What is a plastic pipe cap

What is a plastic pipe cap?

Plastic pipe cap is a pipe cap processed with plastic as the main raw material. Plastic is a kind of plastic synthetic polymer material. Together with synthetic rubber and synthetic fiber, it has formed three indispensable synthetic materials in today’s daily life. Specifically, plastic is a material with synthetic resin as the main component, which can be molded into a certain shape under certain temperature and pressure and keep the shape unchanged at room temperature.

20210819131816 19377 - What is a plastic pipe cap

Technical parameters of plastic pipe cap

There are many plastic pipe caps, and the size of the pipe cap is relatively small, which can be forged; The pipe cap is generally used at the end of the pipe, and the head is used at the upper and lower parts (vertical equipment) or left and right ends (horizontal equipment) of the container equipment.

  • Packing method: wooden box shockproof film packing or other;
  • Specification of plastic pipe cap: Ф 32-6000;
  • Plastic pipe cap material: PVC-U: PVC-C

Raw material composition of plastic pipe cap

1. Stabilizer
In order to prevent the synthetic resin from being decomposed and damaged by light and heat in the process of processing and use, and prolong the service life, a stabilizer should be added to the plastic. Commonly used are stearate, epoxy resin, etc.
2. Colorant
Colorants can make plastics have various bright and beautiful colors. Organic dyes and inorganic pigments are commonly used as colorants.
3. Lubricant
The function of lubricant is to prevent the plastic from sticking to the metal mold during molding, and make the plastic surface smooth and beautiful. Common lubricants include stearic acid and its calcium magnesium salts.
4. Synthetic resin
Synthetic resin is the main component of plastics, and its content in plastics is generally 40% ~ 100%. Because of its high content and the nature of resin often determines the nature of plastics, people often regard resin as a synonym for plastics. For example, PVC resin and PVC plastic, phenolic resin and phenolic plastic are confused. In fact, resin and plastic are two different concepts. Resin is an unprocessed original polymer. It is not only used to make plastics, but also used as raw material for coatings, adhesives and synthetic fibers. In addition to a small part of plastics containing 100% resin, the vast majority of plastics need to add other substances in addition to the main component resin.
5. Filler
Fillers, also known as fillers, can improve the strength and heat resistance of plastics and reduce costs. For example, the addition of wood powder to phenolic resin can greatly reduce the cost, make phenolic plastic one of the cheapest plastics, and significantly improve the mechanical strength. Fillers can be divided into organic fillers and inorganic fillers, the former such as wood powder, rags, paper and various fabric fibers, and the latter such as glass fiber, diatomite, asbestos, carbon black, etc.
6. Plasticizer

Plasticizers can increase the plasticity and softness of plastics, reduce brittleness and make plastics easy to process and shape. Plasticizers are generally high boiling organic compounds that are miscible with resin, non-toxic, odorless and stable to light and heat. Phthalates are the most commonly used. For example, in the production of PVC plastics, if more plasticizers are added, soft PVC plastics can be obtained. If no or less plasticizers are added (dosage < 10%), rigid PVC plastics can be obtained.

Main performance characteristics of plastics

Compared with other materials, plastics have the following performance characteristics.

  • 1. Light weight plastic is a relatively light material with a relative density of 0.90-2.2.
  • 2. Excellent chemical stability most plastics have good corrosion resistance to acids, alkalis and other chemicals.
  • 3. Excellent electrical insulation. Ordinary plastics are poor conductors of electricity. Their surface resistance and volume resistance are very large, which can be expressed in numbers up to 109-1018 ohms.
  • 4. the poor conductor of heat has the function of noise elimination and shock absorption. Generally speaking, the thermal conductivity of plastic is relatively low, which is equivalent to 1/75 – 1/225 of steel, and the micropore of foam plastics contains gas, and its heat insulation, sound insulation and shockproof are better.
  • 5. Wide distribution of mechanical strength and high specific strength. From the mechanical properties of plastics such as hardness, tensile strength, elongation and impact strength, it has a wide distribution range and has a great choice of use.
  • Foam tube cap is made of foam as raw material, and foam plays the role of heat preservation, heat insulation and silencing.

Raw material performance characteristics of plastic products such as plastic pipe caps:
1. Excellent electrical insulation performance
Ordinary plastics are poor conductors of electricity, with great surface resistance and volume resistance. The breakdown voltage is large and the dielectric loss tangent is very small. Therefore, plastics are widely used in electronic industry and mechanical industry. Such as plastic insulated control cable.
2. Wide distribution of mechanical strength and high specific strength
Some plastics are as hard as stone and steel, while others are as soft as paper and leather; From the mechanical properties of plastics such as hardness, tensile strength, elongation and impact strength, it has a wide distribution range and has a great choice of use. Because of its small specific gravity and high strength, plastics have high specific strength. Compared with other materials, plastics also have obvious disadvantages, such as easy combustion, lower stiffness than metal, poor aging resistance, heat resistance and so on.
3. Light weight
Plastic is a lighter material with a relative density of 0.90-2.2. Obviously, can plastic float to the water? In particular, foamed plastics have lighter texture due to micropores, and the relative density is only 0.01. This characteristic makes plastics available for the production of products requiring reduced self weight.
4. Excellent chemical stability
Most plastics have good corrosion resistance to acids, alkalis and other chemicals. In particular, the chemical stability of polytetrafluoroethylene (F4), commonly known as the king of plastics, is even better than gold. It will not deteriorate even if it is boiled in “aqua regia” for more than ten hours. F4 is an ideal corrosion-resistant material because of its excellent chemical stability. For example, F4 can be used as the material of pipeline conveying corrosive and viscous liquid.
Development trend of raw materials for plastic products such as plastic pipe caps:
The development direction of plastics can be summarized into two aspects. First, improve the performance, that is, modify the existing varieties by various methods to improve their comprehensive performance; The second is the development of function, that is, the development of polymer materials with optical, electrical, magnetic and other physical functions, so that plastics can have photoelectric effect, thermoelectric effect, piezoelectric effect and so on.

Identification method of raw materials of plastic pipe cap

There are also advantages and disadvantages of plastic pipe cap raw materials. Let me introduce the methods of plastic identification:
1. Appearance identification of plastics
By observing the appearance of plastics, we can preliminarily identify the categories of plastic products: Thermoplastics, thermosetting plastics or elastomers. General thermoplastics are crystalline and amorphous. The appearance of crystalline plastic is translucent, milky or opaque. It is transparent only in the film state, and its hardness ranges from soft to horny. Amorphous is generally colorless, completely transparent when no additives are added, and its hardness is from hard to horny rubber (plasticizers and other additives are often added at this time). Thermosetting plastics usually contain fillers and are opaque. If they do not contain fillers, they are transparent. The elastomer has a rubber like feel and a certain tensile rate.
2. Solvent treatment and identification of plastics
Thermoplastics swell in solvents, but are generally insoluble in cold solvents. In hot solvents, some thermoplastics will dissolve. For example, polyethylene is dissolved in xylene, thermosetting plastics are insoluble in solvents, generally do not swell or only slightly swell, and elastomers are insoluble in solvents, but usually swell.
3. Density identification of plastics
The density of plastics varies with the variety of plastics. The method of measuring density can be used to identify plastics; But foam products should be separated at this time, because the density of foamed plastics is not the true density of materials. In the actual industry, there are also ways to sort plastics by using different densities of plastics.
4. Heating identification of plastics
The heating characteristics of the above three types of plastics are also different, which can be identified by heating method. Thermoplastics soften when heated, melt easily, and become transparent when melted. They can often pull wires from the melt and are usually easy to heat seal. The thermosetting plastic shall be heated until the material is chemically decomposed, its original hardness shall not be softened, its size shall be stable, and it shall be carbonized at the decomposition temperature. When the elastomer is heated, it will not flow until the chemical decomposition temperature, and the material will decompose and carbonize at the decomposition temperature.

Introduction of thermoplastic raw materials for plastic pipe cap

Thermoplastic of plastic pipe cap: refers to the plastic that will melt after heating, can flow to the mold to be formed after cooling, and will melt after reheating; Heating and cooling can be used to produce reversible changes (liquid ←→ solid), which is the so-called physical change. The continuous service temperature of general thermoplastic is below 100 ℃. Polyethylene, polyvinyl chloride, polypropylene and polystyrene are called the four general plastics. Thermoplastics are divided into hydrocarbons, vinyl containing polar genes, engineering, cellulose and other types. It softens when heated and hardens when cooled. It can soften and harden repeatedly and maintain a certain shape. Soluble in certain solvents, with fusible and soluble properties. Thermoplastics have excellent electrical insulation, especially polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE) and polypropylene (PP) have very low dielectric constant and dielectric loss, and are suitable for high frequency and high voltage insulation materials. Thermoplastics are easy to form and process, but they have low heat resistance and are easy to creep. Their creep degree changes with load, ambient temperature, solvent and humidity. In order to overcome these weaknesses of thermoplastics and meet the needs of applications in space technology, new energy development and other fields, all countries are developing melt forming heat-resistant resins, such as polyether ether ketone (PEEK), polyether sulfone (PES), polyarylene sulfone (PASU), polyphenylene sulfide (PPS), etc. The composites with them as matrix resin have high mechanical properties and chemical corrosion resistance, can be thermoformed and welded, and the interlaminar shear strength is better than that of epoxy resin. If peek is used as matrix resin and carbon fiber is made into composite, the fatigue resistance is better than that of epoxy / carbon fiber. It has good impact resistance, good creep resistance at room temperature and good processability. It can be used continuously at 240 ~ 270 ℃. It is a very ideal high temperature resistant insulating material.

Structural types and characteristics of plastic pipe cap raw materials

There are basically two types of structures of plastic polymers as raw materials for plastic pipe caps: the first is linear structure, and the polymer compounds with this structure are called linear polymer compounds; The second is the body structure. The polymer compound with this structure is called the body polymer compound. Some polymers have branched chains, called branched polymers, which belong to linear structure. Although some polymers have cross-linking between molecules, they have less cross-linking, which is called network structure and belongs to body structure.
Two different structures exhibit two opposite properties. Linear structure (including branched chain structure) polymers have the characteristics of elasticity, plasticity, solubility in solvent, melting when heated, and low hardness and brittleness due to the existence of independent molecules. Due to the absence of independent macromolecules, body structure polymers have no elasticity and plasticity, can not dissolve and melt, can only swell, and have high hardness and brittleness. Plastics have both kinds of polymers. Thermoplastic is made of linear polymers and thermosetting is made of body polymers.
Raw material characteristics of plastic pipe cap:

  • ① Most plastics are light, chemically stable and will not rust;
  • ② Good impact resistance;
  • ③ It has good transparency and wear resistance;
  • ④ Good insulation and low thermal conductivity;
  • ⑤ Generally, it has good formability and coloring, and low processing cost;
  • ⑥ Most plastics have poor heat resistance, high thermal expansion rate and easy combustion;
  • ⑦ Poor dimensional stability and easy deformation.

Types of plastic pipe caps

Plastic pipe cap includes steel pipe cap, flange cap, steel pipe plug, etc.
The plastic pipe cap includes the design of convex pipe cap, conical shell, reducing section, flat cover and tightening mouth.
The convex pipe cap comprises a hemispherical pipe cap, an elliptical pipe cap, a dished pipe cap and a spherical crown pipe cap. From the point of view of stress, the hemispherical pipe cap in the convex pipe cap is gradually bad, but from the point of view of manufacturing difficulty, it is gradually good to manufacture.

Advantages and disadvantages of plastic pipe cap

Advantages of plastic pipe cap

  • 1. Most plastics have strong corrosion resistance and do not react with acid and alkali.
  • 2. Plastic molding cost is low.
  • 3. Durable, waterproof and light.
  • 4. Chaozhuo is molded into different shapes.
  • 5. It is a good margin body.
  • 6. Plastics can be used to prepare fuel oil and fuel gas, which can reduce the consumption of crude oil.

Defects of plastic pipe cap

  • 1. There are few types and incomplete specifications of pipe fittings, which can not meet the needs of the project.
  • 2. Product standards, design and construction specifications lag behind, and engineering and technical personnel lack professional training.
  • 3. Lack of standardized management in the market, blind project construction and lack of unified planning lead to excess production capacity and serious shortage of operating rate of production equipment in some areas. Coupled with insufficient quality supervision and management, fake and shoddy products flooded the market.
  • 4. The variety of raw materials is few, the quality is unstable, and there is a certain gap with foreign famous brand special materials, resulting in some raw materials relying on import.

Several forming steps of plastic pipe cap

Plastic molding refers to the process of making final plastic products from polymers manufactured by synthetic resin manufacturers. Processing methods (commonly referred to as one-time processing of plastics) include compression molding (Molding), extrusion molding (extrusion molding), injection molding (injection molding), blow molding (hollow molding), calendering, etc.
Compression molding
Compression molding is also called molding or press molding. Compression molding is mainly used for the molding of thermosetting plastics such as phenolic resin, urea formaldehyde resin and unsaturated polyester resin.
Extrusion
Extrusion, also known as extrusion molding, is a method of using an extruder (extruder) to continuously pass the heated resin through the mold to extrude products of the required shape. Extrusion is also sometimes used in moulding of thermosetting plastics and can be used in molding of foamed plastics. The advantage of extrusion is that it can extrude products of various shapes, with high production efficiency and automatic and continuous production; The disadvantage is that thermosetting plastics can not be widely processed by this method, and the product size is easy to deviate.
Injection molding
Injection molding is also called injection molding. Injection molding is a method of using injection molding machine (or injection machine) to inject thermoplastic melt into the mold under high pressure and obtain products after cooling and curing. Injection molding can also be used for molding thermosetting plastics and foam plastics. Injection molding has the advantages of fast production speed, high efficiency, automatic operation, and can shape complex parts, especially suitable for mass production. The disadvantages are high cost of equipment and mold, difficult cleaning of injection molding machine, etc.
Blow molding
Blow molding is a common method for manufacturing hollow thermoplastic products, such as plastic pipe caps. The main products are cylindrical membranes and hollow containers. The plastic cap blow molding machine can plasticize the preform by heating, and then enter the mold for blow molding. This method is mainly used for the production of high-speed and high-yield PET bottles and BOPP bottles, that is, two-step process; Blow molding can also be combined with injection molding process to form an integrated injection, pull and blow machine, which is also a common method for producing containers in pet; The blow molding process can also be combined with the extrusion process. The extrusion blow molding equipment has a wider application range and can produce more abundant products. The products include multi-layer composite films and various polyolefin hollow containers, which are widely used in food, medicine and cosmetics industries.
According to the production process of plastic pipe cap products, plastic machinery can be divided into four categories: plastic mixing machinery, plastic forming machinery, plastic secondary processing machinery and plastic processing auxiliary machinery or devices. Plastic pipe cap mixing machine is used for the manufacture of various forms of plastic mixing materials, including kneader, plastic mixer (open mixer and internal mixer), pelletizer, screening machine, crusher and grinder. Plastic molding machinery, also known as plastic primary processing machinery, is used for the molding of plastic semi-finished products or products, including compression molding machine, injection molding machine, extrusion machine, blow molding machine, calender, roll molding machine, foaming machine, etc. Plastic secondary processing machinery is used for reprocessing and post-treatment of plastic semi-finished products or products, including thermoforming machine, welding machine, heat sealing machine, hot stamping machine, vacuum evaporation machine, flocking machine, printing machine, etc. Metal processing machine tools are also commonly used for secondary processing of plastics. Plastic cap processing auxiliary machinery or devices are used to realize the rationalization of plastic processing process, including automatic metering and feeding device, automatic recovery device of leftover materials, automatic extraction device of injection molding products, rapid replacement device of injection mold, injection mold cooler, automatic thickness measurement device, raw material conveying and storage equipment, etc. This kind of auxiliary machinery or device has become an indispensable part of the automation of modern plastic processing process.
Calendering
Calendering is a forming method in which the resin and various additives are processed into films or sheets through the gap between two or more calendering rollers of the calender turning opposite after expected treatment (kneading, filtration, etc.), then stripped from the calender roller, and then cooled and shaped. Calendering is a molding method mainly used for PVC resin, which can manufacture films, sheets, plates, artificial leather, floor tiles and other products.
Foaming molding
The process of adding appropriate foaming agent to foaming materials (PVC, PE, PS, etc.) to make plastics produce microporous structure. Almost all thermosets and thermoplastics can be made into foam plastics. According to the bubble structure, they are divided into open cell foams (most pores are interconnected) and closed cell foam (most pores are separated). This is mainly determined by the manufacturing methods (divided into chemical foaming, physical foaming and mechanical foaming).
Instructions for rubber mouth guard forming
Rubber is a thermosetting elastomer, while plastic is a thermosetting elastomer. Due to different types and main bodies of sulfides, there is a considerable gap in the temperature range of forming and curing of rubber, and it can even be affected by climate change and indoor temperature and humidity. Therefore, the production conditions of rubber products need to be adjusted appropriately at any time. If not, there may be differences in product quality. When the rubber mouth guard is formed, it can not be eliminated due to the cohesion of the elastomer after high pressure pressing. When the rubber mouth guard is formed and removed from the mold, it often produces extremely unstable shrinkage, which can be gentle and stable only after a period of time. Therefore, at the beginning of the design of a rubber product, no matter the formula or mold, it is necessary to calculate the coordination carefully. If not, it is easy to cause the instability of product size and low product quality.

Selection of plastic molding

The choice of plastic molding mainly depends on the type of plastic (thermoplastic or thermosetting), initial form and the shape and size of the product. Common methods for processing thermoplastic plastics include extrusion, injection molding, calendering, blow molding and thermoforming. Molding, transfer molding and injection molding are generally used for processing thermosetting plastics. Plastic molding is the process of making plastics in various forms (powder, particle, solution and dispersion) into products or blanks with required shapes. There are more than thirty molding methods. Its choice mainly depends on the type of plastic (thermoplastic or thermosetting), initial form, and the shape and size of the product. Common methods for processing thermoplastic plastics include extrusion, injection molding, calendering, blow molding and thermoforming. Molding, transfer molding and injection molding are generally used for processing thermosetting plastics. Lamination, molding and thermoforming are the process of forming plastics on a flat surface. The above plastic processing methods can be used for rubber processing. In addition, there are casting with liquid monomer or polymer as raw material. Among these methods, extrusion and injection molding are the most used and the most basic molding methods.
Plastic molding instructions:

  • (1) Linear size shrinkage of plastic parts due to thermal expansion and cold shrinkage, elastic recovery and plastic deformation during plastic part demoulding, the size of plastic parts is reduced after demoulding and cooling to room temperature. Therefore, compensation must be considered in cavity design.
  • (2) During shrinkage directional forming, the molecules are arranged according to the direction, so that the plastic parts are anisotropic. Along the material flow direction (i.e. parallel direction), the shrinkage is large and the strength is high, while in the direction perpendicular to the material flow (i.e. vertical direction), the shrinkage is small and the strength is low. In addition, due to the uneven distribution of density and filler in each part of the plastic part during forming, the shrinkage is also uneven. Shrinkage difference makes plastic parts prone to warpage, deformation and crack, especially in extrusion and injection molding. Therefore, the shrinkage directionality should be considered in die design, and the shrinkage rate should be selected according to the shape of plastic parts and flow direction.
  • (3) During the forming of post shrinkage plastic parts, due to the influence of forming pressure, shear stress, anisotropy, uneven density, uneven filler distribution, uneven die temperature, uneven hardening, plastic deformation and other factors, a series of stresses can not disappear in the viscous flow state. Therefore, there are residual stresses during the forming of plastic parts in the stress state. After demoulding, due to the influence of stress balance and storage conditions, the residual stress changes and the plastic part shrinks again, which is called post shrinkage. Generally, the plastic parts change the most within 10 hours after demoulding, and basically set after 24 hours, but the final stability takes 30-60 days. Generally, the post shrinkage of thermoplastic is greater than that of thermosetting, and the specific pressure of extrusion and injection molding is higher.

Manufacturing requirements for plastic pipe caps

  • 1) The appearance of the pipe cap shall be free of cracks and double skin, and the wall thickness shall be greater than that of the pipe section at the large diameter end.
  • 2) The roundness of the pipe cap shall not be greater than 1% of the outer diameter of the corresponding end, and the allowable deviation shall be ± 3mm; The center lines at both ends of the concentric pipe cap shall coincide, and the allowable deviation of its eccentricity value shall be ± 5mm.

The method of filling deacidification cotton is simple and easy. It should be noted that the burnt cotton wadding should be replaced frequently. The method of filling silicon aluminum cotton can not be replaced for a long time, but it should be noted that when replacing a new pipe cap, do not forget to fill again. If the glass melting plate becomes black and loses air permeability, please refer to Article 10 maintenance method for treatment.
Due to the simple structure of pipe cap, concentric pipe cap and eccentric pipe cap are similar to straight pipe and reducing pipe cap is similar to equal diameter elbow (elbow). People usually use the relevant theories of straight pipe and equal diameter elbow to analyze the problem of pipe cap. Its characteristics have been ignored for a long time, and there are many potential safety hazards from manufacturing, installation to operation.

Traditional methods for testing moisture permeability of plastic pipe caps

At present, the container moisture permeability test method commonly used for plastic pipe cap plastics is developed on the basis of the film moisture permeability test weighing method. The weighing method test principle is adopted. The relevant test standards include GB/T 6981-1986, GB/T 6982-1986 and ASTM D3079-94. According to the properties of materials, it is divided into the moisture permeability test of flexible packaging containers and the moisture permeability test of hard packaging containers, There are slight differences in the specific operation steps of detecting these two types of containers, but the basic test methods are the same.
The test method is as follows: put the desiccant (containing accessories can be used) into the container sample for test, seal the test sample, preheat the test sample, immediately transfer it to the test chamber (chamber) under constant damp heat conditions for damp heat test, and then weigh the sample at appropriate intervals according to the moisture permeability of the container material, When the penetration is stable, the moisture permeability of the container is calculated by the increase in the weight of the sample.
Working principle of plastic pipe cap injection molding machine
The working principle of the plastic cap plastic cap injection molding machine is similar to that of the syringe for injection. It is a process in which the plasticized molten plastic (i.e. viscous flow) is injected into the closed mold cavity with the help of the thrust of the screw (or plunger), and the products are obtained after curing and shaping.
Injection molding is a cycle process, each cycle mainly includes: quantitative feeding – melting and plasticization – pressure injection – mold filling and cooling – mold opening and taking parts. After taking out the plastic part, close the mold again for the next cycle.
Operation items of plastic cap injection molding machine: the operation items of plastic cap injection molding machine include control keyboard operation, electrical control system operation and hydraulic system operation. Select the injection process action, feeding action, injection pressure, injection speed and ejection type, monitor the temperature of each section of the barrel, and adjust the injection pressure and back pressure.
The adjustment of process in the production process is a necessary way to improve the product quality and output. Because the injection molding cycle itself is very short, if the process conditions are not well mastered, there will be an endless stream of waste products. When adjusting the process, it is best to change only one condition at a time and observe more times. If the pressure, temperature and time are all adjusted together, it is easy to cause confusion and misunderstanding. If there is a problem, I don’t know the reason. There are many measures and means to adjust the process. For example, there are more than ten possible solutions to the problem of dissatisfaction with product injection. Only by selecting one or two main solutions to solve the crux of the problem can we really solve the problem. In addition, attention should also be paid to the dialectical relationship in the solution. For example, if the product is sunken, sometimes the material temperature should be increased and sometimes the material temperature should be reduced; Sometimes it is necessary to increase the material quantity, and sometimes it is necessary to reduce the material quantity. We should recognize the feasibility of reverse measures to solve the problem.

Development of plastic pipe caps

Plastic pipe cap is a pipe cap processed with plastic as the main raw material. Plastic is a kind of plastic synthetic polymer material. Together with synthetic rubber and synthetic fiber, it has formed three indispensable synthetic materials in today’s daily life. Specifically, plastic is a material with synthetic resin as the main component, which can be molded into a certain shape under certain temperature and pressure and keep the shape unchanged at room temperature. At present, the high barrier and multifunctional film of plastic pipe cap is developing to a new technical level. The high barrier and multifunctional soft plastic packaging material has become a hot spot in recent years. The original composite film is developing to a deeper level, the bag making and printing technology has reached a new level and entered the era of “Color Revolution”. There are offset, gravure and flexographic color systems in the whole industry, which has promoted the in-depth development of soft plastic packaging materials. The anti-counterfeiting packaging film is developing with each passing day, which is called the flower of soft plastic packaging. In particular, the successful development of anti-static packaging film is of great significance.

Function and application of pipe plug

The pipe inner plug belongs to the technical field of pipe sealing parts, including a plug body with a plug cover fixed at the upper end, and no less than two rings with increasing outer diameter are fixed on the outer wall of the plug body from bottom to top. Pipe fittings welded on the pipe end or installed on the external thread of the pipe end to cover and plug the pipe. The utility model is used to close the pipeline and has the same function as the pipe plug. The pipe inner plug of the utility model can be applied to pipes with various diameters at the same time, reducing the cost. It is also applicable to pipe fittings, hydraulic valves, hydraulic oil pipes, valves, flanges, transition interfaces, threaded screws and oil tanks to protect internal and external products. It can not only improve the aesthetic effect, but also make the internal and external products dustproof, ash and oil proof.

What is a plastic inner cap?

The production of plastic inner cap has solved many problems in the fields of chemical industry, petroleum, pharmacy and so on. Its main materials are: PTFE seals, gaskets and gaskets. The main characteristics of its materials are: PTFE seals, gaskets and gaskets are made of suspension polymerized PTFE resin molding. Compared with other plastics, polytetrafluoroethylene has the characteristics of chemical corrosion resistance. It has been widely used as sealing material and filling material. Used as engineering plastics, it can be made into Teflon pipes, rods, belts, plates, films, etc. It is generally used in corrosion-resistant pipes, containers, pumps, valves with high performance requirements, radar, high-frequency communication equipment, wireless electrical materials, etc. The dispersion can be used as insulation impregnation liquid of various materials and anti-corrosion layer on the surface of metal, glass and pottery. All kinds of PTFE rings, PTFE gaskets and PTFE packing are widely used for flange sealing of all kinds of anti-corrosion pipelines. In addition, it can also be used for drawing, polytetrafluoroethylene fiber – fluorine fiber (foreign trade name is Teflon).

Use difference between inner and outer caps of plastic pipe caps

The plastic inner cap is used to close the pipeline and has the same function as the pipe plug. It can prevent dust, water and corrosion. It has strong corrosion resistance, cold resistance and electrical insulation. The plasticity of the plastic itself makes the pipe cap have the characteristics of strong, good and high specific strength.
Plastic outer cap is a pipe cap processed with plastic as the main raw material. Plastic is a kind of plastic synthetic polymer material. Together with synthetic rubber and synthetic fiber, it has formed three indispensable synthetic materials in today’s daily life. Specifically, plastic is a material with synthetic resin as the main component, which can be molded into a certain shape under certain temperature and pressure and keep the shape unchanged at room temperature.

How to choose a good plastic pipe cap?

Let’s look at the three steps of purchasing plastic pipe caps, as follows:

  • 1. Look at the appearance – if the product has rough appearance, molding defects, incorrect color, impurities and poor printing quality, it is best not to use it. Products with unqualified appearance quality will affect consumers’ visual perception. At the same time, appearance is a reflection of internal quality. Products with unqualified appearance often have poor internal quality and affect their use. If the printing quality is unqualified, it will affect the beauty, or fade and pollute other articles.
  • 2. Smell – the main reason for the strange smell of plastic products is the use of recycled materials and inferior additives. The pungent smell emitted by products with different smell will harm the respiratory system of human body, so it is best not to use it.
  • 3. Try it — some products are very bright in color in order to attract the attention of consumers. The pigments of dark products with poor quality will appear in the process of use. These pigments are generally industrial pigments. Consumers can check whether the selected dark color product is qualified by themselves: pour a little edible vinegar on the degreasing cotton ball, and then touch the food surface to wipe it back and forth 100 times. If the degreasing cotton ball is stained with color, it indicates that the product is unqualified.

Precautions: in order to avoid pigment infiltration into food, it is recommended not to use dark color plastic products to contain oily liquid food. In winter, due to the drop of temperature, the plastic pipe cap is fragile, and improper inventory will lead to unnecessary losses. In order to overcome these weaknesses of thermoplastic plastics and meet the needs of large-scale operations in space technology and new energy, countries are rejecting melting and forming heat-resistant resins, such as polyether ether ketone (PEEK), polyether sulfone (PES), polyarylene sulfone (PASU), polyphenylene sulfide (PPS), etc. Plastic pipe cap thermoplastic has excellent electrical insulation, especially polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE) and polypropylene (PP) have extremely low dielectric constant and dielectric consumption, and are suitable for high frequency and high voltage insulation materials. Thermoplastics are easy to form and process, but they have low heat resistance and are easy to creep. Their creep degree changes with load, scene temperature, solvent and humidity. If polyether ether ketone is used as matrix resin and carbon fiber is made into composite material, the decadent resistance exceeds that of epoxy / carbon fiber. The composites with them as matrix resin have high mechanical properties and chemical corrosion resistance, can be thermoformed and welded, and the interlaminar shear strength is better than that of epoxy resin. It has good impact resistance, excellent creep resistance at room temperature and good processability. It can continue to operate at 240 ~ 270 ℃. It is an ideal low temperature resistant insulating material.

Source: China Pipe Cap Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at sales@steeljrv.com

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