KR840002424B1 - Method of making reinforced tubular artides - Google Patents

Abstract

Reinforced hose is made by extruding and partially vulcanizing a rubber tube, coating the tube with a liquefied polymer such as a PVC plastisol or latex, and overwrapping the coated tube with reinforcing filaments so that the reinforcement is immersed or permeated by the coating before the coating is solidified. The hose surface may be pretreated by e.q. halogenation or oxidation to enhance adhesion of the coating.

Description

Manufacturing method of reinforcement pipe product

1 shows a diagram of an apparatus for use in one method according to the invention.

2 shows a detail of a part of the apparatus of FIG. 1;

3 shows a diagram of an apparatus for use in another method according to the invention.

The present invention relates to reinforcing pipe products and in particular to the manufacture of pipe products such as hoses.

One common method of manufacturing a long hose is to extrude a non-hardened rubber on a nylon core to form an inner wall of the tube, wrap the inner layer wall with a reinforcing cord layer, and then extrude another rubber layer to form an outer sheath layer for the hose. It was to form. The assembly thus formed is refurbished with lead and heated in an autoclave, which acts with the mandrel to squeeze the hose wall and harden the rubber as the component layers consolidate and solidify.

This method is time consuming, requires a lot of thermal energy and compromises health and safety.

Related devices are also expensive and cumbersome. The present invention provides an improved hose or other related article and a method of making the same.

According to the present invention, a method for producing a reinforcement pipe product having an inner tube of hardened rubber is constituted as follows. The inner tube of a rubber composition that can be cured is formed, and a reagent for halogenating the surface is applied to the outer surface of the inner tube. Then, the aforementioned inner tube is passed through the fluidized-phase hardening unit so that at least part of the inner tube is cured and the aforementioned tube is self-helping continuously. And a reinforcing material assembly is formed on the outer surface of the inner tube by the solidifying liquid polymer material so that the outer surface of the reinforcing material and the tube when the solidified. It is desirable to enclose the reinforcement in a highly compatible liquid polymer.

The reinforcement assembly can, for example, apply a reinforcing material to the tube and then contact the reinforcing material assembly by applying a reinforcing material to the tube and then applying the reinforcing material to the tube. have.

It is considered that the method of applying the reinforcement to the surface of the tube treated with the highly polymerizable liquid polymer is more effective than using the reinforcement material soaked in the liquid in advance.If there is a gap between neighboring reinforcements, the liquid polymer deforms on the inner surface of the pipe. The reinforcement should be used under pressure that can penetrate between the gaps without causing them.

It is desirable to harden or partially cure the inner tube to form a self-supporting force capable of maintaining its cross section without the use of a solid or rigid mandrel when forming the reinforcement assembly. However, especially when the thickness of the pipe wall is less than the total cross sectional area of the pipe, the pipe can be pressurized from the inside so that the shape of the cross section of the pipe can be maintained when forming the reinforcement assembly.

The reinforcement may be in the form of, for example, strips, coats, yarns, strands or filaments, and may in particular consist of a group of filaments that are slightly twisted or barely twisted. The reinforcement material may be a fabric such as an aromatic polyamide such as rayon, polarizer, or kevlar (dupont), or a metallic material such as glass or steel strip or steel wire.

The reinforcement may be applied parallel or helically to the inner tube long axis, for example woven or knitted or plaited.

After the reinforcing material assembly is produced on the inner tube circumference, the outer layer of the polymerizable material may be formed on the circumference of the reinforcing material by extruding or wrapping the polymeric material. In order to secure the adhesion between the outer layer and the reinforcing material, the liquid reinforcing material which combines the reinforcing material with the inner tube should be covered with the liquid reinforcing material which is not sufficiently present in the assembly skin in advance. Although it is necessary to pretreat the solidification material to solidify it selectively, it is surprisingly possible to apply the outer layer while the solidification material is still in the liquid state, especially if the solidification liquid polymer is a PVC (PVC) plastisol. Yes it was found. A suitable form for the outer layer material is plastisol, which may be the same material as which the reinforcement is combined with the inner tube or may be a specially processed or colored material with selected physical properties or colors, for example. If the reinforcement is placed in a highly polymerizable polymer, the polymer may be first heated to an appropriate temperature or optionally treated with a solution or solvent consisting of PVC, cyclohexanone and methyl ethyl ketone to help achieve good skin adhesion. have.

Another suitable material for the outer layer is a thermoplastic polyurethane such as Daltomold 238 (ex. ICI), which may be applied to the solidified liquid polymer if at least the solid polymer is PVC plastisol containing resorcinol and hexamethylenetetramine. It has been found to give good adhesion. If the pipe product is in the form of a hose, the inner pipe mentioned above may constitute the pipe wall of the hose finished product, which may form an inner layer under the reinforcement and surrounding the pipe wall material.

It is understood from the foregoing that the present invention represents a method of making a hose or tubular article having at least part of an inner layer of a cured rubber composition, wherein the outer layer provided by the present invention is a rubber composition or a plastics material.

When a reinforcing pipe product manufactured according to the method of the present invention is provided, the pipe product is composed of an inner tube made of a rubber composition at least partially cured by an assembly of reinforcing materials bonded to the inner pipe by a solidifying polymer material.

The rubber composition is preferably composed of unsaturated rubbers containing 5 or more unsaturated bonds per 100 carbon atoms of the main carbon chain, more preferably 15 or more unsaturated bonds. The rubber composition is preferably based on nonpolar rubber, such as natural rubber, styrene / butadiene rubber, but may be based on polar rubber such as polychloroprene or mixtures thereof. The rubber composition may contain conventional additives (eg fillers) or processing agents. The rubber composition may be cured with sulfur or by other conventional curing methods.

Examples of suitable treatment agents that will halogenate the rubber surface of the inner tube include, for example, trichloro isocyanuric acid (Fisons trademark Fi-Clor 91 may be used), acidified inorganic hypophosphite (e.g., acidified sodium hypochlorite). And chemical reagents such as alkylhypohalite (e.g. butylhypochlorite). Preferably chemical reagents are applied in a conventional manner, for example by dipping, spraying and brushing, with a non-aqueous solution such as a solution in an organic solvent such as ethyl acetate or acetone.

및-OH로 부터 선택된 극성형태의 기를 적어도 하나 함유하는 극성중합체인 것이 바람직하며, 9(cals/cc)^½이상의 용해도 파라메타를 갖는 것이 바람직하며 9(cals/cc)^½이상인 것이 바람직하다. "용해도 파라메타"는 응집에너지밀도의 평방근을 뜻하며 중합체내의 분자간력의 크기를 나타낸다.Highly flammable liquid polymers

-OH, and preferably at least one polar group-containing polymer of polar type is selected from, and 9, it is preferable, and preferably not less than 9 (cals / cc) ^½ having the (cals / cc) a solubility parameter at least ^½. "Solubility parameter" refers to the square root of the cohesive energy density and represents the magnitude of the intermolecular force in the polymer.

Examples of suitable materials include vinyl chloride polymers in the form of plastisols, aliphatic polyamides, polyurethanes, poly (vinel acetate) ethylene / vinylacetate copolymers and rubbers in the form of latexes, nitrated rubbers or carboxylated nitrile rubbers. .

The term "vinyl chloride polymer" is used herein to include poly (vinyl chloride) and copolymers of vinyl chloride and other monomers. Other monomers are vinyl esters and alkacrylates. The copolymer should contain at least 50% by weight vinyl chloride units. Examples of suitable copolymers include vinyl chloride and vinyl acetate or methyl acrylate.

Solidified liquid polymers can be used in the form of solutions, suspensions (such as in plastisols), latex, or two liquid compositions that form a solid polymer by interaction. The liquid substance is used in the rubber composition and then heated to a temperature (such that it can solidify on cooling). If desired, it can be further solidified after the first solidification. It is preferable that the solidification liquid polymer material contains a component that produces a resin such as a condensation aldehyde resin. Examples of suitable suitable aldehyde condensation resin-producing components include aromatic hardygosy compounds, in particular resorcinol, prologlusinoltetramine, hexamethylmelamine, lauryloxymethyl pyridinium chloride, cetyloxymethylpyridinium chloride or formaldehyde polymer. It is a compound capable of releasing methylene groups when heated. Alternatively, partially or completely condensed resins, such as condensation aldehyde resins, may be contained in the solidified liquid polymer, such as melamine and urea-formaldehyde resins. When the resin-forming component or the partially or completely condensed resin is included in the polymeric material, it is preferable to include the epoxy resin or isocyanate in the polymeric material. These other ingredients can reduce the potential porosity of the highly polymerizable polymer.

The resin raw component, partial condensation resin or complete condensation resin is preferably present at a ratio of 3.2 to 12 parts by weight based on 100 parts by weight of the polymer. In the case of using the aromatic hydroxy chemical and the compound which releases the methylene group when heated as the resin generating component, they are preferably present in the range of 2-7.5 parts and 1.2-7.5 parts, respectively, based on 100 parts by weight of the polymer.

In case the solid polymer liquid or the outer layer is a liquid that generates polyurethane by reaction, to prevent the liquid from sedimenting itself when mixing the components (for example, by adding a stabilizer such as sodium chloride to the diamine component of the liquid or protecting isocyanate) Methods well known in the art, such as reacting with a phenolic reagent. Stabilizers have been shown to inhibit the reaction of liquids that produce polyurethane when heated above a certain temperature, and thus such materials can be conveniently coated on partially formed hoses.

Two embodiments of the present invention will be described with reference to the accompanying drawings. The inner tube 10 made of styrene / butadiene rubber is extruded from the extruder 11 to form an inner wall layer of a 100 mm diameter hose. The wall thickness of the tube is 2mm. Prior to vulcanization of the outer surface of the tube from the extruder, it is sprayed in units of 22 using ethyl acetate or acetone solution containing 1% isocyanuric acid, such as Fi-clor 91 (ex Fisons).

The surface treated tube 10 is passed through a fluidized bed 12 to cure the tube. In order to help uniformly cure the material around the tube circumference, an infrared heater (not shown) is placed on the fluidized bed surface to completely cure the tube or the closest surface of the fluidized bed.

Surprisingly, by treating the tube before curing, it was surprisingly found that the surface of the tube was not tacky so that the fluid particles did not adhere to the surface of the tube as it passed through the fluidized bed.

Therefore, the outer skin of the pipe (23) is only slightly washed, the pipe directly to the reinforcing composition application unit 13 (see also Figure 2). The application unit 13 is rotated in the opposite direction to the die 14, which is applied as a thin coating around the tube where the PVC plastic sol is cooled through the pump 14a, and treated with plastisol to form a spiral nylon cord around the tube. It consists of two carousels that produce a pair of stiffener layers 16. The die 14 is cooled with water to neutralize the heating effect of the plastisol passing therethrough, thus allowing the applied plastisol to have a uniform viscosity while using the die.

At the outlet of the application unit 13 is provided a smoothing die 17 incorporating the reinforcing cord and the plastisol, allowing the plastisol to penetrate into the gap between the cord and the filament of the cord, The die also gives the hose assembly a smooth appearance.

At the outlet of the application unit 13 is provided a smoothing die 17 incorporating the reinforcing cord and the plastisol, which allows the plastisol to penetrate into the gap between the cord and the filament of the cord, This die also gives the hose assembly a smooth appearance.

The hose assembly is sent to the heating chamber 18 (where the heat supplied by the heating chamber and the heat of the newly reinforced inner tube 10 combine to solidify the PVC plastisol) and a haul-off capstan. (25) Pass the circumference.

The hose assembly is then passed through an extruder 19, which coats the PVC shell layer 20 of about 2 mm thickness to the assembly. The hose is then wound on the drum 24 through the cooling bath 21. The cooling outlet is equipped with a camstan (not shown) to help the inner tube extruded from the extruder to flow out smoothly through the device line. This is because the hardening of the inner tube 10 in this method helps to maintain the annular cross section of the hardened extruded tube by deforming in the fluidized bed.

The maintenance of the annular cross section is aided by the slight air pressure maintained in the hardened inner tube through a passage (not shown) in the extruder 11.

The use of a treating agent for good bonding with PVC plastisols in the above process is described. This treatment also serves to prevent the fluid phase particles from adhering to the outer surface of the tube 10 to some extent.

After curing, the treatment of the inner tube surface instead of curing has the advantage of avoiding the risk of the curing step, which makes the tube surface dirty and insensitive to treatment.

In this way the hose can be made by moving the inner tube 10 horizontally but it can be advantageous by moving the tube vertically, preferably the extruded tube upwards if space permits. In the vertical operation, the liquid applied to the tube, i.e. the treatment agent or plastisol, does not tend to move circumferentially around the tube, so that a coating of more uniform thickness can be obtained.

A second embodiment of the present invention will be described with reference to FIG. In this method, an uncured hose inner tube is formed by the extruder 30 and surface treated with the treatment agent in the applicator 31 and cured in the fluidized bed 32 as in the previous embodiment.

However, the outer surface must be cooled before PVC plastisol is applied to the outer surface. This is done by passing the inner tube through a spray chamber 33 into which liquid nitrogen is sprayed. The surface of the cooled inner tube is then coated with PVC plastisol using a plastisol applicator 34 positioned adjacent to the spray chamber 33. The tube treated with plastisol is then passed through the spiral unit 35 to wind the two layers of reinforcement over the hose pole and through the infrared heater 36 and then operate as in the first embodiment.

In the method described above, cooling the inner tube surface with liquid nitrogen results in a rapid temperature gradient on the tube wall, which prevents the initial gelling of the plastisol until a reinforcement is used and buried. However, after the reinforcing material is wound, the generous heat is applied to the external surface to help the PVC plastisol to gel, and the infrared heater 36 serves to provide another heat necessary for complete gelation. The extruder 37 provides a shell layer and the hose assembly thus formed is cooled in the cooling chamber 38 and submerged in units 39.

The present invention is carried out in one step as detailed above, but the present invention can be used to manufacture hoses or other reinforcement pipe products using a multi-step method consisting of two or more steps at intervals of time. Thus, for example, in the first step of a modified method of making a hose, at least a portion of the inner tube is formed of cured rubber, almost as described in the first embodiment of the invention, coated with PVC plastisol, and then PVC plastisol is applied. Solidify.

The assembly thus formed is stored to complete the production of the reinforcement tube product in a two step operation.

In step 2, the inner tube coated with the PVC plastisol is coated with the PVC plastisol once more, and the reinforcing filament is wound to generate the reinforcing structure, and then operated as in the first embodiment to prepare a complete hose.

The bond strength between the reinforcing structure and the inner tube produced by the dividing method as described above is not significantly affected by the bond strength obtained by the one-step process.

Highly flexible PVC plastisols provide a surface to which highly compatible plastisols can be easily attached to an inner tube that has a strong bond to the inner tube but has an uncontaminated outer surface.

While the conventional method uses plastics of almost solid non-vulcanized soft rubber to fill the gaps between the reinforcing materials, the present invention uses a solidified liquid polymer to fill such gaps. Since the liquid polymer moves more easily than soft rubber, the penetration of the reinforcement is better and thus a more reliable, consistent quality product can be obtained. By eliminating the need for using support shafts and lead retrofits, the present invention also provides a faster, safer and less energy consuming method. There is no need to heat and cool the mandrel while curing the canal and solidifying the liquid polymer.

The present invention can be used not only to produce flexible hoses but also to manufacture other tubular products, such as cylindrical or conical structures, used to produce reinforcing pipes and air suspension plates.

Claims (1)

Forming the inner tube of the rubber composition which can be cured, applying a reagent for halogenating the surface to the outer surface of the inner tube, and then passing the inner tube through the fluidized-phase hardening unit so that at least part of the inner tube is cured. This self-help, and the reinforcing material assembly is formed on the outer surface of the inner tube as described above by the solidifying liquid polymer material to combine the reinforcing material and the outer surface of the tube when the solidifying liquid polymer is solidified A method of making a reinforcement tube product having an inner lining tube of cured rubber consisting of:

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