{"id":5656,"date":"2025-06-17T12:21:37","date_gmt":"2025-06-17T04:21:37","guid":{"rendered":"https:\/\/hkcablemachine.com\/?p=5656"},"modified":"2026-10-01T00:31:35","modified_gmt":"2026-09-30T16:31:35","slug":"huong-dan-co-ban-ve-cach-lam-loi-soi","status":"publish","type":"post","link":"https:\/\/hkcablemachine.com\/vi\/fiber-core-manufacturing-guide\/","title":{"rendered":"H\u01b0\u1edbng d\u1eabn t\u1ed1i \u01b0u v\u1ec1 s\u1ea3n xu\u1ea5t v\u00e0 ch\u1ebf t\u1ea1o l\u00f5i s\u1ee3i"},"content":{"rendered":"

\u0110ang g\u1eb7p kh\u00f3 kh\u0103n v\u1edbi \u0111\u1ed9 ph\u1ee9c t\u1ea1p trong s\u1ea3n xu\u1ea5t l\u00f5i s\u1ee3i quang? Vi\u1ec7c ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng k\u00e9m d\u1eabn \u0111\u1ebfn t\u1ed5n hao t\u00edn hi\u1ec7u v\u00e0 l\u1ed7i trong s\u1ea3n xu\u1ea5t.<\/p>\n

Optical-fiber production starts with a glass preform, followed by heating, drawing, diameter control and protective coating. The drawn glass contains both core and cladding; it is not an isolated core. Confirm the preform route, furnace settings and finished-fiber specification for the selected process.<\/strong><\/p>\n

When assessing a fiber core manufacturing project, distinguish glass preform fabrication and fiber drawing from downstream cable production. Use this guide to identify the process stages, equipment interfaces and evidence to request from suppliers. For a HONGKAI Cable Machinery enquiry, confirm the proposed equipment scope, responsible manufacturer and acceptance requirements in the project documents.<\/p>\n

B\u1ea1n c\u1ea7n v\u1eadt li\u1ec7u g\u00ec \u0111\u1ec3 s\u1ea3n xu\u1ea5t l\u00f5i s\u1ee3i?<\/h2>\n

Raw-material composition and contamination control are part of fiber quality, but they are not the only factors. Assess material records together with preform inspection and finished-fiber tests; do not diagnose optical loss or fiber breaks from a nominal purity grade alone.<\/p>\n

Define the intended fiber and preform route before specifying chemical inputs. A chloride-based MCVD process uses volatile glass-forming precursors, but material grades, dopants, gases and thermal settings must match the qualified process. Buying finished preforms is a different supply scope from manufacturing them.<\/strong><\/p>\n

\"Conceptual<\/p>\n

Minh h\u1ecda kh\u00e1i ni\u1ec7m v\u1ec1 \u0111\u1ea7u v\u00e0o v\u1eadt li\u1ec7u v\u00e0 ki\u1ec3m so\u00e1t nhi\u1ec5m b\u1ea9n trong qu\u00e1 tr\u00ecnh chu\u1ea9n b\u1ecb preform; kh\u00f4ng ph\u1ea3i \u1ea3nh ch\u1ee5p trong ph\u00f2ng th\u00ed nghi\u1ec7m.<\/em><\/p>\n

Raw-material selection and contamination control belong in the project’s quality plan. Request material specifications and batch records from the proposed producer, and confirm how nonconforming batches are handled. T\u1ed5ng quan s\u1ea3n xu\u1ea5t s\u1ee3i quang c\u1ee7a Heraeus<\/a> gi\u1ea3i th\u00edch vai tr\u00f2 c\u1ee7a th\u00e0nh ph\u1ea7n v\u1eadt li\u1ec7u, h\u00ecnh h\u1ecdc v\u00e0 h\u1ed3 s\u01a1 chi\u1ebft su\u1ea5t. Ch\u1ec9 ri\u00eang t\u1ef7 l\u1ec7 \u0111\u1ed9 tinh khi\u1ebft kh\u00f4ng x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c hi\u1ec7u su\u1ea5t c\u1ee7a s\u1ee3i th\u00e0nh ph\u1ea9m.<\/p>\n

Th\u00e0nh ph\u1ea7n h\u00f3a h\u1ecdc ch\u00ednh<\/h3>\n

C\u00e1c M\u00f4 t\u1ea3 MCVD c\u1ee7a \u0110\u1ea1i h\u1ecdc Leibniz Hannover<\/a> identifies SiCl4, GeCl4 and POCl3 as examples of volatile glass-forming precursors. This is not a mandatory ingredient list for every fiber. For each selected chemical, request the supplier’s grade specification, batch certificate and relevant trace-impurity results; the process owner must approve its suitability.<\/p>\n

Germanium doping can raise the refractive index of silica, but the finished fiber must be defined by its complete core-and-cladding design. Do not infer numerical aperture or other optical performance from a germanium concentration alone. Confirm the intended refractive-index profile, dopant formulation and applicable measurements with the preform producer.<\/p>\n

Qu\u00e1 tr\u00ecnh ph\u1ea3n \u1ee9ng h\u00f3a h\u1ecdc<\/h3>\n

In the MCVD route described by Leibniz University Hannover, precursor vapors pass through a fused-silica tube and an external traversing burner initiates glass formation. Particles deposit on the tube’s inner wall. Deposition, consolidation and tube collapse are distinct stages; one generic reaction-temperature range is not an operating specification for all of them.<\/p>\n

Require the process owner to define and qualify the temperature and gas-delivery settings for each stage. The production record should identify the recipe version, measured variables, permitted deviations and response to an excursion. Do not adopt an unsourced temperature-change threshold or flow-stability percentage as proof of complete reaction or acceptable fiber.<\/p>\n

Y\u00eau c\u1ea7u v\u1ec1 \u0111\u1ed9 tinh khi\u1ebft v\u00e0 th\u1eed nghi\u1ec7m<\/h3>\n

Define impurity limits for the specific input material and intended fiber, not by comparison with another industry. Heraeus’ overview distinguishes hydroxyl-content requirements for UV and infrared transmission, illustrating why application matters. For moisture, metals and other specified impurities, identify the material being tested, concentration units, analytical method and reporting limit. Do not interchange a precursor-gas specification with a finished-glass measurement.<\/p>\n

Request the producer’s incoming-material inspection plan, batch certificates and laboratory reports. Ask which analytical methods are used, which contaminants are assessed and how each result is compared with the agreed material specification. Confirm the responsible laboratory and traceability arrangements rather than assuming that the equipment supplier performs these tests.<\/p>\n

S\u1eed d\u1ee5ng ma tr\u1eadn n\u00e0y \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c t\u00e0i li\u1ec7u nghi\u1ec7m thu v\u1eadt li\u1ec7u \u0111\u1ea7u v\u00e0o. \u0110\u00e2y kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u1eb7c t\u1ea3 \u0111\u1ed9 tinh khi\u1ebft h\u00f3a h\u1ecdc mang t\u00ednh ph\u1ed5 qu\u00e1t hay quy tr\u00ecnh th\u1eed nghi\u1ec7m trong ph\u00f2ng th\u00ed nghi\u1ec7m.<\/p>\n\n\n\n\n\n\n\n\n
\u0110\u1ea7u v\u00e0o \u0111\u1ec3 \u0111\u1ee7 \u0111i\u1ec1u ki\u1ec7n<\/th>\nTh\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt c\u1ea7n \u0111\u1ea1t \u0111\u01b0\u1ee3c<\/th>\nB\u1eb1ng ch\u1ee9ng l\u00f4 h\u00e0ng ho\u1eb7c cung \u1ee9ng<\/th>\nAcceptance decision<\/th>\n<\/tr>\n<\/thead>\n
SiCl4, n\u1ebfu \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng<\/td>\nC\u1ea5p \u0111\u1ed9 \u0111\u1ea1t y\u00eau c\u1ea7u v\u00e0 gi\u1edbi h\u1ea1n t\u1ea1p ch\u1ea5t \u0111\u00e3 \u0111\u1eb7t t\u00ean k\u00e8m \u0111\u01a1n v\u1ecb<\/td>\nBatch certificate, relevant analytical results and reporting limits<\/td>\nProcess owner approves the material for the intended recipe<\/td>\n<\/tr>\n
GeCl4 or other dopant precursor, if used<\/td>\nSelected chemistry, grade and impurity limits for the fiber design<\/td>\nTraceable lot results using methods suitable for that material<\/td>\nCompare with the approved dopant-material specification<\/td>\n<\/tr>\n
O2, if used<\/td>\nGas grade and contaminant limits required by the process<\/td>\nSupply certificate and agreed point-of-use checks<\/td>\nVerify the specified gas-delivery conditions<\/td>\n<\/tr>\n
Carrier or process gases, if used<\/td>\nGas identity, purity and delivery requirements for the actual route<\/td>\nSupplier records and agreed line-condition checks<\/td>\nApprove against the process utility specification<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

L\u01b0u tr\u1eef v\u00e0 x\u1eed l\u00fd c\u00e2n nh\u1eafc<\/h3>\n

Before specifying chemical storage, request the current safety data sheets and the chemical supplier’s storage and compatibility requirements. Have the proposed facility design reviewed by qualified personnel. Container materials, atmosphere controls and environmental limits must be established for the actual chemicals and process, not inferred from a generic article.<\/p>\n

Require documented procedures for chemical transfer, contamination control, personnel protection and emergency response. Confirm tubing and fitting compatibility, any purge requirements and the applicable training with the responsible process and safety specialists. This overview is not an operating procedure for chemical handling.<\/p>\n

Include the required material-handling facilities, inspection work and maintenance in the project scope and cost comparison. Ask for the proposed producer’s contamination-control records, and confirm which safeguards and records are included before comparing quotations.<\/p>\n

L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 t\u1ea1o ra ph\u00f4i th\u1ee7y tinh?<\/h2>\n

Ch\u1ea5t l\u01b0\u1ee3ng ph\u00f4i\u76f4\u63a5\u5f71\u54cd \u0111\u1ebfn \u0111\u1eb7c t\u00ednh s\u1ee3i quang. Vi\u1ec7c l\u1eafng \u0111\u1ecdng kh\u00f4ng \u0111\u1ed3ng \u0111\u1ec1u d\u1eabn \u0111\u1ebfn s\u1ef1 thay \u0111\u1ed5i \u0111\u01b0\u1eddng k\u00ednh v\u00e0 t\u1ed5n hao quang h\u1ecdc d\u1ecdc theo chi\u1ec1u d\u00e0i s\u1ee3i.<\/p>\n

MCVD deposits glass on the inside wall of a silica tube. OVD builds a porous soot preform around the outside of a target rod before consolidation. These are different fabrication routes; preform dimensions depend on the selected process and equipment.<\/strong><\/p>\n

\"S\u01a1<\/p>\n

Minh h\u1ecda kh\u00e1i ni\u1ec7m MCVD: th\u1ee7y tinh \u0111\u01b0\u1ee3c l\u1eafng \u0111\u1ecdng b\u00ean trong \u1ed1ng tr\u01b0\u1edbc khi \u00e9p l\u1ea1i th\u00e0nh ph\u00f4i \u0111\u1eb7c. Kh\u00f4ng theo t\u1ef7 l\u1ec7.<\/em><\/p>\n

For a fiber core manufacturing project, confirm whether preforms will be purchased or fabricated as part of the proposed scope. Request the preform specification, inspection records and compatibility requirements for the drawing equipment. Identify the party responsible for preform production separately from the equipment supplier.<\/p>\n

Qu\u00e1 tr\u00ecnh l\u1eafng \u0111\u1ecdng h\u01a1i h\u00f3a h\u1ecdc \u0111\u01b0\u1ee3c s\u1eeda \u0111\u1ed5i (MCVD)<\/h3>\n
\n

In the Quy tr\u00ecnh MCVD \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 b\u1edfi \u0110\u1ea1i h\u1ecdc Leibniz Hannover<\/a>, precursor gases flow through a fused-silica tube while an external burner travels along it. Glass particles form and deposit on the tube’s inner wall. The gas composition and deposition conditions control the refractive-index profile; tube dimensions must match the specific process and equipment.<\/p>\n

For the proposed MCVD lathe and traversing burner, obtain the qualified tube-size range, rotation and traverse settings, alignment requirements and thermal-control method. Identify whether a reported temperature refers to the flame, tube surface or another target. Treat rotation speed and temperature as equipment- and recipe-specific values rather than universal MCVD settings.<\/p>\n

Review the gas-delivery sequence and control arrangement for the proposed MCVD process. Require calibrated flow measurement, a documented deposition schedule and traceable process records. The number of passes, deposited-layer dimensions and permitted flow variation must come from the qualified preform design and demonstrated process, not an assumed standard cycle.<\/p>\n

The deposition process creates "soot" – submicron glass particles that form in the hot zone and deposit on the inner wall of the tube. The high temperature consolidates these particles into dense, transparent glass as the burner passes over the deposited soot. The consolidation temperature must be carefully controlled to prevent bubble formation while ensuring complete densification.<\/p>\n

Qu\u00e1 tr\u00ecnh l\u1eafng \u0111\u1ecdng h\u01a1i b\u00ean ngo\u00e0i (OVD)<\/h3>\n

In Gi\u1ea3i th\u00edch c\u1ee7a Corning v\u1ec1 L\u1eafng \u0111\u1ecdng H\u01a1i b\u00ean Ngo\u00e0i<\/a>, c\u00e1c h\u1ea1t th\u1ee7y tinh m\u1ecbn, \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 mu\u1ed9i, t\u00edch t\u1ee5 xung quanh b\u1ec1 m\u1eb7t ngo\u00e0i c\u1ee7a m\u1ed9t thanh m\u1ee5c ti\u00eau ho\u1eb7c \"thanh m\u1ed3i.\" Kh\u00e1c v\u1edbi MCVD, qu\u00e1 tr\u00ecnh l\u1eafng \u0111\u1ecdng n\u00e0y kh\u00f4ng x\u1ea3y ra tr\u00ean th\u00e0nh trong c\u1ee7a \u1ed1ng n\u1ec1n.<\/p>\n

Successive soot layers build outward around the target. The deposition equipment and dopant delivery must follow the intended preform design. This is an external buildup of soot, not deposition within a hollow tube.<\/p>\n

Preform size and production output are equipment-specific. Do not use one diameter or length as a universal OVD capability; confirm the qualified preform range with the process-equipment supplier.<\/p>\n

Trong tuy\u1ebfn \u0111\u01b0\u1eddng \u0111\u01b0\u1ee3c Corning m\u00f4 t\u1ea3, c\u1ea7n m\u1ed3i \u0111\u01b0\u1ee3c th\u00e1o ra tr\u01b0\u1edbc khi c\u1ed1 k\u1ebft. Trong su\u1ed1t qu\u00e1 tr\u00ecnh Giai \u0111o\u1ea1n h\u1ee3p nh\u1ea5t OVD<\/a>, nhi\u1ec7t chuy\u1ec3n \u0111\u1ed5i kh\u1ed1i mu\u1ed9i x\u1ed1p th\u00e0nh th\u1ee7y tinh trong su\u1ed1t v\u00e0 \u0111\u1eb7c. C\u00e1c \u0111i\u1ec1u ki\u1ec7n k\u1ebft r\u1eafn ph\u1ea3i tu\u00e2n theo quy tr\u00ecnh \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00ea chu\u1ea9n thay v\u00ec m\u1ed9t c\u00f4ng th\u1ee9c nhi\u1ec7t \u0111\u1ed9 chung chung.<\/p>\n

Ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng trong qu\u00e1 tr\u00ecnh ch\u1ebf t\u1ea1o ph\u00f4i<\/h3>\n

For thermal monitoring during preform fabrication, specify the actual measurement target and the instrument suitable for it. Ask the supplier to state calibration, measurement uncertainty and relevant operating limitations. A non-contact temperature reading should not be treated automatically as an accurate flame-temperature or glass-temperature measurement.<\/p>\n

Ask the preform producer for refractive-index profile measurements and the stated test method. The report should identify the measured preform, instrument, calibration status and acceptance criteria. Agree how out-of-specification results are handled before the preform is released for drawing.<\/p>\n

Include preform diameter, concentricity, straightness and roundness in the agreed dimensional inspection plan. Require the supplier to state the measurement method, units and acceptance tolerances for the specified preform and drawing equipment. Do not adopt an unsourced percentage as a universal limit.<\/p>\n

Compare MCVD and OVD proposals against the same intended fiber design and supply scope. Route names alone do not establish fixed core diameters, numerical apertures or attenuation limits. Keep preform inspection separate from acceptance of the fiber drawn from it.<\/p>\n\n\n\n\n\n\n\n\n\n
M\u1ee5c \u0111\u1ec3 so s\u00e1nh<\/th>\nB\u1eb1ng ch\u1ee9ng \u0111\u1ec1 xu\u1ea5t MCVD<\/th>\nB\u1eb1ng ch\u1ee9ng \u0111\u1ec1 xu\u1ea5t OVD<\/th>\nAcceptance boundary<\/th>\n<\/tr>\n<\/thead>\n
Tuy\u1ebfn l\u1eafng \u0111\u1ecdng v\u00e0 giai \u0111o\u1ea1n cung c\u1ea5p<\/td>\nX\u00e1c \u0111\u1ecbnh \u1ed1ng n\u1ec1n, qu\u00e1 tr\u00ecnh l\u1eafng \u0111\u1ecdng b\u00ean trong v\u00e0 giai \u0111o\u1ea1n preform \u0111\u01b0\u1ee3c cung c\u1ea5p<\/td>\nX\u00e1c \u0111\u1ecbnh s\u1ef1 l\u1eafng \u0111\u1ecdng mu\u1ed9i than b\u00ean ngo\u00e0i, qu\u00e1 tr\u00ecnh k\u1ebft kh\u1ed1i v\u00e0 giai \u0111o\u1ea1n ph\u00f4i \u0111\u01b0\u1ee3c cung c\u1ea5p<\/td>\nCompare equivalent supply stages, not route labels alone<\/td>\n<\/tr>\n
Preform geometry<\/td>\nB\u1ea3n v\u1ebd v\u00e0 k\u1ebft qu\u1ea3 ki\u1ec3m tra cho ph\u00f4i \u0111\u1ec1 xu\u1ea5t<\/td>\nB\u1ea3n v\u1ebd v\u00e0 k\u1ebft qu\u1ea3 ki\u1ec3m tra cho ph\u00f4i \u0111\u1ec1 xu\u1ea5t<\/td>\nH\u00e3y n\u00eau r\u00f5 t\u1eebng k\u00edch th\u01b0\u1edbc \u0111\u1ec1 c\u1eadp \u0111\u1ebfn ph\u00f4i hay s\u1ee3i k\u00e9o, k\u00e8m theo \u0111\u01a1n v\u1ecb<\/td>\n<\/tr>\n
Refractive-index profile and fiber design<\/td>\nH\u1ed3 s\u01a1 \u0111o \u0111\u01b0\u1ee3c v\u00e0 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt s\u1ee3i m\u1ee5c ti\u00eau<\/td>\nH\u1ed3 s\u01a1 \u0111o \u0111\u01b0\u1ee3c v\u00e0 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt s\u1ee3i m\u1ee5c ti\u00eau<\/td>\nAgree the profile and any applicable numerical-aperture test separately<\/td>\n<\/tr>\n
\u0110\u1ed9 \u0111\u1ed3ng t\u00e2m, \u0111\u1ed9 th\u1eb3ng v\u00e0 \u0111\u1ed9 tr\u00f2n<\/td>\nInspection method, measured results and proposed tolerances<\/td>\nInspection method, measured results and proposed tolerances<\/td>\nApply the approved preform drawing and inspection plan<\/td>\n<\/tr>\n
Finished-fiber optical performance<\/td>\nTraceable results from fiber drawn from the proposed preform<\/td>\nTraceable results from fiber drawn from the proposed preform<\/td>\nUse the selected fiber specification and agreed test conditions, not a generic MCVD\/OVD limit<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

T\u1ed1i \u01b0u h\u00f3a quy tr\u00ecnh v\u00e0 x\u1eed l\u00fd s\u1ef1 c\u1ed1<\/h3>\n

Require a documented trial plan before changing preform-fabrication parameters. Identify the variables, permitted operating boundaries, measurements and approval responsibilities with the process owner. Keep trial results traceable to the material batch and equipment settings, and record the process owner’s approval.<\/p>\n

For a suspected preform defect, first identify the measured feature: interface condition, refractive-index profile or geometry. Compare inspection results with the approved preform design and the corresponding material, deposition and equipment records. A defect name alone does not establish whether contamination, thermal conditions, gas delivery or alignment caused it. Ask the process owner to document the evidence for the proposed cause before changing the recipe.<\/p>\n

Request the equipment manufacturer’s preventive-maintenance schedule and calibration requirements. Confirm which burner components, flow controllers and alignment checks are included, who performs each task and what records are required. Agree the maintenance scope before equipment acceptance.<\/p>\n

Preform acceptance is one checkpoint, not a guarantee of trouble-free drawing. Link each preform’s inspection record to the drawing run and finished-fiber results so a defect can be investigated across stages. Release the fiber only against the agreed geometry, optical and mechanical requirements.<\/p>\n

Thi\u1ebft b\u1ecb n\u00e0o l\u00e0 c\u1ea7n thi\u1ebft cho vi\u1ec7c k\u00e9o s\u1ee3i?<\/h2>\n

L\u1ef1a ch\u1ecdn thi\u1ebft b\u1ecb sai d\u1eabn \u0111\u1ebfn th\u1ea5t b\u1ea1i trong s\u1ea3n xu\u1ea5t. H\u1ec7 th\u1ed1ng k\u00e9o kh\u00f4ng ph\u00f9 h\u1ee3p g\u00e2y \u0111\u1ee9t s\u1ee3i, thay \u0111\u1ed5i \u0111\u01b0\u1eddng k\u00ednh v\u00e0 l\u1ed7i l\u1edbp ph\u1ee7 khi\u1ebfn s\u1ea3n ph\u1ea9m kh\u00f4ng s\u1eed d\u1ee5ng \u0111\u01b0\u1ee3c.<\/p>\n

Specify the drawing system as a complete process: preform feed, furnace, cooling, diameter measurement, coating, curing and take-up. Require the supplier to demonstrate the agreed fiber dimensions and quality at the proposed production speed; a speed figure alone is not an acceptance criterion.<\/strong><\/p>\n

\"Optical<\/p>\n

Tr\u00ecnh t\u1ef1 giai \u0111o\u1ea1n b\u1ea3n v\u1ebd s\u01a1 \u0111\u1ed3, kh\u00f4ng ph\u1ea3i b\u1ea3n v\u1ebd c\u1ee7a m\u1ed9t m\u00e1y c\u1ee5 th\u1ec3 \u0111\u01b0\u1ee3c cung c\u1ea5p. Kh\u00f4ng theo t\u1ef7 l\u1ec7.<\/em><\/p>\n

Coordinate the interfaces between the preform, drawing equipment and coating system before accepting a line proposal. Record the target fiber type, glass-cladding diameter, coated-fiber outer diameter and test conditions so each supplier works to the same product definition.<\/p>\n

B\u1ea3n v\u1ebd k\u1ebft c\u1ea5u v\u00e0 thi\u1ebft k\u1ebf th\u00e1p<\/h3>\n

When reviewing a th\u00e1p k\u00e9o s\u1ee3i<\/a>, request the supplier’s layout, structural requirements and vibration-control provisions for the proposed configuration. Confirm the required building height, foundations, service access and utility interfaces from the actual equipment drawings rather than assuming a standard tower size.<\/p>\n

Th\u00e1p ch\u1ee9a nhi\u1ec1u v\u00f9ng, m\u1ed7i v\u00f9ng c\u00f3 ch\u1ee9c n\u0103ng c\u1ee5 th\u1ec3 trong qu\u00e1 tr\u00ecnh k\u00e9o. Ph\u1ea7n tr\u00ean c\u00f9ng ch\u1ee9a c\u01a1 c\u1ea5u n\u1ea1p ph\u00f4i v\u00e0 l\u00f2 nung. Ph\u1ea7n gi\u1eefa cung c\u1ea5p kh\u00f4ng gian \u0111\u1ec3 l\u00e0m m\u00e1t s\u1ee3i v\u00e0 \u0111o \u0111\u01b0\u1eddng k\u00ednh. Ph\u1ea7n d\u01b0\u1edbi c\u00f9ng ch\u1ee9a h\u1ec7 th\u1ed1ng \u1ee9ng d\u1ee5ng l\u1edbp ph\u1ee7, l\u00f2 nung v\u00e0 thi\u1ebft b\u1ecb thu h\u1ed3i.<\/p>\n

Ask the drawing-equipment and coating suppliers to specify the required cleanliness, temperature, humidity and ventilation conditions. Record operating and shutdown requirements in the utility schedule, together with monitoring methods and acceptance limits. Assign responsibility for establishing and maintaining these conditions.<\/p>\n

H\u1ec7 th\u1ed1ng l\u00f2 nung nhi\u1ec7t \u0111\u1ed9 cao<\/h3>\n

Confirm the furnace heating technology, usable hot zone, preform-size range and qualified operating window with the equipment manufacturer. Furnace dimensions and maximum temperature must come from the proposed equipment specification, not a generic production-line example.<\/p>\n

Request the furnace supplier’s temperature-measurement and control specification, including sensor type, calibration, measurement uncertainty and demonstrated control performance. Distinguish a stated controller resolution from verified furnace stability, and agree the acceptance test for the supplied system.<\/p>\n

Confirm furnace-gas requirements with the furnace manufacturer and responsible process engineer. The utility specification should identify gas type, quality, flow requirements, monitoring and safety provisions for the actual system. Do not use a generic oxygen limit or gas selection as an approved operating recipe.<\/p>\n

\n

For the preform-feed system, request the supported preform dimensions and mass, feed range, positioning performance and coordination with draw control. Agree a test using the intended preform rather than assuming a universal positioning tolerance.<\/p>\n

\u0110o l\u01b0\u1eddng v\u00e0 ki\u1ec3m so\u00e1t \u0111\u01b0\u1eddng k\u00ednh<\/h3>\n

Specify what each gauge measures: bare-glass outer diameter, coated-fiber outer diameter or another defined feature. Request the instrument’s measurement range, accuracy, repeatability, sampling rate and calibration requirements. Do not treat resolution, response time and achieved production tolerance as interchangeable specifications.<\/p>\n

Draw speed is one control variable used to regulate bare-glass diameter, but it interacts with preform feed, thermal conditions and tension. Confirm which variables the proposed controller actually adjusts, where the diameter is measured and how transport delay is handled. Require a recorded trial showing diameter and tension together during steady running and approved speed changes; a simple ‘speed up when thick’ rule is not a complete control specification.<\/p>\n

Predictive and learning-based control should be treated as specific proposed functions, not standard features of every drawing line. For example, the research paper Dynamic Control of a Fiber Manufacturing Process using Deep Reinforcement Learning<\/a> reports tests on a compact fiber-drawing system. It does not establish deployment or performance on the production line being quoted. Request the actual control architecture, operating limits and acceptance demonstration for any such claim.<\/p>\n\n\n\n\n\n\n\n\n
Tham s\u1ed1<\/th>\nX\u00e1c \u0111\u1ecbnh trong \u0111\u1ec1 xu\u1ea5t<\/th>\nC\u0103n c\u1ee9 ch\u1ea5p nh\u1eadn<\/th>\nEvidence to request<\/th>\n<\/tr>\n<\/thead>\n
Furnace operation<\/td>\nHeating technology, usable hot zone and operating window<\/td>\nQualified settings for the selected preform<\/td>\nEquipment specification and recorded trial conditions<\/td>\n<\/tr>\n
Glass-cladding diameter<\/td>\nBare-glass outer diameter, distinct from core diameter<\/td>\nTarget and tolerance in the selected fiber specification<\/td>\nCalibrated gauge data and agreed inspection method<\/td>\n<\/tr>\n
T\u1ed1c \u0111\u1ed9 v\u1ebd<\/td>\nAgreed production speed for the specified fiber<\/td>\nQuality demonstrated at that speed<\/td>\nB\u1ea3n ghi th\u1eed nghi\u1ec7m li\u00ean k\u1ebft t\u1ed1c \u0111\u1ed9 v\u1edbi h\u00ecnh h\u1ecdc v\u00e0 k\u1ebft qu\u1ea3 quang h\u1ecdc<\/td>\n<\/tr>\n
Coated-fiber outer diameter<\/td>\n\u0110\u01b0\u1eddng k\u00ednh tr\u00ean l\u1edbp ph\u1ee7 \u0111\u00e3 l\u01b0u h\u00f3a, kh\u00f4ng ph\u1ea3i \u0111\u1ed9 d\u00e0y l\u1edbp ph\u1ee7 h\u01b0\u1edbng k\u00ednh<\/td>\nM\u1ee5c ti\u00eau v\u00e0 dung sai cho thi\u1ebft k\u1ebf l\u1edbp ph\u1ee7 \u0111\u00e3 ch\u1ecdn<\/td>\nK\u1ebft qu\u1ea3 \u0111\u01b0\u1eddng k\u00ednh v\u00e0 \u0111\u1ed9 \u0111\u1ed3ng t\u00e2m t\u1eeb ph\u00e9p th\u1eed \u0111\u00e3 th\u1ecfa thu\u1eadn<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

H\u1ec7 th\u1ed1ng \u1ee9ng d\u1ee5ng l\u1edbp ph\u1ee7<\/h3>\n

H\u1ec7 th\u1ed1ng ph\u1ee7 \u00e1p d\u1ee5ng c\u00e1c l\u1edbp polyme b\u1ea3o v\u1ec7 l\u00ean s\u1ee3i th\u1ee7y tinh tr\u1ea7n ngay sau khi h\u00ecnh th\u00e0nh. L\u1edbp ph\u1ee7 ph\u1ea3i \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng \u0111\u1ed3ng t\u00e2m v\u00e0 \u0111\u1ed3ng \u0111\u1ec1u \u0111\u1ec3 ng\u0103n ng\u1eeba t\u1ed5n th\u1ea5t do u\u1ed1n cong vi m\u00f4 v\u00e0 cung c\u1ea5p kh\u1ea3 n\u0103ng b\u1ea3o v\u1ec7 c\u01a1 h\u1ecdc. H\u1ea7u h\u1ebft c\u00e1c h\u1ec7 th\u1ed1ng s\u1eed d\u1ee5ng \u0111\u1ea7u phun khu\u00f4n \u00e1p l\u1ef1c \u0111\u1ec3 \u00e9p v\u1eadt li\u1ec7u ph\u1ee7 d\u1ea1ng l\u1ecfng xung quanh s\u1ee3i.<\/p>\n

The primary coating is the polymer layer next to the glass. Confirm its material, cured outer diameter and acceptance requirements in the qualified coating design. Do not assume a fixed radial thickness for every optical-fiber product.<\/p>\n

The secondary coating surrounds the primary layer. Distinguish its outer diameter from the thickness of either layer. For concentric circular layers, total radial coating thickness = (coated-fiber outer diameter – glass-cladding diameter) \/ 2. This relation alone does not determine how the thickness is divided between primary and secondary coatings.<\/p>\n

\u0110\u1ed1i v\u1edbi m\u1ed9t v\u00ed d\u1ee5 c\u1ee5 th\u1ec3 v\u1ec1 s\u1ea3n ph\u1ea9m, Corning’s SMF-28 Ultra product sheet, July 2025, page 2<\/a> lists a glass-cladding diameter of 125.0 \u00b1 0.7 \u03bcm and coated diameters of 242 \u00b1 5 \u03bcm or 200 \u00b1 5 \u03bcm, depending on the option. Using nominal diameters gives combined radial coating thicknesses of 58.5 \u03bcm and 37.5 \u03bcm respectively. These are calculated examples for that product, not universal coating recipes or HONGKAI equipment guarantees.<\/p>\n

Request the proposed coating-concentricity measurement method and die-alignment procedure, with acceptance limits tied to the specified fiber and coating system. Keep geometry checks and optical-performance tests separate: a concentricity result alone does not establish the fiber’s polarization-mode-dispersion performance.<\/p>\n

H\u1ec7 th\u1ed1ng x\u1eed l\u00fd UV<\/h3>\n

H\u1ec7 th\u1ed1ng x\u1eed l\u00fd b\u1eb1ng tia c\u1ef1c t\u00edm tr\u00f9ng h\u1ee3p l\u1edbp ph\u1ee7 acrylate l\u1ecfng th\u00e0nh l\u1edbp b\u1ea3o v\u1ec7 r\u1eafn. Qu\u00e1 tr\u00ecnh x\u1eed l\u00fd ph\u1ea3i ho\u00e0n ch\u1ec9nh v\u00e0 \u0111\u1ed3ng \u0111\u1ec1u \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o c\u00e1c \u0111\u1eb7c t\u00ednh ph\u1ee7 th\u00edch h\u1ee3p. X\u1eed l\u00fd kh\u00f4ng ho\u00e0n ch\u1ec9nh c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn b\u1ec1 m\u1eb7t d\u00ednh v\u00e0 c\u00e1c \u0111\u1eb7c t\u00ednh c\u01a1 h\u1ecdc k\u00e9m.<\/p>\n

Vi\u1ec7c l\u00e0m kh\u00f4 l\u1edbp ph\u1ee7 s\u1ee3i quang kh\u00f4ng b\u1ecb gi\u1edbi h\u1ea1n b\u1edfi m\u1ed9t c\u00f4ng ngh\u1ec7 \u0111\u00e8n n\u00e0o. T\u00e0i li\u1ec7u \u1ee9ng d\u1ee5ng chi\u1ebfu x\u1ea1 UV-LED c\u1ee7a Excelitas \u0111\u1ec3 l\u00e0m \u0111\u00f4ng s\u1ee3i c\u00e1p<\/a> describes conventional arc\/microwave lamp systems and UV LED systems, and stresses testing the coating with the selected light source. Ask the coating and equipment suppliers to qualify the spectral match, exposure, optical arrangement and thermal conditions at the proposed line speed; lamp layout alone does not prove uniform cure.<\/p>\n

If the proposed curing system uses nitrogen inerting, obtain the required gas specification, chamber conditions, monitoring and alarm limits from the coating and curing-equipment suppliers. Verify the cured coating against an agreed test method. Nitrogen supply alone is not evidence that the coating has reached its required cure state.<\/p>\n

H\u1ec7 th\u1ed1ng ki\u1ec3m so\u00e1t v\u00e0 thu h\u1ed3i l\u1ef1c c\u0103ng<\/h3>\n

Tension control throughout the drawing process is essential for consistent fiber properties. Excessive tension can cause fiber breaks or diameter variations, while insufficient tension can lead to loose winding and handling problems. Agree the drawing-tension range, force units, measurement method and acceptance conditions for the actual fiber and drawing system.<\/p>\n

For the capstan system, request the drive-control specification, fiber-contact surface details and maintenance requirements. Ask the supplier to demonstrate the proposed speed-control performance and fiber-handling results under agreed test conditions rather than relying on an unsupported accuracy figure.<\/p>\n

Take-up systems wind the finished fiber onto spools for storage and shipping. The winding pattern must prevent fiber damage while allowing easy unwinding for subsequent processing. Confirm the traverse mechanism, winding pattern and take-up tension requirements with the supplier, then verify the result using the agreed spool and fiber specification.<\/p>\n

If the take-up uses a dancer, confirm its loading method, usable travel, position feedback and connection to reel-speed control. Verify winding tension during acceleration, steady running and spool build-up with the intended fiber and reel. A dancer’s presence does not guarantee constant tension, and take-up tension must not be confused with the tension measured in the hot drawing zone.<\/p>\n

L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng s\u1ee3i trong qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t?<\/h2>\n

Ki\u1ec3m so\u00e1t ch\u1ea5t l\u01b0\u1ee3ng ng\u0103n ng\u1eeba c\u00e1c l\u1ed7i s\u1ea3n xu\u1ea5t t\u1ed1n k\u00e9m. N\u1ebfu kh\u00f4ng c\u00f3 s\u1ef1 gi\u00e1m s\u00e1t th\u00edch h\u1ee3p, to\u00e0n b\u1ed9 qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t c\u00f3 th\u1ec3 kh\u00f4ng \u0111\u00e1p \u1ee9ng \u0111\u01b0\u1ee3c c\u00e1c y\u00eau c\u1ea7u v\u1ec1 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt, d\u1eabn \u0111\u1ebfn t\u1ed5n th\u1ea5t \u0111\u00e1ng k\u1ec3 v\u1ec1 v\u1eadt li\u1ec7u v\u00e0 th\u1eddi gian.<\/p>\n

Use a quality plan that separates inline process measurements from optical and mechanical acceptance tests. Define each measured feature, test method, inspection frequency and acceptance limit; inline diameter feedback alone does not verify every finished-fiber requirement.<\/strong><\/p>\n

\"Ki\u1ec3m<\/p>\n

Minh h\u1ecda kh\u00e1i ni\u1ec7m v\u1ec1 c\u00e1c ph\u00e9p ki\u1ec3m tra h\u00ecnh h\u1ecdc, quang h\u1ecdc v\u00e0 c\u01a1 h\u1ecdc; kh\u00f4ng hi\u1ec3n th\u1ecb k\u1ebft qu\u1ea3 \u0111o th\u1eed n\u00e0o.<\/em><\/p>\n

Define the fiber-production quality plan before accepting the equipment. Identify the measurements, inspection frequency, acceptance criteria and responsibility for nonconforming material at each stage. Request sample records from the proposed producer and agree which checks are included in the supplied scope.<\/p>\n

Gi\u00e1m s\u00e1t quy tr\u00ecnh th\u1eddi gian th\u1ef1c<\/h3>\n

For each inline measurement, record the sensor principle, accuracy, sampling rate, filtering and position on the line. Ask the supplier to demonstrate which defects the complete measurement-and-control system can detect at the proposed draw speed. Do not infer a minimum detectable defect length or closed-loop response from the gauge resolution alone.<\/p>\n

For coating inspection, ask whether the proposed instrument reports coated outer diameter, concentricity or individual-layer geometry. An outer-diameter reading alone does not establish the separate primary and secondary layer thicknesses. Document which features are measured, the calibration method and how the results are checked against the selected coating design.<\/p>\n

\u0110\u1eebng gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng m\u1ecdi ph\u00e9p \u0111o l\u1ef1c k\u00e9o d\u00e2y \u0111\u1ec1u s\u1eed d\u1ee5ng c\u1ea3m bi\u1ebfn l\u1ef1c. M\u00f4 t\u1ea3 c\u1ee7a SIKORA v\u1ec1 ph\u00e9p \u0111o l\u1ef1c c\u0103ng s\u1ee3i quang<\/a> discusses vibration-based measurement and a birefringence-based optical method. Confirm the proposed instrument, measurement location, units and validation procedure. Define separately whether its signal is displayed, logged, used for an alarm or connected to an automatic control loop; measurement alone does not prove automatic break prevention.<\/p>\n

List the thermal and environmental measurements actually included in the proposed line, such as fiber temperature before coating and conditions in the coating or curing area. Identify each measurement target, sensor, logging interval and alarm boundary. Verify any thermal-imaging or contamination-monitoring function explicitly rather than assuming it is supplied with the tower.<\/p>\n

Ki\u1ec3m tra t\u00ednh ch\u1ea5t quang h\u1ecdc<\/h3>\n

Ch\u1ecdn m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p th\u1eed nghi\u1ec7m suy hao ph\u00f9 h\u1ee3p v\u1edbi s\u1ee3i quang v\u00e0 b\u00e1o c\u00e1o y\u00eau c\u1ea7u. The IEC 60793-1-40:2024 attenuation-method overview<\/a> lists cut-back, insertion-loss and backscattering methods, as well as spectral modelling with a narrower scope. Record the selected method, test wavelengths, launch conditions, sample identification and acceptance limits; do not assume every production test uses cut-back.<\/p>\n

\u0110\u1ed1i v\u1edbi s\u1ee3i quang \u0111a mode, h\u00e3y x\u00e1c \u0111\u1ecbnh th\u00f4ng s\u1ed1 b\u0103ng th\u00f4ng y\u00eau c\u1ea7u v\u00e0 \u0111i\u1ec1u ki\u1ec7n kh\u1edfi \u0111\u1ed9ng. IEC 60793-1-41:2024<\/a> distinguishes time-domain, frequency-domain and DMD-derived overfilled-launch bandwidth methods. IEC 60793-1-49:2018<\/a> describes DMD characterization of graded-index multimode fiber for bandwidth assessment under different launch conditions. Do not describe a DMD report as a direct refractive-index-profile measurement. Ask the laboratory to identify the fiber category, wavelength, method and reported bandwidth metric.<\/p>\n

Distinguish measured numerical aperture from a value calculated using refractive indices. The IEC 60793-1-43:2015 overview<\/a> covers specified multimode-fiber categories and distinguishes far-field numerical aperture from theoretical numerical aperture. Ask the laboratory to state the applicable fiber category, sample length, measurement threshold and uncertainty. Do not use a numerical-aperture result as a substitute for a required single-mode cutoff-wavelength test.<\/p>\n

For single-mode fiber, specify the mode field diameter (MFD) test method and reporting wavelength together. IEC 60793-1-45:2024<\/a> addresses MFD measurement. Compare results with the selected fiber specification at the same stated wavelength; do not treat an MFD value without its wavelength as a complete acceptance requirement.<\/p>\n

Ki\u1ec3m tra t\u00ednh ch\u1ea5t c\u01a1 h\u1ecdc<\/h3>\n

Proof testing applies a specified tensile stress to screen fiber for weak sections. As one documented example, section 1.4 of Corning’s PGSF001 fiber specification<\/a> specifies a minimum of 100 kpsi (approximately 0.69 GPa)<\/strong> for the fibers covered by that document. Here, 100 kpsi means 100,000 psi. Use the applicable fiber specification and test procedure for the product being manufactured.<\/p>\n

Coating adhesion testing verifies that the polymer coatings bond properly to the glass surface and to each other. Poor adhesion can lead to coating delamination during handling or environmental exposure. Request the applicable coating-adhesion and stripping test procedures, reported results and acceptance criteria from the fiber producer.<\/p>\n

Th\u1eed nghi\u1ec7m u\u1ed1n cong \u0111\u00e1nh gi\u00e1 kh\u1ea3 n\u0103ng ch\u1ed1ng l\u1ea1i t\u1ed5n th\u1ea5t u\u1ed1n cong v\u0129 m\u00f4 v\u00e0 u\u1ed1n cong vi m\u00f4 c\u1ee7a s\u1ee3i. Th\u1eed nghi\u1ec7m u\u1ed1n cong v\u0129 m\u00f4 qu\u1ea5n s\u1ee3i quanh c\u00e1c tr\u1ee5c c\u00f3 \u0111\u01b0\u1eddng k\u00ednh kh\u00e1c nhau \u0111\u1ec3 m\u00f4 ph\u1ecfng c\u00e1c \u0111i\u1ec1u ki\u1ec7n l\u1eafp \u0111\u1eb7t. Th\u1eed nghi\u1ec7m u\u1ed1n cong vi m\u00f4 \u00e1p d\u1ee5ng \u00e1p l\u1ef1c ngang \u0111\u01b0\u1ee3c ki\u1ec3m so\u00e1t \u0111\u1ec3 m\u00f4 ph\u1ecfng c\u00e1c t\u00e1c \u0111\u1ed9ng c\u1ee7a qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t c\u00e1p v\u00e0 \u1ee9ng su\u1ea5t m\u00f4i tr\u01b0\u1eddng.<\/p>\n

Ki\u1ec3m tra m\u00f4i tr\u01b0\u1eddng cho ph\u00e9p c\u00e1c m\u1eabu s\u1ee3i ti\u1ebfp x\u00fac v\u1edbi chu k\u1ef3 nhi\u1ec7t \u0111\u1ed9, \u0111\u1ed9 \u1ea9m v\u00e0 m\u00f4i tr\u01b0\u1eddng h\u00f3a h\u1ecdc c\u00f3 th\u1ec3 g\u1eb7p ph\u1ea3i trong qu\u00e1 tr\u00ecnh s\u1eed d\u1ee5ng. C\u00e1c th\u1eed nghi\u1ec7m n\u00e0y gi\u00fap d\u1ef1 \u0111o\u00e1n \u0111\u1ed9 tin c\u1eady l\u00e2u d\u00e0i v\u00e0 x\u00e1c \u0111\u1ecbnh c\u00e1c ch\u1ebf \u0111\u1ed9 h\u1ecfng h\u00f3c ti\u1ec1m \u1ea9n tr\u01b0\u1edbc khi ch\u00fang x\u1ea3y ra t\u1ea1i hi\u1ec7n tr\u01b0\u1eddng.<\/p>\n

Use the following planning matrix to agree the product-specific quality plan. A measurement standard defines how a test is performed; it is not, by itself, a universal product limit or a sampling plan. Adapt the wavelength rows to the selected fiber rather than applying them to every fiber type.<\/p>\n\n\n\n\n\n\n\n\n\n
Test parameter<\/th>\nMethod to specify<\/th>\nCoverage or sampling to agree<\/th>\nC\u0103n c\u1ee9 ch\u1ea5p nh\u1eadn<\/th>\n<\/tr>\n<\/thead>\n
Attenuation at 1310 nm, if specified<\/td>\nApplicable method under IEC 60793-1-40:2024<\/td>\nDefined in the product quality plan<\/td>\nMaximum loss for the selected fiber at this wavelength<\/td>\n<\/tr>\n
Attenuation at 1550 nm, if specified<\/td>\nApplicable method under IEC 60793-1-40:2024<\/td>\nDefined in the product quality plan<\/td>\nMaximum loss for the selected fiber at this wavelength<\/td>\n<\/tr>\n
MFD s\u1ee3i \u0111\u01a1n mode t\u1ea1i b\u01b0\u1edbc s\u00f3ng \u0111\u00e3 n\u00eau<\/td>\nApplicable method under IEC 60793-1-45:2024<\/td>\nDefined in the product quality plan<\/td>\nNominal value and tolerance at that same wavelength<\/td>\n<\/tr>\n
Ki\u1ec3m tra b\u1eb1ng ch\u1ee9ng<\/td>\nIEC 60793-1-30:2010 fibre proof-test procedure<\/a><\/td>\nChi\u1ec1u d\u00e0i \u0111\u00e3 th\u1eed nghi\u1ec7m theo y\u00eau c\u1ea7u v\u00e0 h\u1ed3 s\u01a1 cu\u1ed9n d\u00e2y c\u00f3 th\u1ec3 truy xu\u1ea5t \u0111\u01b0\u1ee3c<\/td>\nM\u1ee9c \u0111\u1ed9 \u1ee9ng su\u1ea5t v\u00e0 c\u00e1c quy t\u1eafc ch\u1ea5p nh\u1eadn t\u1eeb \u0111\u1eb7c t\u1ea3 s\u1ee3i quang \u0111\u00e3 ch\u1ecdn<\/td>\n<\/tr>\n
Coated-fiber outer diameter<\/td>\nPh\u01b0\u01a1ng ph\u00e1p th\u1eed nghi\u1ec7m k\u00edch th\u01b0\u1edbc \u0111\u00e3 th\u1ecfa thu\u1eadn<\/td>\nDefined in the quality plan<\/td>\nM\u1ee5c ti\u00eau v\u00e0 dung sai t\u1eeb th\u00f4ng s\u1ed1 s\u1ee3i\/l\u1edbp ph\u1ee7 \u0111\u00e3 ch\u1ecdn<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Ki\u1ec3m so\u00e1t quy tr\u00ecnh th\u1ed1ng k\u00ea<\/h3>\n

Statistical process control (SPC) can help identify changes in recorded process measurements. NIST’s control-chart guidance<\/a> explains that both points outside control limits and non-random patterns can warrant investigation. Control limits describe process behavior; they are not the product’s specification limits. A stable process can still produce nonconforming fiber. For the proposed quality system, identify the measured feature, chart type, sampling method, investigation rules and responsible person. Confirm whether alerts are actually implemented; a chart alone does not prevent defects or release a spool for shipment.<\/p>\n

Tr\u01b0\u1edbc khi di\u1ec5n gi\u1ea3i Cp ho\u1eb7c Cpk, h\u00e3y \u0111\u1ea3m b\u1ea3o r\u1eb1ng qu\u00e1 tr\u00ecnh l\u00e0 \u1ed5n \u0111\u1ecbnh v\u00e0 d\u1eef li\u1ec7u c\u00f9ng ph\u01b0\u01a1ng ph\u00e1p t\u00ednh to\u00e1n l\u00e0 ph\u00f9 h\u1ee3p. NIST’s process-capability overview<\/a> compares stable-process variation with specification limits and states the normal-distribution assumption of the conventional indices. Cp compares specification width with process spread; Cpk also accounts for an off-center process mean. Ask for the underlying measurements, units, sampling period, specification limits and statistical assumptions, not just an index on a dashboard. Agree any required capability criterion for the project; do not substitute an unsourced universal threshold for the fiber’s acceptance tests.<\/p>\n

Design of experiments (DOE) techniques help optimize process parameters and understand the relationships between different variables. For any proposed optimization trial, agree the factors, response measurements and permitted operating boundaries with the process owner, and require a traceable report of the results.<\/p>\n

Correlation analysis helps identify relationships between different measurements that might not be obvious. Treat a measured correlation as a finding to investigate, not proof of a causal relationship or a guaranteed process improvement.<\/p>\n

<\/span><\/p>\n

H\u1ec7 th\u1ed1ng ch\u1ea5t l\u01b0\u1ee3ng t\u1ef1 \u0111\u1ed9ng<\/h3>\n

For an automated quality-control proposal, require a list of measured inputs, controlled outputs, alarm actions and operator responsibilities. Ask the supplier to demonstrate each promised feedback or predictive function on the proposed system. Do not assume that machine-learning prediction or automatic defect prevention is included in a standard drawing line.<\/p>\n

Specify which process and test data will actually be recorded, with timestamps, length or spool references, retention and export requirements. Check a sample production record before acceptance; an automation interface does not establish that every quality parameter is captured or traceable.<\/p>\n

Ask the supplier to demonstrate how an out-of-specification segment is identified, located, segregated and documented. State whether handling requires stopping, cutting, transfer or later rewinding, and define the restart and retest procedure. Do not assume defective fiber can be removed while drawing continues without interruption.<\/p>\n

If ERP or other factory-system integration is required, define the data fields, spool identifiers, interfaces, access rights and responsibility for failed transfers. Test a sample record from measurement through export and retrieval before acceptance. An available interface does not by itself establish end-to-end traceability or regulatory compliance.<\/p>\n

Nh\u1eefng v\u1ea5n \u0111\u1ec1 th\u01b0\u1eddng g\u1eb7p trong s\u1ea3n xu\u1ea5t v\u00e0 gi\u1ea3i ph\u00e1p l\u00e0 g\u00ec?<\/h2>\n

C\u00e1c v\u1ea5n \u0111\u1ec1 s\u1ea3n xu\u1ea5t c\u00f3 th\u1ec3 l\u00e0m d\u1eebng to\u00e0n b\u1ed9 d\u00e2y chuy\u1ec1n s\u1ea3n xu\u1ea5t. C\u00e1c v\u1ea5n \u0111\u1ec1 ch\u01b0a \u0111\u01b0\u1ee3c gi\u1ea3i quy\u1ebft d\u1eabn \u0111\u1ebfn h\u01b0 h\u1ecfng thi\u1ebft b\u1ecb, l\u00e3ng ph\u00ed v\u1eadt li\u1ec7u v\u00e0 b\u1ecf l\u1ee1 cam k\u1ebft giao h\u00e0ng g\u00e2y t\u1ed5n h\u1ea1i \u0111\u1ebfn m\u1ed1i quan h\u1ec7 v\u1edbi kh\u00e1ch h\u00e0ng.<\/p>\n

C\u00e1c s\u1ef1 c\u1ed1 \u0111\u1ee9t s\u1ee3i, bi\u1ebfn \u0111\u1ed5i \u0111\u01b0\u1eddng k\u00ednh v\u00e0 khuy\u1ebft t\u1eadt l\u1edbp ph\u1ee7 \u0111\u00f2i h\u1ecfi quy tr\u00ecnh x\u1eed l\u00fd s\u1ef1 c\u1ed1 c\u00f3 h\u1ec7 th\u1ed1ng c\u00f9ng c\u00e1c giao th\u1ee9c b\u1ea3o tr\u00ec ph\u00f2ng ng\u1eeba nh\u1eb1m duy tr\u00ec ch\u1ea5t l\u01b0\u1ee3ng s\u1ea3n xu\u1ea5t \u1ed5n \u0111\u1ecbnh.<\/strong><\/p>\n

\"Conceptual<\/p>\n

Minh h\u1ecda kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 mang t\u00ednh kh\u00e1i ni\u1ec7m. C\u00e1c ki\u1ec3m tra \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea l\u00e0 c\u00e1c g\u1ee3i \u00fd \u0111i\u1ec1u tra, kh\u00f4ng ph\u1ea3i nguy\u00ean nh\u00e2n \u0111\u00e3 \u0111\u01b0\u1ee3c x\u00e1c nh\u1eadn ho\u1eb7c bi\u1ec7n ph\u00e1p kh\u1eafc ph\u1ee5c \u0111\u1ea3m b\u1ea3o.<\/em><\/p>\n

Use production records, alarms, inspection results and supplier procedures to investigate fiber-manufacturing problems. Establish the observed symptom and operating conditions before proposing a cause. Follow the applicable manufacturer’s safety and maintenance instructions before making adjustments.<\/p>\n

C\u00e1c v\u1ea5n \u0111\u1ec1 \u0111\u1ee9t s\u1ee3i<\/h3>\n

Fiber breaks represent one of the most common and disruptive problems in fiber manufacturing. These breaks can occur at any point in the drawing process, from the furnace exit to the take-up reel. Understanding the different types of breaks and their causes is essential for effective troubleshooting.<\/p>\n

For a break near the furnace exit, preserve the time, preform identity, break location and preceding thermal, feed and tension records. Review relevant preform inspections and furnace alarms with the process owner. Do not diagnose ‘thermal shock’ or contamination solely from the break location. Inspection of the furnace or hot-zone components must follow the manufacturer’s safe shutdown and maintenance procedure.<\/p>\n

For a suspected tension-related break, compare the tension trace with capstan speed, dancer position, reel events and the recorded break time. First confirm the measurement location and signal validity. A tension change after the fiber has broken may be a consequence, not its cause. Have qualified personnel review the evidence before changing control settings or inspecting the fiber path.<\/p>\n

If breaks appear near coating or downstream handling equipment, retain representative samples and record their position relative to dies, guides, capstan and take-up. Check the applicable coating-geometry, cure, adhesion and mechanical-test results with the suppliers. Neither an eccentric coating nor a tacky surface alone proves the failure mechanism; compare the findings with the actual break evidence.<\/p>\n

V\u1ea5n \u0111\u1ec1 ki\u1ec3m so\u00e1t \u0111\u01b0\u1eddng k\u00ednh<\/h3>\n

S\u1ef1 thay \u0111\u1ed5i \u0111\u01b0\u1eddng k\u00ednh c\u00f3 th\u1ec3 khi\u1ebfn s\u1ee3i kh\u00f4ng s\u1eed d\u1ee5ng \u0111\u01b0\u1ee3c cho c\u00e1c \u1ee9ng d\u1ee5ng ch\u00ednh x\u00e1c. Nh\u1eefng thay \u0111\u1ed5i n\u00e0y c\u00f3 th\u1ec3 x\u1ea3y ra \u1edf kho\u1ea3ng c\u00e1ch ng\u1eafn (bi\u1ebfn th\u1ec3 vi m\u00f4) ho\u1eb7c kho\u1ea3ng c\u00e1ch d\u00e0i (bi\u1ebfn th\u1ec3 v\u0129 m\u00f4), m\u1ed7i lo\u1ea1i y\u00eau c\u1ea7u c\u00e1c ph\u01b0\u01a1ng ph\u00e1p kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 kh\u00e1c nhau.<\/p>\n

Compare a diameter excursion with the identified preform, feed position and preform inspection records, but do not assume that a preform dimension transfers directly into the finished-fiber diameter. The drawing process and its control response also matter. Confirm the measured feature and units before comparing preform geometry, glass-cladding diameter or core geometry.<\/p>\n

When investigating thermal conditions, compare the diameter trace with the furnace setpoint, measured temperature, power and relevant utility records. Distinguish the controller reading from the actual temperature of the glass. Check timing and measurement limitations before assigning a thermal cause or approving a recipe change.<\/p>\n

For a suspected control problem, compare commanded and measured speed with the raw and filtered diameter signals. Ask the controls specialist to check sensor validity, delay, output limits and interactions between loops. Do not begin with arbitrary PID changes; use the approved trial procedure and retain before-and-after records.<\/p>\n

If the diameter signal is periodic, compare its timing with known equipment cycles and environmental measurements. Check whether the pattern is present in an independent measurement or is an artefact of the gauge, filtering or sampling. A frequency match is an investigation lead, not proof that vibration or airflow caused the product defect.<\/p>\n

S\u1eed d\u1ee5ng ma tr\u1eadn ch\u1ea9n \u0111o\u00e1n n\u00e0y \u0111\u1ec3 thu th\u1eadp b\u1eb1ng ch\u1ee9ng tr\u01b0\u1edbc khi l\u1ef1a ch\u1ecdn bi\u1ec7n ph\u00e1p can thi\u1ec7p. C\u00e1c ki\u1ec3m tra c\u1ee7a ma tr\u1eadn kh\u00f4ng ph\u1ea3i l\u00e0 nguy\u00ean nh\u00e2n \u0111\u01b0\u1ee3c x\u00e1c nh\u1eadn hay h\u01b0\u1edbng d\u1eabn v\u1eadn h\u00e0nh ph\u1ed5 qu\u00e1t.<\/p>\n\n\n\n\n\n\n\n\n
Observed symptom<\/th>\nB\u1eb1ng ch\u1ee9ng c\u1ea7n b\u1ea3o qu\u1ea3n<\/th>\nKi\u1ec3m tra ban \u0111\u1ea7u v\u1edbi chuy\u00ean vi\u00ean ph\u1ee5 tr\u00e1ch<\/th>\nRecovery evidence<\/th>\n<\/tr>\n<\/thead>\n
S\u1ee3i \u0111\u1ee9t<\/td>\nV\u1ecb tr\u00ed \u0111\u1ee9t, th\u1eddi gian, m\u00e3 \u0111\u1ecbnh danh preform\/\u1ed1ng ch\u1ec9 v\u00e0 c\u00e1c t\u00edn hi\u1ec7u tr\u01b0\u1edbc \u0111\u00f3<\/td>\nValidate the tension trace and correlate it with thermal, feed and handling events<\/td>\nApproved restart plus the required geometry, mechanical and optical results for the affected material<\/td>\n<\/tr>\n
Bi\u1ebfn th\u1ec3 \u0111\u01b0\u1eddng k\u00ednh<\/td>\nRaw gauge trace, units, speed\/feed records and event times<\/td>\nValidate the gauge and separate measurement artefacts from process changes before tuning<\/td>\nAgreed diameter tolerance demonstrated under the documented trial conditions<\/td>\n<\/tr>\n
L\u1ed7i l\u1edbp ph\u1ee7<\/td>\nSamples, material lot, coating geometry, curing and handling records<\/td>\nCheck the specified geometry and cure tests; review alignment and exposure only within supplier procedures<\/td>\nResults meeting the selected coating specification, with traceability to the trial<\/td>\n<\/tr>\n
T\u0103ng suy gi\u1ea3m<\/td>\nTest method, wavelength, sample identity, launch conditions and handling history<\/td>\nConfirm the test setup and repeatability before investigating material or process causes<\/td>\nRepeatable results meeting the fiber specification and documented disposition of affected spools<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

C\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 \u1ee9ng d\u1ee5ng l\u1edbp ph\u1ee7<\/h3>\n

C\u00e1c l\u1ed7i l\u1edbp ph\u1ee7 c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn c\u1ea3 t\u00ednh ch\u1ea5t quang h\u1ecdc v\u00e0 c\u01a1 h\u1ecdc c\u1ee7a s\u1ee3i th\u00e0nh ph\u1ea9m. Nh\u1eefng v\u1ea5n \u0111\u1ec1 n\u00e0y th\u01b0\u1eddng ph\u00e1t tri\u1ec3n d\u1ea7n d\u1ea7n, khi\u1ebfn vi\u1ec7c ph\u00e1t hi\u1ec7n s\u1edbm tr\u1edf n\u00ean c\u1ea7n thi\u1ebft \u0111\u1ec3 ng\u0103n ng\u1eeba s\u1ed1 l\u01b0\u1ee3ng l\u1edbn s\u1ea3n ph\u1ea9m l\u1ed7i.<\/p>\n

\n

For a coating-dimension change, establish whether the measurement concerns total coated diameter, an individual layer or concentricity. Compare the validated trace with coating pressure, material temperature, lot history and die inspection records. The rate of change alone does not distinguish die wear from pressure, material or measurement issues.<\/p>\n

When coating concentricity is outside the agreed limit, inspect fiber centering, die alignment and the measurement setup using the supplier’s procedure. Record the geometry results and perform any required optical tests separately. Do not diagnose polarization-mode dispersion from coating eccentricity alone.<\/p>\n

For a suspected cure problem, record the coating formulation and lot, light-source type, exposure conditions, line speed and any specified inerting conditions. Compare the agreed cure and mechanical tests with the qualified coating process. A tacky surface or brittle sample is a symptom, not a complete diagnosis. Do not prescribe more UV exposure or attribute cracking to excessive cure without the coating supplier’s assessment.<\/p>\n

When adhesion or stripping results are out of specification, confirm the test method and sample conditioning before comparing material, surface-handling and cure records. Ask the coating supplier to assess retained samples. Record the evidence and disposition rather than assuming contamination or material degradation is the cause.<\/p>\n

Ph\u01b0\u01a1ng ph\u00e1p kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 c\u00f3 h\u1ec7 th\u1ed1ng<\/h3>\n

Effective troubleshooting requires a systematic approach that considers all possible causes and uses data to guide the investigation. Start by reviewing when the problem began, the recorded operating conditions and any changes made before the symptom appeared.<\/p>\n

Ph\u00e2n t\u00edch d\u1eef li\u1ec7u \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c x\u00e1c \u0111\u1ecbnh c\u00e1c m\u00f4 h\u00ecnh v\u1ea5n \u0111\u1ec1. Bi\u1ec3u \u0111\u1ed3 xu h\u01b0\u1edbng c\u00f3 th\u1ec3 ti\u1ebft l\u1ed9 nh\u1eefng thay \u0111\u1ed5i d\u1ea7n d\u1ea7n m\u00e0 c\u00f3 th\u1ec3 kh\u00f4ng r\u00f5 r\u00e0ng t\u1eeb c\u00e1c ph\u00e9p \u0111o ri\u00eang l\u1ebb. Ph\u00e2n t\u00edch t\u01b0\u01a1ng quan c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh m\u1ed1i quan h\u1ec7 gi\u1eefa c\u00e1c th\u00f4ng s\u1ed1 kh\u00e1c nhau g\u1ee3i \u00fd nguy\u00ean nh\u00e2n g\u1ed1c r\u1ec5.<\/p>\n

Use batch comparisons to narrow the investigation, not to assign blame. If an excursion occurs with one preform batch, check whether recipe, operator, instrument, equipment or environmental conditions also changed. Compare equivalent runs and record which alternative explanations the evidence actually excludes.<\/p>\n

A fishbone diagram or five-why review can organize hypotheses, but the diagram is not proof of root cause. Assign an owner to each check, document supporting and conflicting evidence, and verify the approved corrective action against the agreed acceptance criteria. Continue monitoring after restart; one successful trial does not guarantee that the problem cannot recur.<\/p>\n

Chi\u1ebfn l\u01b0\u1ee3c b\u1ea3o tr\u00ec ph\u00f2ng ng\u1eeba<\/h3>\n

C\u00e1c ch\u01b0\u01a1ng tr\u00ecnh b\u1ea3o tr\u00ec ph\u00f2ng ng\u1eeba gi\u00fap tr\u00e1nh nhi\u1ec1u v\u1ea5n \u0111\u1ec1 s\u1ea3n xu\u1ea5t ph\u1ed5 bi\u1ebfn b\u1eb1ng c\u00e1ch gi\u1ea3i quy\u1ebft c\u00e1c v\u1ea5n \u0111\u1ec1 ti\u1ec1m \u1ea9n tr\u01b0\u1edbc khi ch\u00fang g\u00e2y gi\u00e1n \u0111o\u1ea1n s\u1ea3n xu\u1ea5t. C\u00e1c ch\u01b0\u01a1ng tr\u00ecnh n\u00e0y ph\u1ea3i d\u1ef1a tr\u00ean khuy\u1ebfn ngh\u1ecb c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t thi\u1ebft b\u1ecb, d\u1eef li\u1ec7u l\u1ed7i l\u1ecbch s\u1eed v\u00e0 y\u00eau c\u1ea7u quy tr\u00ecnh.<\/p>\n

C\u00e1c ho\u1ea1t \u0111\u1ed9ng b\u1ea3o tr\u00ec theo l\u1ecbch tr\u00ecnh bao g\u1ed3m hi\u1ec7u chu\u1ea9n th\u01b0\u1eddng xuy\u00ean c\u00e1c h\u1ec7 th\u1ed1ng \u0111o l\u01b0\u1eddng, thay th\u1ebf c\u00e1c th\u00e0nh ph\u1ea7n b\u1ecb m\u00f2n v\u00e0 v\u1ec7 sinh c\u00e1c khu v\u1ef1c quan tr\u1ecdng. L\u1ecbch tr\u00ecnh b\u1ea3o tr\u00ec n\u00ean xem x\u00e9t c\u1ea3 kho\u1ea3ng th\u1eddi gian d\u1ef1a tr\u00ean th\u1eddi gian v\u00e0 d\u1ef1a tr\u00ean m\u1ee9c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a \u0111\u1ed9 tin c\u1eady c\u1ee7a thi\u1ebft b\u1ecb.<\/p>\n

K\u1ef9 thu\u1eadt gi\u00e1m s\u00e1t t\u00ecnh tr\u1ea1ng c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c v\u1ea5n \u0111\u1ec1 \u0111ang ph\u00e1t tri\u1ec3n tr\u01b0\u1edbc khi ch\u00fang g\u00e2y ra h\u1ecfng h\u00f3c. Ph\u00e2n t\u00edch \u0111\u1ed9 rung c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n ra c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 \u0111\u1ed9 m\u00f2n \u1ed5 tr\u1ee5c ho\u1eb7c c\u0103n ch\u1ec9nh. Ch\u1ee5p \u1ea3nh nhi\u1ec7t c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 \u0111i\u1ec7n ho\u1eb7c h\u1ec7 th\u1ed1ng l\u00e0m m\u00e1t. Ph\u00e2n t\u00edch d\u1ea7u c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n ra s\u1ef1 m\u00e0i m\u00f2n b\u00ean trong trong h\u1ec7 th\u1ed1ng th\u1ee7y l\u1ef1c ho\u1eb7c b\u00f4i tr\u01a1n.<\/p>\n

Qu\u1ea3n l\u00fd h\u00e0ng t\u1ed3n kho ph\u1ee5 t\u00f9ng \u0111\u1ea3m b\u1ea3o c\u00e1c th\u00e0nh ph\u1ea7n quan tr\u1ecdng c\u00f3 s\u1eb5n khi c\u1ea7n b\u1ea3o tr\u00ec ho\u1eb7c s\u1eeda ch\u1eefa kh\u1ea9n c\u1ea5p. H\u00e0ng t\u1ed3n kho ph\u1ea3i bao g\u1ed3m c\u1ea3 c\u00e1c h\u1ea1ng m\u1ee5c b\u1ea3o tr\u00ec th\u01b0\u1eddng xuy\u00ean v\u00e0 c\u00e1c ph\u1ee5 t\u00f9ng c\u1ea7n thi\u1ebft c\u00f3 th\u1ec3 g\u00e2y ra th\u1eddi gian ng\u1eebng ho\u1ea1t \u0111\u1ed9ng k\u00e9o d\u00e0i n\u1ebfu kh\u00f4ng c\u00f3 s\u1eb5n.<\/p>\n

C\u00e1c ch\u01b0\u01a1ng tr\u00ecnh \u0111\u00e0o t\u1ea1o \u0111\u1ea3m b\u1ea3o r\u1eb1ng ng\u01b0\u1eddi v\u1eadn h\u00e0nh v\u00e0 nh\u00e2n vi\u00ean b\u1ea3o tr\u00ec hi\u1ec3u c\u00e1c quy tr\u00ecnh ph\u00f9 h\u1ee3p v\u00e0 c\u00f3 th\u1ec3 nh\u1eadn ra c\u00e1c d\u1ea5u hi\u1ec7u s\u1edbm c\u1ee7a s\u1ef1 c\u1ed1 \u0111ang ph\u00e1t tri\u1ec3n. C\u00e1c b\u1ea3n c\u1eadp nh\u1eadt \u0111\u00e0o t\u1ea1o th\u01b0\u1eddng xuy\u00ean gi\u00fap duy tr\u00ec c\u00e1c k\u1ef9 n\u0103ng v\u00e0 gi\u1edbi thi\u1ec7u c\u00e1c k\u1ef9 thu\u1eadt ho\u1eb7c c\u00f4ng ngh\u1ec7 m\u1edbi.<\/p>\n

H\u1ec7 th\u1ed1ng t\u00e0i li\u1ec7u theo d\u00f5i c\u00e1c ho\u1ea1t \u0111\u1ed9ng b\u1ea3o tr\u00ec, l\u1ecbch s\u1eed s\u1ef1 c\u1ed1 v\u00e0 xu h\u01b0\u1edbng hi\u1ec7u su\u1ea5t thi\u1ebft b\u1ecb. Th\u00f4ng tin n\u00e0y gi\u00fap t\u1ed1i \u01b0u h\u00f3a l\u1ecbch tr\u00ecnh b\u1ea3o tr\u00ec, x\u00e1c \u0111\u1ecbnh c\u00e1c s\u1ef1 c\u1ed1 th\u01b0\u1eddng xuy\u00ean v\u00e0 h\u1ed7 tr\u1ee3 c\u00e1c n\u1ed7 l\u1ef1c c\u1ea3i ti\u1ebfn li\u00ean t\u1ee5c.<\/p>\n

Ph\u1ea7n k\u1ebft lu\u1eadn<\/h2>\n

S\u1ea3n xu\u1ea5t l\u00f5i s\u1ee3i th\u00e0nh c\u00f4ng \u0111\u00f2i h\u1ecfi ph\u1ea3i ki\u1ec3m so\u00e1t ch\u00ednh x\u00e1c v\u1eadt li\u1ec7u, thi\u1ebft b\u1ecb v\u00e0 quy tr\u00ecnh trong to\u00e0n b\u1ed9 chu\u1ed7i s\u1ea3n xu\u1ea5t.<\/p>\n

\"Conceptual<\/p>\n

Minh h\u1ecda s\u01a1 \u0111\u1ed3 c\u00e1c giai \u0111o\u1ea1n ch\u00ednh trong s\u1ea3n xu\u1ea5t s\u1ee3i quang; kh\u00f4ng theo t\u1ef7 l\u1ec7.<\/em><\/p>\n

\n

Nghi\u00ean c\u1ee9u li\u00ean quan<\/h2>\n