When filling a new or unfamiliar mould for the first time, where shot size for that mould is unknown, a technician/tool setter may perform a trial run before a full production run. They start with a small shot weight and fills gradually until the mould is 95 to 99% full. Once they achieve this, they apply a small amount of holding pressure and increase holding time until gate freeze off (solidification time) has occurred. Gate freeze off time can be determined by increasing the hold time, and then weighing the part. When the weight of the part does not change, the gate has frozen and no more material is injected into the part. Gate solidification time is important, as this determines cycle time and the quality and consistency of the product, which itself is an important issue in the economics of the production process.[31] Holding pressure is increased until the parts are free of sinks and part weight has been achieved.

Although most injection moulding processes are covered by the conventional process description above, there are several important moulding variations including, but not limited to:

American inventor John Wesley Hyatt, together with his brother Isaiah, patented one of the first injection moulding machines in 1872.[7] This machine was relatively simple compared to machines in use today: it worked like a large hypodermic needle, using a plunger to inject plastic through a heated cylinder into a mould. The industry progressed slowly over the years, producing products such as collar stays, buttons, and hair combs(generally though, plastics, in its modern definition, are a more recent development c. 1950s).

Rubber injection moulding process produces a high yield of durable products, making it the most efficient and cost-effective method of moulding. Consistent vulcanisation processes involving precise temperature control significantly reduces all waste material.

PEEK has several uses in electrical engineering since it is a high-performance material that retains its mechanical properties even when heated. Therefore, we might utilize it in high-temperature electrical tools like soldering irons.

The industry expanded rapidly in the 1940s because World War II created a huge demand for inexpensive, mass-produced products.[9] In 1946, American inventor James Watson Hendry built the first screw injection machine, which allowed much more precise control over the speed of injection and the quality of articles produced.[10] This machine also allowed material to be mixed before injection, so that coloured or recycled plastic could be added to virgin material and mixed thoroughly before being injected. In the 1970s, Hendry went on to develop the first gas-assisted injection moulding process, which permitted the production of complex, hollow articles that cooled quickly. This greatly improved design flexibility as well as the strength and finish of manufactured parts while reducing production time, cost, weight and waste. By 1979, plastic production overtook steel production, and by 1990, aluminium moulds were widely used in injection moulding.[11] Today, screw injection machines account for the vast majority of all injection machines.

The number of cavities incorporated into a mould directly correlate in moulding costs. Fewer cavities require far less tooling work, so limiting the number of cavities lowers initial manufacturing costs to build an injection mould.

To allow for removal of the moulded part from the mould, the mould features must not overhang one another in the direction that the mould opens, unless parts of the mould are designed to move from between such overhangs when the mould opens using components called Lifters.

Specific instances include removing of parts from the mould immediately after the parts are created, as well as applying machine vision systems. A robot grips the part after the ejector pins have been extended to free the part from the mould. It then moves them into either a holding location or directly onto an inspection system. The choice depends upon the type of product, as well as the general layout of the manufacturing equipment. Vision systems mounted on robots have greatly enhanced quality control for insert moulded parts. A mobile robot can more precisely determine the placement accuracy of the metal component, and inspect faster than a human can.[32]

According to testing, the maximum temperature at which PEEK may be used continuously is 260 degrees Celsius, and its melting point is 341. Because of this, you can use it widely in sectors subject to high temperatures, such as the oil and gas and automotive sectors.

Injection moulding uses a ram or screw-type plunger to force molten plastic or rubber material into a mould cavity; this solidifies into a shape that has conformed to the contour of the mould. It is most commonly used to process both thermoplastic and thermosetting polymers, with the volume used of the former being considerably higher.[3]: 1–3  Thermoplastics are prevalent due to characteristics that make them highly suitable for injection moulding, such as ease of recycling, versatility for a wide variety of applications,[3]: 8–9  and ability to soften and flow on heating. Thermoplastics also have an element of safety over thermosets; if a thermosetting polymer is not ejected from the injection barrel in a timely manner, chemical crosslinking may occur causing the screw and check valves to seize and potentially damaging the injection moulding machine.[3]: 3

The automotive components industry in Europe is seeing the most significant growth in using PEEK resin. Components around the engine, variable speed transmission parts, steering elements, and so on were all manufactured using a PEEK plastic injection mould instead of some customary expensive metals. As the automobile industry adapts to the needs of miniaturization, low weight, and cost reduction, the demand for injection moulded PEEK resin will grow.

A mould can produce several copies of the same parts in a single "shot". The number of "impressions" in the mould of that part is often incorrectly referred to as cavitation. A tool with one impression is often called a single impression (cavity) mould.[19]: 398  A mould with two or more cavities of the same parts is usually called a multiple impression (cavity) mould. (Not to be confused with "Multi-shot moulding" {which is dealt with in the next section.})[19]: 262  Some extremely high production volume moulds (like those for bottle caps) can have over 128 cavities.

Most polymers, sometimes referred to as resins, may be used, including all thermoplastics, some thermosets, and some elastomers.[13] Since 1995, the total number of available materials for injection moulding has increased at a rate of 750 per year; there were approximately 18,000 materials available when that trend began.[14] Available materials include alloys or blends of previously developed materials, so product designers can choose the material with the best set of properties from a vast selection. Major criteria for selection of a material are the strength and function required for the final part, as well as the cost, but also each material has different parameters for moulding that must be taken into account.[12]: 6  Other considerations when choosing an injection moulding material include flexural modulus of elasticity, or the degree to which a material can be bent without damage, as well as heat deflection and water absorption.[15] Common polymers like epoxy and phenolic are examples of thermosetting plastics while nylon, polyethylene, and polystyrene are thermoplastic.[1]: 242  Until comparatively recently, plastic springs were not possible, but advances in polymer properties make them now quite practical. Applications include buckles for anchoring and disconnecting outdoor-equipment webbing.

PEEK may react with several acids, including nitric solid, sulphuric, and chromic acid. This eliminates its usefulness in a few situations.

For a two-shot mould, two separate materials are incorporated into one part. This type of injection moulding is used to add a soft touch to knobs, to give a product multiple colours, or to produce a part with multiple performance characteristics.[5]

Studies have demonstrated that PEEK is more durable than other polymers and certain metals. PEEK is resistant to creep deformation under extreme loads and temperatures. Its low friction coefficient resists wear and tear and generates less commotion. Because of these advantages, it is an excellent option for use in automotive parts. PEEK also performs very well when tested for fatigue from repeated pressure and stress, another wear indicator. Because of its lower weight compared to comparable metals, it finds use in the transportation industry and beyond, particularly in cars and planes, where it helps save fuel. PEEK’s exceptional durability makes it an excellent choice for creating artificial organs and other medical devices.

Usually, the plastic materials are formed in the shape of pellets or granules and sent from the raw material manufacturers in paper bags. With injection moulding, pre-dried granular plastic is fed by a forced ram from a hopper into a heated barrel. As the granules are slowly moved forward by a screw-type plunger, the plastic is forced into a heated chamber, where it is melted. As the plunger advances, the melted plastic is forced through a nozzle that rests against the mould, allowing it to enter the mould cavity through a gate and runner system. The mould remains cold so the plastic solidifies almost as soon as the mould is filled.[1]

In some cases, multiple cavity tooling moulds a series of different parts in the same tool. Some toolmakers call these moulds family moulds, as all the parts are related—e.g., plastic model kits.[20]: 114

Tensile strengths of 29000 psi at 299°C are possible for PEEK-based composites reinforced with carbon fibre. In this way, it outperforms nylons, acetal (PolyOxyMethylene or POM), polyesters, and polycarbonates in terms of strength and stiffness.

Moulds are built through two main methods: standard machining and EDM. Standard machining, in its conventional form, has historically been the method of building injection moulds. With technological developments, CNC machining became the predominant means of making more complex moulds with more accurate mould details in less time than traditional methods.

The amount of resin required to fill the sprue, runner and cavities of a mould comprises a "shot". Trapped air in the mould can escape through air vents that are ground into the parting line of the mould, or around ejector pins and slides that are slightly smaller than the holes retaining them. If the trapped air is not allowed to escape, it is compressed by the pressure of the incoming material and squeezed into the corners of the cavity, where it prevents filling and can also cause other defects. The air can even become so compressed that it ignites and burns the surrounding plastic material.[12]: 147

PEEK may be reprocessed several times without changing in any noticeable way because of the extreme stability of its molecules. Companies may reduce their waste management costs while still accomplishing their environmental goals.

To ease maintenance and venting, cavities and cores are divided into pieces, called inserts, and sub-assemblies, also called inserts, blocks, or chase blocks. By substituting interchangeable inserts, one mould may make several variations of the same part.

In place of metal, PEEK resin may make lighter, fatigue-resistant, and oil-free components. This includes the separating claws of copiers, special heat-resistant bearings, chains, gears, and so on.

Injection moulding (U.S. spelling: injection molding) is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed (using a helical screw), and injected into a mould cavity, where it cools and hardens to the configuration of the cavity.[1]: 240  After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker (or toolmaker) from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds.

Some moulds allow previously moulded parts to be reinserted to allow a new plastic layer to form around the first part. This is often referred to as overmoulding. This system can allow for production of one-piece tires and wheels.

With high-performance features, PEEK is one of the most popular plastic injection molding materials today because of its excellent all-around properties, which may allow it to replace traditional materials like metals and ceramics in many applications. Presently, its most common applications are in the aerospace, automotive, electrical, electronic, and medical device industries.

As the number of cavities play a vital role in moulding costs, so does the complexity of the part's design. Complexity can be incorporated into many factors such as surface finishing, tolerance requirements, internal or external threads, fine detailing or the number of undercuts that may be incorporated.[25]

PEEK is a semi-crystalline, opaque substance that belongs to the family of polymers known as PAEK, which comprises aryl, ether, and ketone chemical groups. PAEK is a subset of the PolyKetone family of polymers. PEEK’s high melting point and excellent mechanical properties come from the aryl and ketone components in its composition. PEEK’s ether group allows it to be both malleable, which contributes to its toughness, and chemically inert, providing resistance to chemical exposure.

Pre-moulded or machined components can be inserted into the cavity while the mould is open, allowing the material injected in the next cycle to form and solidify around them. This process is known as Insert moulding and allows single parts to contain multiple materials. This process is often used to create plastic parts with protruding metal screws so they can be fastened and unfastened repeatedly. This technique can also be used for In-mould labelling and film lids may also be attached to moulded plastic containers.

PEEK may still be utilized in certain airplanes despite aluminum being the material of choice in the aerospace industry due to its reduced weight. PEEK has better recyclability than aluminum, but it is more expensive to make, which is the material’s only real drawback.

Traditionally, the injection portion of the moulding process was done at one constant pressure to fill and pack the cavity. This method, however, allowed for a large variation in dimensions from cycle-to-cycle. More commonly used now is scientific or decoupled moulding, a method pioneered by RJG Inc.[27][28][29] In this the injection of the plastic is "decoupled" into stages to allow better control of part dimensions and more cycle-to-cycle (commonly called shot-to-shot in the industry) consistency. First the cavity is filled to approximately 98% full using velocity (speed) control. Although the pressure should be sufficient to allow for the desired speed, pressure limitations during this stage are undesirable. Once the cavity is 98% full, the machine switches from velocity control to pressure control, where the cavity is "packed out" at a constant pressure, where sufficient velocity to reach desired pressures is required. This lets workers control part dimensions to within thousandths of an inch or better.[30]

Tool steel is often used. Mild steel, aluminium, nickel or epoxy are suitable only for prototype or very short production runs.[1] Modern hard aluminium (7075 and 2024 alloys) with proper mould design, can easily make moulds capable of 100,000 or more part life with proper mould maintenance.[23]

Since moulds have been expensive to manufacture, they were usually only used in mass production where thousands of parts were being produced. Typical moulds are constructed from hardened steel, pre-hardened steel, aluminium, and/or beryllium-copper alloy.[17]: 176  The choice of material for the mold is not only based on cost considerations, but also has a lot to do with the product life cycle. Generally speaking, those who have matured, the need for mass production of the product selection of materials will be better, and hope that the mold circle time the larger the better so that the total cost will be reduced. For those who have just developed, not very mature, just want to produce a small-scale market test products, the choice of material is often some lower cost of aluminum alloy and so on. These mould called rapid tooling. In general, steel moulds cost more to construct, but their longer lifespan offsets the higher initial cost over a higher number of parts made before wearing out. Pre-hardened steel moulds are less wear-resistant and are used for lower volume requirements or larger components; their typical steel hardness is 38–45 on the Rockwell-C scale. Hardened steel moulds are heat treated after machining; these are by far superior in terms of wear resistance and lifespan. Typical hardness ranges between 50 and 60 Rockwell-C (HRC). Aluminium moulds can cost substantially less, and when designed and machined with modern computerised equipment can be economical for moulding tens or even hundreds of thousands of parts. Beryllium copper is used in areas of the mould that require fast heat removal or areas that see the most shear heat generated.[17]: 176  The moulds can be manufactured either by CNC machining or by using electrical discharge machining processes.

More complex parts are formed using more complex moulds. These may have sections called slides, that move into a cavity perpendicular to the draw direction, to form overhanging part features. When the mould is opened, the slides are pulled away from the plastic part by using stationary “angle pins” on the stationary mould half. These pins enter a slot in the slides and cause the slides to move backward when the moving half of the mould opens. The part is then ejected and the mould closes. The closing action of the mould causes the slides to move forward along the angle pins.[12]: 268

The power required for this process of injection moulding depends on many things and varies between materials used. Manufacturing Processes Reference Guide states that the power requirements depend on "a material's specific gravity, melting point, thermal conductivity, part size, and molding rate." Below is a table from page 243 of the same reference as previously mentioned that best illustrates the characteristics relevant to the power required for the most commonly used materials.

Injection moulding is a complex technology with possible production problems. They can be caused either by defects in the moulds, or more often by the moulding process itself.[3]: 47–85

Injection moulding uses a special-purpose machine that has three parts: the injection unit, the mould and the clamp. Parts to be injection-moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be taken into account. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.

The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903, which was much less flammable than cellulose nitrate.[8] It was eventually made available in a powder form from which it was readily injection moulded. Arthur Eichengrün developed the first injection moulding press in 1919. In 1939, Arthur Eichengrün patented the injection moulding of plasticised cellulose acetate.

Injection moulding consists of the high pressure injection of the raw material into a mould, which shapes the polymer into the desired form.[3]: 14  Moulds can be of a single cavity or multiple cavities. In multiple cavity moulds, each cavity can be identical and form the same parts or can be unique and form multiple different geometries during a single cycle. Moulds are generally made from tool steels, but stainless steels and aluminium moulds are suitable for certain applications. Aluminium moulds are typically ill-suited for high volume production or parts with narrow dimensional tolerances, as they have inferior mechanical properties and are more prone to wear, damage, and deformation during the injection and clamping cycles; however, aluminium moulds are cost-effective in low-volume applications, as mould fabrication costs and time are considerably reduced.[1] Many steel moulds are designed to process well over a million parts during their lifetime and can cost hundreds of thousands of dollars to fabricate.

You should calculate how much of a return on investment PEEK injection molding will deliver in light of its more excellent price, even though it will enable you to make lighter, stronger, and more chemically resistant components that will last longer. Prototool‘s material selection experts are here to provide a hand. With our help, even the most complex products may be designed and manufactured in weeks and brought to market.

Further details, such as undercuts, or any feature that needs additional tooling, increases mould cost. Surface finish of the core and cavity of moulds further influences cost.

A mould is usually designed so that the moulded part reliably remains on the ejector (B) side of the mould when it opens, and draws the runner and the sprue out of the (A) side along with the parts. The part then falls freely when ejected from the (B) side. Tunnel gates, also known as submarine or mould gates, are located below the parting line or mould surface. An opening is machined into the surface of the mould on the parting line. The moulded part is cut (by the mould) from the runner system on ejection from the mould.[18]: 288  Ejector pins, also known as knockout pins, are circular pins placed in either half of the mould (usually the ejector half), which push the finished moulded product, or runner system out of a mould.[12]: 143 The ejection of the article using pins, sleeves, strippers, etc., may cause undesirable impressions or distortion, so care must be taken when designing the mould.

Injection moulding machines consist of a material hopper, an injection ram or screw-type plunger, and a heating unit.[1]: 240  Also known as platens, they hold the moulds in which the components are shaped. Presses are rated by tonnage, which expresses the amount of clamping force that the machine can exert. This force keeps the mould closed during the injection process.[16] Tonnage can vary from less than 5 tons to over 9,000 tons, with the higher figures used in comparatively few manufacturing operations. The total clamp force needed is determined by the projected area of the part being moulded. This projected area is multiplied by a clamp force of from 1.8 to 7.2 tons for each square centimetre of the projected areas. As a rule of thumb, 4 or 5 tons/in2 can be used for most products. If the plastic material is very stiff, it requires more injection pressure to fill the mould, and thus more clamp tonnage to hold the mould closed.[12]: 43–44  The required force can also be determined by the material used and the size of the part. Larger parts require higher clamping force.[13]

Nave ISK-8, Parque Industrial y Logístico Sky Plus, Avenida Mineral de Cinco Señores No.100, del Parque Industrial Santa Fe, Silao de la Victoria, Guanajuato, México

The standard method of cooling is passing a coolant (usually water) through a series of holes drilled through the mould plates and connected by hoses to form a continuous pathway. The coolant absorbs heat from the mould (which has absorbed heat from the hot plastic) and keeps the mould at a proper temperature to solidify the plastic at the most efficient rate.[12]: 86

PEEK injection molding, compared with other plastic injection moldings, needs to provide higher injection pressure, injection speed, and stable heating. In addition, you must pay attention to the mold design, so it’s best to find a professional special plastic injection factory to produce what you want. It would be better if all of these were effectively controlled from the beginning of the mold design, which can avoid unnecessary risks in production. This article is a thorough introduction to PEEK injection molding, including its types, applications, considerations, and other aspects.

Among these qualities, PEEK excels in mechanical, wear, heat, and chemical strength. It can be recycled and repurposed without much hassle. High purity, corrosion resistance, and electrical insulation are additional features.

Two-shot, double-shot or multi-shot moulds are designed to "overmould" within a single moulding cycle and must be processed on specialised injection moulding machines with two or more injection units. This process is actually an injection moulding process performed twice and therefore can allow only for a much smaller margin of error. In the first step, the base colour material is moulded into a basic shape, which contains spaces for the second shot. Then the second material, a different colour, is injection-moulded into those spaces. Pushbuttons and keys, for instance, made by this process have markings that cannot wear off, and remain legible with heavy use.[12]: 174

PEEK injection molding will be at the top of your list if you’re looking for an injection molding material that balances your performance needs, financial constraints, and environmental and sustainability goals.

A parting line, sprue, gate marks, and ejector pin marks are usually present on the final part.[3]: 98  None of these features are typically desired, but are unavoidable due to the nature of the process. Gate marks occur at the gate that joins the melt-delivery channels (sprue and runner) to the part forming cavity. Parting line and ejector pin marks result from minute misalignments, wear, gaseous vents, clearances for adjacent parts in relative motion, and/or dimensional differences of the melting surfaces contacting the injected polymer. Dimensional differences can be attributed to non-uniform, pressure-induced deformation during injection, machining tolerances, and non-uniform thermal expansion and contraction of mould components, which experience rapid cycling during the injection, packing, cooling, and ejection phases of the process. Mould components are often designed with materials of various coefficients of thermal expansion. These factors cannot be simultaneously accounted for without astronomical increases in the cost of design, fabrication, processing, and quality monitoring. The skillful mould and part designer positions these aesthetic detriments in hidden areas if feasible.

PEEK, or polyetheretherketone is a semi-crystalline polymer and a high-performance engineering plastic. This material is biocompatible, has a high melting point (343°C), and has excellent mechanical properties. It is presently a popular research injection molding material. The advantages, features, and potential uses of PEEK injection molding are briefly discussed in this post.

Several types of high-performance polymers may only fulfill a single need, such as resistance to chemicals or extreme temperatures. On the other hand, most of them fall short of meeting different standards, such as resistance to wear or mechanical strength.

Medical analysis instruments, such as endoscope components and dental instrument cleaners, can all be made from autoclave-safe PEEK. With its high strength and low solubility, PEEK has also been used in liquid chromatography columns, tubes, and instrument analytical accessories. Due to its biocompatibility, PEEK has also primarily supplanted titanium as the metal of choice for artificial bone.

Moulds for highly precise and extremely small parts from micro injection molding requires extra care in the design stage, as material resins react differently compared to their full-sized counterparts where they must quickly fill these incredibly small spaces, which puts them under intense shear strains.[22]

Sides of the part that appear parallel with the direction of draw (the axis of the cored position (hole) or insert is parallel to the up and down movement of the mould as it opens and closes)[18]: 406  are typically angled slightly, called draft, to ease release of the part from the mould. Insufficient draft can cause deformation or damage. The draft required for mould release is primarily dependent on the depth of the cavity; the deeper the cavity, the more draft necessary. Shrinkage must also be taken into account when determining the draft required.[18]: 332  If the skin is too thin, then the moulded part tends to shrink onto the cores that form while cooling and cling to those cores, or the part may warp, twist, blister or crack when the cavity is pulled away.[12]: 47

Because of its large volume and surface resistivity, PEEK can maintain its excellent insulating performance even when subjected to wide swings in temperature and other environmental factors.

For thermosets, typically two different chemical components are injected into the barrel. These components immediately begin irreversible chemical reactions that eventually crosslinks the material into a single connected network of molecules. As the chemical reaction occurs, the two fluid components permanently transform into a viscoelastic solid.[3]: 3  Solidification in the injection barrel and screw can be problematic and have financial repercussions; therefore, minimising the thermoset curing within the barrel is vital. This typically means that the residence time and temperature of the chemical precursors are minimised in the injection unit. The residence time can be reduced by minimising the barrel's volume capacity and by maximising the cycle times. These factors have led to the use of a thermally isolated, cold injection unit that injects the reacting chemicals into a thermally isolated hot mould, which increases the rate of chemical reactions and results in shorter time required to achieve a solidified thermoset component. After the part has solidified, valves close to isolate the injection system and chemical precursors, and the mould opens to eject the moulded parts. Then, the mould closes and the process repeats.

Our experts have compiled the following information about PEEK to help you decide whether it is suitable material for your project.

Tolerance depends on the dimensions of the part. An example of a standard tolerance for a 1-inch dimension of an LDPE part with 0.125 inch wall thickness is +/- 0.008 inch (0.2 mm).[18]: 446

Automation means that the smaller size of parts permits a mobile inspection system to examine multiple parts more quickly. In addition to mounting inspection systems on automatic devices, multiple-axis robots can remove parts from the mould and position them for further processes.[32]

The electrical discharge machining (EDM) or spark erosion process has become widely used in mould making. As well as allowing the formation of shapes that are difficult to machine, the process allows pre-hardened moulds to be shaped so that no heat treatment is required. Changes to a hardened mould by conventional drilling and milling normally require annealing to soften the mould, followed by heat treatment to harden it again. EDM is a simple process in which a shaped electrode, usually made of copper or graphite, is very slowly lowered onto the mould surface over a period of many hours, which is immersed in paraffin oil (kerosene). A voltage applied between tool and mould causes spark erosion of the mould surface in the inverse shape of the electrode.[24]

PEEK is impervious to moisture and many different solvents (even when subjected to them in high-temperature and high-pressure steam conditions). Thus PEEK is ideal for use in the oil and gas industry, where chemicals can eat away at subsea pipes, gears, and machinery. It is resistant to jet fuel, hydraulic fluids, and de-icers, all of which are used in the aerospace industry.

The plastic injection moulding industry has evolved over the years from producing combs and buttons to producing a vast array of products for many industries including automotive, medical, aerospace, consumer products, toys, plumbing, packaging, and construction.[12]: 1–2

PEEK may serve dependably within the human body for long periods since it is non-toxic and does not harm living tissue. The quality makes it so useful for usage in medical implant components. However, due to its chemically inert and physiologically unresponsive nature, PEEK has a limited ability to attach to bone tissue after implantation in vivo.

The sequence of events during the injection mould of a plastic part is called the injection moulding cycle. The cycle begins when the mould closes, followed by the injection of the polymer into the mould cavity. Once the cavity is filled, a holding pressure is maintained to compensate for material shrinkage. In the next step, the screw turns, feeding the next shot to the front screw. This causes the screw to retract as the next shot is prepared. Once the part is sufficiently cool, the mould opens and the part is ejected.[26]: 13

The PAEK (PolyArylEtherKetone) category is the most prominent of the few high-performance polymers, with PEEK (PolyEtherEtherKetone) being the most prevalent.

Injection moulding is used to create many things such as wire spools, packaging, bottle caps, automotive parts and components, toys, pocket combs, some musical instruments (and parts of them), one-piece chairs and small tables, storage containers, mechanical parts (including gears), and most other plastic products available today. Injection moulding is the most common modern method of manufacturing plastic parts; it is ideal for producing high volumes of the same object.[2]

The mould consists of two primary components, the injection mould (A plate) and the ejector mould (B plate). These components are also referred to as moulder and mouldmaker. Plastic resin enters the mould through a sprue or gate in the injection mould; the sprue bushing is to seal tightly against the nozzle of the injection barrel of the moulding machine and to allow molten plastic to flow from the barrel into the mould, also known as the cavity.[12]: 141  The sprue bushing directs the molten plastic to the cavity images through channels that are machined into the faces of the A and B plates. These channels allow plastic to run along them, so they are referred to as runners.[12]: 142  The molten plastic flows through the runner and enters one or more specialised gates and into the cavity[18]: 15  geometry to form the desired part.

When thermoplastics are moulded, typically pelletised raw material is fed through a hopper into a heated barrel with a reciprocating screw. Upon entrance to the barrel, the temperature increases and the Van der Waals forces that resist relative flow of individual chains are weakened as a result of increased space between molecules at higher thermal energy states. This process reduces its viscosity, which enables the polymer to flow with the driving force of the injection unit. The screw delivers the raw material forward, mixes and homogenises the thermal and viscous distributions of the polymer, and reduces the required heating time by mechanically shearing the material and adding a significant amount of frictional heating to the polymer. The material feeds forward through a check valve and collects at the front of the screw into a volume known as a shot. A shot is the volume of material that is used to fill the mould cavity, compensate for shrinkage, and provide a cushion (approximately 10% of the total shot volume, which remains in the barrel and prevents the screw from bottoming out) to transfer pressure from the screw to the mould cavity. When enough material has gathered, the material is forced at high pressure and velocity into the part forming cavity. The exact amount of shrinkage is a function of the resin being used, and can be relatively predictable.[4] To prevent spikes in pressure, the process normally uses a transfer position corresponding to a 95–98% full cavity where the screw shifts from a constant velocity to a constant pressure control. Often injection times are well under 1 second. Once the screw reaches the transfer position the packing pressure is applied, which completes mould filling and compensates for thermal shrinkage, which is quite high for thermoplastics relative to many other materials. The packing pressure is applied until the gate (cavity entrance) solidifies. Due to its small size, the gate is normally the first place to solidify through its entire thickness.[3]: 16  Once the gate solidifies, no more material can enter the cavity; accordingly, the screw reciprocates and acquires material for the next cycle while the material within the mould cools so that it can be ejected and be dimensionally stable. This cooling duration is dramatically reduced by the use of cooling lines circulating water or oil from an external temperature controller. Once the required temperature has been achieved, the mould opens and an array of pins, sleeves, strippers, etc. are driven forward to demould the article. Then, the mould closes and the process is repeated.

Additionally, PEEK does not require metal machining or thermoset curing to be mass-produced via injection molding, which reduces the number of processing steps required. In the end, you’ll save money and time thanks to this. In harsh environments, PEEK injection molding typically performs better than metal. Because of this, it is used frequently in the manufacture of the airplane and car parts, as well as medical and industrial components, semiconductors, and electrical and electronic gadgets.

Like all industrial processes, injection molding can produce flawed parts, even in toys. In the field of injection moulding, troubleshooting is often performed by examining defective parts for specific defects and addressing these defects with the design of the mould or the characteristics of the process itself. Trials are often performed before full production runs in an effort to predict defects and determine the appropriate specifications to use in the injection process.[3]: 180

While PEEK naturally has poor resistance to ultraviolet (UV) radiation, this may be remedied by using a carbon addition in the material’s composition.

Manufacturers go to great lengths to protect custom moulds due to their high average costs. The perfect temperature and humidity level is maintained to ensure the longest possible lifespan for each custom mould. Custom moulds, such as those used for rubber injection moulding, are stored in temperature and humidity controlled environments to prevent warping.

With a flammability grade of UL 94 V-0, PEEK is safe to use in environments where temperatures reach over 600 °C during combustion. When burnt at high temperatures, it also creates less smoke. This is why it is so famous for making components for passenger planes.