JP2015512021A - HVAC duct using phenolic foam and method for producing the same - Google Patents

Abstract

The present invention relates to an HVAC duct and a method of manufacturing the same, wherein the duct includes a core layer including phenol foam, and a front plate and a rear plate formed on the front and rear surfaces of the core layer, each having a metal layer. Complementing the disadvantages of secondary construction of heat insulation material on existing metal ducts, the construction is simple, high thermal insulation performance with a thermal conductivity of 0.020 W / mK or less and non-combustibility equivalent to flame retardant grade 2 The present invention relates to a technology for providing a high-performance HVAC duct, which is excellent in air density, does not cause condensation, and has a sound insulation effect.

Description

  The present invention relates to a duct for HVAC and a method for manufacturing the same. More specifically, the present invention relates to a metal layer on a front surface and a rear surface and a core layer therebetween, and by forming a phenol foam in an integrated manner, The present invention relates to a technology for providing a duct for HVAC that satisfies the shortcoming of covering a metal duct with a heat insulating material to satisfy high heat insulating performance, flame retardancy, workability, and airtightness.

  Composite panels requiring heat insulation and heat resistance are applied to ducts for HVAC (Heating, Ventilation, and Air Conditioning). In such a composite panel, the front plate and the rear plate are made of steel plates such as aluminum, magnesium, and iron.

  And in the case of the existing metal duct, there exists a problem that construction is troublesome by using the method which covers glass wool, a heat insulating material, etc. as a secondary operation | work at the time of installation after primary manufacture.

  Here, when the core layer is formed of polyethylene (PE), since polyethylene is easily ignited, it is very vulnerable to fire hazard.

  As an example, Korean Patent Publication No. 10-0828630 discloses a flame retardant composite panel containing a flame retardant synthetic resin mainly composed of polyethylene (PE).

  The core layer is filled with a flame retardant or an excessive amount of talc. However, in this case, since the specific gravity is large, the construction is difficult and the construction cost is increased.

  In addition, when the core layer is filled with glass wool or rock wool, the panel has an advantage that it is nonflammable, but there is a problem in that the heat insulation performance is lowered due to high thermal conductivity. Furthermore, glass wool or rock wool has a problem of acting as an element harmful to the human body.

  The present invention can solve the problem of fire occurrence and the generation of gas harmful to the human body at the time of combustion, which has been a problem with HVAC ducts using glass wool, rubber foam flame retardant, or hard urethane, and secondarily It is an object of the present invention to provide an integrated HVAC duct and a method for manufacturing the same that can solve the construction cost problem caused by the work of covering the heat insulating material.

  The present invention also provides an HVAC duct having high heat insulation performance with a thermal conductivity of 0.020 W / mK or less and nonflammability equivalent to flame retardant class 2, and a method for producing the same.

  In order to achieve the above object, an HVAC duct according to the present invention includes a core layer including phenol foam, and a front plate and a rear plate formed on the front and rear surfaces of the core layer, each having a metal layer. It is characterized by.

Moreover, the manufacturing method of the HVAC duct concerning this invention for achieving the said objective is (a).
A step of preparing a front plate and a rear plate having a metal layer; and (b) a phenol resin composition is introduced between the front plate and the rear plate and then foam-cured to form a duct-forming panel containing phenol foam. And (c) curing and aging the phenolic foam contained in the panel.

  The HVAC duct according to the present invention can ensure both heat insulation and flame retardancy by forming the core layer with phenol foam. Therefore, the HVAC duct to which the present invention is applied has an incombustible level of flame retardancy, and thus has an advantage of improving safety during a fire.

  Moreover, since the HVAC duct according to the present invention exhibits a high thermal insulation property with a thermal conductivity of 0.020 W / mK or less, it can save heating costs, has excellent airtightness, does not cause condensation, and has a sound insulation effect. There is an advantage of being excellent.

  Further, the phenol foam forming the core layer of the present invention does not use chlorofluorocarbon and uses an environmentally friendly blowing agent such as hydrocarbon which is not HCFC (hydro-chloro-fluor-carbon) blowing agent. Therefore, there is no risk factor for global warming, providing the effect of maintaining high thermal insulation performance and prevention of condensation in the long term.

  Further, in the case of the existing metal duct, there is a disadvantage that the construction is troublesome by the operation of covering the heat insulating material secondarily, but the duct according to the present invention is an integrated type, and the upper / lower metal layer and phenol Since the foam is included, the construction is simple, and it is easy to cut.

It is sectional drawing showing the HVAC duct containing the phenol foam concerning this invention. It is a flowchart showing the manufacturing step of the HVAC duct containing the phenol foam concerning this invention.

  The advantages and features of the present invention, and the manner in which they are accomplished, will become apparent with reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in various forms different from each other. The embodiments merely provide a complete disclosure of the present invention and the technical field to which the present invention belongs. In order to fully inform those skilled in the art of the scope of the invention, the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

  Hereinafter, an HVAC duct according to a preferred embodiment of the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an HVAC duct using a phenol foam according to the present invention.

  Referring to FIG. 1, the illustrated HVAC duct 100 includes a core layer 10, a front plate 11, and a rear plate 12.

The phenol foam contained in the core layer 10 is a foam mainly composed of a phenol resin. The phenol foam is formed of a phenol foam resin composition containing a phenol resin, a hydrocarbon foaming agent, and an additive.

  Examples of the phenol resin include a resol type phenol resin synthesized with an alkali metal hydroxide or an alkaline earth metal hydroxide. In addition to the resol type phenol resin, a novolak type phenol resin synthesized by an acid catalyst, an ammonia resol type phenol resin synthesized by ammonia, a benzyl ether type phenol resin synthesized by lead naphthenate, or the like can be given. The phenolic resin may be a mixture of different types.

  As an example, the resol type phenol resin can be obtained by polymerizing by using phenol and formalin as raw materials and heating with an alkali catalyst in a temperature range of 40 ° C. to 100 ° C. Moreover, you may add additives, such as a urea, at the time of resole resin polymerization as needed. When adding urea, it is more preferable to mix urea methylolated with an alkali catalyst in advance into the resole resin. Since the resole resin after synthesis usually contains excess water, it is adjusted to a moisture content suitable for foaming at the time of foaming. Such a phenolic resin may be included in an amount of 60% by weight to 80% by weight based on the total weight of the composition.

  Moreover, the phenol foam resin composition concerning this invention contains a hydrocarbon type foaming agent. The foaming agent functions to form a foam structure.

  In the present invention, an aliphatic hydrocarbon blowing agent having 1 to 8 carbon atoms is used as the blowing agent. Previously, chlorofluorocarbon or HCFC (hydro-chloro-fluoro-carbon) was used as a foaming agent, which caused a problem of global warming due to ozone layer destruction. However, in the present invention, by using a hydrocarbon as a blowing agent, it is possible to eliminate the burden on the danger of threatening the environment as compared with the conventional case.

  Examples of hydrocarbons that can be used as a blowing agent in the present invention include cyclopentane, isopentane, and isobutane, and it is preferable to select them in consideration of the thermal conductivity and boiling point of the blowing agent.

  The foaming agent preferably contains one or more selected from the group consisting of one or more of isopentane, isobutane, and cyclopentane.

  By using the hydrocarbon as a blowing agent, the initial thermal conductivity and long-term durability of the phenol foam according to the present invention can have the desired physical property values, and the burden on environmental pollution can be eliminated. become.

  The foaming agent is preferably included in an amount of 3% to 15% by weight based on the total weight of the phenol foam resin composition. When the content of the foaming agent is less than 3% by weight, sufficient foaming is not performed, so that heat transfer is performed through the solid surface of the foam, resulting in a decrease in efficiency. On the contrary, when the content of the foaming agent exceeds 15% by weight, a phenomenon in which an excessive amount of the foaming agent breaks out of the cell wall during the curing and expansion process and the closed cell rate and the thermal conductivity are deteriorated.

  The phenol foam resin composition according to the present invention may further contain a surfactant, a curing agent, a plasticizer, and a neutralizing agent as additives.

In the present invention, the surfactant not only serves to stabilize the interface between a finely dispersed hydrophobic substance such as a foaming agent and a hydrophilic substance such as a resin, but also stabilizes the cell surface when foaming proceeds. It will be formed and will not break. Specific examples include non-ionic surfactants such as polysiloxanes, polyoxyethylene sorbitan fatty acid esters, and castor oil ethylene oxide adducts.

  The surfactant is preferably included in an amount of 0.5 to 10% by weight based on the total weight of the phenol foam resin composition. If the surfactant content is less than 0.5% by weight, the compatibility between the raw materials is reduced, and a phenol foam having a large bubble and a low closed cell ratio is formed. If the content exceeds 5% by weight, the hardness of the phenol foam is increased. It becomes low and handling of the finished product becomes poor.

  In the present invention, the curing agent serves to cure the phenol resin at a temperature of 100 ° C. or lower. Specific examples include inorganic acids such as sulfuric acid and phosphoric acid, and organic acids such as benzenesulfonic acid, ethylbenzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, naphtholsulfonic acid, and phenolsulfonic acid. Of these, benzenesulfonic acid, ethylbenzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, naphtholsulfonic acid and phenolsulfonic acid are preferred. One of these curing agents may be used alone, or two or more thereof may be used in combination.

  The curing agent is preferably included in an amount of 5 to 20% by weight based on the total weight of the phenol foam resin composition. When the content of the curing agent is less than 5% by weight, foaming is performed before the curing, so the foaming gas escapes and bubbles are not formed well. When the content exceeds 20% by weight, the curing progresses quickly and foaming is sufficient. In addition to not being carried out, the pH becomes too low.

  On the other hand, in the duct containing the phenol foam according to the present invention, in order to increase the density of the phenol foam and ensure the rigidity of the duct, the content of the foaming agent is slightly reduced to 3 to 10% by weight, More preferably, the content is in the range of 10% to 25% by weight.

  In the present invention, the plasticizer plays a role of enhancing long-term durability in order to impart flexibility to the bubble wall surface and prevent the wall surface from cracking or deteriorating to prevent the foaming gas in the bubble from being replaced by air. Specific examples include triphenyl phosphate, dimethyl terephthalate, dimethyl isophthalate, polyethylene glycol, polyol, and the like.

  The plasticizer is preferably included in an amount of 1% to 15% by weight based on the total weight of the phenol foam resin composition. If the content of the additive is less than 1% by weight, the long-term durability is not affected, and if it exceeds 15% by weight, the performance of the phenol foam is deteriorated.

  In the present invention, the neutralizing agent serves to increase the pH of the phenol foam resin composition to about 3 to 9.

  Generally, since an acidic curing agent is used during the production of phenol foam, the product is acidic, and there is a problem of reliability such that corrosion occurs on the bonded surface between the finished plate and the metal.

  Therefore, the present invention uses a neutralizing agent to make the phenolic resin cured foam neutral. Examples of the neutralizing agent in the present invention include hydroxides and oxides of metals such as aluminum hydroxide, magnesium hydroxide, calcium oxide, magnesium oxide, aluminum oxide, and zinc oxide, metal powders such as zinc, calcium carbonate, Metal carbonates such as magnesium carbonate, barium carbonate, and zinc carbonate can be contained. These may be used individually by 1 type and may be used in combination of 2 or more type. The neutralizing agent is preferably included in an amount of 0.5 to 50% by weight based on the total weight of the phenol foam resin composition.

  When the content of the neutralizing agent is less than 0.5% by weight, the phenol foam becomes acidic, and when it exceeds 50% by weight, a problem of physical property change occurs.

  The phenol foam which forms the core layer of this invention can be manufactured with the above phenol foam resin compositions.

  On the other hand, the closed cell content of the phenol foam of the present invention is preferably 85% or more. The closed cell ratio means a fraction of bubbles confined among bubbles formed in a unit area. In the present invention, when the closed cell ratio is less than 85%, the foaming agent slowly escapes to the outside, leading to long-term performance degradation, and the structural strength can be significantly lowered to deteriorate the properties of the HVAC duct.

  The duct containing the phenolic resin cured foam of the present invention as described above has a thermal conductivity of 0.02 W / mK or less, and exhibits extremely excellent heat insulation performance.

  In the present invention, the HVAC duct containing phenol foam includes a front plate and a rear plate each having a metal layer on the front and rear surfaces of the core layer.

  Each of the front plate and the rear plate includes a metal layer. The metal layer may be formed of one or more metal foil layers, and the thickness of the metal layer is preferably 10 μm to 90 μm. At this time, if the thickness of the metal layer is less than 10 μm, there is a risk of fire because the flame retardancy cannot be satisfied. The duct according to the present invention has a problem that since the thickness of the metal layer is 90 μm and flame retardancy is ensured, when the thickness exceeds 90 μm, the weight is rather increased and the construction efficiency is relatively lowered. .

  The metal layer can be used without particular limitation as long as it is formed of a metal that ensures heat insulation of the duct according to the present invention, but preferably aluminum, stainless steel, magnesium, gold, silver, copper, What contains 1 or more types chosen from lead and titanium can be used.

  Further, in the front plate or the rear plate, a reinforcing material layer and a protective layer formed of glass fiber, glass mat, tissue, etc. are provided on the outer surface of the metal layer. Furthermore, it can be formed to complement flame retardancy and dimensional stability.

Below, the manufacturing method of the HVAC duct of this invention is demonstrated in detail.
Unlike the method of covering glass wool and heat insulating material as a secondary work during installation after primary production in existing metal ducts, in the case of ducts using phenol foam, a metal layer is placed on the front and rear plates. And since the phenol foam which has high heat insulation performance as a core layer is integrally formed, the duct satisfy | filling airtightness, workability, and heat insulation can be manufactured.

  FIG. 2 is a flow chart showing manufacturing steps of the HVAC duct according to the present invention.

Referring to FIG. 2, the HVAC duct manufacturing method shown in the figure includes a front plate / rear plate preparation step (S100), a phenol foam resin composition is foam-cured to form a duct forming panel containing phenol foam ( S110) and a curing / aging step (S130).

In addition, after the manufacturing step of the panel for forming the HVAC duct, it may further include a cutting step (S120) for high-temperature compression and trimming, and may further include a step of finally cutting into a duct shape.

  The front plate 11 is formed on one surface of the core layer 10 (upper portion of the core layer in FIG. 1), and the rear plate 12 is formed on the other surface of the core layer 10. The front plate 11 and the rear plate 12 include metal layers 11b and 12b.

  The HVAC duct according to the present invention can be completed with only the basic structure of the front plate 11 and the rear plate 12 including the core layer 10 and the metal layers 11b and 12b formed of the phenol foam.

  As shown in FIG. 1, the HVAC duct according to the present invention includes separate reinforcing material layers 11 c and 12 a and a protective layer formed on the outer surface of the metal layers provided on the front plate 11 and the rear plate 12. 11a etc. can be further formed.

  First, in the front plate / rear plate preparation step (S100), a front plate and a rear plate corresponding to the outer skin of the duct are prepared (S100).

  Next, in the step of forming a duct-forming panel containing phenol foam by foam-curing the phenol foam resin composition (S110), the phenol resin composition is charged between the front plate and the rear plate and foamed. A core layer is formed between the front plate and the rear plate.

Next, in the curing / aging step (S130), the phenol foam contained in the panel is cured and aged. At this time, curing is performed for the purpose of post-curing and includes an aging step for removing VOC (volatile organic compounds). It is preferable that the duct is placed in an oven and is performed at 70 ° C. or less for 10 to 200 minutes per 1 cm ² of the core layer. When the curing time is less than 10 minutes, curing and aging are not sufficiently performed, so that the thermal conductivity increases and the heat insulating properties may be deteriorated. In addition, if the curing time exceeds 200 minutes, only the cost may be wasted because the degree of characteristics improved compared to the time and cost spent for curing is weak. Curing and aging are preferably performed at a temperature of 70 ° C. or less, and when performed at a temperature exceeding 70 ° C., problems such as a decrease in heat insulating properties and durability may occur.

  The method for manufacturing an HVAC duct according to the present invention may further include a high temperature compression step (S120) of compressing the front metal layer and the rear metal layer through a high temperature compression press process after the step S110. If the size is determined, it may include trimming and cutting to the determined size.

  In addition, after the curing and aging step, it may further include a step of cutting into a target duct shape. Since the duct according to the present invention can be easily cut after completion, it is advantageous in workability and workability.

  By the duct manufacturing method as described above, an HVAC duct having a core layer formed of a phenol resin cured foam and a front plate / rear plate including a metal layer can be manufactured.

  Specific examples of the HVAC duct according to the present invention are as follows.

[Manufacture of HVAC duct]
Example 1
A metal aluminum layer 30 μm is prepared for each of the upper surface and the lower surface. A phenol resin (premixer) containing 3% by weight of a surfactant, 3% by weight of a plasticizer, and 5% by weight of a foaming agent (isopentane) is mixed with a phenol resin using a mechanical mixer, and then a curing agent 17 Add wt% and mix. The mixed slurry was put between metal aluminum layers, and a phenol resin cured foam having a closed cell ratio of 95% was formed while being cured and foamed at 80 ° C. in a high temperature compression process. After the primary cutting for the purpose of trimming, curing and aging are performed for 60 minutes per 1 cm ² at 65 ° C. Then, the HVAC duct was manufactured by secondary cutting.

Example 2
An HVAC duct was manufactured under the same conditions as in Example 1, but a 30 μm stainless steel layer was used instead of the aluminum layer, and the closed cell ratio was 85%.

Example 3
An HVAC duct was manufactured under the same conditions as in Example 1, but a metal aluminum layer including a reinforcing material layer in which a glass mat was woven with a PVA binder was used.

Comparative Example 1
A duct was manufactured under the same conditions as in Example 1, except that the closed cell ratio was 60%.

Comparative Example 2
An HVAC duct was manufactured under the same conditions as in Example 1 except that urethane foam was used as the core layer instead of phenol foam.

[Performance test and evaluation]
The HVAC ducts manufactured according to Examples 1 to 3 and Comparative Examples 1 and 2 are placed in a constant temperature chamber at 85 ° C., and maintained for 3 months. It was carried out. At this time, the heat conductivity was measured using an HC-074-200 (manufactured by EKO) heat conductivity measuring machine. Next, the thermal conductivity from 0 to 10 years was predicted by applying an acceleration factor, and the results were as shown in Table 1 below.

  In Examples 1 to 3, it can be seen that not only the initial thermal conductivity is lower than that of the comparative example, but also the amount of increase with time appears lower than that of the comparative example.

  Therefore, in the case of the HVAC duct containing the phenol foam according to the present invention, it can be seen that both the initial heat insulation performance and the long-term durability performance are excellent. Accordingly, it can be seen that the energy load saving rate is high, so that it can be used as a high-efficiency HVAC duct.

Moreover, the phenolic foam of the core layer has quasi-incombustibility according to flame retardant second grade. The quasi-incombustible grade certification experiment method includes a heat release rate test (KS F ISO 5660-1) and a gas hazard test (KS F 2271). The heat release rate test must be less than 8MJ / m ² when the radiant heat of 50kW / m ² is applied for 10 minutes using the corn calorimeter method, and the maximum heat release rate must exceed 200kW / m ² . The gas hazard test can be subjected to quasi-incombustibility certification if the average behavior stop time when observing 8 mice with the combustion gas of the test specimen is 9 minutes or more. It can be seen that phenol foam is low in environmental load by using non-fluorocarbon gas, does not generate harmful gas, and has excellent flame retardancy, so the risk of fire is low.

  Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and can be manufactured in various different forms, and is usually used in the technical field to which the present invention belongs. Those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea and essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not limiting.

  10: Core layer, 11: Front plate, 12: Rear plate, 100: HVAC duct

Claims (11)

A duct comprising: a core layer including phenol foam; and a front plate formed on a front surface and a rear surface of the core layer, each including a metal layer; and a rear plate. The phenolic foam is
The duct according to claim 1, wherein the duct is formed of a phenol foam resin composition containing a phenol resin, a hydrocarbon-based foaming agent, and an additive. The phenolic foam is
The duct according to claim 1, wherein the closed cell ratio is 85% or more. The duct is
The duct according to claim 1, wherein the thermal conductivity is 0.020 W / mK or less. In the front plate or the rear plate,
The duct according to claim 1, wherein a reinforcing material layer including glass fiber or glass mat is further formed on an inner surface of the metal layer. The metal layer is
The duct according to claim 1, wherein the duct has a thickness of 10 μm to 90 μm. The metal layer is
The duct according to claim 1, comprising at least one selected from aluminum, stainless steel, magnesium, gold, silver, copper, lead and titanium. (A) providing a front plate and a rear plate with a metal layer;
(B) a step of forming a duct forming panel containing phenol foam by foaming and curing after the phenol resin composition is charged between the front plate and the rear plate; and (c) a phenol foam contained in the panel. Curing and aging steps; The step (c) includes:
The method for producing a duct according to claim 8, wherein the method is performed at a temperature of 70 ° C or less for 10 minutes to 200 minutes per 1 cm ^{2 of the} phenol foam. After step (b),
The method of manufacturing a duct according to claim 8, further comprising a step of trimming the panel to a predetermined size and cutting the panel. After step (c),
The method for manufacturing a duct according to claim 8, further comprising a step of cutting the panel into a duct shape.

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