17 results about "Draw ratio" patented technology

The present invention relates to: a polyester-based composite false-twisted yarn in which a PET / PTT latent crimped yarn is used as a core yarn, and a partially oriented yarn is loosely arranged on the exterior as an effect yarn by minimizing the draw ratio during the manufacture of the composite false-twisted yarn; and a method for manufacturing same. The polyester-based composite false-twisted yarn of the present invention has improved elasticity due to waves of the core yarn, compared to conventional composite false-twisted yarns, and can provide the effect of improving touch feel due to waves of the effect yarn.

The invention relates to a method for preparing polypropylene fibers by high-power stretching oriented crystallization, which comprises the following steps of: pretreating raw materials, melting, plasticizing and accurately metering, spinning and forming, and treating by using a three-section temperature control channel: enabling nascent fiber trickles to enter a temperature-controllable channel of a high-temperature slow cooling area, a medium-temperature oriented crystallization area and a low-temperature shaping area which are sequentially arranged from top to bottom; the areas are independently controlled in temperature and have a synergistic effect. According to the method disclosed by the invention, through coordinated regulation and control of three-section type temperature gradient and high-power stretching, a molecular chain is fully unwound and stretched in a high-temperature region firstly, and then is subjected to high-power stretching induction in an optimal crystallization temperature region to form a perfect crystal structure with high orientation, high crystallinity and narrow grain size distribution, so that high-strengthening structures such as shishkebab shish-kebab crystals and extended-chain crystals can be stably obtained; and the tensile strength and the initial modulus of the prepared polypropylene fiber are remarkably improved, the dry heat shrinkage rate is greatly reduced, the mechanical property and the dimensional stability are far superior to those of traditional process products, and the strict requirements of high-end industrial textiles are met.

The invention belongs to the technical field of melt spinning, and relates to a melt spinning method of a low-molecular-weight polymer containing asphalt, and the average molecular weight of the low-molecular-weight polymer is less than 5000Da. A slow cooler containing cooling round pipes is installed below the spinneret plate, and the number and arrangement of the cooling round pipes are designed according to distribution of spinneret orifices. A spiral channel arranged around the central axis of the cooling round pipe is arranged in the pipe wall of each cooling round pipe, one end of each spiral channel is communicated with the outside, and the other end of each spiral channel is communicated with the air blowing assembly. And the air blowing assembly blows cooling air into the spiral pipe. By adjusting the cooperation of parameters of a slow cooler, melt properties and spinning process parameters, the drawing force required by melt trickle deformation is smaller than the breaking strength of melt trickles, and therefore the diameter of fibers at a take-up roller is smaller than or equal to the target diameter of the fibers. The problems that in the melt spinning process of low-molecular-weight polymers or other melts low in mechanical property, a draftable area is narrow, and continuous gradient cooling is difficult to apply are solved, the yarn breaking risk is reduced, the spinning duration time is prolonged, and the draft multiple is increased.

The invention discloses a polyamide 12 draw-textured yarn with both high resilience and excellent dimensional stability and a preparation method thereof, polyamide 12 slices with the relative viscosity of 2.0-3.5 are dried until the water content is lower than 700 ppm, melt spinning is performed at the temperature of 210-245 DEG C, and winding is performed at the spinning speed of 1000-4500 m / min to prepare a pre-oriented yarn; then the pre-oriented yarn subjected to hot stretching is subjected to false twisting deformation, the draw ratio is 1.20-1.80, the D / Y ratio is 1.5-2.4, the temperature of a deformation hot box is 100-170 DEG C, the temperature of a microwave-assisted shaping hot box is 120-160 DEG C, and therefore the polyamide 12 stretch-textured yarn is obtained. According to the scheme, by optimizing the pre-oriented yarn structure of the polyamide 12 and precisely controlling the texturing process of deformation and heat setting, the problems of narrow processing window and poor stability of the polyamide 12 in high-speed false twist deformation are solved; the prepared polyamide 12 draw-textured yarn not only retains the characteristics of low water absorption and light weight of the original polyamide 12, but also has high elasticity and excellent dimensional stability, and is suitable for the fields of high-end sportswear, swimwear, medical textiles and the like.

Methods and (articles of manufacture therefrom) including forming an elastic film from a polymer composition; tensioning the elastic film to a stretch ratio of between 2 and 6 in the MD; laminating the elastic film to an extensible facing to provide an elastomeric laminate having a CD hysteresis loss of 70% or less and an MD hysteresis loss of 50% or less.

The invention relates to a hollow ES (Ethylene-Propylene-Styrene) fiber production process which comprises the following steps: (1) respectively drying and preheating a skin layer raw material and a core layer raw material, and feeding into a screw extruder for melt blending; (2) conveying the melt-blended material to a spinning box, extruding the melt-blended material through a skin-core composite spinneret plate to form nascent fibers, and introducing compressed air with the pressure of 200-300Pa into a core layer channel of the spinneret plate to form a hollow structure; (3) the formed nascent fibers are sequentially subjected to heat preservation treatment and stepped slow cooling treatment, then first-time drafting is carried out, and the first-time drafting multiple is 1.5-2.5 times; (4) the fibers subjected to primary stretching are introduced into a steam box to be evenly heated and softened, then secondary stretching is conducted, and the secondary stretching multiple is 1.2-1.5 times; (5) applying controllable tension to the fibers subjected to secondary drafting for heat setting; and (6) winding. The method is reasonable in design, the technological process is shortened, the pollution risk is effectively reduced, and the fiber forming quality is improved.

The invention relates to a coagulation forming process parameter optimization method, which comprises the following steps of: constructing a coagulation forming process optimization model by taking a stock solution DMSO (Dimethylsulfoxide) concentration, an air layer height and a coagulation bath draw ratio in a coagulation forming process as decision variables and taking an absolute error between a nascent fiber DMSO residual volume and a nascent fiber radius and an expected radius value as an optimization target; based on the environment change, determining a plurality of environment windows, each environment window comprising a preset number of continuous dynamic environments; and based on a solidification forming process parameter time domain robust optimization algorithm, solving the solidification forming process optimization model in each environment window to obtain a deployment solution of each environment window. According to the method, the solidification forming process model is solved in the environment window, multiple environments in the same environment window multiplex deployment solutions to reduce the switching frequency of the solutions, theoretical support is provided for solidification forming process parameter setting in actual carbon fiber production, and the quality and performance of carbon fiber precursors are improved.

This invention belongs to the field of ultra-high molecular weight polyethylene (UHMWPE) fiber preparation technology, and discloses an UHMWPE fiber, its drawing method, and a preparation apparatus. The drawing method includes: performing multi-stage continuous drawing on UHMWPE gel filaments prepared using a dry-wet method to obtain UHMWPE fibers; wherein the multi-stage continuous drawing includes pre-drawing and hot drawing; the initial feed speed of the UHMWPE gel filaments entering the pre-drawing stage is 1.5-4 m / min, and the total draw ratio is 2-15 times. The UHMWPE fibers prepared using the method of this invention have excellent mechanical properties, low coefficient of variation, adjustable fineness, and can improve production capacity.

A method of forming an article, the method comprising: (a) providing a mould having a first mould part and a second mould part, the first and second mould parts having respective first and second cavity-forming surfaces; (b) closing the mould thereby defining a cavity between the first and second cavity-forming surfaces; (c) injecting a molten plastic composition comprising a polymer and a physical blowing agent into the cavity, wherein during or after the injecting step (c), the injected plastic composition in contact with the first and second cavity- forming surfaces is cooled to form first and second solid skins respectively adjacent to and in contact with the first and second cavity-forming surfaces, whereby in at least one region of the cavity is respectively located at least one portion of the plastic composition in which portion at least some of the plastic composition between the first and second solid skins remains molten, wherein the thickness of the respective portion is constant within a tolerance of + / - 0.5%, preferably + / - 0.2%, based on a nominal thickness of the respective portion; (d) opening the mould before the molten plastic composition between the first and second solid skins has solidified in the at least one portion, so as to expose the molten plastic composition of the respective portion to an external pressure lower than the injection pressure thereby allowing the molten plastic composition between the first and second solid skins of the respective portion to expand by foaming to form an expanded cellular foam as a result of the molten plastic composition beneath the first solid skin expanding outwardly away from the second solid skin which stretches the first solid skin in the respective portion, wherein the opening step comprises removing the first mould part so that the first solid skin is no longer in contact with the first cavity-forming surface; and (e) cooling the expanded cellular foam to cause the molten plastic composition between the first and second solid skins of the respective portion to solidify and to form in the article at least one first part comprising a core layer of cellular foam between the first and second solid skins, wherein after the cooling step (e) the length of the first solid skin in the respective portion has stretched, as compared to the first solid skin present prior to the opening step (d), by a stretch ratio of from 0.5 to up to 3%, wherein the stretch ratio is the ratio of the increase in the length of the first solid skin after cooling step (e) based on length of the first solid skin before the opening step (d).

A method for preparing a polyethylene furanoate fiber, comprising: drying polyethylene furanoate chips and then performing melt-blending spinning, wherein after the drying, the moisture content of the polyethylene furanoate chips is less than or equal to 200 ppm, the crystallinity is 30% to 50%, and the softening temperature is 120-140°C; the melt-blending spinning comprises a screw extruder melt extrusion process, a spinning process, an annular cross-flow cooling process, a two-stage drawing process, and a tension heat setting process; process parameters of the melt-blending spinning comprise: a screw rotation speed of 28-35 r / min, a spinning beam temperature of 265-280°C, an annular cross-flow air supply-return pressure difference of 600-800 Pa, a first-stage drawing temperature of 70-80°C, a second-stage drawing temperature of 100-120°C, a total drawing ratio of 2.94-3.52, and a tension heat setting temperature of 140-160°C. The polyethylene furanoate fiber has excellent mechanical properties.

The present invention provides a composite fiber that can be processed into a fibrous structure having good flexibility and bulkiness, a method for manufacturing the same, and a fibrous structure containing the same. [Solution] This invention relates to a composite fiber comprising a first component containing poly-L-lactic acid with an optical purity of 95% or more, and a second component containing an aliphatic polyester composed of glycol and dicarboxylic acid, wherein, in a DSC curve obtained by differential scanning calorimetry (DSC), the crystallization temperature of the second component during the cooling process is 78°C or higher, and the heat of fusion per unit mass of the second component during the second heating process is 73.5 mJ / mg or less. The composite fiber can be manufactured by melt-spinning the first component at a lower temperature than the second component, and then stretching it at a temperature of 55°C to 90°C and a stretch ratio of 1.4 times or more. This makes it possible to provide a composite fiber that can be processed into a fiber structure having good flexibility and bulkiness, a method for manufacturing the same, and a fiber structure containing the same.

The invention provides a preparation method of an aramid phase change composite fiber, which comprises the following steps: a) extruding an aramid nanofiber spinning solution through a (0.25-0.4 mm) * (1-100) orifice spinneret plate, and drafting through a multi-stage coagulating bath to obtain a hydrogel fiber with a draw ratio of 1-2 and a diameter of 120-140 [mu] m; b) melting or dissolving the phase-change material in a proper replacement solvent to obtain a solvent-dispersed phase-change material; and c) immersing the hydrogel fiber prepared in the step a) into the solvent-dispersed phase-change material prepared in the step b) for in-situ phase-change material replacement, wiping off the redundant phase-change material after replacement, and drying at normal pressure to obtain the aramid phase-change composite fiber. According to the method, the technical bottleneck of a traditional preparation method is broken through, the high load rate of the phase change material in an aramid fiber matrix is achieved, and the prepared composite fiber has the high phase change enthalpy value and the excellent flame retardant property.

The application discloses a kind of multi-factor multi-scale mechanical property determination method and system of high molecular shock absorber, the method according to the relationship of energy storage modulus of high molecular material and arbitrary strain amplitude, the difference of arbitrary strain and infinite strain amplitude, the difference of characteristic strain and infinite strain amplitude and the force-displacement relationship of single molecular chain, the force-displacement relationship of single molecular chain under energy storage modulus and loss modulus is obtained;In the relationship between the micro-molecular chain stress of high molecular material and the tensile ratio, load in the principal axis direction is introduced, shear stress and shear modulus are obtained, according to the principal stress, shear stress and shear modulus of high molecular material, the macro-scale model of high molecular rubber-based material is constructed, and temperature correlation is introduced to form a multi-scale refinement model, which can accurately describe the influence of frequency, temperature, displacement amplitude and microstructure on the multi-scale mechanical properties of high molecular rubber-based damper, and provide a theoretical basis for multi-scale design and development of high-damping damper.

This invention discloses a method for temperature-controlled fiber tow drawing ratio allocation. The water washing and drawing section is divided into three stages: water drawing one, water drawing two, and water drawing three. Water drawing one and three are driven to control the drawing ratio, while water drawing two is fixed by bearings and its drawing ratio is adaptively adjusted by a temperature sensor. The fiber tow passes through rollers, water drawing tank one, and water drawing tank two to complete the water washing and drawing process. In the new water drawing section, the drawing ratios of water drawing one and three are adjusted by the water temperature, while water drawing two is passively drawn. When the temperature of water drawing tank one changes, water drawing tank two remains constant, and the drawing ratios of the two sections are b(1-k) / a and a, respectively. 2 c / 1-k; When the temperature of water-drawing tank two changes while water-drawing tank one remains constant, the draw ratios of the two sections are ab and b respectively. 2 (1-k), c / (1-k)b; When the temperature of water drawing tank one changes, water drawing tank two also changes, and the draw ratio is determined by the temperature of the two sections with the largest temperature changes. The method of temperature-controlled fiber bundle draw ratio distribution is beneficial for the fiber to autonomously adjust the draw ratio, save energy, and ensure stable operation of the water drawing section.

The present application provides a method for manufacturing a laminate, which can stably manufacture a laminate including a coating layer having a desired thickness. A method for manufacturing a laminate according to one embodiment includes: a coating step of coating a coating agent on a substrate being conveyed using a coating roll to form a coating layer on the substrate, the coating agent being coated on the substrate based on a ratio of a rotation speed of the coating roll to a conveyance speed of the substrate, i.e., a coating draw ratio; a thickness acquisition step of acquiring a thickness of the coating layer; a calculation step of calculating a difference between the thickness of the coating layer and a prescribed thickness; and a change step of changing the coating draw ratio in the coating step based on the difference between the thickness of the coating layer and the prescribed thickness, the coating step, the thickness acquisition step, the calculation step, and the change step being repeatedly performed while automatically implementing the coating step, the thickness acquisition step, the calculation step, and the change step.

The invention relates to the field of carbon fiber preparation, in particular to a polyacrylonitrile-based carbon fiber precursor as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out steam drafting on polyacrylonitrile fibers; the steam drafting step comprises the following steps: performing first steam drafting on the polyacrylonitrile fiber at a drafting ratio of less than or equal to 1 to obtain a carbon fiber precursor, and then performing second steam drafting on the carbon fiber precursor at a drafting ratio of more than 1. According to the method, the first steam drafting with the draw ratio smaller than or equal to 1 and the second steam drafting with the draw ratio larger than 1 are sequentially and continuously carried out, so that when polyacrylonitrile fiber drafting is actually carried out, the temperature uniformity in tows is greatly improved, and the quality of the tows is remarkably improved.

This application discloses a silk-like FDY fiber and its preparation method. The method involves adding 1-3% by weight of modified zinc oxide whiskers to a polyester melt via an online addition system. The melt is then extruded from a spinning assembly to obtain monofilaments with a fineness of 0.5-1 dtex. These monofilaments are then sequentially cooled, oiled, pre-networked, hot-rolled, main-networked, and wound to obtain the silk-like FDY fiber. The hot-rolled rollers used for hot-rolling are HR1, HR2, HR3, HR4, and HR5. The temperatures of HR1, HR2, and HR3 are 82±2℃, and the temperatures of HR4 and HR5 are 132±2℃. The draw ratio between HR1 and HR2 is 1.01-1.06, between HR2 and HR3 is 1.08-1.12, and between HR3 and HR4 is 1.20-1.32. The silk-like FDY fiber of this application exhibits good dyeing performance, can be dyed in dark colors, and has high strength, with minimal fuzzing or breakage.