PTFE slide bearing sheets

PTFE has the lowest friction coefficient of all plastics even if these are lubricated. Typical behaviour is whenever the load on PTFE increases friction coefficient becomes lower. PTFE has no "stick slip" behaviour which is unique in slide bearing technology.

Characteristics as stated above means an advantage for PTFE in bearing applications. Due to the fact no lubricants are required, PTFE (or compounds) is often used in food industry, road (bridge) construction, support of pipe systems and heavy installation constructions. By adding PTFE to the free movable construction parts (metal, rubber and so on) shrink and expansion, due to temperature movements, will not become an issue.

PTFE 100% virgin is a relatively soft material and can be too porous for heavy constructions. By adding fillers to the PTFE, required characteristics for specific applications will improve.
For example glass, bronze, graphite or carbon are commonly used. Friction coefficient will be slightly influenced due to these fillers. In general most optimal gliding construction with lowest friction is obtained in case PTFE is maximal loaded and counter surface is highly polished.

Properties PTFE

• Lowest friction coefficient
• No stick slip behaviour
• No cleaning required, material is chemical and weather resistant, does not age
• Simple engineered
• No material breakdown
• Electric and thermal isolating
• Absorption in movement

Source:https://www.sukoptfe.com/ptfe-slide-bearing-sheets

Types of Plastic Blow and Injection Molding

Each plastic part requires a specific manufacturing process which can be significantly different from one product to another. Injection molding is used to manufacture solid components while blow molding is used to make plastic products with hollow areas, such as bottles and containers

Injection stretch blow molding combines the injection molding and blow molding processes.The plastic is first molded into a solid preform, to create a threaded bottle neck. Once the preform cools it is fed into a stretch blow mold machine. The preform is then reheated using an infrared heater and blown into a plastic bottle with forced compressed air.

The Injection Molding Process

Injection molding is used to manufacture higher volume quantities of plastic products ranging in size from large components to small components requiring micro-precision accuracy.

There are many types of manufacturing  methods categorized under injection molding, such as thermoplastic injection molding, over molding, insert molding, cold runner molding and hot runner molding.

Thermoplastic Injection Molding

Thermoplastic injection molding uses thermoplastic polymer, meaning it changes to a liquid state when heated. Unlike thermoset plastics that cool into permanent solid, thermoplastics can be remitted into a liquid after cooling into a solid.

Overmolding

Overmolding, or two shot molding, is a process that covers an injection mold over another substance, such as metal, to improve the performance or durability of a product. A rubber-like compound, called thermoplastic elastomer (TPE), is a commonly used overmold material. An example of a TPE overmold application is the handle grips on a toothbrush.  Overmolds can also be used to seal products with parts made from several injection molds.

Insert Molding

Like overmolding, insert molding is an injection moldingprocess that combines two or more components into a single finished product. Insert injection molding inserts a component into the injection mold cavity and plastic material is filled around the insert. Inserts can add strength to a product and eliminate the need for additional parts to reduce the product weight.

Cold Runner Injection Molding

Cold runner molds use a sprue to fill the runners that inject plastic resin into the mold cavity.  In 2 plate molds, the runner system and parts are attached, and an ejection system may be used to separate the pair from the mold.The cold runner can reduce waste by recycling and regrinding the material, but this can also increase the total cycle time. Cold runner systems can be used for a wide variety of polymers and can allow for easy color changes.

Hot Runner Molds

Hot runner molds use a manifold to heat melted plastic resin and then send the material through a gate to fill the mold cavity. The two main types of hot runner molds are externally heated and internally heated.  The externally heated molds can be used with polymer that is less sensitive to thermal variations while internally heated hot runner molds allow for better control of material flow.

Because  hot runner molding  does not require the use of runners, potential waste material is reduced and  the recycling and regrind and process of virgin plastic does not impact the total run cycle time.

The Blow Molding Process

During the blow molding process, the raw plastic material is shaped into a hollow tube with one open end called a parison. The parison is pressed into a cooled metal mold and compressed air is forced into the parison. When the formed plastic cools and hardens, the metal mold opens and expels the product.

Source:https://www.sukoptfe.com/types-of-plastic-blow-and-injection-molding

PTFE Adhesive High-Temp Tape

PTFE high-temperature adhesive tape is produced by using base cloth weaved from imported glass fiber that is coated with polytetrafluoroethylene and processed with a special process. It is a new high performance and multipurpose composite material. Due to its excellent performance, it is extensively applied in the fields including paper making,foods, environment protection, printing and dyeing, garment, chemical engineering, glass, medicines, electronics, insulation, grinding wheel slicing and machinery.

1. With good wear resistance, penetration resistance, breakage resistance, it is easy to use and has long service life.
2. Applied in between -70°C and 260°C, it features weathering resistance and aging resistance. The actual application proves that when it is placed at 250°C for continuous200 days, both of its strength and weight will not be reduced; when it is placed at 350°C for 120 hours, its weight reduces by only about 0.6%; the original flexibility is well maintained at -180°C.
3.Non-adhesion: Smooth surface, not adhesive to any substance. Oil stain, smudge or other deposits adhered to its surface can be easily cleaned; almost all deposits such as paste, resin or coating can be easily removed.
4. Chemical corrosion resistance, resistance to strong acid, strong base and various organic solvents.
5. Chemical resistance and non-toxicity. Resistant to almost all chemical reagents.
6. High insulation (low dielectric constant: 2.6, tangent below 0.0025),ultraviolet-proof, anti-static.
7. Fire-proofing.

Main Applications

A. Coating of various high-temperature rollers, heating sheet and demoulding workpiece.
B. Sealing of foods, chemicals and plastic bags.
C. Pad pasting for sliding chute, hopper and aviation molds, also suitable forrollers of sizing machine and thermoplastic demoulding. It can be repeatedlyused and is easily replaceable.
D. Suitable for surface treatment requiring anti-sticking, anti-corrosion and high-temperatureresistant surface.
E. Applied in the fields such as packaging, thermoplastic, compound and sealing,electronics.

Industry:
1, LCD, FPC / PCB and other optoelectronics industry
2, food, pharmaceutical packaging industry
3, plastic heat sealing machine, high-speed sealing machine
4, hot melt machine
5, motors, high and low voltage electrical products, wire and cable insulation, battery manufacturing
6, sewing machine car, shovel Paper Machine
7, rubber-coated plastic rollers
8, other required high temperature, wear, corrosion resistance, anti-sticking place

Source:https://www.sukoptfe.com/ptfe-adhesive-high-temp-tape

PTFE Properties & PTFE Product Processing

PTFE is a thermoplastic polymer, which is a white solid at room temperature, with a density of about 2200 kg/m3. It maintains high strength, toughness and self-lubrication at low temperatures down to 5 K (−268.15 °C; −450.67 °F), and good flexibility at temperatures above 194 K (−79 °C; −110 °F). PTFE gains its properties from the aggregate effect of carbon-fluorine bonds, as do all fluorocarbons. The only chemicals known to affect these carbon-fluorine bonds are highly reactive metals like the alkali metals, and at higher temperatures also such metals as aluminium and magnesium, and fluorinating agents such as xenon difluoride and cobalt(III) fluoride.

The coefficient of friction of plastics is usually measured against polished steel. PTFE's coefficient of friction is 0.05 to 0.10, which is the third-lowest of any known solid material. PTFE's resistance to van der Waals forces means that it is the only known surface to which a gecko cannot stick.In fact, PTFE can be used to prevent insects climbing up surfaces painted with the material. PTFE is so slippery that insects cannot get a grip and tend to fall off.

Because of its chemical inertness, PTFE cannot be cross-linked like an elastomer. Therefore, it has no "memory" and is subject to creep. Because of its superior chemical and thermal properties, PTFE is often used as a gasket material within industries that require resistance to aggressive chemicals such as pharmaceuticals or chemical processing. However, because of the propensity to creep, the long-term performance of such seals is worse than for elastomers which exhibit zero, or near-zero, levels of creep.

Processing PTFE can be difficult and expensive, because the high melting temperature, 327 °C (621 °F), is above the initial decomposition temperature, 200 °C (392 °F). Even when melted, PTFE does not flow, but instead behaves as a gel due to the absence of crystalline phase and high melt viscosity.

Some PTFE parts are made by cold-moulding, a form of compression molding. Here, fine powdered PTFE is forced into a mould under high pressure . After a settling period, lasting from minutes to days, the mould is heated at 360 to 380 degrees Celsius , allowing the fine particles to fuse into a single mass.

Source:https://www.sukoptfe.com/ptfe-properties-ptfe-product-processing

PTFE Lined Bushing

The metal shell of a PTFE-lined bushing is not ideal for applications where water or caustic chemicals are present. In these types of applications, PTFE-lined bushings can rust, corrode, contaminate sensitive areas, and ultimately fail. Since plastic bushings are made solely of high-performance polymers, they offer both corrosion- and chemical-resistance and operate unaffected in those types of environments.

Steel backed PTFE lined bushings is a low cost, general purpose bearing product that provides excellent wear characteristics at high loads, speeds over a wide temperature range.

Designed to be self-lubricating bushings they are rolled bushings composed of a steel backing, for structural strength, with bonded layers of sintered bronze and PTFE for a maintenance free bearing surface.

The thin wall bearing design, excellent performance features, and low cost make this product one of the most popular self lubricating bearings in the industrial global marketplace.

PTFE-lined bushings weigh more than plastic bushings. When using a heavier bushing, no matter what material it is comprised of, more energy is required for the bushing to operate. This can be troublesome, especially in automotive, aerospace, recreational vehicle, and bicycle applications.

In contrast, plastic bushings are lightweight, which helps decrease fuel consumption and carbon dioxide output. The reduced weight can also help reduce carbon dioxide output, lower masses and subsequently, lower energy consumption.

Source:https://www.sukoptfe.com/ptfe-lined-bushing