CN112917938B - Preparation method of neutral low-heat-conductivity phenolic material composite air pipe - Google Patents

Abstract

The invention discloses a preparation method of a neutral low-heat-conduction phenolic aldehyde composite air duct, which comprises an anticorrosive color steel plate positioned at the outer side and an insulating base layer positioned at the inner side, wherein a connecting layer and a core layer of the insulating base body are made of foaming phenolic aldehyde resin materials with different components, a vertical square forming die is adopted in the preparation process, two lifting clapboards with controllable speed are arranged in a cavity of the die, the cavity is divided into side cavities at two sides and a central cavity, the connecting layer phenolic aldehyde resin material and the core layer phenolic aldehyde resin material are respectively injected into the side cavities and the central cavity, the lifting clapboards are lifted upwards after a certain time of injection, so that the connecting layer phenolic resin material and the core layer phenolic resin material are foamed and formed, the die is opened to obtain an integrated composite forming air duct plate, four composite air duct plates are connected together through flanges, and a composite air duct is obtained, and the performance of the composite air duct prepared by the invention is excellent, the air supply, return, fresh air and air supplement pipeline is suitable for air supply, return air and fresh air supplement pipelines of air conditioners in public places with higher air pressure requirements and high purification special environments.

Description

Preparation method of neutral low-heat-conductivity phenolic material composite air pipe

Technical Field

The invention relates to the technical field of heat-insulating composite materials, in particular to a neutral low-heat-conductivity phenolic material and a preparation method of a composite air duct.

Background

The air pipe is an important component of air conditioners and ventilation equipment in modern buildings, and has the advantages of good heat insulation performance required for the air pipe, higher deformation resistance, quiet system operation, simple installation, lower cost and longer service life. At present, the composite air duct as a new generation of environment-friendly and energy-saving air duct has gradually replaced an iron sheet air duct and a glass fiber air duct. The basic structure of the existing product is that two layers of high-strength metal materials and one layer of heat insulation material are used as base materials, and the base materials are combined and connected by adopting an adhesive technology and a special structure. The prior insulation material usually adopts phenolic resin foam insulation material. The existing product mainly has the following technical problems that firstly, the phenolic resin foam heat-insulating material is formed by foaming, curing and forming after phenolic resin is added with a foaming agent and a curing agent, the used curing agent is a strong acid curing agent, the acid remained in a foam body enables the material to be an acid material, and the material can corrode a contacted metal material, meanwhile, the composite air pipe formed by an adhesion technology has the problems of multiple processes, high labor cost and the like, and meanwhile, the phenolic resin foam material with strong acid can also react on an adhesive layer, so that the adhesion strength is reduced. Therefore, the developed phenolic material composite air pipe which is low in heat conductivity coefficient, good in heat preservation performance, low in acidity and neutral and easy to prepare has important practical significance for the current production.

Disclosure of Invention

In order to solve the technical problems, the invention provides a neutral low-thermal-conductivity phenolic material and a preparation method of a composite air pipe.

The complete technical scheme of the invention comprises the following steps:

a preparation method of a neutral low-heat-conduction phenolic aldehyde composite air pipe comprises the following steps that the composite air pipe comprises a pipe body, and the pipe body is formed by connecting four composite air pipe plates together through flanges;

the composite air duct plate comprises an anticorrosive color steel plate positioned on the outer side and a heat-insulating base layer positioned on the inner side, the heat-insulating base body comprises a connecting layer and a core layer, the connecting layer and the core layer are made of foaming phenolic resin materials with different components,

wherein the preparation components of the connecting layer are phenolic resin: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: 50 parts of filler (1-2): (0.5-0.8): (1-1.5): (20-25), wherein the ratio is a weight ratio, and zinc stearate is added into the phenolic resin for modification; the filler is a mixture of magnesium oxide powder and aluminum hydroxide powder; the core layer is prepared from the following components: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: 50 parts of silicone oil (2-3): (1-1.2): (6-8): (1-1.5), wherein the weight ratio is the above ratio;

the preparation method comprises the following steps:

(1) preparing raw materials: adding corresponding amounts of isopentane, polyoxyethylene ether and filler into the phenolic resin of the connecting layer, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use;

adding corresponding isopentane, polyoxyethylene ether and silicone oil into the core layer phenolic resin, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use;

(2) preparing a mould: the used mould is a vertical square forming mould and comprises an outer wall of the mould and an upper cover of the mould positioned above the outer wall, the outer wall and the upper cover enclose a mould cavity, two liftable partition plates with controllable speed are arranged in the center of the cavity, the cavity is divided into a side cavity at two sides and a central cavity at the center, prepared anti-corrosion color steel plates are placed at two sides of the mould cavity in advance, the anti-corrosion color steel plates are fixed through steel plate positioning grooves, and a composite interlocking metal frame for improving the connection strength is arranged on the inner side surface of the anti-corrosion color steel plate connected with the heat-insulating base body; and then heating the mold to 60-80 ℃.

(3) After the preparation of the mold is finished, the connecting layer phenolic resin material and the core layer phenolic resin material are respectively injected into the side cavity and the central cavity from the upper injection port, and the liftable partition plate is lifted upwards after a certain period of injection, so that the connecting layer phenolic resin material and the core layer phenolic resin material are foamed and molded.

(4) And after the foaming molding is finished, opening the mold to obtain an integrally and compositely molded composite air duct plate, and connecting the four composite air duct plates together through flanges to obtain the composite air duct.

Drawings

Fig. 1 is a schematic structural view of a neutral low-thermal-conductivity phenolic aldehyde composite air duct disclosed by the invention.

Fig. 2 is a schematic diagram of a phenolic aldehyde composite air duct preparation process.

Fig. 3 is a physical diagram of the phenolic aldehyde composite air duct.

In the figure: 1-anticorrosive color steel, 2-interlocking metal frame, 3-connecting layer, 4-core layer, 5-outer wall of mould, 6-upper cover of mould, 7-partition plate capable of being lifted, 8-side cavity and 9-central cavity; 10-color steel positioning groove.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only illustrative and are not intended to limit the present application.

The neutral low-heat-conductivity phenolic material and the composite air pipe are integrally formed, and the composite air pipe comprises a pipe body which is formed by connecting four composite air pipe plates together through flanges.

As shown in fig. 1, the composite air duct plate comprises an anticorrosive color steel plate 1 positioned on the outer side and a heat insulation base layer positioned on the inner side, the heat insulation base body comprises a connecting layer 3 and a core layer 4, and the connecting layer and the core layer are made of foamed phenolic resin materials with different components.

This compound tuber pipe is through integral type composite forming mode, and the inboard surface that anticorrosive various steel sheet and heat preservation base member are connected is equipped with interlocking metal crate 2 that is used for improving joint strength, and this metal crate can adopt wire netting or stainless wire net, and the lug weld is inboard in the steel sheet.

The preparation components of the connecting layer are phenolic resin: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: 50 parts of filler (1-2): (0.5-0.8): (1-1.5): (20-25), wherein the ratio is a weight ratio, and zinc stearate is added into the phenolic resin for modification; the filler is a mixture of magnesium oxide powder and aluminum hydroxide powder.

The core layer is prepared from the following components: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: 50 parts of silicone oil (2-3): (1-1.2): (6-8): (1-1.5) in a weight ratio.

The preparation method comprises the following steps:

(1) preparing raw materials: adding corresponding amount of isopentane, polyoxyethylene ether and filler into the phenolic resin of the connecting layer, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use.

Adding corresponding isopentane, polyoxyethylene ether and silicone oil into the core layer phenolic resin, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use.

(2) Preparing a mould: the used mould is a vertical square forming mould, as shown in figure 2, the mould comprises a mould outer wall 5 and a mould upper cover 6 positioned above the mould outer wall, the outer wall and the upper cover enclose a mould cavity, the central part of the cavity is provided with two speed-controllable lifting partition plates 7, the cavity is divided into side cavities at two sides and a central cavity at the central part, the two sides of the mould cavity are pre-provided with prepared anti-corrosion color steel plates, the anti-corrosion color steel plates are fixed through a steel plate positioning groove 10, and then the mould is heated to 60-80 ℃.

(3) After the preparation of the mold is finished, the connecting layer phenolic resin material and the core layer phenolic resin material are respectively injected into the side cavity and the central cavity from the upper injection port, and the liftable partition plate is lifted upwards after a certain period of injection, so that the connecting layer phenolic resin material and the core layer phenolic resin material are foamed and molded.

(4) And after the foaming molding is finished, opening the mold to obtain an integrally and compositely molded composite air duct plate, and connecting the four composite air duct plates together through flanges to obtain the composite air duct.

In the steps, firstly, the invention is different from the combination of the steel plate and the phenolic resin foaming material which are respectively processed and then cemented in the prior art, but the foaming process is adopted for integral forming, the obtained products are directly combined together, the production efficiency is improved, and the automatic production can be realized. Secondly, in order to overcome the problem that the prior phenolic resin foam material has large acidity and is easy to corrode an outer steel plate, the invention adoptsThe composite structure, the connecting layer and the core layer adopt foaming phenolic resin materials with different components. Wherein, the material of the connecting layer directly connected with the steel plate is modified by zinc stearate during the preparation of the phenolic resin, the residual acid is neutralized, the consumption of an acid curing agent is obviously reduced in the foaming process so as to further reduce the acidity, and meanwhile, magnesia powder and aluminum hydroxide powder are also used, so that the connecting strength is improved, and Al (OH) in the connecting layer is utilized in case of fire₃Decomposition reaction can occur, and the flame retardant effect of the phenolic resin foam is further improved. For the core layer, the components of the traditional phenolic resin heat-insulating material are adopted, and the foam stabilizer is added to improve the heat-insulating property of the core layer. Meanwhile, in the preparation method, the method is different from the existing horizontal die, the vertical square die is adopted, the partition plate capable of being lifted is adopted, the phenolic resin materials with different components are added simultaneously, and the partition plate is lifted upwards at the same time, so that the phenolic resin materials in the liquid state are naturally combined in the curing process. Meanwhile, in order to improve the connection strength of the phenolic foam and the steel plate, a composite interlocking metal frame for improving the connection strength is arranged on the steel plate, and the metal frame can be directly welded on the inner side of the steel plate by adopting a wire mesh movable stainless steel wire mesh. In the foaming process, the phenolic material of the connecting layer is directly immersed into the wire mesh and solidified, and firm connection can be realized without adopting a bonding material.

In the aspect of an injection molding process, the speed of injecting a phenolic resin material into a vertical mold and the speed of pulling a partition plate are critical parameters, if the relative injection speed of pulling the partition plate is too high, connecting layers and core layer materials are fused together before being solidified, the effect of reducing corrosion by low acid cannot be achieved, the pulling speed is too low, the two layers are not well combined, and the strength of the whole product is seriously affected due to the fact that steel plates on two sides are stressed by an integral heat-preservation base layer formed by the core layer and the connecting layers and poor middle combination. Through design and experimental verification, the injection speed of the phenolic aldehyde adopts V₁H/8, where H is the height of the entire mold in mm, V₁The unit is mm/min. In particular to a 1200mm high mould, the injection speed is 150 mm/min, which is different from the prior artThe method adopts gradual injection to ensure that the material on the lower layer has time to be firstly cured, the material on the bottom is cured after the material is fully injected, and the material is lifted and pulled by matching with the partition plate to ensure firm connection and prevent mixed layers. The partition board starts to be pulled 200s after the injection is started, and the pulling speed is the same as the injection speed, so that the materials of all layers start to contact at the curing rate of about 40%, good connection strength can be guaranteed, and the core layer is prevented from excessively permeating into the connection layer.

The actual photo of the composite air pipe prepared by the invention is shown in figure 3, the composite air pipe has the advantages of wind pressure resistance of more than 2000PA, good heat insulation performance, low heat conductivity coefficient of 0.018-0.020 w/(m.k), pH value of a heat insulation base layer connected with a metal piece of 4-7 which is close to a neutral material, good protection of a steel plate from corrosion, wide application and particular suitability for air supply, return air, fresh air and air supply pipelines of air conditioners in public places with high wind pressure requirements and high purification special environments. The main properties are shown in the following table:

TABLE 1 composite air duct Properties

The above applications are only some embodiments of the present application. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept herein, and it is intended to cover all such modifications and variations as fall within the scope of the invention.

Claims (1)

1. The preparation method of the neutral low-heat-conduction phenolic aldehyde composite air pipe is characterized in that the composite air pipe comprises a pipe body, and the pipe body is formed by connecting four composite air pipe plates together through flanges;

the composite air duct plate comprises an anticorrosive color steel plate positioned on the outer side and a heat-insulating base layer positioned on the inner side, the heat-insulating base layer comprises a connecting layer and a core layer, the connecting layer and the core layer are made of foaming phenolic resin materials with different components,

wherein the preparation components of the connecting layer are phenolic resin: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: filler =50 (1-2): (0.5-0.8): (1-1.5): (20-25), wherein the ratio is a weight ratio, and zinc stearate is added into the phenolic resin for modification; the filler is a mixture of magnesium oxide powder and aluminum hydroxide powder; the core layer is prepared from the following components: isopentane: polyoxyethylene ether: p-toluenesulfonic acid: silicone oil =50 (2-3): (1-1.2): (6-8): (1-1.5), wherein the weight ratio is the above ratio;

the preparation method comprises the following steps:

(1) preparing raw materials: adding corresponding amounts of isopentane, polyoxyethylene ether and filler into the phenolic resin of the connecting layer, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use;

adding corresponding isopentane, polyoxyethylene ether and silicone oil into the core layer phenolic resin, uniformly stirring at a high speed, adding p-toluenesulfonic acid, and continuously stirring at a high speed for later use;

(2) preparing a mould: the used mould is a vertical square forming mould and comprises an outer wall of the mould and an upper cover of the mould positioned above the outer wall, the outer wall and the upper cover enclose a mould cavity, two liftable partition plates with controllable speed are arranged in the center of the cavity, the cavity is divided into a side cavity at two sides and a central cavity at the center, prepared anti-corrosion color steel plates are placed in advance at two sides of the mould cavity and fixed through steel plate positioning grooves, and a composite interlocking metal frame for improving the connection strength is arranged on the inner side surface of the anti-corrosion color steel plate connected with the heat-insulation base layer; then heating the die to 60-80 ℃;

(3) after the preparation of the die is finished, respectively injecting the connecting layer phenolic resin material and the core layer phenolic resin material into the side cavity and the central cavity from an upper injection port;

the injection speed of the phenolic resin adopts V₁= H/8, where H is the height of the entire mold in mm, V₁The unit is mm/min, the partition board starts to be pulled up 200s after the injection is started, the pulling speed is the same as the injection speed, and the layers are ensured to be allThe materials start to contact at the curing rate of about 40 percent, so that the phenolic resin material of the connecting layer and the phenolic resin material of the core layer are foamed and molded;

(4) and after the foaming molding is finished, opening the mold to obtain an integrally and compositely molded composite air duct plate, and connecting the four composite air duct plates together through flanges to obtain the composite air duct.

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