Explanation of main test indicators of PTFE products
PTFE products are a special type of plastic, which is quite different from other plastics. According to the industry standard of the Ministry of Light Industry, the PTFE products produced must meet the requirements of the index. Below we list the definitions of the 13 main test indicators for PTFE products for reference.
- The coefficient of linear expansion indicates the degree of expansion or contraction of the material. It refers to the expansion ratio of the finishedpolytetrafluoroethylene plastic at a temperature of 1 ° C under a certain pressure, expressed as the coefficient of linear expansion relative to the unit length. This coefficient is one of the important indicators for understanding the degree of change in product size with increasing temperature of PTFE products, expressed in units of 1/°C or 1/K. The coefficient of linear expansion coefficient is α = ΔL / (L * ΔT), where ΔL is the change in the length of the object at the given temperature change ΔT, and L is the initial length. The linear expansion coefficient of PTFE is about 10-12*10-5/°C (ambient temperature 25-250°C), ie (0.01-0.012)%, and the linear expansion coefficient of PTFE is 10~20 times that of iron, which is larger than most plastics.
- Thermal conductivity: Also called thermal conductivity, it reflects the thermal conductivity of the material. It is defined as two parallel planes with an area of 1 m2 perpendicular to the direction of heat conductioninside the object.If the temperatures of the two planes differ by 1 K, the heat is transferred from one plane to the other in 1 second. The unit is defined as the thermal conductivity of the substance, and its unit is watt·m-1·open-1 (W·m-1·K-1). It is a reference indicator for studying the thermal insulation of target products when designing products.
- The tensile strain at break is the tensile strain corresponding to the tensile fracture stress when the sample of the polytetrafluoroethylene product is not fractured under the tensile load, and the tensile strain is just when the sample material is plastically shaped. The ratio of the difference between the length to the original length and the original length, expressed as a percentage (%).
- Tensile strength: In the test of tensile specimens, the critical value of the transition from uniform plastic deformation to local concentrated plastic deformation, characterizing the resistance of the material to the maximum uniform plastic deformation, is also the maximum load carrying capacity of plastic under static tensile conditions ( Maximum tensile stress). The unit is MPa.
- Elongation at break: It is the increment of the index from the original unit length (ie the rate of change of length), which is the ratio of the difference between the length of the pull-off and the original length to the original length, expressed as a percentage (%).
- Electrical strength: A parameter indicating the breakdown of equipment insulation at a certain rated voltage, indicating the degree of insulation of the product withstand voltage. It means that under certain conditions, the ratio of the breakdown voltage to the thickness of the sample to be broken is the electrical strength of the product.
- Breakdown voltage: The voltage at which the test piece breaks down is thehighest voltagebefore being penetrated. That is, the sample does not break down at this voltage. The breakdown is usually caused by a partial discharge in the gas or liquid medium surrounding the sample and the electrode, and the sample at the edge of the smaller electrode (or equal-diameter two electrodes) is destroyed.
- Density The ratio of the mass of a substance to its volume, that is, the mass of a substance per unit volume, is called the density of this substance. Kilograms/meter 3 or 1 gram per cubic centimeter 1.0 x 103 kg/m3 of polytetrafluoroethylene plastic products are usually tested by dipping, liquid pycnometer and titration.
- Withstand voltage is the sample between the electrodes, the power frequency AC voltage rises to the voltage before the breakdown is the withstand voltage of the sample.
- Fracture Nominal strain refers to the tensile strain corresponding to the fracture stress when the tensile specimen is not yielded and the fracture specimen is subjected to the specified specimen size, and the % is expressed by a dimensionless ratio or percentage.
- The longitudinal dimensional change rate means that the pipe (100 ± 1) with a certain length is placed in a (260 ± 2 ° C) oven for 3 hours, and taken out at a normal temperature of 23 ± 2 ° C for 4 hours. The length of the treated sample is The percentage of the difference between the original size and the original size.
- Dielectric strength is a measure of the electrical strength of a material as an insulator. It is defined as the maximum voltage per unit thickness that a unit is subjected to when it is broken down, in volts per unit thickness. The ratio of breakdown voltage to sample thickness. The breakdown voltage is tested according to GB/T1408.1-2006. The dielectric strength is in kilovolts per millimeter (KV/mm).
Introduction to seal gasket
With the advent of mechanization era, a variety of machinery and equipment emerge in endlessly, in a variety of mechanical equipment, sealing gaskets become unnecessary parts, is the industrial production enterprises and related industries to solve the gas, liquid medium "run, run, drip, leakage", root cure leakage effective tools.
As the name suggests, the seal gasket is a seal, mainly play the role of sealing, it is generally used for machinery, equipment, pipelines and other places where there is a fluid through.Used for connection between pipes or parts of equipment.
Popular at present, the market of sealing gaskets are metal or nonmetal after cutting, stamping or tailor made after processing, such as the common have high pressure asbestos rubber gasket, oil resistant rubber gasket, cylinder gasket, aramid fiber gasket, asbestos gasket, asbestos gasket, rubber mat and so on seven big classes, different material sealing gasket its specific applicable environment is different also, if the gasket failure, not only affects the operation of equipment, sometimes even cause an accident, a threat to the personal and property of people.
Relevant data shows that different gaskets have their national standards are different, in quality, density, corrosion resistance, lubricity resistance, oxidation resistance and other aspects of strict requirements, as long as all the parameters to achieve national standards, before entering the market.
Sealing gasket is commonly used in ptfe gasket, with good flexibility, compression resilience, creep resistance, high and low temperature resistance and excellent corrosion resistance, aging resistance, self-lubrication.With its very low leakage rate and excellent heat resistance and radiation resistance, and at the same time very convenient installation and use, is the chemical industry, medicine, petrochemical, food and beverage, electronics, power, metallurgy, shipping and other industries extremely ideal sealing material.
The application of UHMWPE
The molecular chain length of UHMWPE is 10 ~ 20 times that of hdpe. The main advantages of longer molecular chains (higher molecular weight) give UHMWPE are toughness, wear resistance and resistance to stress cracking. Because it is a kind of polyethylene, UHMWPE also has lubricity, chemical resistance and general purpose HDPE excellent electrical properties.
Long molecular chains make materials difficult to process in common moulding and extrusion equipment. When heated above the melting point, UHMWPE becomes transparent but does not flow.Chemical and performance UHMWPE is produced by ziegler polymerization. The process requires a particularly high degree of purity, ethylene monomer impurity control in a few parts per million. The product is a white powder with a particle size similar to that of table salt.
UHMWPE is used for low speed bearing housing. Low friction coefficient is further reduced by adding siloxane, aluminum disulfide, graphite and special paraffin wax. In the food processing industry, UHMWPE self-lubricity, easy purification, low flavor gas/flavor transmission and boiling water resistance are used. Has met FDA and USDA requirements for use in food, water, and pharmaceutical industries. Some of the USES of UHMWPE are based on its noise absorption and shock absorption. If UHMWPE is needed, dye can be used for coloring, while pigments are slightly inferior. PTFE/Polymer/UHMWPE Tube Ram Extruder， PTFE/Polymer/UHMWPE Rad Ram Extruder, Gasket machine, Plastic Pipe machine, etc. These machines can be used to produce a variety of fields need some ptfe, polymer, ultra high molecular weight and other products.
UHMWPE may be used in a new generation of self-unloading ore carriers, railway wagons and large trucks due to its smooth, non-viscous and abrasion resistance. These properties make it also useful for agriculture and earth-moving machinery, with UHMWPE materials to protect steel. The combination of chemical resistance and surface smoothness has many applications. For food processing industry, UHMWPE is used as the surface material of meat cutting board. UHMWPE is used as contact surface and roller for processing food and medicine conveyors. It has the properties of self-lubricating, resistance to boiling water and resistance to chemical cleaner.
Introductions of sintering furnace
What is a Sintering Furnace?
A sintering furnace is used during the sintering process, which involves the heating of powder compacts in order to increase the product’s mechanical strength, density, and translucency. This type of oven must be able to maintain heating temperatures below the product’s melting point, as the goal is not to liquefy the material. Rather, a sintering furnace is used more to shape materials into their final product.
How Sintering Furnaces are Used
Sintering furnaces are used within the manufacturing industry when producing metals, ceramics, plastics, and other materials:
• Metal sintering is used to develop a wide variety of products including shotgun shells used by the military, aircraft hydraulic systems, and stainless steel tools.
• Ceramic sintering uses substances like glass, aluminum, zirconia, and silica to develop pottery and other ceramic products.
• Plastic sintering is used to develop products that require wicking properties, as well as materials used as ski and snowboard bases.
A Simple Guide To Plastic Molding
A Simple Guide To Plastic Molding
Is Rotational Molding Right For You?
So you need a custom plastic part or product, but you don’t know how to get it made.
Is it large or small? Should it be flexible or stiff? Is it round, square, or some weird shape? Do you already have a mold, or do you need to have one made?
This guide will explain the different kinds of molding processes available today to help you discover the ideal process for your product.
What Is Plastic Molding?
Molding, also sometimes spelled moulding, is the process of manufacturing by shaping liquid or pliable material using a rigid frame called a mold or matrix.
When molding plastics, a powder or liquid polymer such as polyethylene or polypropylene is placed into a hollow mold so the polymer can take its shape. Depending on the type of process used, various ranges of heat and pressure are used to create an end product.
The History of Plastic Molding
Plastic molding began in the late 1800’s to fill the need for plastic billiard balls as opposed to the commonly used ivory billiard balls of the time. In 1868, John Wesley Hyatt invented a way to make billiard balls by injecting celluloid into a mold. Four years later, Hyatt and his brother invented and patented a machine to automate the process. This was the first plastic injection molding machine in existence and it used a basic plunger to inject plastic into a mold through a heated cylinder.
In 1946, the screw injection molding machine was invented by James Hendry, which replaced the plunger injection technique. This is the technique most commonly used today.
Modern rotational molding also has a rich history beginning in 1855 when rotation and heat were used to produce metal artillery shells in Britain.
Plastics were introduced into the process in the early 1950’s, when rotational molding was first used to manufacture doll heads. And then in the 1960’s the modern process of rotational molding that allows us to create large hallow containers with low-density polyethylene was developed. In recent history, process improvements, better equipment, and plastic powder developments have sped up the process of creating finished products which has caused rotational molding to grow rapidly in popularity.
The Types of Plastic Molding
The most popular techniques in plastic molding are rotational molding, injection molding, blow molding, compression molding, extrusion molding, and thermoforming. We’ll cover all these techniques in this guide to help you discover the best process to make your part or product.
Rotational Molding
Rotational Molding, also called rotomolding, is a manufacturing process for producing large hollow parts and products by placing a powder or liquid resin into a metal mold and rotating it in an oven until the resin coats the inside of the mold. The constant rotation of the mold creates centrifugal force forming even-walled products. Once the mold cools, the hardened plastic is removed from the mold.
Very little material is wasted during the process, and excess material is often re-used, making it economical and environmentally friendly.
Common Uses for Rotational Molding
Rotational molding is commonly used to make large hollow plastic products like utility carts, storage tanks, car parts, marine buoys, pet houses, recycling bins, road cones, kayak hulls, and playground slides.
Rotational Molds Are Highly Customizable And Cost Effective
The mold itself can be highly intricate to facilitate the molding of a wide range of products. Molds can include inserts, curves, and contours as well as logos and slots for plastic or metal inserts to be placed after a product is molded.
Tooling costs are lower with rotational molds than injection or blow molds. The results are lower start-up costs and cost-effective production runs even when producing as few as 25 items at a time.
Injection Molding
Injection molding is the process of making custom plastic parts by injecting molten plastic material at high pressure into a metal mold. Just like other forms of plastic molding, after the molten plastic is injected into the mold, the mold is cooled and opened to reveal a solid plastic part.
The process is similar to a Jello mold which is filled then cooled to create the final product.
Common Uses for Injection Molding
Injection molding is commonly used for making very high volume custom plastic parts. Large injection molding machines can mold car parts. Smaller machines can produce very precise plastic parts for surgical applications. In addition, there are many types of plastic resins and additives that can be used in the injection molding process, increasing its flexibility for designers and engineers.
Injection molds, which are usually made from steel or aluminum, carry a hefty cost. However, the cost per part is very economical if you need several thousand parts per year.
With injection molding, tooling usually takes 12-16 weeks with up to four more weeks for production.
Blow Molding
Blow molding is a method of making hollow, thin-walled, custom plastic parts. It is primarily used for making products with a uniform wall thickness and where the shape is important. The process is based upon the same principle as glass blowing.
Blow molding machines heat up plastic and inject air blowing up the hot plastic like a balloon. The plastic is blown into a mold and as it expands, it presses against the walls of the mold taking its shape. After the plastic “balloon” fills the mold, it is cooled and hardened, and the part is ejected. The whole process takes less than two minutes so an average 12 hour day can produce around 1440 pieces.
Common Uses for Blow Molding
Blow molding processes generate, in most cases, bottles, plastic drums, and fuel tanks. If you need a hundred thousand plastic bottles, this is the process for you. Blow molding is fast and economical with the mold itself costing less than an injection molding, but more than rotational molding … sometimes as high as 6 to 7 times as much as a roto-molding tool.
Compression Molding
Compression molding is done exactly like the name suggests. A heated plastic material is placed into a heated mold and then pressed into a specific shape. Usually, the plastic comes in sheets, but can also be in bulk. Once the plastic is compressed into the right shape, the heating process ensures that the plastic retains maximum strength. The final steps in this process involve cooling, trimming, and then removing the plastic part from the mold.
Common Uses of Compression Molding
The best use of compression molding is the replacement of metal parts with plastic parts. It is mostly used for small parts and products in very high volume. The automotive industry uses compression molding heavily because the final products are very strong and durable.
The initial cost of a compression mold is substantial, depending on several factors including the number of cavities, the size of the parts, the complexity of the pieces, and the surface finish among other things. But the cost of each individual part is low at high quantities, so large quantities of parts are ideal for this form of molding.
Extrusion Molding
Extrusion molding is similar to injection molding except that a long continuous shape is produced. Another difference in extrusion molding is that the process uses a “die” not a “mold.”
Extruded parts are made by squeezing hot raw material through a custom die. A simplistic visualization would be like squeezing Play Doh through a shaped hole.
While other forms of molding use extrusion to get the plastic resins into a mold, this process extrudes the melted plastic directly into a die. The die shape, not a mold, determines the shape of the final product.
Common Uses of Extrusion Molding
Parts made from extrusion have a fixed cross-sectional profile. Examples of extruded products include PVC piping, straws, and hoses. The parts do not need to be round but they need to have the same shape along the length of the part.
The cost of extrusion molding is relatively low compared to other molding processes because of the simplicity of the die and the machines themselves.
However, the nature of the extrusion molding process limits the kinds of products that can be manufactured with this technique.
Thermoforming
Thermoforming is a manufacturing process where a plastic sheet called thermoplastic is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. Thermoplastic comes in a wide variety of materials, colors, finishes, and thickness.
Thermoforming uses several different types of molds and processes in order to achieve the final product. To create 3D products, the mold is typically a single 3D form made out of aluminum. Because thermoforming uses low pressures, molds can be produced for a low cost using inexpensive materials.
Common Uses of Thermoforming
Thin-gauge thermoforming is commonly used to manufacture disposable cups, containers, lids, trays, blisters, clamshells, and other products for the food and general retail industries. Thick-gauge thermoforming includes parts as diverse as vehicle door and dash panels, refrigerator liners, and utility vehicle beds.
On average, it takes about 8 weeks to get a thermoform mold ready for production. The cost of a thermoform mold is based upon the size of the part that needs to be produced. A mold for a small part can cost as little as $20,000 while the cost of a larger mold can be upwards of $50,000.
Black PTFE rod ordered by Belgian customers to complete production and delivery
A batch of black PTFE rods ordered by Belgian customers has been produced.
Our company can produce extruded rods and molded rods of various sizes according to customers' needs. we can produce different colors, increase the graphite powder of carbon powder, etc. The materials can choose new materials and recycled materials.
Email：info@sukoptfe.com
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The Bush Automatic Press Machine ordered by the Indian customer on site has completed the equipment commissioning
The Indian customer purchased an Bush Automatic Press Machine. Our engineers went to india to know the equipment installation. The installation process was very smooth and the equipment production quality was good.
The commissioning process was smooth, and the equipment was running well during the trial run. Our company also provided customers with recycled raw materials for testing, saving customers unnecessary waste during trial operation. Our engineers also provide guidance and training to the technical staff of the customer, and the customer is very satisfied with our service.
We have three types of automatic molding machines.
Can produce the following specifications:
1, gasket: maximum outer diameter 70Mm, thickness 7mm, 1500 / hour.
2, large gasket: maximum outer diameter of 350mm, thickness of 10mm, 400-900 / hour.
3, molded tube / rod: maximum outer diameter 110mm, length 110mm. 200-400 / hour.
