444 results about "Shrinkage rate" patented technology

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.

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 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 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 discloses a thin-wall shell plastic part injection molding process parameter multi-objective optimization method, which is based on an RIME-RF-MOGWO framework, takes a simulation sample as a research object, selects a volume shrinkage rate and a buckling deformation amount as optimization objectives, and firstly adopts SMOTE to process a data imbalance problem; establishing a nonlinear mapping relation between the process parameters and the quality target by using RF; an RIME is introduced to optimize the hyper-parameter of the RF; multi-objective optimization of process parameters is realized in combination with MOGWO, and a Pareto frontier solution set is obtained through non-dominated sorting and a congestion degree control mechanism. A multi-round optimization and simulation verification result shows that the multi-objective optimization method for the injection molding process parameters of the thin-wall shell plastic part can effectively obtain an optimal process parameter combination, the volume shrinkage rate is reduced by 19.02%, the buckling deformation amount is reduced by 50.63%, and the molding quality of the thin-wall plastic part can be remarkably improved.

The present invention provides a method of removing a foreign particle on a first member, comprising: supplying a composition on the first member; pressing a second member against the composition supplied on the first member; curing the composition on the first member after the pressing; and separating the second member together with the composition from the first member, after the curing, wherein in the supplying, a supply amount of the composition to be supplied on the first member is controlled based on a cure shrinkage rate of the composition in the curing and an estimated size of a foreign particle being presumably adhered on the first member, such that a thickness of a portion of the composition cured in the curing, which exists between the second member and the first member, becomes larger than the estimated size.

The invention discloses a preparation process of composite cement based on activation of steel slag micro powder, belongs to the technical field of cement preparation, and aims to solve the technical problem that durability and stability of cement are difficult to further improve in the prior art. A composite cement preparation process based on steel slag micro powder activation comprises the following steps: adding final powder, a polycarboxylate superplasticizer, a retarder and a defoaming agent into a stirring kettle, and uniformly stirring to obtain composite cement; according to the invention, through synergistic combination of the composite activator, the activated steel slag micro powder and the porous silicon-aluminum-calcium sustained-release microspheres, a multi-layer reaction system with early-stage excitation, middle-stage reinforcement and long-term reinforcement effects is constructed; all the components are complementary in time and space to form a compact and continuous skeleton structure, the aperture is refined, the interface is stabilized, and the internal humidity and ion supply are maintained, so that the compressive strength and breaking strength of the concrete are remarkably improved, the shrinkage rate is reduced, and the impermeability and freeze-thaw resistance are improved.

The invention discloses a device and method for testing the thermal shrinkage rate of a diaphragm, and the method comprises the steps: S1, cutting a diaphragm into a preset size in advance, and placing the diaphragm on a lower loading plate according to the position of a reference line; s2, a dyeing auxiliary plate is placed, and a dyeing agent is used for dyeing; s3, taking down the dyeing auxiliary plate and horizontally placing an upper pressing plate; s4, applying a preset pressure, simulating the stress condition of the diaphragm in the battery cell, maintaining a constant pressure, assembling the bolt, and fixing a torque; s5, placing in a temperature control box, heating to a preset temperature, and standing; s6, the camera captures and records changes of multiple groups of region areas and relative positions of diaphragm dyeing along with time, and the total shrinkage rate and the shrinkage rates of different dyeing regions are calculated respectively; and S7, collecting the real-time shrinkage rates of multiple groups of positions of the diaphragm at different temperatures, judging whether the local shrinkage rates of the whole diaphragm and each region are qualified or not, and providing reference for subsequent adjustment of a coating formula.

The invention provides a dry-type iron core reactor coil resin anti-cracking method, and relates to the technical field of dry-type iron core reactor preparation, and the method comprises the following steps: configuring a mold system, carrying out resin pre-curing treatment, carrying out dynamic stress compensation curing, and carrying out demolding treatment. According to the invention, the mold system comprising the elastic buffer layer, the radial adjustable slide block group and the partition temperature control system is configured, and a complete process chain of vacuum pouring-gradient temperature control pre-curing-dynamic stress compensation curing-temperature control demolding is combined, so that the internal stress generated by the difference between the shrinkage rate of resin and the shrinkage rate of a metal framework or a wire can be effectively relieved; local stress concentration caused by rigid mold constraint is reduced, the problem of uneven curing caused by improper temperature gradient control is solved, and the problem of resin cracking caused by stress concentration in a traditional process is solved on the whole.

The invention discloses an LTCC (Low Temperature Co-Fired Ceramic) material with a controllable shrinkage rate and a preparation method thereof. The material comprises microcrystalline glass A and a glass devitrification material B, wherein the glass devitrification material B is obtained by devitrifying microcrystalline glass C according to a specific temperature system. The glass ceramic A and the glass ceramic C have different softening temperatures. And accurately regulating and controlling the crystallization state of the glass crystallization material B by regulating and controlling the crystallization treatment temperature and / or crystallization treatment time of the microcrystalline glass C. The LTCC substrate prepared from the LTCC material can be co-fired with a silver conductor while ensuring sintering compactness and excellent high-frequency performance, and the sintering shrinkage rate is controllable in the range of 14%-18% on the X / Y axis.

A method for producing expanded beads that have excellent in-mold moldability and produce a molded article of polyethylene-based resin expanded beads having a low shrinkage rate while increasing a biomass degree is provided. In the method, the polyethylene-based resin particles is composed of a mixed resin, which is obtained by kneading linear low-density polyethylene and branched low-density polyethylene, wherein the branched low-density polyethylene has a biomass degree of 30% or more and a heat of fusion of 95 J / g or more; a blending amount of the branched low-density polyethylene in the mixed resin is 5% by mass or more and less than 40% by mass, where a total of the linear low-density polyethylene and the branched low-density polyethylene is 100% by mass; and a heat of fusion of the polyethylene-based resin particle is 90 J / g or more.

The invention relates to the technical field of polyester yarns, in particular to a high-strength polyester yarn and a preparation method thereof.The method comprises the steps that PET slices with the intrinsic viscosity of 0.85-1.00 dL / g are subjected to melt spinning and cooled through circular blowing to obtain nascent fibers, the nascent fibers are subjected to surface activating treatment through low-temperature plasma or esterase bio-enzyme, and the high-strength polyester yarn is obtained; the preparation method comprises the following steps: firstly, activating fibers, then carrying out graft copolymerization reaction on the activated fibers and graft monomer solutions such as fluorinated acrylate and acrylic acid, and finally, cleaning, drying, carrying out thermal network and winding on the composite fibers, so that the prepared polyester yarn has the breaking strength of more than or equal to 7.7 g / D, the dry heat shrinkage rate of less than or equal to 3.5% and the shrinkage tension of less than or equal to 0.03 g / D, has the high functional characteristics of lasting super-hydrophobicity, antibacterial property and the like, is excellent in washing resistance, and is suitable for industrial production. The problem that functionalization is difficult due to surface inertia of the polyester fiber is solved, and the mechanical property and the surface characteristic of the polyester fiber are comprehensively improved.

The application discloses a low-shrinkage polyester shrink film for labels, which adopts a three-layer co-extrusion structure and comprises an A-layer surface layer, a B-layer core layer and a C-layer bottom layer; the A-layer and the C-layer are arranged on the two sides of the B-layer and are both made of common PETG film; the B-layer is made of PETG shrink film functional master batch chips, hydroxyethyl cellulose and polysulfone; the total weight of the PETG shrink film functional master batch chips, the hydroxyethyl cellulose and the polysulfone is 100 wt%; the adding amount of the PETG shrink film functional master batch chips is 90 wt% to 95 wt%; the adding amount of the hydroxyethyl cellulose is 1 wt% to 3 wt%; and the rest is the polysulfone. The application further discloses a preparation method of the shrink film. After a small amount of hydroxyethyl cellulose and polysulfone are added into the PETG shrink film functional master batch of the core layer, the shrinkage of the shrink film can be obviously reduced, the shrinkage rate is relatively high, and the shrinkage temperature is relatively low; the improved shrink film is especially suitable for being used as a label with low shrinkage; and in post-processing and use, the improved shrink film is beneficial to improving the product yield.

The present disclosure relates generally to cladding for covering a building surface. The present disclosure relates more particularly to a method of manufacturing a building surface panel. The method includes providing a foam piece having a 30 day / 23° C. residual shrinkage of no more than 0.2%. The foam piece having the 30 day / 23° C. residual shrinkage of no more than 0.2% is attached to a rear side of an outer shell so as to form the building surface panel. In some embodiments, a front side of the outer shell forms a visible surface of the building surface panel. The foam piece can be provided, e.g., by aging the foam piece for a time and at a temperature such that the 30 day / 23° C. residual shrinkage is no more than 0.2%. The foam piece to be aged can, in some embodiments, be cut from a body of foam.

The invention relates to the technical field of physical performance detection, and provides a method and a system for measuring anisotropic shrinkage of glue based on CCD (Charge Coupled Device) vision. The method comprises the following steps: constructing a measuring system, wherein the measuring system comprises a laser, a plane mirror, a convex lens, a CCD camera and a mirror base for bearing glue to be measured; when the glue is not cured, collecting an initial light spot image through the CCD camera, and determining the position coordinates of the initial light spot on the CCD camera; in the glue curing process, dynamic light spot images are collected in real time through the CCD camera, and the light spot offset in the first direction and the light spot offset in the second direction in the glue curing process are calculated respectively; calculating the shrinkage rate of the glue in the first direction and the shrinkage rate of the glue in the second direction; and obtaining the anisotropic shrinkage rate of the glue according to the shrinkage rate in the first direction and the shrinkage rate in the second direction. The method accurately evaluates the anisotropic shrinkage characteristic of the glue.

Provided is an olefin-based heat-shrinkable multilayer film that is substantially free of a cyclic olefin-based resin, is easy to use for solvent bonding and gravity separation, and has excellent heat shrinkability and transparency.　The olefin-based heat-shrinkable multilayer film comprises a first surface layer and a second surface layer, which are derived from a polystyrene-based resin, and an intermediate layer derived from a polyolefin-based resin, wherein (a) the polystyrene-based resin contains at least 50 wt% of a styrene-butadiene copolymer, (b) the crystal melting enthalpy of the intermediate layer is set to a value of 135 mJ / mg or less, (c) the thermal shrinkage rate in the TD direction is 50-80% under the shrinkage conditions of 100°C and 10 seconds, (d) the haze value is 10% or less, and (e) the specific gravity is 0.95 or less.

The present invention is a multilayer polylactic acid film including a particle-containing layer and a first stretched polylactic acid film formed from a first film-forming material containing polylactic acid. The multilayer polylactic acid film has a tensile elastic modulus Ea in the longitudinal direction and a tensile elastic modulus Eb in the width direction that satisfy the formula Ea + Eb > 8.0 GPa and a crystallinity of 40-90%, and when heated at 150°C for 30 minutes, exhibits both a thermal shrinkage rate in the longitudinal direction and a thermal shrinkage rate in the width direction of 10.0% or less. According to the present invention, it is possible to provide a multilayer polylactic acid film having excellent elastic modulus and heat resistance by using polylactic acid being derived from a biomass raw material and having biodegradability.

A base film for use in laminating with a sealing film to form a packaging film, the base film being composed of a stretched film made of a polyethylene resin having a density of 0.95 g / cm 3 The above at least one base layer having high-density polyethylene as a main component, the base film having a heat shrinkage rate in a stretching direction of less than 5% at 120°C and a tensile elastic modulus of 2000 MPa or more.

The invention discloses a method for improving the crimp shrinkage rate of polylactic acid ultrahigh-elastic fibers, and belongs to the technical field of fibers. Two polylactic acid POYs sequentially pass through a raw yarn frame, a first roller, a deformation hot box and a cooling plate and then are input into a false twister to be twisted in the same direction, two fibers output from the false twister are input into the same second roller together to be plied, plied tows sequentially pass through a network nozzle, an auxiliary roller, a shaping hot box and a feeding roller and then are subjected to oiling and winding treatment, and the polylactic acid POYs are obtained. The ultrahigh-elasticity fiber is prepared. The finished product fiber formed by stranding and elasticizing the two strands of yarns can be a single-strand yarn elasticized fiber, so that the crimp shrinkage rate of the polylactic acid ultrahigh-elastic fiber is improved, and the subsequent dyeing quality risk is overcome.

The invention relates to a double-resin interpenetrating network photo-thermal dual-curing optical fiber bonding and fixing adhesive which comprises the following components in parts by weight: 20-60 parts of epoxy resin, 10-30 parts of acrylate resin, 5-10 parts of a diluent, 0.5-3 parts of an auxiliary agent, 1-10 parts of a cationic photoinitiator, 1-10 parts of a free radical photoinitiator and 50-80 parts of filler. The shrinkage rate of the cured optical fiber bonding and fixing glue is not greater than 0.2%. According to the optical fiber bonding fixing glue provided by the invention, a low-shrinkage technical route for realizing co-growth of a double-resin interpenetrating network by regulating and controlling the curing reaction rate by virtue of photo-thermal dual-curing of the double-resin interpenetrating network and a filler in cooperation with the double-resin interpenetrating network.

To provide a reinforcing film which includes a base material layer and an adhesive layer, achieves both excellent low elasticity and excellent heat resistance, and hardly causes, for example, IC connection failure.SOLUTION: A reinforcing film according to an embodiment of the present invention is a reinforcing film including a base material layer and a pressure-sensitive adhesive layer, in which the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive layer has surface elasticity at 25 °C of from 50kPa to 1000kPa, and an MD direction heat shrinkage rate when the reinforcing film is heated at 180 °C for 5 minutes is 1.0% or less.SELECTED DRAWING: Figure 1

Provided is a heat-shrinkable polyester film having a high thermal shrinkage in the main shrinkage direction, a high film puncture strength, a high density, and thus an excellent elastic feeling, and a high bag breaking resistance when a bottle falls. A heat-shrinkable polyester film containing 60 mol% or more and 95 mol% or less of terephthalic acid ethylene glycol units in 100 mol% of all ester units, 5 mol% or more and 40 mol% or less of diethylene glycol in 100 mol% of polyol components, and 0 mol% or more and 5 mol% or less of constituent units derived from a monomer component capable of becoming an amorphous component in all polyester resin components, the film having a hot water heat shrinkage rate when immersed in hot water at 90°C for 10 seconds, a film puncture strength, a film density, and a refractive index in the film length direction within a prescribed range.

The application discloses a sintering material pressing device, which comprises supporting frames arranged on both sides of a sintering trolley and material pressing mechanisms capable of adjusting the material pressing position, the material pressing angle and the material pressing height. At least one set of material pressing mechanisms is arranged on each side of the supporting frames to compact the sintering material on the sintering trolley. By adjusting the material pressing position of the material pressing mechanisms, a density difference can be formed between the compacted part and the un-compacted part, and the shrinkage rate of the compacted part after sintering can be reduced. By adjusting the material pressing angle of the material pressing mechanisms, the resistance of the sintering material passing through the material pressing mechanisms during the pressing process can be reduced, and the surface shape of the sintered material after pressing can be changed. By adjusting the material pressing height of the material pressing mechanisms, the height of the sintering material in the sintering trolley can be adapted, and the pressure of the sintering material exerted by the material pressing mechanisms can be adjusted. By adjusting the material pressing position, the material pressing angle and the material pressing height of the material pressing mechanisms, a better compacting effect can be achieved, so that the influence of the edge effect on the sintering material can be reduced.

This invention discloses a floor repair agent and its preparation method, belonging to the field of building materials technology. The repair agent comprises a modified resin component, a curing agent component, a modified composite functional filler, and composite additives. The modified resin is a composite system of silane coupling agent-modified epoxy resin and terminally hydroxylated polyurethane. The modified composite filler consists of modified nano-silica, passivated quartz sand, and hydroxylated recycled polyurethane rigid foam powder. The composite additives include a compound toughening agent and composite modified polypropylene fibers. During preparation, each component undergoes targeted modification pretreatment, followed by temperature-controlled stirring and step-by-step mixing to obtain the finished product. This invention solves the problems of poor resin compatibility, weak filler bonding force, and easy cracking and debonding in existing repair agents. The product has high bonding strength, low shrinkage, wear resistance, and impact resistance. It can be used stably in environments ranging from -30℃ to 80℃, is environmentally friendly and odorless, and is easy to apply. It combines performance and cost advantages, and is suitable for long-term repair of various floor types and heavy-duty, high- and low-temperature conditions.

This invention discloses a 3D printing material with adjustable PBT crystallinity and its preparation method, relating to the field of polymer materials technology. This 3D printing material with adjustable PBT crystallinity utilizes a terpolymer containing epoxy functional groups as a crystallinity regulator, blended with PBT resin in a specific ratio, to achieve precise control over the crystallization behavior of PBT. During melt blending, the epoxy groups on the crystallinity regulator molecular chain can chemically react with the terminal carboxyl or hydroxyl groups of the PBT resin, forming appropriate grafting or crosslinking points. Simultaneously, by controlling the amount of crystallinity regulator added, the crystallinity of the final composite material can be continuously and precisely adjusted within the range of 25% to 40%, thereby fundamentally balancing the warping force caused by crystallization shrinkage with the material's ability to maintain its shape, solving the problems of large crystallization shrinkage, narrow processing window, and poor performance stability in existing technologies.

The present invention provides a decorative laminate member capable of imparting high designability and excellent adhesion and suppressing generation of warping, and a decorative molded body comprising the same. A decorative laminate member having a transparent coating film layer (A), a resin substrate layer (B), a design layer (C), an adhesive layer (D), and a heat-resistant film layer (E), characterized in that the heat shrinkage rate of the decorative laminate member when heated from 35°C to 105°C and then cooled from 105°C to 35°C is 0% or more and 3.0% or less.

The application discloses a fabric and a preparation method thereof. The fabric comprises at least a first weaving area and a second weaving area. The first weaving area is interwoven by warp yarns and weft yarns according to a two-over weft weave. The second weaving area is interwoven by warp yarns and weft yarns according to a single-layer change warp weave. The weft yarns of the surface layer of the first weaving area are surface layer weft yarns. The weft yarns of the inner layer of the first weaving area are inner layer weft yarns. The shrinkage rate of the surface layer weft yarns is less than that of the inner layer weft yarns. The shrinkage rate of the surface layer weft yarns of the two-over weft weave is less than that of the inner layer weft yarns. Because the shrinkage rate of the surface layer weft yarns is low and the shrinkage rate of the inner layer weft yarns is high, the shrinkage amount of the inner layer weft yarns is large and the shrinkage amount of the surface layer weft yarns is small after the fabric is shaped at high temperature. Therefore, the surface layer weft yarns are longer than the inner layer weft yarns and are forced to bow and present a convex state. After the surface layer weft yarns are convex, the fabric presents a three-dimensional effect.

The invention provides a method for realizing accurate regeneration and functional reconstruction of a gingival structure in combination with regeneration induction, relates to the field of traction gingival structure regeneration and functional reconstruction, and relates to 4D bionic scaffold design, a cell activation and directional regeneration system, a microorganism-immune regulation and control network and real-time monitoring and self-adaptive repair. The 4D bionic stent is designed into a shape memory hydrogel matrix, a 4D response mechanism and a bionic micro-gradient structure. The shape memory hydrogel matrix is specifically composed of materials; according to the material, a shape memory hydrogel matrix is prepared from 60% of PVA, 30% of gelatin and 10% of an elastin system, temperature triggering is carried out, a response mechanism is started when the oral temperature is lower than 37 DEG C, the crystal glue matrix is attached to the curved surface of the gingiva, and the shape memory hydrogel matrix and the curved surface of the gingiva are in contact. The shrinkage rate of the hydrogel matrix is 15%. The method has the advantage that the regeneration and functional reconstruction of the gingival structure can be accurately realized.

The invention provides a low-water-absorption glass bead modified PBT (polybutylene terephthalate) material and a preparation method thereof. The low-water-absorption glass bead modified PBT material comprises the following components in parts by weight: 70-100 parts of PBT resin; 0 to 30 parts of solid glass beads; 0-5 parts of a toughening agent; 0-2 parts of an antioxidant; 0-2 parts of a lubricant; 0-2 parts of black color master batch; 0-2 parts of a coupling agent; 0-5 parts of polytetrafluoroethylene wax; wherein the average particle size of the solid glass beads is 1-50 [mu] m; the average particle size of the polytetrafluoroethylene wax is 3-15 [mu] m, and the weight-average molecular weight of the polytetrafluoroethylene wax is 10000-30000 g / mol; the weight ratio of the solid glass beads to the polytetrafluoroethylene wax is (5-10): 1. According to the invention, the polytetrafluoroethylene wax is added into the solid glass bead modified PBT material, so that the shrinkage difference between the material flow direction and the vertical flow direction is effectively reduced, the water absorption rate of the material is remarkably reduced, the preparation process is simple, and the production process is easy to control.