阅读说明：本技术 一种纤维全缠绕气瓶塑料内胆超声波注射-胀形一体化成型方法 (Ultrasonic injection-bulging integrated molding method for plastic inner container of fiber fully-wound gas cylinder ) 是由 王辉 刘兆义 华林 陈一哲 付爽 于 2020-05-26 设计创作，主要内容包括：一种纤维全缠绕气瓶塑料内胆超声波注射-胀形一体化成型方法,涉及储气装置领域。该纤维全缠绕气瓶塑料内胆超声波注射-胀形一体化成型方法包括以下步骤：对金属阀口接头进行表面纳米化处理；将金属阀口接头固定、加热后使用超声波处理金属阀口接头；将塑料内胆的熔体注入模具的型腔中,使金属阀口接头与塑料内胆在压力和超声波振动作用下形成锚栓连接,保压冷却得到型胚；将型胚沿轴向拉伸的同时使用气体加压胀形,冷却、脱模。本实施例提供的纤维全缠绕气瓶塑料内胆超声波注射-胀形一体化成型方法既保证了气瓶塑料内胆的气密性,又明显提高了气瓶塑料内胆的金属阀口接头与塑料内胆封头的连接强度。(An ultrasonic injection-bulging integrated molding method for a plastic inner container of a fiber fully-wound gas cylinder relates to the field of gas storage devices. The ultrasonic injection-bulging integrated molding method for the plastic inner container of the fiber fully-wound gas cylinder comprises the following steps of: carrying out surface nanocrystallization treatment on the metal valve port joint; fixing the metal valve port joint, heating and then treating the metal valve port joint by using ultrasonic waves; injecting the melt of the plastic liner into a cavity of a mold, enabling the metal valve port connector and the plastic liner to form anchor bolt connection under the action of pressure and ultrasonic vibration, and maintaining the pressure and cooling to obtain a parison; and (3) stretching the blank along the axial direction, pressurizing and expanding by using gas, cooling and demolding. The ultrasonic injection-bulging integrated molding method for the plastic liner of the gas cylinder by fully winding the fibers provided by the embodiment not only ensures the air tightness of the plastic liner of the gas cylinder, but also obviously improves the connection strength between the metal valve port joint of the plastic liner of the gas cylinder and the seal head of the plastic liner.)

1. An ultrasonic injection-bulging integrated molding method for a plastic liner of a fiber fully-wound gas cylinder is characterized by comprising the following steps of:

carrying out surface nanocrystallization treatment on the connecting surface of the metal valve port joint, which is used for being connected with the plastic liner;

fixing the metal valve port joint after surface nanocrystallization, heating the metal valve port joint until the temperature reaches the glass transition temperature of the polymer raw material forming the plastic liner, and vibrating the metal valve port joint by using ultrasonic waves;

injecting a melt formed by mixing and melting a polymer raw material and a modified master batch into a cavity of a mold to form a plastic liner, and enabling the connection surface of the metal valve port joint and the end socket of the plastic liner to be connected under the action of pressure and ultrasonic vibration to form anchor bolt connection;

carrying out pressure maintaining cooling on the connected metal valve port joint and the plastic inner container to obtain a parison;

and (3) stretching the blank along the axial direction, pressurizing and expanding by using gas, cooling and demolding.

2. The ultrasonic injection-bulging integrated molding method for the plastic inner container of the fiber fully-wound gas cylinder according to claim 1, characterized in that the surface nanocrystallization treatment comprises the steps of electrochemical polishing, absolute ethyl alcohol cleaning, drying, alkali washing, deionized water washing, drying, acid washing, deionized water washing, drying, anodic oxidation treatment, deionized water washing and drying of the connecting surface of the metal valve port joint in sequence.

3. The ultrasonic injection-bulging integrated molding method for the plastic inner container of the fully-wound fiber gas cylinder according to claim 1, characterized in that an electric heating tube or an infrared heating device is used for heating when the mold is heated.

4. The ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wound fiber gas cylinder according to claim 1, wherein the frequency of ultrasonic treatment is 15-55 KHz; the injection pressure of the melt is 10-20MPa, and the injection speed is 300-; the injection temperature of the melt is 120-180 ℃, and the mold temperature when the melt is injected is 100-150 ℃.

5. The ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wound fiber gas cylinder according to claim 1, wherein the polymer raw material is polyamide-6, and the modified master batch is prepared from the following raw materials in percentage by mass: 79-89.5% of polyamide-6, 2.5-5% of blocking agent, 1.5-3% of antistatic agent, 0.5-1% of antioxidant, 1.5-3% of dispersing agent, 1.5-3% of light stabilizer and 3-6% of coupling agent; the weight ratio of the polymer raw material to the modified master batch is 80-90: 10-20.

6. The ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wound fiber gas cylinder according to claim 1, characterized in that the pressure of the pressure maintaining is 0.5-3MPa, and the medium used for pressure maintaining cooling is water or air.

7. The ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wound fiber gas cylinder according to claim 1, characterized in that air or inert gas is adopted during pressure bulging of the parison, the bulging pressure is 0.1-0.5MPa, and the bulging ratio is 2.5-6.

Technical Field

The application relates to the field of gas storage devices, in particular to an ultrasonic injection-bulging integrated forming method for a plastic inner container of a fiber fully-wound gas cylinder.

Background

The pressure gas storage and transportation gas cylinder is widely applied to the fields of new energy automobile equipment, back-worn respirators and the like. At present, the domestic market mainly takes an all-metal or fiber winding gas cylinder with a metal inner container as a main part, but the gas cylinder has the problems of low gas storage and transportation density, hydrogen embrittlement risk, short service life and the like. The gas cylinder with the plastic liner and fully wound with fibers has the characteristics of better impact toughness, corrosion resistance and the like, can greatly reduce the quality of the gas cylinder on the premise of ensuring the application safety, and becomes the main research direction of the pressure gas cylinder in recent years.

The cylinder with the fully wound material liner fiber needs to be made of metal materials at the opening of the cylinder due to the requirements of connection and rigidity. At present, the commonly adopted connection mode is that the metal valve port connector is bonded with the plastic liner or the metal valve port connector insert is welded with the straight line section of the cylinder body after injection molding, but the secondary connection process can cause the problems of stress concentration, poor air tightness and the like, and in order to realize better combination of metal and plastic at the bottle mouth, reasonable design and reasonable process are needed to be carried out on the structure and the shape of the metal connector.

Therefore, a new process for integrally forming the liner, which can solve the problem of airtight connection between the metal valve port joint and the plastic liner and avoid a secondary connection process, is urgently needed.

Disclosure of Invention

The application aims to provide an ultrasonic injection-bulging integrated forming method for a plastic liner of a gas cylinder by fully winding fibers, which not only ensures the air tightness of the plastic liner of the gas cylinder, but also obviously improves the connection strength between a metal valve port joint of the plastic liner of the gas cylinder and a seal head of the plastic liner.

The embodiment of the application is realized as follows:

the embodiment of the application provides an ultrasonic injection-bulging integrated forming method for a plastic inner container of a fiber fully-wound gas cylinder, the plastic inner container of the gas cylinder is formed by connecting a metal valve port connector and the plastic inner container, the plastic inner container is formed by polymer raw materials and modified master batches, and the method comprises the following steps:

carrying out surface nanocrystallization treatment on the connecting surface of the metal valve port joint, which is used for being connected with the plastic liner;

fixing the metal valve port joint after surface nanocrystallization, heating the metal valve port joint until the temperature reaches the glass transition temperature of the polymer raw material forming the plastic liner, and vibrating the metal valve port joint by using ultrasonic waves;

injecting a melt formed by mixing and melting a polymer raw material and a modified master batch into a cavity of a mold to form a plastic liner, and enabling the connection surface of the metal valve port joint and the end socket of the plastic liner to be connected under the action of pressure and ultrasonic vibration to form anchor bolt connection;

carrying out pressure maintaining cooling on the connected metal valve port joint and the plastic inner container to obtain a parison;

and (3) stretching the blank along the axial direction, pressurizing and expanding by using gas, cooling and demolding.

In some alternative embodiments, the surface nanocrystallization process is sequentially performed by performing electrochemical polishing, absolute ethanol cleaning, drying, alkali cleaning, deionized water rinsing, drying, acid cleaning, deionized water rinsing, drying, anodizing, deionized water rinsing and drying on the connection surface of the metal valve port joint.

In some alternative embodiments, the heating of the mold is performed using an electrically heated tube or an infrared heating device.

In some alternative embodiments, the frequency of sonication is 15-55 KHz; the injection pressure of the melt is 10-20MPa, and the injection speed is 300-; the injection temperature of the melt is 120-180 ℃, and the mold temperature when the melt is injected is 100-150 ℃.

In some alternative embodiments, the polymer raw material is polyamide-6, and the modified masterbatch is made from the following raw materials in percentage by mass: 79-89.5% of polyamide-6, 2.5-5% of blocking agent, 1.5-3% of antistatic agent, 0.5-1% of antioxidant, 1.5-3% of dispersing agent, 1.5-3% of light stabilizer and 3-6% of coupling agent; the weight ratio of the polymer raw material to the modified master batch is 80-90: 10-20.

In some alternative embodiments, the pressure of the dwell pressure is 0.5 to 3MPa, and the medium used for dwell cooling is water or air.

In some alternative embodiments, the parison is expanded under pressure using air or an inert gas, the expansion pressure is 0.1 to 0.5MPa, and the expansion ratio is 2.5 to 6.

The beneficial effect of this application is: the ultrasonic injection-bulging integrated molding method for the plastic inner container of the fiber fully-wound gas cylinder provided by the embodiment comprises the following steps of: carrying out surface nanocrystallization treatment on the connecting surface of the metal valve port connector, which is used for being connected with the plastic liner; fixing the metal valve port joint subjected to surface nanocrystallization, heating a mold to reach the glass transition temperature of a polymer raw material forming the plastic liner, and treating the metal valve port joint by using ultrasonic waves; injecting a melt formed by mixing and melting a polymer raw material and a modified master batch into a cavity of a mold to form a plastic liner, and enabling the connection surface of the metal valve port joint and the end socket of the plastic liner to be connected under the action of pressure and ultrasonic vibration to form anchor bolt connection; carrying out pressure maintaining cooling on the connected metal valve port joint and the plastic inner container to obtain a parison; and (3) stretching the blank along the axial direction, pressurizing and expanding by using gas, cooling and demolding. The ultrasonic injection-bulging integrated molding method for the plastic liner of the gas cylinder by fully winding the fibers provided by the embodiment not only ensures the air tightness of the plastic liner of the gas cylinder, but also obviously improves the connection strength between the metal valve port joint of the plastic liner of the gas cylinder and the seal head of the plastic liner.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a sectional view of a plastic liner of a gas cylinder prepared by an ultrasonic injection-bulging integrated molding method for a plastic liner of a fiber fully-wound gas cylinder provided in an embodiment of the application;

fig. 2 is a schematic structural diagram of a first view angle of a mold for fixing a metal valve port joint in an ultrasonic injection-bulging integrated molding method for a plastic liner of a fiber fully-wound gas cylinder according to an embodiment of the present application;

FIG. 3 is a structural diagram of a second view angle of a mold for fixing a metal valve port connector in the ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wrapped fiber gas cylinder according to the embodiment of the present application;

fig. 4 is a sectional view taken along line a-a in fig. 3.

In the figure: 100. a metal valve port fitting; 101. a connecting surface; 110. a plastic inner container; 111. sealing the end; 200. a left die; 210. a right die; 220. a guide post; 230. ultrasonic vibration horn; 240. a connecting flange; 250. an ultrasonic transducer; 260. heating the tube.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The ultrasonic injection-bulging integrated molding method for the plastic liner of the fully-wound fiber gas cylinder is specifically described below.

The embodiment of the application provides an ultrasonic injection-bulging integrated molding method for a plastic liner of a fully-wound fiber gas cylinder, as shown in fig. 1, the plastic liner of the gas cylinder is formed by connecting a metal valve port connector 100 and a plastic liner 110, and a connecting surface 101 of the metal valve port connector 100 is connected with a seal head 111 of the plastic liner 110. The plastic inner container is composed of a polymer raw material and a modified master batch, wherein the polymer raw material is polyamide-6, and the modified master batch is prepared from the following raw materials in percentage by mass: 79-89.5% of polyamide-6, 2.5-5% of blocking agent, 1.5-3% of antistatic agent, 0.5-1% of antioxidant, 1.5-3% of dispersing agent, 1.5-3% of light stabilizer and 3-6% of coupling agent; the weight ratio of the PA6 to the master batch is 80-90: 10-20.

As shown in fig. 2, 3 and 4, the die for fixing the metal valve port connector 100 used in the method for integrally molding the plastic liner of the fully-wrapped fiber gas cylinder by ultrasonic injection-bulging is a split die consisting of a left die 200, a right die 210 and two guide posts 220 for connecting the left die 200 and the right die 210, the left die 200 and the right die 210 are respectively connected with an ultrasonic vibration amplitude transformer 230 penetrating into the die, the two ultrasonic vibration amplitude transformers 230 are respectively connected with an ultrasonic transducer 250 through a connecting flange 240, and four heating pipes 260 are respectively inserted into the left die 200 and the right die 210.

The ultrasonic injection-bulging integrated molding method for the plastic inner container of the fiber fully-wound gas cylinder comprises the following steps of:

the surface nanocrystallization treatment is carried out on the connecting surface 101 of the metal valve port joint 100, which is used for being connected with the plastic liner 110; the surface nanocrystallization treatment is to carry out electrochemical polishing, absolute ethyl alcohol cleaning, drying, alkali washing, deionized water washing, drying, acid washing, deionized water washing, drying, anodic oxidation treatment, deionized water washing and drying on the connecting surface of the metal valve port connector in sequence; optionally, the electrolyte used for electrochemical polishing is perchloric acid and ethanol in a volume ratio of 1: 5, the polishing voltage is 6V-15V, and the polishing time is 6min-15 min; optionally, the cleaning time of the absolute ethyl alcohol cleaning is 2min-5 min; optionally, drying is carried out at normal temperature; optionally, the alkali washing is carried out by washing with 20-50g/L NaOH solution at 40-60 ℃ for 3-6 min; optionally, the acid washing is performed by using hydrochloric acid with the mass percentage concentration of 30-50%, and the acid washing time is 40-80 s; optionally, the anodic oxidation treatment is to treat the metal as an anode, the stainless steel as a cathode and the sulfuric acid solution as an electrolyte for 20-40min under the conditions of 8-12V of voltage and 18-25 ℃, wherein the mass percentage concentration of the sulfuric acid solution is 10-30%.

Fixing the metal valve port connector with the nano-treated surface in the mold, heating the mold until the temperature reaches the glass transition temperature of the polymer raw material forming the plastic liner, and treating the metal valve port connector 100 by using ultrasonic waves; optionally, when the mold is heated, an electric heating tube or an infrared heating device is used for heating; optionally, the frequency of ultrasonic treatment is 15-55 KHz; the mold temperature at the time of injection of the melt was 100-.

Injecting a melt formed by mixing and melting a polymer raw material and a modified master batch into a cavity of a plastic liner forming die to form a plastic liner, and enabling the connection surface of the metal valve port joint 190 and the end socket of the plastic liner to be connected under the action of pressure and ultrasonic vibration to form anchor bolt connection; optionally, the injection temperature of the melt is 120-180 ℃, the injection pressure of the melt is 10-20MPa, and the injection speed is 300-500 mm/s.

Carrying out pressure maintaining cooling on the connected metal valve port joint and the plastic inner container to obtain a parison; optionally, the pressure of the pressure maintaining is 0.5-3MPa, and the medium adopted for pressure maintaining cooling is water or air.

And (3) stretching the blank along the axial direction, pressurizing and bulging, cooling and demolding. Optionally, when the parison is pressurized and expanded, air or inert gas is adopted, the expansion pressure is 0.1-0.5MPa, and the expansion ratio is 2.5-6.

The ultrasonic injection-bulging integrated forming method for the plastic inner container of the fiber fully-wound gas cylinder provided by the embodiment of the application combines the technical advantages of high welding strength and bulging manufacturing of an orientation reinforced structure by pressure injection forming, combines two processes through a set of die, and utilizes the comprehensive action of pressure and ultrasonic to fill a plastic melt in a nano-scale cavity on the treated metal surface and form a microscopic anchor bolt connecting structure, so that the reinforced connection and high tightness of the end socket of the plastic inner container and the metal valve port joint connecting surface are achieved, and the forced orientation and forming of polymer macromolecular chains are completed by utilizing an air pressure bulging process, so that the shaping of a cylinder section of a plastic inner container component is completed, the connecting processes of secondary cylinder welding, bonding, post-treatment and the like in the traditional forming process are omitted, the process is simple, the production period is shortened, and the air tightness, the bulging performance and the like of the inner container are improved, Long cycle life of high and low pressure, safe reliability and economic benefit.

The features and properties of the present invention are described in further detail below with reference to specific examples.