CN1327154C

CN1327154C - Thermal contracting directional memory polyvinyl chloride pipe and manufacture thereof

Info

Publication number: CN1327154C
Application number: CNB2004100655419A
Authority: CN
Inventors: 徐益鑫
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-23
Filing date: 2004-11-23
Publication date: 2007-07-18
Anticipated expiration: 2024-11-23
Also published as: CN1614279A

Abstract

The present invention relates to a thermal contracting directional memory polyvinyl chloride pipe which belongs to the material field, and the material of the pipe has thermal directional contractibility memory in the radical direction and/or in the longitudinal direction. The present invention has manufacturing method which comprises the steps that polyvinyl chloride pipes are shaped, both ends of the shaped polyvinyl chloride pipes are blocked, and radical and longitudinal limiting stoppers are arranged on the shaped polyvinyl chloride pipes; sealing pipes are pressurized, and plastic pipes are heated to make shaped polyvinyl chloride pipes expanded; and contrarily, the plastic pipes are firstly heated until the plastic pipes are softened, and then, the sealing pipes are pressurized to make the shaped polyvinyl chloride pipes expanded. After the polyvinyl chloride pipes are cooled and shaped, pressure is released. The directional memory polyvinyl chloride pipes made of memory by physical pipe expansion not only ensures that the polyvinyl chloride pipes generate memory, but also ensures that the molecular structure of the polyvinyl chloride pipes which generate memory is not changed, the performance of plastic is not destroyed, and the plastic can be recycled; and meanwhile, radical and longitudinal directional contracting memory can be formed by the radical and longitudinal limiting stoppers in front of the expanding pipes, and the pipes can expand to the state of the original pipe diameter under the temperature condition of expanding the pipes. The product has the advantage of wide adaptation range and is especially suitable for conveying cold and hot water, chemical industry fluid, fuel gas, etc.

Description

The manufacture method of thermal contracting directional memory polyvinyl chloride pipe

Technical field

The present invention relates to the material field, refer in particular to a kind of manufacture method with thermal contracting directional memory polyvinyl chloride pipe.

Technical background

Macromolecular material thermal shrinkage memory, be applied in many occasions, as utilize thermal shrinkage memory to make two kinds of materials having different thermal expansion coefficient (steel, mould) fixing compound, and it can effectively prevent to be subjected in the using process thermally stratified layer, this utilizes moulds tubing at steel and has advantage especially in compound.Yet existing have a heat shrinkable material, be generally the polyethylene material, and need to form memory, as described in Chinese patent 00122353.4 through high-strength x radiation x, with the polyethylene adding assistant is that raw material is made the thermal contraction type pipe fitting, and it is cross-linking modified that stereotyped pipe fitting is injected row with the γShe Xian width of cloth.Because common polyethylene pipe does not have thermal shrinkage, but it is under actinism, crosslinked result makes polyvinyl plastics become reticular structure by linear structure, it is stereochemical structure, make newly-generated material production " memory effect ", for example squeeze the trombone slide material and can become big caliber through hot-expanding pipe processing, plastic tube is met the former caliber size before heat can be returned to expander once more.This polyethylene pipe with thermal shrinkage, make material sex change typing by optical radiation, therefore changed the characteristic of polyvinyl plastics, cause thermal shrinkage to use the non-renewable reuse in back, waste plastic not only brings harmful effect to environment, and waste material, make the renewable resources recycling of can not regenerating.The polyethylene pipe that another kind of manufacturing has thermal shrinkage is to handle by conduction oil, the oil temperature is higher, and the temperature of recovering former caliber size is also higher, and cost is bigger, particularly this recovery only is a kind of contraction memory, rather than can control radially, vertically shrink the directional memory of yardstick.In addition, simple polyethylene can't add additive owing to be monocrystal in the material, and tubing is in use aging easily, and the life-span is not long.Polyethylene forms memory temperature degree height, though can produce memory, owing to form the memory temperature height, difficult in practice the answer adopted polyethylene or crosslinked polyethylene, and they can not add admixture, and can not satisfy and go up a little special right to use requirements,

Chinese patent 98122029.0 discloses the manufacture method of a kind of hair side shape PVC packing with thermo-contract film, be that PVC, polyvinyl chloride surface are handled blending agent, stabilizer, plasticizer, tough dose and processing aid, in prescription regulation ratio mixing and stirring, heat first, be cooled to room temperature, send into extruder then, through making product after the heating for the second time.What the method was produced is to have the polychloroethylene film of remembering character, this film formed memory is nondirectional, and can't extend to production memory-type polychloroethylene pipes, because of pipe thickness is far longer than film, be difficult to form memory, the particularly memory of orthotype during production.

Summary of the invention

The present invention is just in order to overcome above-mentioned deficiency, a kind of method that is had the plastic tube of thermal contracting directional memory by the PVC manufacturing is provided, not only processing temperature is low, and, can realize many bluk recombinations because of PVC is a polycrystal, can in material, add special additive, as ultraviolet protecting agent etc., the thermal contracting directional memory polyvinyl chloride pipe that obtains life-span longer tubing, particularly treated one-tenth can continue reuse, can not destroy original character of material.The present invention is achieved like this: the manufacture method of thermal contracting directional memory polyvinyl chloride pipe, moulding polychloroethylene pipes at first, in the two ends shutoff of moulding pipe, and be provided with the footpath, longitudinal spacing, annotate with pressure and add thermoplastic tube to sealing tube and make its expansion or add thermoplastic tube to softening the notes to sealing tube more earlier and make its expansion with pressure, release pressure behind the cooling and shaping, the temperature that it is characterized in that adding thermoplastic tube is 70-110 ℃, directly, longitudinal spacing is metal tube, described metal tube is radially offered some break-through holes.

The present invention can add the admixture that some can guarantee some special-purpose according to different usage requirements when producing polychloroethylene pipes, for example antiager, antifungus, fire retardant etc. are so that pipe satisfies some specific usage requirement.

Of the present invention will moulding managed heating, and main effect is to make to mould to manage to soften, and it is expanded under the effect of interior swelling pressure power.Determine to mould pipe and be heated to and softeningly can both realize the pressure expand tube to plasticization temperature through testing, but wherein suitable to mould the pipe heating-up temperature be 70-110 ℃ that it is low to heat, and can cause expand tube pressure to increase, the expand tube overlong time, this be produce worthless; Heating-up temperature is too high, can be because pipe be burst near plasticization temperature, and tubing is difficult to return back to fully life size in the process of memory that sets back, and therefore proposing the preference temperature scope is 70-110 ℃.Wherein the better heating temperature is 80-100 ℃.

Described pipe is heated, and can carry out in air, also can carry out in liquid medium.For favourable expand tube evenly carries out, heat medium better adopts liquid medium, promptly for example makes pipe thermoplastic expand tube in water or the oil bath at liquid medium, and the method also helps and reduces production costs.

Expand tube of the present invention can be pressurization (applying swelling pressure power) in pipe earlier, and thermoplastic makes its expansion again; Also can be first with the pipe thermoplastic, pressurization makes its expansion again; Can also be that heating, pressurization are carried out simultaneously.These do not have essential distinction to the inventive method, but think through test, better be to adopt heating earlier to make pipe softening, and the expand tube that pressurizes again, expand tube even is good to property like this, and owing to pressing time is short, little to the tube wall damage, and help reminiscence.

Expand tube of the present invention radially, vertically limit, its mainly act on be limit in the expand tube process expand tube radially, longitudinal size.A kind of better is the hard microdilatancy or the pipe that do not expand that adopts the design final size, and for example metal tube can certainly adopt other can place restrictions on expansion gear.Make the bloated device of limit with pipe, a kind of better is radially to offer some break-through holes at pipe, is beneficial to the current drainage of tubing gas-liquid in liquid medium.

Cooling and shaping behind the expand tube, main effect are to make the softening solid type of pipe cooling of moulding, and it can the solid type of natural cooling, also can the solid type of quenching.Just can solid type as long as be lower than softening temperature theoretically, but consider the effect of producing memory, the present invention better adopts the solid type of quenching, and from easy to operate consideration, common quenching is to room temperature.

The PVC electrostatic storage tube that the present invention produces owing to adopt the physics expand tube to form memory, can not only make the PVC pipe can produce memory, and the plastics that generation is recalled not changed structure of molecule, does not destroy plastics performance, can reuse; Simultaneously can by before the expand tube radially, longitudinal spacing, make merely the tubing that vertically all there are different directional retraction in radially thermal shrinkage (vertically not shrinking), simple vertically thermal shrinkage (radially not shrinking) or footpath, required to be fit to different occasions.Make the polyvinyl chloride pipe that forms in this way, under the temperature conditions of expand tube, tubing can return to former caliber state, and by footpath, longitudinal register before the expand tube, makes it possess the directional memory of thermal shrinkage.In addition because of can adding functional admixture in the tubing, the tubing longer service life, accommodation is extensive, is particularly suitable for the conveying of hot and cold water, chemical industry fluid, combustion gas etc.

Embodiment

Embodiment 1, thermal contracting directional memory polyvinyl chloride pipe radially, manufacture method is earlier PVC to be squeezed pipe, the shutoff of pipe two ends, put a diameter greater than tubing and radially offer the metal tube of some break-through holes on the tube wall, the metal tube longitudinal length is that pipe length is promptly controlled tubing and vertically do not extended leeway with resistance head, air valve length sum, fix position-limiting tube, be immersed in thermoplastic in the water-bath about 100 ℃, inflation in pipe simultaneously during immersion, the expand tube while softening, quenching to room temperature is finalized the design, position-limiting tube is withdrawed from the venting decompression.

Embodiment 2, vertical thermal contracting directional memory polyvinyl chloride pipe, manufacture method is will be added with ageing-resistant PVC earlier to squeeze pipe, the shutoff of pipe two ends, an internal diameter is equal to tube outer diameter and radially offers the metal tube of some break-through holes on the tube wall on the cutting ferrule, the metal tube longitudinal length is the controlling value greater than pipe length, even it does not radially have elongation leeway, fix position-limiting tube, after sealing tube is annotated with pressure, it is immersed in thermoplastic in the water-bath about 70 ℃, tubing after expanding then is cooled to room temperature, and the releasing tube internal pressure withdraws from position-limiting tube.

Embodiment 3, reference example 1,2, change the length and the internal diameter of spacing metal tube, use to produce radially, vertically all have inotropic directional memory polyvinyl chloride pipe, wherein be added with external additives such as antifungus, fire retardant during the moulding polychloroethylene pipes with quadrat method, plastic tube is softening with 110 ℃ oil bath earlier, pressurising is expanded in it again, and quenching to room temperature is finalized the design, and removes spacing metal tube after moving back pressure.

Claims

1. the manufacture method of thermal contracting directional memory polyvinyl chloride pipe, moulding polychloroethylene pipes at first, in the two ends shutoff of moulding pipe, and be provided with the footpath, longitudinal spacing, annotate with pressure and add thermoplastic tube to sealing tube and make its expansion or add thermoplastic tube earlier and make its expansion with pressure to softening the notes to sealing tube again, release pressure behind the cooling and shaping, the temperature that it is characterized in that adding thermoplastic tube is 70-110 ℃, directly, longitudinal spacing is metal tube, described metal tube is radially offered some break-through holes.

2. method according to claim 1, the optimum temperature that it is characterized in that adding thermoplastic tube is 80-100 ℃.

3. method according to claim 1 and 2 is characterized in that adopting the liquid medium heating.

4. method according to claim 3 is characterized in that liquid medium is water-bath or oil bath.

5. method according to claim 1, the best mode that it is characterized in that cooling and shaping is quenching, quench temperature is a room temperature.

6. method according to claim 1 when it is characterized in that the moulding polychloroethylene pipes, can be added with admixture.