In recent years, with the rapid development of materials science, medical polymer materials have become the most widely used and the most used materials. Polyether ether Ketone as a new type of medical implant materials, with its own excellent characteristics in many medical materials stand out. According to Radiant Insightsanalysts consultancy, the global market for Peek will continue to grow at an average annual rate of 10.43% annually in 2017-2022.
Polyether ether Ketone (PEEK) is a crystalline high-performance special Engineering Plastics, with excellent high-temperature resistance, self-lubricating, corrosion resistance, flame retardant, mechanical properties, electrical properties, resistance to hydrolysis, weather resistance ... Wait a minute. Since 1978 by the British Empire Chemical Industry Company (ICI) cutting-edge materials, Victrex research and Invention, in 1978 large-scale production and into the market since Peek has excellent comprehensive physical, mechanical, electrical, thermal, chemical and other properties, can be used in traditional thermoplastic molding processing methods such as injection , extrusion, molding, coating, mechanical cutting, etc. made of various parts, by the sample designers, molding processing enterprises, product manufacturing suppliers of widespread concern and attention, so peek in the petrochemical industry, transportation, electronic and electrical, medical and health, food processing, aerospace and other fields have been widely used.
Peek it in the design of the freedom of expression, in the process of forming the economic benefits and the workpiece in the use of the display of the quality of stability, making it a lot of common materials successful successor. Peek has good mechanical properties, chemical resistance, radiation resistance and high temperature performance, can withstand up to 0.25MPa of pressure and 260 ℃ of high temperature, and insoluble in addition to concentrated sulfuric acid in all solvents. In the chemical industry and other industries, peek resin is often used to make compressor valve plate, piston ring, seals and a variety of chemical pumps, valves and other components; using this material instead of stainless steel to make eddy current pump impeller, can significantly reduce the wear and noise levels, with a longer life. At present, the wire and cable made by peek, coil skeleton has been successfully applied to the nuclear power plant, but also can be used for oil exploration and mining machinery special geometry function probes. In addition, as the peek resin meets the specifications of the casing assembly material, the adhesive can be used at high temperature, so the modern connector will be another potential application market.
Medical grade peek--Performance: Peek has outstanding thermal aging properties, the material after 250 ℃ thermal aging of the bending strength retention rate is still high. Recognized heat-resistant materials PPS Anti-Aging test is less than 3000h, and peek can exceed 5000h. Commonly used nylon 66 and PBT are generally less than 500h. Peek Flame retardant is excellent, has the self extinguishing nature. Peek has good hydrolysis resistance, 23 ℃ saturated water absorption rate is only 0.5%, is the lowest in engineering plastics. And its heat-resistant water is better, can be used in 300 ℃ pressurized hot water or steam. Peek is superior to polyamide for fatigue resistance and better than PES and nylon. Peek is also an excellent radiation-resistant material, peek electromagnetic line of high radiation-resistant dosage, its performance exceeds the general radiation-resistant materials polystyrene, far superior to PTFE. Polyether ether ketone has excellent electrical insulation, usually, the volume resistivity is very high. It still has small dielectric constant and dielectric loss in the high frequency range. Polyether ether ketone, except concentrated sulfuric acid, can almost withstand any chemical, even at a higher temperature, it will still maintain good chemical stability. Peek resins have superior sliding properties in all plastics, in a variety of pressure, temperature, speed and relative roughness of the contact surface, can provide excellent wear-resistant properties, peek resin peel is very good, so can be made into a very thin wire or electromagnetic wire, and under harsh conditions to use. Peek has the best fatigue resistance in all resins.
Medical grade peek--Processing molding: The use of traditional extruder and appropriate nose and traction device to produce Peek film and sheet. Most of the use of slot-type nose, melt flow channel should be streamlined, internal surface to throw, light, to prevent melt stagnation or adhesion. Die temperature on the diaphragm surface finish and size control is very important, usually to maintain 380 ℃ soil 2 ℃, commonly used in Peek film and sheet traction equipment has two, that is, casting rollers and three-roll calender. The former is used for peek films with a thickness of less than 500um, which is used for thicker peek films and sheets. Regardless of the casting roller or the three-roll calender, you have to Polish chrome, and the DC speed motor drive and speed. By controlling the temperature of the casting roller, a semi crystalline or amorphous sheet with a thickness greater than 500um can be produced. 50 ℃ Casting Roller temperature can obtain amorphous transparent film, while 170 ℃ casting roller temperature produces opaque semi crystalline film. When the film thickness is increased continuously (﹥500um), the crystallization degree will become more and more difficult to control, when necessary, the heat treatment can be processed to obtain the most suitable crystallinity of Peek film. The extruder equipped with a gear metering pump, combined with downstream traction, tensile and winding devices, can produce peek monofilament. The metering pump ensures that the molten body is squeezed into the nose very precisely under constant pressure. The post-processing of monofilament extrusion die is divided into two parts, namely the orientation and relaxation of the molten body. When directed, the extrusion is cooled with wind cooling and water cooling and is stretched at a VL speed, and the filament is stretched at the V2 speed through a temperature setting in the oven above the glass transition temperature of the material. The difference between velocity VL and V2 is mainly used to stretch polymers, to reduce the diameter of monofilament and to align molecules. When Slack, the extrusion is set at V3 speed through a second temperature setting at the oven near the melting temperature of the material. The speed difference between V2 and V3 is mainly used to relax the polymer, the result will increase the filament diameter. Peek monofilament physical mechanical properties can be improved through solid-phase directional stretching, such as monofilament in the second phase of the process of stretching, monofilament left the nose must be quenched to make it amorphous, but not too fast cooling, so as not to produce gas postman L. The satisfactory results can be obtained when the single wire is cooled and then immersed in a water bath or directly immersed in a heated water bath. Head Distance water bath The nearest distance and the water bath temperature depends on the filament diameter, small diameter monofilament (0 25mm) requires air cooling distance of 1.0012 million mm, and then in 20,150 ℃ cooling. If the single wire temperature is higher than the water bath temperature, water bath will produce local boiling, resulting in a single silk surface damage. Peek Monofilament either uses a single stage or uses two stages of stretch orientation, in which the monofilament is ' ℃ ' at 120, and then tensile at 200 ℃, the tensile performance depends on the tensile degree. The recommended tensile ratio of 2.5:1 and 3:1, the maximum ratio is 3.8:1, more than 3:1 of the monofilament, the kink strength will rapidly decline, the single wire directional arrangement, must be under the tensile heat stereotypes. Thermal stereotypes must be achieved when the temperature is close to the polymer's melting point and the tensile relaxation ratio is 0.95:l (usually 260 ℃ 6s). The resulting monofilament has a tenacity, highly directional arrangement and a controllable diameter that retains its shape and properties above the glass temperature of the material.
Medical grade peek--application: In the chemical industry, by means of cylindrical filler material conversion chemical separation. The essence of chemical process requires that cylindrical fillers endure and resist corrosion under high temperature and harsh reaction conditions. Eldorodo Century Plastics company uses peek to make cylindrical filler, because it prolongs the service life. Cylindrical fillers made from general-purpose thermoplastics can only be replaced in six months, while peek fillers can be used for up to 3 years. A device that is considered to permit or prevent the flow of gas or liquid in a system. According to this definition, the valve seat is the key part of the valve, because in the valve closed position this is to prevent leakage of the part of the flow. For rigid seats (metal to metal), contamination of the system and local blockage will prevent the device from fully closing. Use Peek to form the soft seat of the valve, as it has the ability to deform to complete the sealing effect in this case. The Saunder company uses 30% glass fiber reinforced peek as the seat material for these devices, as it shows outstanding creep resistance and fatigue resistance, even within a very high temperature range. The excellent chemical resistance and tensile strength of peek components also provide longer service life than metal rigid seats or other thermoplastic soft seats. Danish Company, Inc., says it has revolutionized the way it cleans water by using peek. The new design operation revolves around two principles. ① first involves creating larger droplets of water, in 600km/h, the total impulse loss is very small; ② the impact frequency between the water droplets and the cleaning surface in the 80~ 100Hz. Peek creates exactly the same two parts in the device, which acts as an eccentric cam, which feeds the droplets from a fixed nozzle. Flow. Operating pressure up to 15MPa, local rotational heat is estimated to be higher than 100 ℃, so high performance peek is required. Peek is used for this purpose to increase product diversification because it can be used as a cleaning device for many chemicals previously considered to be too aggressive. The equipment currently in use has proven to be beneficial to the user, as 50% of the water and power can be saved according to the cleaning operation.
Because Peek has excellent comprehensive performance, in many special fields can replace the metal, ceramics and other traditional materials, make it become one of the hottest high-performance engineering plastics, more and more used in plastic surgery, cardiovascular, artificial spine and other fields, currently has applications as follows:
1, Peek material medical implant
Excellent performance is the closest bone material: biocompatibility is the most basic factor in measuring whether a material is suitable for human implantation, the material must be non-toxic, mutagenic, carcinogenic, and does not cause allergy. Implantable grade peek in foreign independent testing institutions in strict accordance with the requirements of ISO10993, the complete biocompatibility test. The results showed that implantable grade peek had excellent biocompatibility without any side effects.
The famous Wolf law states that the bone is grown where it is needed, that it is absorbed where it is not needed, that the growth, absorption and reconstruction of the bone are related to the state of the force of the bone. Because the elastic modulus of the metal is far beyond the skeleton, so when the metal is implanted in the human body to bear most of the mechanical load, the burden of the bone to reduce, forming a stress shielding effect, the result is delayed bone healing, over time, the bone becomes loose, and even degenerate. In contrast, Peek's elastic modulus is very close to the bone, and the stress of the skeleton is not entirely borne by the implant, making the bones healthier.
Repair skull to avoid cold winter and hot summer embarrassment: The researchers found that peek is currently the closest performance to the human skeleton of the clinical skull repair material, compared with the commonly used titanium alloy, peek physical properties close to the human skeleton, strong texture, do not appear the risk of stress sag, good insulation, can avoid cold summer heat. Although the heat transfer of titanium alloy material is good, but for patients, this is a disadvantage. When the patient is affected by the external hot and cold temperature difference, the cranial environment changes, will affect the comfortable feeling. For example, in the winter when the patient from the warm indoor to the cold outside, the titanium skull plate excellent thermal conductivity of the patients feel pain and discomfort. and peek insulation good, to avoid the titanium alloy mesh cold summer hot embarrassing situation.
Peek abandoned the organic glass, bone cement, titanium alloy and other conventional skull repair material rejection reaction strong, the shape effect is poor, the heat insulation effect is poor, the comfort is poor, the X-ray permeability is bad after the operation, avoids the discomfort caused by the temperature difference, the use of 3D printing technology molding, embedding, perfect shape, with good organizational compatibility; Mechanical properties close to human bone. This new type of material is expected to be the preferred material for skull repair.
Repair of the spine to reduce the incidence of complications: In recent years, the incidence of lumbar spine disease in China has increased year in, and tend to younger. China's lumbar spine disease patients have broken through 200 million people, cervical spondylosis of the population also has 200 million people. If the patient has a degenerative spinal lesion, the doctor recommends that the lesion be removed and replaced with a prosthetic prosthesis known as the intervertebral fusion cage.
At present, the common Interbody fusion device in China is mainly titanium alloy fusion and Peek Fusion device. Because of the high elastic modulus of titanium alloy, the delay of fusion caused by stress shielding is more likely to occur after operation, which is gradually replaced by Peek fusion device in recent years. The intervertebral fusion cage made of peek material can be compatible with X-ray photography and MRI, and has low elastic modulus, which can avoid the complications of autologous grafts and the defects of allogeneic allograft.
Modified peek performance is more powerful, the use of type I collagen adsorption cross-linking, can improve the peek material surface hydrophobicity and cell adhesion proliferation, modified materials than the modified materials have better biocompatibility and bone fusion ability.
Dental accessories make patients more comfortable to wear: peek is increasingly used in the field of Stomatology because of its excellent chemical stability and the ability to withstand the corrosion of most chemical reagents. Peek material is mainly used in dental implant parts, such as temporary abutment, healing caps, healing base and so on. Compared with commonly used metal, zirconia and alumina materials, peek does not need sintering, more accurate, low density, light weight, patients wear comfort, soft texture, to the occlusion played a role in damping.
In addition to medical implant accidents peek is also widely used in the field of medical devices to apply the following:
2, Peek material medical equipment
Intramedullary nail Peek Sight rod bracket
Peek sights for distal locking
X-Ray Peek-and-bone connecting rod for external fixation bracket (spark surface)
Minimally Invasive Peek Guide tail (aiming rod)
Peek has the advantages of abrasion resistance, corrosion resistance, high temperature, strong strength, X-ray/good biocompatibility, etc. Compared with the typical medical materials, such as titanium and cobalt-chromium alloy, Peek offers a number of additional advantages: (1) Lower elastic modulus (2) can be achieved through X-ray (3) Excellent disinfection properties (4) Better biocompatibility (5) Mechanical properties can be adjusted (6) Greater design freedom.
3. Peek High temperature 3D printer
Small high temperature 3D printer real picture
Industrial large-scale high temperature 3D printer (two colors) real picture
PEEK 3D print piece real picture
Peek Wire real shot map
High temperature 3D printing equipment has the following characteristics:
1, up to 450 ℃ of metal print head, independent patent, to ensure the smooth flow of high temperature extrusion structure;
2, up to 90 ℃ of the thermostat, to protect the temperature gradient;
3, up to 120 ℃ special material of the hot-bed floor, to ensure that the viscous edge;
4, the core components of temperature-resistant materials;