1: material preparation and hot melting: preparing raw materials of the inner liner, the polyethylene supporting layer and the halogen-free protective layer respectively, dehumidifying and drying, and then adding the raw materials of each layer into an open mill respectively for hot melt mixing;

s2: and (3) extrusion molding: extruding the raw materials subjected to hot melting in the step S1 in an extruder at the same time, wherein the extrusion process parameters are as follows: the head pressure is 9 MPa; the machine barrel is divided into four sections, and the temperature is 185 ℃, 190 ℃, 195 ℃ and 200 ℃ in sequence; the die head zone is divided into 4 sections, the temperature is 210 ℃, 215 ℃, 220 ℃ and 225 ℃, the rotating speed of the extruder is 30rad/min, and the traction speed is 100 cm/min;

s3: cooling and cutting: and (4) carrying out spray cooling on the pipe extruded in the step S2 under the condition that the vacuum degree is 0.3Mpa, and then cutting to obtain the polyethylene pipe for the coal mine.

Has the advantages that:

compared with the prior art, the invention has the following beneficial effects:

the steel lining synthesized by the ultra-high molecular weight polyethylene is arranged in the polyethylene pipe layer as the main body, so that the wear resistance of the pipe wall is improved, the composite pipe can be used for conveying mortar, tailings and slurry particles, can also be used for conveying ores and coal cinder with larger granularity, and even can replace the application of a ceramic composite pipe, and the application range of the polyethylene pipe is widened. In addition, the halogen-free protective layer is coated outside the pipe, so that the adaptability of the pipe to the external environment is improved, the pipe is protected, the flame resistance is good, and the safety of the pipe used in a coal mine is improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments.