872 results about "Shrinkage rate" patented technology

The invention relates to a liquid silica gel injection molding process optimization method and system in the field of intelligent manufacturing, and the method comprises the steps: obtaining mold structure data adaptive to a shrinkage rate, combining geometric characteristics of a complex structure product, adopting a topological optimization algorithm to redesign a parting surface and a demolding path, and determining a lossless demolding mold parting scheme; whether the product damage risk is lower than a preset threshold value or not is judged by simulating stress distribution of the demolding path, and if the product damage risk is lower than the threshold value, final mold manufacturing parameters are generated, and an optimized production process configuration file is obtained; extracting production rhythm data from the optimized production process configuration file, dynamically adjusting the operation cycle of the injection molding machine in combination with the demolding efficiency monitored in real time, and determining equipment parameter configuration for efficient mass production; and generating a control instruction sequence according to the equipment parameter configuration, and transmitting the control instruction sequence to the injection molding equipment and the mold heating system through the industrial Internet of Things to obtain operation state data of the automatic production line.

The invention relates to the technical field of railway engineering, and provides a cantilever hoop attitude detection method and system based on visual inspection, and the method comprises the steps: calculating the dynamic shrinkage rate and stress distribution gradient of a metal material at a preset low temperature, and generating a deformation compensation coefficient; acquiring surface geometric deformation data of the cantilever hoop at a preset low temperature and non-uniform distribution data of a surface temperature field; and obtaining corrected deformation data, obtaining aligned data based on the corrected deformation data and the non-uniform distribution data, and performing low-temperature deformation field reconstruction on the aligned data to obtain a low-temperature deformation field reconstruction result so as to extract an overlapping region of a surface deformation path and a temperature abnormal boundary of the cantilever hoop. According to the surface deformation path and the geometric center offset of the overlapping region, calculating a posture offset parameter of the cantilever hoop, and generating a low-temperature deformation early warning signal; according to the method, the problem of insufficient detection precision caused by data collaboration loss is solved, and high precision, high robustness and scene adaptability of high-iron cantilever hoop low-temperature deformation detection are realized.

The invention discloses a slab surface crack prediction method based on PSO-MXGBoost and a prediction model construction method, and belongs to the technical field of surface defect prediction. According to the method, on the basis of a metallurgical mechanism embedded MXGBoost algorithm, a solidification shrinkage rate dynamic correction item is implanted into a traditional XGBoost loss function, the sample weight is adjusted according to a shrinkage rate coefficient calculated according to steel grade components, a theoretical reference value of crack tendency is quantified through a thermodynamic equation, and prediction output of XGBoost is restrained to conform to a continuous casting solidification heat transfer mechanism; meanwhile, key hyper-parameters of the MXGBoost model are optimized through a PSO algorithm, so that an optimal crack prediction model is obtained. According to the method, the prediction precision of the slab surface cracks can be effectively improved, meanwhile, the hyper-parameters of the MXGBoost model are automatically adjusted through the PSO algorithm, manual intervention can be reduced, the training efficiency and prediction accuracy of the model are improved, and therefore multi-target collaborative optimization of model precision and metallurgical feasibility can be achieved.

The invention discloses a flexible structure 3D printing support control method combined with a resistor, and relates to the technical field of 3D printing, and the flexible structure 3D printing support control method comprises the following steps: generating a continuous density field and a dynamic damping parameter field of a support structure based on multi-target topological optimization of dynamic stiffness constraint and material distribution; quantifying the contact probability of the support structure and the target model through a membership function, and constructing a nonlinear gradient field of a contact interface; the stress coupling relation between the supporting structure and the model interface is defined based on the mixed constitutive tensor, the interface stress transfer coefficient is adaptively updated based on the material shrinkage rate difference, multi-physics field collaborative optimization is achieved in combination with regularization constraint, the key part of the supporting structure is recognized, and the resistor is integrated to the key part of the supporting structure. Through multi-target topological optimization, membership construction and adaptive stress transfer coefficient updating, the material consumption is reduced, the printing efficiency is improved, stress concentration at an interface is inhibited, the forming defect risk is reduced, and the structural reliability is improved.

The invention relates to a hot-rolled wire rod for a 2400 MPa bridge cable and a manufacturing method of the hot-rolled wire rod, after high-carbon components of Cr-Mo-V are rolled and spun into a wire rod, the wire rod is subjected to online molten salt rapid cooling isothermal treatment, so that the wire rod is cooled at the cooling speed of more than or equal to 32 DEG C / s and enters a sorbite phase region from an austenite state to form a structure taking sorbite as a main part, and precipitation and growth of carbides are controlled; and finally, roller way slow cooling is conducted, the hot-rolled wire rod with the microscopic structure comprising a mixed structure composed of tempered sorbite, ferrite and fused pearlite is prepared, the strength and plasticity matching performance of the wire rod can be improved, the mechanical property fluctuation can be reduced, the tensile strength can reach 1640-1680 MPa, the percentage reduction of area can reach 27%-32%, the mechanical property same-circle difference is smaller than or equal to 45 MPa, and the tensile strength of the wire rod can reach 1640-1680 MPa, the percentage reduction of area can reach 27%-32%, and the mechanical property same-circle difference is smaller than or equal to 45 MPa. And rapid and stable production is facilitated, the method is used for manufacturing the 2400 MPa bridge cable, and the wire breaking risk can be reduced easily.

The invention discloses an injection molding process parameter multi-objective optimization method based on a high-precision prediction model, and the method comprises the steps: carrying out the enhancement of data through MIC and GAN based on a simulation test result, so as to improve the quality of simulation data; then carrying out hyper-parameter tuning by using a KOA and IVYA mixed framework; then, an SHAP method is adopted to enhance the interpretability of the XGBoost model, and an optimized process parameter search range is provided; and finally, searching a Pareto leading edge of a quality target by applying MOCGO, and determining an optimal process parameter combination. Test results show that the buckling deformation and the volume shrinkage are respectively reduced by 35.7% and 10.1% by using the technological parameter combination optimized by the method disclosed by the invention, the buckling deformation and the volume shrinkage of the molded plastic part can be effectively reduced, so that a high-quality plastic part product is obtained, and the product quality is improved. And a theoretical basis and data support can be provided for obtaining an optimal process parameter combination of injection molding.

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 provides a spirocyclic expansion monomer, a preparation method thereof and a resin composition. The structural formula of the spirocyclic expansion monomer is as shown in formula I in the specification. The spiro expansion monomer has the advantages of high reaction activity, low shrinkage rate, good compatibility and the like, and the curing volume shrinkage rate of epoxy resin can be reduced through the ring opening effect of the spiro monomer after the spiro expansion monomer is added into an epoxy resin system, so that the curing shrinkage stress is reduced. The invention also provides a resin composition. The resin composition comprises epoxy resin and the spiro-expansive monomer and / or the oligomer of the spiro-expansive monomer. The spiro expansion monomer is applied to an epoxy resin system to prepare a precise fixing adhesive, the shrinkage rate of the adhesive in the curing process can be effectively reduced, so that the curing shrinkage stress is reduced, the coupling precision is improved, and the spiro expansion monomer is mainly applied to the fields of electronic component bonding, optical device bonding and fixing and the like.

The invention discloses a mobile phone narrow frame low-pressure injection molding sealing adhesive and a preparation method thereof, and belongs to the technical field of adhesives. According to the technical scheme, the adhesive is characterized by being prepared from, by weight, 35-46 parts of aliphatic epoxy resin, 10-20 parts of polyether polyol, 16-25 parts of reactive diluent, 15-20 parts of toughened resin, 1.4-2.0 parts of initiator, 0.8-1.2 parts of coupling agent and 1.5-2.0 parts of fumed silica, and an adhesive layer obtained after the adhesive is subjected to UV curing is low in shrinkage rate, high in modulus and good in adhesion property. The width of the mobile phone frame can be well controlled, compared with a plastic piece, the screen-to-body ratio of a mobile phone screen can be further improved, and meanwhile the requirements for bonding and reliability of a client side can be met.

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 discloses a paving layer compacting device and method for binder spraying additive manufacturing, belongs to the technical field of additive manufacturing, and aims to solve the problems of large deformation, large shrinkage rate, large self-weight influence and the like in binder spraying additive manufacturing in the prior art. The paving layer compacting device comprises a pressing plate and a reciprocating driving assembly used for driving the pressing plate to be away from or make contact with a paving layer, and the pressing plate is arranged over the paving layer; when the paving layer compacting device has the first compacting mode, the paving layer compacting device is in the first compacting mode, a surface treatment layer is arranged on the face, facing the paving layer, of the pressing plate, and the surface treatment layer is not adhered to or partially adhered to an adhesive in the paving layer. The device and the method can be used for paving and compacting of binder spraying additive manufacturing.

The utility model provides a quick-dry cool stiff and smooth warp knitting fabric, which is formed by knitting at least two guide bars GB1 and GB2, yarns adopted by the guide bar GB1 are high mechanical elasticity synthetic fiber filaments with circular or special-shaped sections, the crimp shrinkage rate of the high mechanical elasticity synthetic fiber filaments must be greater than 25%, and the crimp shrinkage rate of the high mechanical elasticity synthetic fiber filaments must be greater than 25%. Yarns adopted by the GB2 guide bar are elastic polyurethane filaments, the thickness of the high-mechanical-elasticity synthetic fiber filaments is 20-50D, and the thickness of the elastic polyurethane filaments is smaller than or equal to 55D. The high-mechanical-elasticity synthetic fiber filaments with the special-shaped cross sections are adopted, the contact area between fibers and air is large, diffusion and evaporation of water on the surfaces of the fibers are facilitated, and a wearer has the experience of quick-dry and cool feeling after wearing the fabric; meanwhile, due to the high crimp rate of the high-mechanical-elasticity synthetic fiber filaments, the fabric can have high stiffness and smoothness; the fabric obtained by weaving the high-mechanical-elasticity synthetic fiber filaments and the elastic spandex filaments has good elasticity, and the wearing comfort of a user is improved.

The invention discloses a method for improving cloth lines after hot pressing of an epoxy glass fiber composite material, and the method comprises the steps of resin glue solution blending, glass fiber cloth presoaking, gradient pre-drying, hot pressing molding, cooling demolding and the like. The volume expansion rate is accurately matched with the resin curing shrinkage rate, interface stress caused by shrinkage difference is directly counteracted, meanwhile, gradient pre-drying and staged hot pressing processes are combined, and the resin fluidity and interface bonding strength are optimized. The resin conversion rate is controlled in two stages through gradient pre-drying, and flow blocking caused by premature curing is avoided; and secondly, through the chemical compensation mechanism of the expansion monomer, the mechanical property of the material is maintained while the cloth lines are eliminated.

The invention discloses a process for repairing ceramic glaze defects, which comprises the following steps of: A, polishing the defect part of ceramic into a U-shaped groove, and wetting the U-shaped groove to obtain pretreated ceramic; b, the U-shaped groove of the pretreated ceramic is filled with the repairing base material, and the repairing base material is compacted to obtain a repairing bottom layer; c, the repairing bottom layer is sequentially dried and polished, so that the surface of the repairing bottom layer is flush with the surface of the pretreated ceramic; d, the surface of the repairing bottom layer is filled with repairing cover glaze and compacted, and a repairing surface layer is formed; and E, the pretreated ceramic with the repairing surface layer is placed in a shuttle chamber kiln, and repairing is completed. According to the repair process for the ceramic glaze defects, the repair base material formula and the repair process are optimized, so that the firing shrinkage rate and the cracking possibility are reduced, the repair strength is improved, and on the premise of ensuring the repair effect, the repairable defect range can be widened; and the repaired ceramic glaze defect part can be flat and smooth, and the aesthetic property is ensured.

The invention provides an anti-cracking performance evaluation method and system based on a concrete shrinkage rate. The method comprises the following steps: firstly, collecting shrinkage rate real-time sequence data and an acoustic emission signal flow of a concrete sample in a curing process, separating a high-frequency elastic wave energy attenuation characteristic value from the acoustic emission signal flow, and carrying out space-time coupling on the high-frequency elastic wave energy attenuation characteristic value and a shrinkage rate jump point in the shrinkage rate real-time sequence data to generate a crack initiation tendency index; then obtaining a calibrated crack initiation tendency index based on an ambient temperature hysteresis effect and a temperature drift error of the calibrated crack initiation tendency index, and then outputting an anti-crack performance grade according to a grading deviation degree between a pre-designed grading parameter and a fluctuation range of the calibrated crack initiation tendency index; according to the technical scheme provided by the invention, the essential defect that a traditional method cannot correlate material characteristics with environmental response is overcome, direct quantitative mapping of material structure performance and damage evolution is also realized, and a traceable material-level basis is provided for engineering anti-crack design.

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 discloses a polypropylene composition as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. A styrene-ethylene-butylene-styrene block copolymer and an ethylene-butylene copolymer are introduced into a polypropylene resin matrix for compounding to form a resin system; meanwhile, the silicate filler with specific whiteness and the sorbitol anti-reflection agent are selected for compounding, and under the synergistic effect of all the components, the product not only can realize higher light transmittance, but also is low in shrinkage rate, good in low-temperature toughness and excellent in processability and use performance.

The invention relates to the technical field of epoxy resin, in particular to an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof.The preparation method of the epoxy resin composition comprises the steps that S1, modified epoxy resin, a compatilizer, a retarder, a defoaming agent and nano filler are added into a reaction kettle and mixed and stirred, and a mixture A is obtained; s2, a composite curing agent is added into the mixture A, stirring and mixing are conducted, and the epoxy resin composition is obtained and has the advantages of being appropriate in viscosity, good in heat resistance, excellent in impact resistance, large in bending strength, small in volume shrinkage rate in the curing process, moderate in gelation time and capable of being wound with carbon fibers conveniently to prepare the composite material.

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.

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.

The invention discloses a warp-resistant mineral reinforced PC / PBT alloy material with dimensional stability and a preparation method thereof, and relates to the technical field of polymer composite materials. The preparation method comprises the following steps: weighing polycarbonate, polybutylene terephthalate, ureido pyrimidone-polydimethylsiloxane, epoxy polyhedral oligomeric silsesquioxane, polyimide coated halloysite nanotubes, magnesium-aluminum hydrotalcite, perfluoroalkyl modified boron nitride nanosheets, liquid crystal polymer microfibers, modified PVA (Polyvinyl Alcohol) fibers and a silane coupling agent KH550 according to a ratio; the preparation method comprises the following steps: pre-mixing polycarbodiimide and a composite antioxidant to obtain a mixture, mixing, adding into a double-screw extruder, extruding and granulating, drying, carrying out injection molding, and standing at constant temperature and constant humidity to obtain the composite material. The invention has the significance of providing the PBT / PC alloy material with dimensional stability, warping resistance, low shrinkage rate, low hygroscopicity, creep resistance, impact resistance, arc resistance and chemical corrosion resistance for consumer-grade and industrial-grade underwater plastic parts.

The present invention belongs to the technical field of the preparation of bio-based functional fibers, and relates to a preparation method of highly shrinkable polyethylene furandicarboxylate fibers. Preparation method: The polyethylene furandicarboxylate chips are dried and then melt-blended and spun to obtain highly shrinkable polyethylene furandicarboxylate fibers. The linear density of the fibers is 2.22 - 4.44 dtex, and the linear density deviation rate is -5% - 5%. The breaking strength of the fibers is 3.5 - 4.5 cN / dtex, the breaking elongation rate is 53.5 - 68.5%, the content of ultra-long fibers is 0 - 3 mg / 100 g, the content of defects is 3 - 20 mg / 100 g, the number of crimps is 12 - 15 per 25 mm, the crimp rate is 14% - 18%, and the boiling water shrinkage rate is 60 - 80%. The highly shrinkable polyethylene furandicarboxylate fibers prepared by the present invention are 100% highly shrinkable polyester fibers, and the fiber properties far exceed those of conventional highly shrinkable fibers, and can become an alternative product to PET.

The present application provides a display panel and a display device. The display panel comprises a first curved region located between two second curved regions and corresponding to a corner area of a planar region. The display panel comprises a supporting layer and a panel main body, and the supporting layer comprises a first portion being bent and within the first curved region and a second portion being bent and within the second curved region; the panel main body is disposed on the first portion and the second portion and bent along with the first portion and the second portion. a shrinkage rate of the first portion is greater than a shrinkage rate of the second portion.

The invention discloses a high-performance cement-based micro-expansion filling grouting material and a preparation method thereof, and belongs to the technical field of inorganic cementing materials. The high-performance cement-based micro-expansion filling grouting material is prepared from Portland cement, fly ash, graded aggregate, aluminum silicate coated aluminum powder, calcium silicate coated magnesium oxide, tung oil coated iron powder, a calcium formate early strength agent, polycarboxylate superplasticizer powder and water. According to the obtained high-performance cement-based micro-expansion filling grouting material, the fluidity ranges from 432 mm to 441 mm, the 28-day compressive strength ranges from 63.5 MPa to 65.2 MPa, the 28-day breaking strength ranges from 14.3 MPa to 15.1 MPa, the 28-day shrinkage rate ranges from 0.01% to 0.04%, and the 10-time freezing and thawing expansion rate ranges from 0.03% to 0.06%.

A glass substrate of the present invention has a strain point of from 695° C. to 740° C., a temperature at 104.5 dPa·s of 1,300° C. or less, a liquidus viscosity of 104.5 dPa·s or more, a Young's modulus of 78 GPa or more, and a thermal shrinkage rate in heat treatment at 500° C. for 1 hour of 20 ppm or less.

The invention belongs to the technical field of waterproof mortar, and particularly relates to waterproof mortar containing modified basalt fibers as well as a preparation method and application of the waterproof mortar. The waterproof mortar containing the modified basalt fibers is prepared from the following components in parts by weight: 35 to 40 parts of cement, 55.3 to 62.4 parts of aggregate, 1 to 2 parts of the modified basalt fibers, 1 to 1.5 parts of redispersible latex powder, 0.1 to 0.2 part of cellulose ether, 0.1 to 0.2 part of a de-foaming agent, 0.1 to 0.2 part of a water reducing agent and 0.3 to 0.6 part of a water repellent. The waterproof mortar disclosed by the invention is high in bonding strength, good in freeze thawing resistance, high in cracking resistance, low in shrinkage rate and water absorption rate and excellent in comprehensive performance, and has a wide market prospect.

The invention belongs to the field of intelligent materials, and discloses a nematic phase liquid crystal elastomer fiber and a method for optimizing the thermal shrinkage performance of the nematic phase liquid crystal elastomer fiber. According to the method, the mass ratio of a cross-linking agent pentaerythritol tetra (3-mercaptopropionate) (PETMP) to a chain extender 2, 2 '-[1, 2-ethanediyl bis (oxygen)] bis (ethanethiol) (EDDET) in an LCE spinning solution is accurately controlled through a wet spinning technology, and drafting and heat treatment processes are combined, so that the LCE fiber with adjustable and controllable heat shrinkage performance and mechanical performance is prepared. The invention aims to overcome the limitations of low response speed, low shrinkage rate, insufficient environmental stability and the like of the existing LCE fiber. The reversible thermal shrinkage rate of the fiber can reach up to 35%, the maximum shrinkage deformation can be completed within 2 seconds at the soonest at the temperature of 80 DEG C, and the maximum tensile strength can reach 170 MPa. And the catalyst has excellent oxidation stability (the mass retention rate is about 97%), and can maintain efficient thermal response in a water environment. And a new way is provided for development of high-performance intelligent materials.

The purpose of the present invention is to provide a heat-shrinkable film that has a reduced natural shrinkage rate and improved shrink finish. This heat-shrinkable film is composed of polyester and / or polystyrene and satisfies the following (1) to (4): (1) the shrinkage rate in the main shrinkage direction when treated in hot water at 70°C for 10 seconds is 3% or less; (2) the shrinkage rate in the main shrinkage direction when treated in hot water at 80°C for 10 seconds is more than 10% and not more than 50%; (3) the shrinkage rate in the main shrinkage direction when treated in silicon oil at 120°C for 10 seconds is 50-80%; and (4) the natural shrinkage rate (dimensional change rate) in the main shrinkage direction of the film after aging for 168 hours in an atmosphere of 50°C and 40% relative humidity is 1% or less.

The invention belongs to the technical field of precast concrete component crack repairing and solid waste, and particularly relates to a precast concrete component low-carbon repairing material and a preparation method and a use method thereof. The low-carbon repairing material has good compressive strength, breaking strength and bonding strength, the 28-day dry shrinkage rate is low, and the initial setting time and the final setting time of the low-carbon repairing material are short. By adopting the low-carbon repairing material, not only can the compressive strength and breaking strength of the repaired concrete prefabricated component be improved, but also the repairing time of concrete cracks can be shortened, and the repairing efficiency of concrete can be improved.

To provide a wound yarn package and a method for manufacturing the same in which even if sea-island type fibers are wound around a bobbin one by one by a traverse mode, cob-webbing and curling are less likely to occur, and the variation in the heat shrinkage rate between layers constituting the yarn layer is reduced. When winding sea-island type fibers with a fineness of 100 to 6400 dtex around a bobbin one by one by a traverse mode to form a yarn layer, each yarn constituting the n-th yarn layer is wound at a position 0 to x mm away from each yarn constituting the (n−1)-th yarn layer, with the yarn width of the sea-island type fiber being taken as x (mm), to fabricate a wound yarn package.