Background technology
Traditional general cable core of All Dielectric self-support (being called for short ADSS optical cable) adopts layer-twisted type and central tubular structure, layer-twisted type structure has two kinds, as shown in Figure 1, more than wherein the current practical commercial of the two shielding layer structures of layer-twisted type is runed the large 1500m of span, and single sheath layer-twisted type structure is generally used in the built on stilts laying-out of span in 100m according to DL/T 788-2001 < < All Dielectric self-support > > standard-required.Although mention the ADSS optical cable of central tubular in DL/T 788-2001 < < All Dielectric self-support > > standard, but consider the shortcoming of manufacturing process difficulty and optical cable characteristic aspect, in fact almost do not apply, span is had never heard of especially in the commercial operation of 50m.
ADSS optical cable is a kind of nonmetal All Dielectric self-support, full medium be optical cable used be all insulation dielectric material; Self-bearing type refers to that self stiffener can bear deadweight and external load.The version of the ADSS optical cable of business application is in the market mainly loose sleeve pipe layer-twisted type structure.Because in layer-stranding cable, loose sleeve pipe is stranded with S-Z form, forms certain stranded remaining length.The remaining length of ADSS optical fibre in optical cable is very crucial technical indicator, and remaining length is too little, and optical fiber causes that by stressed loss increases, and even optical fiber is pulled off, and this is unallowed.Yu Changtai is large, and loose sleeve pipe is too little around the winding pitch of non-metal reinforcement member (being FRP), causes the static buckling strain of optical fiber excessive, also can affect the optical fiber life-span.Consider that ADSS is in built on stilts laid processes, it is larger that it is affected by meteorological environmental change, and ADSS optical cable must have suitable and stable remaining long control.Because long control more than layer-twisted type structure mainly obtains by the control of S-Z twisting pitch, as long as pitch control is suitable, just can obtain required remaining length.In optical communication industry, S-Z cable-former is quite ripe at present, has therefore brought up at present the primary structure of domestic large-scale use layer-twisted type structure as ADSS optical cable.
Along with the great development that FTTx builds in recent years, optical fiber is progressively unrestrained near to user side, and FTTx construction not only requires networking flexibility convenient, also needs with low cost.The layer stranded ADSS fiber optic cable structure of application is large in the market, and external diameter is thicker, and weight is large, and the load that is subject to external environment wind speed and icing also can increase, corresponding, and the aramid fiber of use is also many, and price will be higher like this, and construction is also inconvenient.
Summary of the invention
For the existing problem of prior art, the present invention proposes a kind of central pipe style complete self supported, and this optical cable comprises optical fiber, water-blocking material, loose sleeve pipe, aramid fiber and oversheath; Optical fiber is filled water-blocking material outward, by loose sleeve pipe, optical fiber and water-blocking material is wrapped up, and loose sleeve pipe is armoured aramid fiber, finally by oversheath, aramid fiber is wrapped up; Pine sleeve pipe comprises that internal layer once overlaps to be moulded and secondary coating, and once cover is moulded process using high-modulus, high strength, low shrinkable polymer, the polyolefine material that secondary coating process using glass temperature is low compared with internal layer polymer; This cable outer diameter is at 5~8mm, and specified tensile strength is 5600~24500 N, and it is 2240~9800 N that tension force is used in maximum permission, can realize wall pressure 2000 ~ 4000N/100mm.
Further, secondary coating polymkeric substance has suitable softening point, guarantees when oversheath extrusion molding, and when through hot water storgae, its oversheath temperature can be softened secondary coating layer, thereby realizes combining closely between secondary coating layer and oversheath.
The present invention also proposes a kind of manufacture method of central pipe style complete self supported, and this this optical cable comprises optical fiber, water-blocking material, loose sleeve pipe, aramid fiber and oversheath; Optical fiber is filled water-blocking material outward, by loose sleeve pipe, optical fiber and water-blocking material is wrapped up, and loose sleeve pipe is armoured aramid fiber, finally by oversheath, aramid fiber is wrapped up; Pine sleeve pipe comprises that internal layer once overlaps to be moulded and secondary coating, and once cover is moulded process using high-modulus, high strength, low shrinkable polymer, the polyolefine material that secondary coating process using glass temperature is low compared with internal layer polymer; This cable outer diameter is at 5~8mm, and specified tensile strength is 5600~24500 N, and it is 2240~9800 N that tension force is used in maximum permission, can realize wall pressure 2000 ~ 4000N/100mm.
This manufacture method comprises the following steps:
A. optical fiber warehouse-in: the optical fiber of warehouse-in is screened, select the good and qualified optical fiber of tension force of transport property.
B. optical fiber coloring: first by optical fiber coloring, the whole chromatogram of selection standard identifies, and requires high temperature colour-fast, easy to identify while guaranteeing to continue.
C. once cover is moulded; Optical fiber after painted is inserted in the high-modulus sleeve pipe that is filled with hydrophobic gel, makes sleeve pipe inner fiber there is stable remaining long control and transport property.
D. secondary coating: extrude again one deck polyolefine material outward at sleeve pipe and realize secondary coating technique.
E. wrap up oversheath: be evenly distributed on inner sheath surface with aramid yarn armouring, be inserted in the outer protective polyethylene cover of high-modulus; Wherein, inner sheath refers to the loose sleeve pipe of secondary coating
.
F. detect outbound: finally optical cable is done to full performance test, guarantee qualified rear encapsulation outbound.
Further, secondary coating polymkeric substance has suitable softening point, guarantees when outer protective sleeve extrusion molding, and when through hot water storgae, its outer protective sleeve temperature can be softened secondary coating layer, thereby realizes combining closely between secondary coating layer and oversheath.
The present invention is simple in structure, lightweight, and easy construction is quick, has reduced greatly construction period and construction cost, for the development of Access Network provides a kind of brand-new solution;
External diameter is little (can realize 12 core fibres, when tension force 5KN is used in the maximum permission of ADSS optical cable, external diameter is no more than 7.0mm), when built on stilts laying, be subject to external diameter environmental impact also just little, i.e. suffered load is little, is therefore meeting identical laying under environment, by mechanics, design, can be less with expensive non-metallic fibers reinforcement material, for the promotion and application of product provide power-assisted, cost basis has been established in the great development of also building for China FTTx.
The present invention adopts all dielectric self-supporting structural design, has obvious lightning protection effect, can utilize existing local telephone network electric pole directly to lay to family in the FTTx process of construction of rural area, and the popularization of building for rural area FTTx has brought facility.
The present invention adopts twice cover of central tubular to mould technique, both can mould operation by twice cover and realize control long more than loose sleeve pipe inner fiber secondary, the requirement of the mechanical property such as required high wall pressure, high strength and environment for use and temperature performance in the time of can realizing again the large span of this product and lay.
Embodiment
Below in conjunction with accompanying drawing, invention is further described.
The present invention adopts central tubular structure, namely whole cable only has a sleeve pipe, and adopt novel structural design and technology controlling and process, not only can well solve the remaining long problem of loose sleeve pipe inner fiber, but also can solve cable outer diameter thick, from problems such as great and construction inconvenience, for China FTTx builds, provide a kind of brand-new optical cable, it is as follows that it designs and develops process.
In structured design process, we have considered emphatically built on stilts feature of laying, i.e. following 3 points.
A. utilize existing local telephone network electric pole to lay, so the present invention considers at aspects such as structural design, technology controlling and process and costs all to lay as Theoretical Design basis so that self-supporting is built on stilts.
B. the present invention is ADSS optical cable, being laid on wire pole tower adopts gold utensil (strain insulator or overhanging golden tool) to be fixed installation, between gold utensil and optical cable, by preformed armor rods, be wound around the optical cable of holding with a firm grip (also can adopt other modes hold with a firm grip optical cable) and draw or hang, therefore ADSS optical cable must have certain anti-measuring pressure in case preformed armor rods (or other gold utensil) is held with a firm grip and damaged optical cable.
C. because it is that Self-bearing-type overhead lays application, therefore must have suitable and stable remaining long control, to guarantee its under complicated external diameter environment (as icing or strong wind situation), optical cable can bear certain load force, guarantees that optical cable normally moves.
By above 3 considerations, we mould by the agent of loose sleeve pipe secondary the high lateral pressure resistant that technique realizes optical cable and stablize suitable remaining long control.Popular saying is exactly first optical fiber to be moulded to technique by cover to be extruded onto into certain thickness loose sleeve pipe, fills water-blocking material in loose sleeve pipe, and then in pine cover tube outside, is extruded onto certain thickness polymeric material (as polyolefin), i.e. secondary coating technique by extruding machine again.Secondary coating technique is long more than conventional tension system and the control of tank step temperature reduction technology realize the secondary of loose sleeve pipe, the most important thing is to control by the wall thickness of secondary coating polymeric material the remaining length of loose sleeve pipe inner fiber, in the situation that other process conditions are identical, polymeric material wall thickness is larger, sleeve pipe shrinks larger, be that after secondary coating technique, loose sleeve pipe inner fiber is remaining long also just larger, while needing only us to secondary coating, wall thickness control obtains, just can obtain required remaining long control, and then realize remaining long control of central tubular ADSS optical cable.
Once cover is moulded technique and is generally adopted high-modulus, high strength, low shrinkable polymer, as polybutylene terephthalate (PBT), nylon or modified polypropene (PP) etc.; And secondary coating technique generally adopts glass temperature compared with polyolefine materials such as the low tygon of internal layer polymer or nylon.
Cable configuration of the present invention is described as: central tubular sleeve pipe, polyolefine material secondary coating, non-metallic fibers are strengthened polyethylene bonding sheath, and non-metallic fibers reinforcement material is generally selected aramid yarn, high carbon fiber yarn or thermosetting glass fiber yarn etc.
Referring to Fig. 2,4.
(1) loose sleeve pipe adopts double-layer composite material structure, greatly improved the lateral pressure resistant power (more than can realizing wall pressure 4000N/100mm) of central tubular ADSS optical cable, being convenient to gold utensil holds with a firm grip and does not damage optical cable, centered by the application of the large span of tubular type ADSS optical cable established theoretical foundation, central tubular ADSS optical cable can be met in the above span of 500m and lays application.
(2) the present invention is because of relatively traditional ADSS optical cable, and external diameter little (below 12 cores, external diameter is generally in 5~8mm), lightweight, intensity is high, and lateral pressure resistant performance is good, and following table is 2 cores, 6 cores and 12 core ADSS optical cable canonical parameter tables.
Table 1:2 core ADSS optical cable canonical parameter table
Table 2:6 core ADSS optical cable canonical parameter table
Table 3:12 core ADSS optical cable canonical parameter table
(3) loose sleeve pipe adopts two technique autofrettages, first with high-modulus, high-intensity polymkeric substance, once overlaps and moulds technique, then outside loose sleeve pipe, is directly coated the relatively little polymkeric substance of the certain thickness softening point of one deck again.
(4) by secondary coating technique, make once to overlap to mould and extrude the loose sleeve pipe forming, remaining temperature heating internal layer pine shell material (as PBT, nylon or PP) during through secondary coating, and higher than the glass temperature of internal layer pine shell material (as PBT, nylon or PP), realize the recrystallization of internal layer pine shell material (as PBT, nylon or PP), thereby can realize stable remaining long control of loose sleeve pipe, can exempt again loose sleeve pipe post shrinkage problem, improve stability and the resistance to temperature performance of product.
(5) secondary coating polymkeric substance of the present invention has suitable softening point, guarantee when outer protective sleeve extrusion molding, when through hot water storgae, its outer protective sleeve temperature can be softened secondary coating layer, thereby realize combining closely between secondary coating layer and oversheath, the required power value of oversheath of extracting 100mm length is not less than 40N, aramid fiber tension force is given full play to, and assurance optical cable entirety has well hales intensity.
(6) remaining long control not only of central tubular ADSS optical cable controlled by the fast difference of traditional retractable cable tension force control, the control of step water temperature and traction, and when the present invention adopts strict control secondary coating, the wall thickness of polymeric material is realized the long control in Dayu stable in loose sleeve pipe.
(7) by secondary coating operation, realize the long control in Dayu, more than loose sleeve pipe inner fiber, grow up in 8.0 ‰, solved the long defect that must adopt layer strand mode to realize of controlling in optical fiber Dayu.
Referring to Fig. 3, Fig. 3 is central pipe style complete self supported process chart, comprising:
A. optical fiber warehouse-in: the optical fiber of warehouse-in is screened, select the good and qualified optical fiber of tension force of transport property.
B. optical fiber coloring: first by optical fiber coloring, the whole chromatogram of selection standard identifies, and requires high temperature colour-fast, easy to identify while guaranteeing to continue.
C. once cover is moulded: the optical fiber after painted is inserted in the high-modulus sleeve pipe that is filled with hydrophobic gel, makes sleeve pipe inner fiber have stable remaining long control and transport property.
D. secondary coating: extrude again one deck polyolefine material outward at sleeve pipe and realize secondary tricks technique.
E. wrap up oversheath: be evenly distributed on inner sheath surface with aramid yarn armouring, be inserted in the outer protective polyethylene cover of high-modulus.
F. detect outbound: finally optical cable is done to full performance test, guarantee qualified rear encapsulation outbound.
Referring to Fig. 4, some optical fiber by internal layer once overlap mould technique by bale breaking loose sleeve pipe in, pine sleeve pipe internal clearance is filled water-blocking material, then in pine cover tube outside, be extruded onto again one layer of polymeric material (as polyolefin) and realize secondary coating technique, by secondary tricks technique, realize long requirement, then waterproofing type aramid yarn armouring and the polyolefin oversheath controlled in loose sleeve pipe inner fiber Dayu.
The above, be only a preferred embodiments of the present invention, and the interest field that the present invention advocates is not limited to this.The present invention also can have other various embodiments; in the situation that not deviating from spirit of the present invention and essence thereof; those skilled in the art are when making according to the present invention various corresponding changes and distortion, but these changes and distortion all should belong to the protection domain of the appended claim of the present invention.