1957 results about "Thermal shrinkage" patented technology

The invention discloses a lithium battery diaphragm coating based on a nano material and application thereof, and relates to the technical field of lithium battery diaphragms. The coating comprises the following raw materials in parts by weight: 15-25 parts of polystyrene maleic anhydride copolymer modified polyvinylidene fluoride, 10-20 parts of polystyrene, 2-4 parts of nano silicon nitride, 3-6 parts of a boehmite / aluminum oxide and silicon dioxide composite material, 1-2 parts of a dispersing agent and 65-90 parts of a solvent, according to the lithium battery diaphragm coating provided by the invention, the wettability and absorptivity of a diaphragm to an electrolyte are remarkably improved, meanwhile, the lithium battery diaphragm coating also has excellent thermal stability, and the diaphragm can be effectively prevented from thermal shrinkage or melting under a high-temperature condition, so that the safety performance of a battery is remarkably enhanced.

The invention relates to an antistatic PET (Polyethylene Terephthalate) base film for preparing a polaroid release film and a preparation method thereof, the release film base film is prepared by taking an optical-grade PET slice as a main body, adding modified PET with a specific structure and a modified SiO2 filler, and carrying out co-extrusion casting, a unique three-section stretching process and coating with a coating liquid. According to the invention, material modification and process improvement are carried out, specifically, an optical-grade PET slice is taken as a main body material, modified PET and a modified SiO2 filler with a specific structure are added, a film is prepared through co-extrusion casting and a unique three-section stretching process, and then the surface of the film is coated with a layer of antistatic coating liquid, so that the antistatic film is obtained. The finally prepared base film has low alignment angle, low transverse hot shrinkage rate and high surface adhesion, keeps the characteristics of high light transmittance and low haze of an optical-grade polyester film, endows the film with certain antistatic property, and is particularly suitable for being used as a release film of a high-end polaroid.

The invention provides an intelligent sorting method and system for radioactive substances. The method comprises the following steps: synchronously detecting surface element composition and radiation intensity of a radioactive substance through an X-ray fluorescence spectrometer, and constructing a spatial difference matrix of element abundance distribution and a radiation gradient topological graph; the three-dimensional coordinates, the pressure threshold value and the shape adaptation parameters of the target grabbing position are determined on the basis, the curvature radius of the clamping jaw deformation contour is dynamically adjusted, and the error of the dynamic geometric envelope and the contour template is converged to be within the threshold value; finally, when the clamping jaw reaches a target position, the area of the heat shrinkage material is activated to be heated according to the radiation intensity abrupt change boundary coordinates, a sealed isolation layer synchronously expanded with the dynamic geometric envelope is generated, and safe grabbing and sealed isolation of radioactive substances are achieved. According to the technical scheme, accurate grabbing of radioactive substances, error self-adaptive compensation and synchronous isolation of radiation leakage can be achieved, and the sorting safety and efficiency are improved.

The invention relates to the technical field of control systems, in particular to a production process optimization control system and method for a heat shrink film. The method comprises the following steps: obtaining resin characteristic parameters of a heat shrink film raw material, and constructing an initial digital twinborn model by using the resin characteristic parameters; acquiring real-time production data, and updating the initial digital twinborn model by using the real-time production data to obtain a complete digital twinborn model; and performing melt ultrasonic-assisted homogenization and two-way stretching process simulation based on the digital twin model, and performing optimization analysis by using a simulation result to generate optimized process parameters. By constructing and updating the digital twinborn model, the melt uniformity and process parameter optimization are accurately controlled, the quality consistency and stability of the thermal shrinkage film are improved, and the product is ensured to meet the mechanical, optical and thermal shrinkage performance requirements.

The invention discloses high-crystallinity superfine nickel powder and a preparation method thereof.The generation size of nickel powder in a liquid phase is adjusted through ultrasonic waves, molten salt heat treatment is combined to obtain the high-crystallinity superfine nickel powder, and the preparation method specifically comprises the following steps that an aqueous solution in which a nickel precursor is dissolved is mixed with a reducing agent; under the action of ultrasonic waves, an alkaline solution is added for a reaction, and nickel powder particles with the adjustable particle size are prepared; and then uniformly mixing the nickel powder with combined salts in different proportions, carrying out heat treatment at different temperatures, and cleaning and separating a cooled product to finally obtain the high-crystallinity superfine nickel powder with the size of 100-200nm. The nickel powder has good size uniformity, oxidation resistance and thermal shrinkage resistance, and can be applied to various fields such as conductive paste, metal electrodes and magnetic shielding materials.

The invention discloses a dry-process high-temperature-resistant lithium battery diaphragm and a preparation method thereof, and relates to the technical field of lithium battery diaphragms. The specific preparation method comprises the following steps: activating and cross-linking polypropylene, polyimide, a PP-b-PI block copolymer and a cross-linking agent BIBP under the protection of nitrogen to prepare a polypropylene-polyimide matrix; after melting, adding a pre-sintered ZrO2-coated Al2O3 core-shell filler, hydroxylated boron nitride and zinc borate, and carrying out double-stage screw extrusion, ultrasonic orientation, nitrogen annealing and cold roller quenching to obtain a mixed melt; carrying out warm stretching and hot air circulation heat treatment to prepare a hard elastic crystal base film; carrying out stretching, thermal relaxation and thermal shaping to obtain a microporous base membrane; after slitting, plasma activation is carried out, epoxy silane and tetraethyl orthosilicate / polybenzimidazole aerogel precursors are sprayed, and a nano closed-pore coating is formed through pre-curing and heat shrinkage curing; and finally eliminating static electricity and rolling to obtain a finished product. The lithium battery diaphragm prepared by the invention is excellent in high temperature resistance and low in thermal shrinkage rate.

The invention belongs to the technical field of lithium battery production, and particularly relates to a cylindrical battery pole end half film sleeving device which comprises a rack large plate, a feeding and discharging mechanism, a push rod mechanism for pushing a battery to a rotating platform, a transplanting mechanism for rotating and positioning the battery, a battery film sleeving mechanism, a battery discharging mechanism, a film sleeving mechanism support and a rotating support mechanism. According to the invention, after thermal shrinkage, the protection on the end face of the positive electrode is ensured, and the code spraying requirement is met; the use amount of materials is effectively saved, so that the production and purchase cost is reduced; the problem of non-uniform thermal shrinkage caused in the production process of the battery cell membrane is solved, and the customization requirement of a user for tagging on a steel shell or membrane can be met; safety protection of an effective physical level is provided for the junction sealing end of the positive electrode and the negative electrode of the battery, and the safety risk caused by short circuit due to collision under the condition that the formation and capacity grading end is electrified and transplanted is avoided; during steel shell code spraying, a code scanning gun reads and stores a code assigned on the sleeve film during use, and battery data can be conveniently traced during production.

The invention relates to the field of heat shrinkage films, in particular to an antistatic PETG heat shrinkage film. The PETG heat shrink film comprises the following components in parts by weight: 100 parts of PETG resin, 2-6 parts of an anti-adhesion agent, 2-5 parts of a lubricant, 1-5 parts of an antistatic modifier, 1-2 parts of an antioxidant and 0.5-1 part of a light stabilizer. In the preparation process of the PETG heat shrink film, a novel borate antistatic agent is introduced, and the antistatic agent is synthesized by taking tris (2-carboxyethyl) isocyanurate and 4-aminophenylboronic acid pinacol ester as raw materials, so that compared with a traditional antistatic agent, the antistatic property is better, the heat stability is obviously improved, and the service life of the heat shrink film is prolonged. And the phenomenon of local deformation or poor arc-shaped shrinkage of the PETG heat shrinkage film when the PETG heat shrinkage film shrinks at a non-uniform interface is reduced.

The invention discloses an aramid fiber coated polyolefin battery diaphragm and a preparation method and application thereof, the aramid fiber coated polyolefin battery diaphragm can be used for manufacturing a lithium ion battery, and the aramid fiber coated polyolefin battery diaphragm is prepared by the following method: (1) treating a polyolefin base membrane by using a strong oxidant to obtain a modified base membrane; (2) dissolving aramid resin in a solvent to obtain an aramid coating solution; and (3) coating the surface of the modified base membrane with the aramid fiber coating liquid, and then curing. According to the invention, the interface bonding strength of the base membrane and the aramid fiber coating is obviously enhanced, so that the aramid fiber coating can give full play to high heat resistance, on the basis of ensuring the tensile strength of the diaphragm, the overall thermal shrinkage rate of the diaphragm is reduced, the risk of high-temperature short circuit is effectively inhibited, and the composite diaphragm with high porosity, strong mechanical property, high uniformity and no surface defect is formed; the method is suitable for high-energy-density lithium ion batteries, and the safety and high-temperature working condition stability of the batteries are remarkably improved.

The invention discloses a multilayer co-extrusion heat-shrinkable film and a preparation method thereof, the film comprises an outer wear-resistant layer, a middle support layer and an inner functional layer, the thickness ratio of each layer is 1: 3: 1-1: 5: 1, the total thickness is 50-150 [mu] m, and the raw materials are prepared according to respective formulas. The preparation method comprises the steps of raw material preparation, melt mixing, die head extrusion, two-way stretching, water-cooling shaping, electronic crosslinking, aging treatment, heating softening and cold and hot shaping. The carbon nanotubes (CNT) and the h-BN nanosheets synergistically hinder crack propagation in the middle layer, so that the crack propagation resistance of the film is remarkably improved, the tensile strength, the thermal shrinkage rate and other properties are also optimized, compared with a traditional film, the comprehensive properties of wear resistance, high strength and high thermal shrinkage rate are achieved through interface collaborative design, meanwhile, the production cost is reduced by 20-30%, and the application prospect is wide. The method is suitable for food packaging, electronic device protection and other fields.

The invention discloses a high-safety temperature-responsive electrolyte, a lithium ion battery and a sodium ion battery, the high-safety temperature-responsive electrolyte comprises a thermal response solvent, a cosolvent and an electrolyte salt, the thermal response solvent is a thermal response polymer monomer, the thermal response polymer monomer has at least one of the structures of vinyl ether, divinyl ether, dialkenyl amide and dialkenyl butanediimine, the thermal response polymer monomer can quickly form a polymer solid electrolyte under the catalysis of an initiator salt in electrolyte salt under a high-temperature condition, and the fixation of the solid electrolyte enables a diaphragm in a battery not to collapse, so that the battery diaphragm can be used as a lithium ion battery diaphragm. Therefore, short circuit caused by thermal shrinkage and fusion of the diaphragm is avoided, and thermal runaway is avoided. The electrolyte can be used for preparing the lithium-ion and sodium-ion battery, and the lithium-ion and sodium-ion battery can keep a relatively high capacity retention rate while giving consideration to the safety performance.

The invention discloses a 110kV high-voltage polypropylene power cable, and relates to the technical field of power cables, and the 110kV high-voltage polypropylene power cable comprises an outer sheath, a conductor is installed in the outer sheath, the conductor is sleeved with a cable core sleeve, a shielding sleeve is embedded in the outer wall of the cable core sleeve, an inner spacer bush is installed on the inner side of the outer sheath, and an outer spacer bush is installed on the outer side of the inner spacer bush. According to the invention, bidirectional limiting and locking protection of the inside and the outside of the cable can be realized, multiple supports are provided for the inside of the cable, the internal stress stability of the cable in the use process is effectively balanced, and the service life of the cable is prolonged. The interface compatibility among the structures in the cable is equivalently improved, the interface air gap generated by the thermal shrinkage of polypropylene is effectively compensated, the double restraint of water branches and electric branches is realized, the multiple optimization of the mechanical performance is structurally realized, the stability of the electric insulation performance is improved, and the effective service life of the cable is prolonged.

The utility model relates to the technical field of beverage cup processing, and provides a printing cup automatic packaging and marking device which comprises a controller, a rack, a first conveying mechanism, a second conveying mechanism, a limiting mechanism, a pushing mechanism, a counting sensor, a sealing, cutting and thermal shrinkage all-in-one machine, an air blowing mechanism and a packaging bag printing machine. The limiting mechanism is arranged on the machine frame in a vertically-lifting mode and located between an outlet of the first conveying mechanism and an inlet of the second conveying mechanism, the conveying of the plastic cups is separated according to the packaging number of the plastic cups, and the blowing mechanism is arranged at the front end of a plastic bag packaging groove of the sealing, cutting and thermal shrinkage all-in-one machine and blows air into a plastic bag space for packaging the plastic cups. The first conveying mechanism, the second conveying mechanism, the limiting mechanism, the pushing mechanism, the sealing, cutting and thermal shrinkage all-in-one machine, the blowing mechanism and the packaging bag printing machine are all connected with and controlled by a controller. The small-package plastic cup packaging machine solves the problems that existing small-package plastic cups are slow in packaging speed and low in efficiency.

The invention provides a rigid-flexible metal-organic framework diaphragm with high selectivity as well as a preparation method and application of the rigid-flexible metal-organic framework diaphragm. Through a seed secondary growth strategy, the problems that MOF particles are easy to fall off and are incompatible with a substrate film are successfully avoided. On one hand, grain seeds embedded in the polyvinylidene fluoride (PVDF) substrate film in advance provide stable anchoring points for growth of MOF, and MOF particles are not prone to falling off due to the high adhesive force of the grain seeds. The high Young modulus of the MOF crystal also effectively improves the thermal shrinkage resistance of the diaphragm, the excellent flexibility of PVDF is complementary with the diaphragm in mechanical property, and the battery diaphragm shows excellent mechanical property and thermal stability due to the rigid-flexible combination strategy. The invention provides an efficient diaphragm construction strategy for developing a lithium metal battery with long cycle life and high safety, and shows a wide application prospect in a next-generation high-safety battery.

The invention provides an ultrahigh-temperature ceramic precursor, a preparation method thereof, a modified high-performance inorganic fiber and application, and relates to the technical field of high-temperature-resistant materials. The preparation of the ultra-high-temperature ceramic precursor comprises the following steps: placing a transition metal compound mixed solution in a low-temperature environment, standing, adding a coordination agent and an exchange agent, reacting, filtering in a low-temperature nitrogen atmosphere, adding a mixed solvent into the filtrate, heating and refluxing, and carrying out a polymerization reaction to obtain the ultra-high-temperature ceramic precursor. The superhigh-temperature ceramic precursor provided by the invention forms a high-temperature protective coating on the surface of a high-performance inorganic fiber and other materials, and meanwhile, a transition metal ion solution is placed under a low-temperature condition through a metal ion stabilization method, so that the internal structure of transition metal ions is more stable, and uniform dispersion at a molecular level is achieved; and the uniformity of the elements can be kept in the curing and cracking processes, and the phenomenon of coating stripping caused by mismatching of thermal shrinkage coefficients of a coating and a substrate material in an extreme environment is avoided.

According to the lithium ion battery diaphragm slurry, the diaphragm and the lithium ion battery disclosed by the invention, a furyl polyamide solution and ceramic powder are mixed to obtain a cortex solution, and furyl polymers have relatively high mechanical properties, so that the mechanical properties of the diaphragm prepared by subsequent coating can be improved. The hollow furyl polyamide nanofiber is prepared from the skin layer solution and the core layer solution, the ceramic particles are added in the process of preparing the hollow fiber instead of mixing the prepared hollow fiber with the ceramic particles, the ceramic particles can be dispersed on the surface and inside the hollow fiber, agglomeration of the ceramic particles is avoided, and the hollow fiber is prepared. The preparation method has the advantages that the dispersion degree of furyl molecular chains is increased, the dispersion degree of the slurry is high, and meanwhile, the surface area of the slurry in contact with the diaphragm during subsequent coating can be increased due to generation of hollow fibers, so that the wettability of the diaphragm to electrolyte is effectively improved, and the heat resistance of the diaphragm is higher and the thermal shrinkage rate is lower.

The invention provides a modified negative pole piece, a battery and a battery system. The modified negative pole piece comprises a negative current collector; the modified active material layer is arranged on the surface of at least one side of the negative electrode current collector; the modified active material layer comprises an active material layer and a surface modification layer which are arranged in a laminated manner along the direction far away from the negative electrode current collector; the surface modification layer comprises at least two sub-modification layers, each sub-modification layer comprises a binder and a fast ion conductor electrolyte, and the content of the binder in the sub-modification layers is gradually reduced along the direction far away from the negative electrode current collector. On one hand, the infiltration state of the pole piece in the battery can be improved, the diffusion path of lithium ions can be shortened, the problem of stripping or falling of the active substance layer on the pole piece can be improved, and the structural stability of the battery can be improved, so that the rate capability and the cycle performance of the battery can be improved; the safety performance of the battery is improved and the overall cost of the battery is reduced.

The present application relates to the technical field of separator material preparation, and specifically relates to a microporous membrane, and a preparation method therefor and an application thereof. The microporous membrane comprises a polymer and an ionic liquid. Based on the total mass of the microporous membrane, the microporous membrane comprises 0.01 wt% to 5 wt% of the ionic liquid, optionally 0.1 wt% to 5 wt% of the ionic liquid. In the present application, an appropriate amount of the ionic liquid is introduced into the microporous membrane, and the ionic liquid can be continuously or discontinuously adsorbed on the surfaces of fibers in the microporous membrane. The ionic liquid is adsorbed on the surfaces of the fibers in the microporous membrane by means of a lipophilic end of the ionic liquid, thereby eliminating internal static electricity, also better reducing the reduction of ionic conductivity, increasing the migration speed of ions in an electrolyte, and reducing lithium dendrites. When the microporous membrane of the present application is used as a battery separator, an appropriate amount of the ionic liquid is added into the microporous membrane, so that the problem of electrostatic accumulation of the microporous membrane can be alleviated, and the microporous membrane has relatively low thermal shrinkage, avoiding problems such as affecting battery capacity, electrochemical safety.

The invention relates to the field of waterproof coiled material production equipment, in particular to a waterproof coiled material packaging machine which comprises a frame body provided with a film covering position. The packaging film conveying mechanism is arranged on the frame body and is used for conveying a packaging film to one side of the feeding end of the film laminating position; the feeding mechanism is arranged on the frame body and is used for conveying the waterproof coiled material to the film covering position; the hot melting cutting mechanism is arranged on the frame body in a lifting mode and located between the packaging film conveying mechanism and the film covering position. The thermal shrinkage chamber is arranged on the frame body and located on one side of the discharging end of the film covering position. The thermal shrinkage supporting balls are arranged in the thermal shrinkage chamber, and the number of the thermal shrinkage supporting balls is four; the two groups of lifting mechanisms are arranged in the thermal shrinkage chamber and are respectively arranged above and below the thermal shrinkage supporting balls; the upper and lower surface thermal shrinkage assembly is arranged at the output end of the lifting mechanism; and a rapid cooling mechanism is also arranged in the thermal shrinkage chamber. The problem that a packaging film is prone to wrinkling due to rolling, large supporting area and the like during thermal shrinkage is solved.

The invention discloses a safety type damaged state rock hydrogen permeation simulation device and method.The simulation device comprises a box body, a simulation mechanism, a hydrogen injection mechanism and an explosion-proof mechanism, and the simulation mechanism comprises a pressure box, a lower cushion block, a thermal shrinkage sleeve, an upper pressing block, an axial pressure assembly and a confining pressure assembly; and the hydrogen injection mechanism is communicated with the gas inlet hole and the gas outlet hole and is used for injecting gas with preset gas pressure and preset hydrogen concentration into the thermal shrinkable sleeve. The device has the beneficial effects that gas with preset pressure and preset hydrogen concentration is continuously injected into the rock sample in the thermal shrinkable sleeve through the hydrogen injection mechanism, the influence of different hydrogen environments on rock mechanical properties can be simulated, meanwhile, the first hydrogen concentration detection piece continuously monitors the hydrogen concentration in the box body, and if the concentration exceeds a preset safety threshold value, the hydrogen concentration is detected. And the fan is immediately started, and hydrogen in the box body is discharged to an outdoor safe area, so that explosion accidents caused by hydrogen leakage can be avoided, and the safety of an experiment process is improved.

A 3-D honeycomb textile can include a textured yarn. The textile can exhibit a heat-shrinkage rate from about 10% to about 60%. The textile can be configured to reversibly change its dimensions under application of stress. Prosthetic valves can have the disclosed textiles as a sealing member. Additionally, prosthetic valves can the disclosed textiles as cushion materials. In addition, methods of making the disclosed textiles and prosthetic valves are described.

The invention provides a battery and an electric device. A positive plate comprises a positive active material, and the positive active material is doped and / or coated with a lanthanum element; the surface of the diaphragm is coated with a ceramic coating; the electrolyte comprises a first solvent, a second solvent, a first additive and a second additive; the first solvent comprises a cyclic carbonate compound, the second solvent comprises a chain fluorosulfonamide compound, the first additive comprises mannitol carbonate sulfate, and the second additive comprises succinonitrile; the lanthanum element is doped / coated on the positive active material, so that the release of lattice oxygen at high voltage or high temperature can be effectively inhibited, and the exothermic reaction activity at the thermal runaway initial temperature is reduced; the first additive and the second additive in the electrolyte respectively form a compact CEI film and an SEI film with high thermal stability on the surfaces of the positive electrode and the negative electrode; the diaphragm ceramic coating provides a physical barrier, the thermal shrinkage temperature of the diaphragm is increased, and internal short circuit is prevented.

The invention provides a composite lithium ion battery diaphragm. The composite lithium ion battery diaphragm is composed of rare earth doped graphene and polyimide. According to the invention, the problem that the existing composite lithium ion battery diaphragm is insufficient in conductivity, dendritic crystal inhibition, stability in long-term use under extreme conditions and the like is solved, and the preparation of the lithium ion battery diaphragm capable of keeping high ionic conductivity, mechanical strength, thermal stability and dendritic crystal inhibition is realized. Experiments prove that the ionic conductivity of the cerium nitrate doped graphene-polyimide composite lithium ion battery diaphragm obtained by the invention is 0.5-1.8 mS / cm; the mechanical strength is 50 to 79 MPa; the thermal shrinkage rate in thermal stability is less than or equal to 5%-12% (150 DEG C / 1h); and the cycle life of a dendritic crystal inhibition test is more than 80-200 times (1mA / cm).

The invention relates to a biodegradable polyester composition as well as a preparation method and application thereof. The biodegradable polyester composition is prepared from the following components in parts by weight: 49 to 81 parts of biodegradable polyester, 20 to 50 parts of polylactic acid, 0.5 to 2 parts of inorganic filler, 0.1 to 2 parts of compatilizer and 0.1 to 2 parts of lubricant. The biodegradable polyester composition has good film blowing stability, and after the biodegradable polyester composition is prepared into a heat shrinkage film, the heat shrinkage film has good transparency, high transverse shrinkage rate and high longitudinal shrinkage rate.

The invention relates to the field of films, in particular to a light-weight anti-shrinkage BOPP (biaxially-oriented polypropylene) laser film and a preparation method thereof.The laser film comprises a mold pressing layer, an upper secondary surface layer, a core layer, a lower secondary surface layer and a light layer which are sequentially arranged, the total thickness is 13-15 microns, and the mold pressing layer comprises ethylene-propylene binary co-polypropylene; the weight-average molecular weight of first homo-polypropylene in the core layer is 250000-35000 g / mol, the number-average molecular weight of the first homo-polypropylene in the core layer is 90000-160000 g / mol, the molecular weight distribution index of the first homo-polypropylene in the core layer is 2-3, the upper secondary surface layer and the lower secondary surface layer are composed of modified polypropylene with the melting point of 170-180 DEG C and the melt index of 2-4 g / 10 min, the grafting rate of N-vinyl pyrrolidone is 2-5%, and the light layer comprises second homo-polypropylene. The modified polypropylene subjected to NVP grafting modification is adopted to form the upper secondary surface layer and the lower secondary surface layer, and the weight-average molecular weight, the number-average molecular weight and the molecular weight distribution index of the first homo-polypropylene are limited, so that the BOPP laser film is light in weight; the heat shrinkage rate of the laser film is reduced, the low haze of the laser film is ensured, and smooth production of the laser film is ensured.

The invention relates to the technical field of PE warning board film covering, in particular to efficient film covering equipment for a PE warning protection board. Comprising a machine frame and a hot-pressing laminating chamber, a hot melting coating mechanism and a curved surface thermal shrinkage laminating mechanism are arranged in the hot-pressing laminating chamber, the hot melting coating mechanism comprises a heating roller and a first supporting roller, a three-layer phase change energy storage nested structure is arranged in the heating roller, and the curved surface thermal shrinkage laminating mechanism comprises a composite elastic roller and an elastic supporting roller. Distributed temperature sensors are arranged in the heating roller and the composite elastic roller, micro-airbag array layers are arranged on the roller surfaces of the composite elastic roller and the elastic supporting roller, pressure detection systems are arranged in the micro-airbag array layers, a cooling mechanism is further arranged behind the hot-pressing film laminating chamber, and the cooling mechanism comprises a cooling roller and two limiting guide rollers which are located on the two sides of the cooling roller and used for guiding. The coating device can adapt to coating operation of the curved-surface PE warning board, it is guaranteed that the surface of the warning board is evenly coated with a hot melt adhesive film, the fitting quality of a complex curved surface is improved, and the energy utilization efficiency is improved while the melting quality of the adhesive film is guaranteed.

The present invention provides a polypropylene resin composition, a high-temperature resistant polymer film containing the same, and a preparation method and application thereof. By mass percentage, the polypropylene resin composition includes 79.7-98.9% of polypropylene resin, 1-20% of cycloolefin copolymer, and 0.1-0.3% of radiation crosslinking agent; the glass transition temperature of the cycloolefin copolymer is 120-160 °C; in the present invention, the film including the polypropylene resin composition has a high heat distortion temperature and a low thermal shrinkage rate, good high-temperature resistance, does not affect the dielectric properties of the film capacitor, has a small dielectric loss, can be biaxially stretched at a high draw ratio, and has a low cost.

The invention belongs to the technical field of dielectric film materials, and in particular relates to a method for preparing a polypropylene film for a film capacitor, comprising the steps of: S1, sheet casting preparation; S2, primary synchronous stretching; S3, primary transverse stretching; S4, secondary transverse stretching; S5, secondary synchronous stretching; S6, post-processing. The method for preparing a polypropylene film of the invention can prepare an ultra-wide polypropylene film for a film capacitor with uniform thickness, high longitudinal tensile strength, high transverse elongation, and low thermal shrinkage.

The invention provides a composite positive pole piece, a battery and a battery system. The composite positive pole piece comprises a current collector; the active material layer is arranged on the surface of at least one side of the current collector; the functional coating is arranged on the outer surface of the active substance layer, and the functional coating comprises a binder and an inorganic material; wherein the functional coating comprises at least two layers of sub-functional coatings, and the mass fraction of the binder in the sub-functional coatings is gradually reduced along the direction far away from the current collector. The functional coating provided by the invention comprises at least two sub-functional coatings, and the mass fraction of the binder in each sub-functional coating is gradually reduced along the direction far away from the current collector, so that on one hand, the infiltration state of the pole piece in the battery can be improved, and the structural stability and the rate capability of the battery are improved; on the other hand, the thermal shrinkage resistance of the diaphragm can be improved, the safety performance of the battery is improved, and the overall cost of the battery is reduced.

Provided is a polyester-based heat-shrinkable film or the like that, even when used in various types of PET bottles and the like, thermally shrinks stably and exhibits excellent wrinkle resistance characteristics.　This polyester-based heat-shrinkable film or the like has the following features (a)-(d). (a) The heat shrinkage rate A1 in the main shrinkage direction when being shrunk in hot water at 80°C at a condition of 10 seconds is set to a value within the range of 21-65%. (b) The heat shrinkage rate A2 in a direction orthogonal to the main shrinkage direction when being shrunk in hot water at 80°C at a condition of 10 seconds is set to a value within the range of -5% to 10%. (c) The absolute value (A1 / A2) of the ratio of the heat shrinkage rates A1 and A2 is 5.5 or more. (d) The neck-in rate measured in hot water at 70°C at a condition of 10 seconds is set to 6% or less.