Polyurea Waterproof Coating

Features:

★High reactivity and fast curing speed.

★98% solid content, no volatilization of organic matter, no mold, is a pollution-free green environmental protection spraying technology.

★Extremely strong adhesion to gold and non-metallic substrates◊Such as steel, aluminum, concrete, wood, glass fiber reinforced plastics, polyurethane foam, etc.

★Not sensitive to temperature and humidity, less affected by ambient temperature and humidity during construction.

★Good low and high temperature stability.

★Radiation and alcohol aging are good.

★ JN coating has excellent physical properties. Such as tensile strength, tear strength, impact strength, adhesion, cathodic disbondment resistance, dielectric strength, elongation, abrasion resistance, etc., excellent low temperature toughness,

★Excellent waterproof, decorative, anti-corrosion, anti-wet and slippery functions.

★Using a complete set of equipment for spraying, on-site construction, fast curing, and high production efficiency.

★According to the requirements of use, various pigments and fillers can be added to make coatings with different colors and functions.

Physical and mechanical performance indicators of polyurea waterproof coating:

It can be widely used in various fields and types of waterproof and anticorrosion projects:

★High-speed railways, tunnels, bridge deck waterproofing of concrete paved roads.

★Waterproofing of various industrial and civil construction surface engineering.

★Waterproof and moisture-proof for underground engineering of industrial and civil buildings, as well as waterproof for structures such as indoor swimming pools and fire-fighting pools.

★Waterproof for municipal projects such as subways, sewage treatment plants, and landfills.

★Waterproof and anticorrosion of water conservancy facilities such as canals and pools.

★Waterproof and anticorrosion for sports fields, stadiums and runways.

★Waterproof and anticorrosion for industrial storage tanks and large components.

★Abraded waterproof layer for bridges, parking aprons, industrial floors, parking lots, etc.

Applied to bridge deck waterproofing of high-speed railways and concrete paved roads

Applied to industrial storage tanks and large components for waterproof and anticorrosion

Yizheng Jinmeilin Construction Materials Co., Ltd.

Construction Technology of Polyurea Waterproof Coating

  "Polyurea waterproof technology" is another major technological breakthrough in the field of environmentally friendly coatings and coating technology after high-solid coatings, water-based coatings, light-curing coatings, and powder coatings technologies. Combining the practical experience of applied engineering and referring to the latest foreign materials, the construction design and construction technology of this technology are introduced in detail.

Compared with large-scale components (such as concrete, steel structures, etc.), the construction design and technology of small-scale components such as statues, props, and specimens are relatively simple, so they will not be discussed in detail here. This paper takes large-area and large-scale components as an example to introduce the basic principles of SPUA technology construction design and technology.

Before construction, carefully inspect the construction site and provide a detailed construction drawing, which should include: 1. Selection and thickness of SPUA materials; 2. Specific treatment plan for joints; treatment plan for non-joints.

1. Selection and thickness of SPUA material

The selection and thickness of SPUA materials are determined according to different uses.

Table 1 lists the models and reference thicknesses of the selected materials, taking several typical applications as examples.

Table 1. SPUA model selection and reference thickness for typical applications:

2. Node processing scheme

The nodes mentioned in this article include the following aspects

1. Ditch—such as inclined ditch, gutter, anti-beam eaves ditch in waterproof treatment, flow channel and chute in anti-corrosion treatment, etc.

2. Hole - such as water drop hole and water hole in waterproof treatment, discharge hole in anticorrosion treatment, etc.

3. Roots - the roots of protrusions such as chimneys and embedded pipe penetrations.

4. Edge - the end of the SPUA coating.

5. Corner - the inner and outer corners at the corners of the plane and the wall.

6. Seam—deformation seam in waterproof treatment, seam of metal substrate.

7. Seat - equipment base, cable seat.

The above parts are weak parts that are likely to cause structural deformation, temperature difference deformation, and drying shrinkage deformation, and must be comprehensively treated. We make full use of the flexibility of the SPUA material to adapt to deformation, and use local reinforcement or reinforcement (such as the use of sealant and reinforcement layer) combined with the overall construction method to improve its ability to resist cracking, which will be introduced below.

Groove treatment

The groove is a place where the stress is relatively concentrated. If it is not handled properly during construction, the coating will be separated from the substrate due to the effect of stress. Hence the trench construction. The sealant should be applied at the corner first, then the reinforcement layer should be prepared, and finally the SPUA material should be applied. In addition, when constructing the trench, pay attention to the uniform thickness of the coating, so as to avoid uneven thickness, resulting in too small slope, so that the liquid flow is not smooth, resulting in fluid accumulation.

Hole treatment

There are two treatment plans for the hole according to the diameter: 1. When the diameter is larger than 20cm, in order to prevent the surrounding coating from falling off due to force, the primer should be painted in the hole first, and the position is from the hole. The top of the top of the hole goes down 10~15cm into the hole, and then adjusts the angle of the spray gun to spray the SPUA paint on the primer; 2 When the diameter is less than 20cm, in this case, if the method of 1 is applied again, the SPUA may The paint enters the hole and causes blockage, so hard materials should be used to cover the hole before construction to prevent the paint from entering by mistake. If the SPUA material sticks to the cover after construction, use a utility knife to cut the SPUA material, and do not tear it hard to prevent the coating from being damaged.

root treatment

The root is also the place where the stress is relatively concentrated, so it should be treated by local reinforcement. The structure of the root is divided into two types: penetrating parts and non-penetrating parts, and the treatment plan is the same. The following uses the penetrating part as an example to introduce its construction plan: first, apply sealant at the connection between the penetrating part and the ground, and then apply the sealant The reinforcement layer is applied on top, and finally the SPUA coating is applied. For example, when our company is constructing the dolphin performance pool of Qingdao Dolphinarium (there are inlet and drainage pipes in the pool), according to the above method, the root of the pipe is sprayed with SPUA material. At present, it has been used outdoors for one year, and the treated parts have no blistering, shedding, or cracking.

edge processing

If the sprayed SPUA is used as the lining of the storage tank, the closing part should be 10~15cm higher than the top of the liquid level. Concrete and metal substrates are closed in different ways, which will be explained separately below.

Treatment of Concrete Substrate Closing

The closing of the concrete substrate is divided into two ways: closing on the plane and closing on the wall.

In the flat end, the method is to open a V-shaped groove on the edge of the substrate, the size is 6mm wide and 6mm deep, and then apply SPUA coating. In places where vehicles frequently come and go, such as parking lots and freight yards, in order to prevent the coating of the ending part from detaching from the V-shaped groove due to frequent stress, the coating of the ending part can be smoothed with an angle grinder. In order to reduce the possibility of stress concentration between it and the wheels or cargo, it is closed on the facade. Closing the inside of the concrete wall and closing the outside of the concrete wall, the processing method is basically the same as that on the plane. For liquid storage tanks, in order to prevent the liquid from entering the connection between the substrate and the end cap, causing the substrate and the coating to fall off, a sealant needs to be added to the end cap inside the wall. Sealant is required.

Finishing of metal substrates

Metal façade closing method. Commonly used end closure methods only need to naturally transition the end portion to the coating surface. For the closing method of the metal storage tank, the method is to fix the end closing on the wall with a metal bead, and seal the fixed part and the end of the coating with a sealing material to prevent the liquid in the storage tank from entering the closing part. Coating and substrate detachment. The closing method of the plane is basically the same as that of the concrete, the difference is that the groove depth of the metal substrate is 0.1mm.

corner treatment

The corner is generally the connection between the wall and the ground. According to the construction requirements, it can be divided into two treatment methods. One kind of SPUA coating also extends to the wall. A sealant is firstly applied at the corner, then a reinforcement layer is applied, and finally SPUA material is applied; the other is SPUA coating only applied on the ground.

seam processing

Deformation seam

The deformation joint of the building is a buffer method adopted to prevent the deformation and damage of the building due to temperature difference deformation, different settlement degrees and earthquakes. Deformation joints can be divided into two types, one is the deformation joint between the ground and the other is the deformation joint between the ground and the wall. The construction method is to fill the deformation joint with glass fiber board first, and then apply SPUA coating , The SPUA coating should go deep into the deformation joint about 25mm. After the coating has cured, the backing material is stuffed into the deformation joint. Before sealing the deformation joints with flexible sealant, sand the surface of the SPUA coating, apply a layer of adhesion promoter, and then apply the sealant, taking care not to allow the sealant to stain the surrounding coating. In order to prevent the color of the sealing material from polluting the SPUA layers on both sides of the seam, which will affect the aesthetics. A pressure-sensitive tape with a width of 40-50mm can be temporarily pasted on the planes on both sides of the seam to prevent pollution. For example, in the waterproof construction of building roofs, in order to fix the backing, after filling the deformation joints with glass fiber boards (the upper part of the glass fiber boards is about 25mm away from the roof), after treating the bottom material from the roof to the glass fiber boards, brush Apply a primer, spray the SPUA material, stuff the polyethylene rod backing into the deformation joint (the width of the backing should be 1-2mm wider than the deformation joint after applying the SPUA material, to prevent the sealant from leaking), and finally construct sealant.

Metal substrate connection seam

The treatment of the joints on the metal substrate is shown. First, use sealant to smooth the positioning bolts and corners to the substrate. After applying the primer, apply the reinforcement layer, and finally apply the SPUA coating.

Seat handling

Including the equipment base, etc., there are fixing devices such as positioning bolts in these parts, and their treatment methods. First, apply sealant to the root of the bolt and the seat into the shape shown in the figure, then apply the reinforcement layer, and finally apply the SPUA coating.

Processing of non-nodes

The treatment of non-nodes includes two types: the substrate is intact and the substrate has cracks. If the substrate is intact, the SPUA coating can be applied directly after applying the primer and sealant. If there are cracks in the substrate and the width of the cracks is greater than 3mm, the cracks should be widened first, cleaned, the dust in the cracks should be blown away, and the caulking material should be embedded. After the reinforcement layer is applied, the SPUA coating should be applied.

【Construction technology】

1. Determination of construction conditions

1. The construction should be carried out before the installation of various equipment, columns, pipelines, penetrations and paint construction.

2. Ensure that the environment and site conditions are suitable for construction and material curing, and the temperature of the substrate surface should be 5°C higher than the dew point temperature.

2. Materials required for construction

1. The selected spraying SPUA material; 2. Sealant; 3. Primer; 4. Topcoat (optional); 5. Caulking material; 6. Interlayer adhesive; 7. Anti-slip particles (quartz sand , rubber particles, etc.); 8. Backing materials (polyethylene foam rods, etc.); 9. Coil materials required for the reinforcement layer (such as glass fiber cloth, chemical fiber non-woven fabric, polyester non-woven fabric, etc.), coatings; 10 . Anti-fouling tape.

3. Construction tools

Except for the H-3500, H-20/35 host and GX-7 spray gun produced by GUSMER, the rest are common tools.

4. Construction

4.1 Substrate treatment

4.1.1 Concrete substrate

(1). The new cement substrate should be completely hydrated. After 28 days of drying, the construction can only be carried out after the water has fully evaporated. Otherwise, the water accumulated inside it will evaporate after being heated, resulting in bubbling of the coating.

(2). Treat the surface of the concrete substrate with sand blasting, so that the surface of the concrete substrate is free of impurities such as oil, dust and broken cement blocks.

(3). The surface of the concrete substrate should be kept dry and intact.

(4). The closing part shall be processed according to the drawing requirements.

4.2 Construction of primer, plugging material and sealant

(1). Construction supporting primer. Do not let the primer stain or block the groove structure of the end closure. Metal substrates generally do not need primer. If spraying SPUA material is used as a lining, the metal substrate needs to be painted with primer.

(2). Fill the holes on the substrate with caulking material, and plug them tightly, otherwise, the heat released during the curing process of SPUA will cause the air in the holes to expand, resulting in bubbling of the coating.

(3). Construction of sealant. Apply the sealant according to the requirements of the construction drawings; when constructing roots, holes, seats, corners and other parts, the profile of the sealant should be a right-angled triangle with a right-angle side of 5mm; when constructing other parts, it is enough to pass down according to the requirements of the drawings .

4.3 Construction of reinforcement layer

Construction of reinforcement layer shall be carried out according to drawing requirements. The specific construction of the reinforcement layer is as follows: after the construction of the previous required process, on the surface of the substrate where the reinforcement layer needs to be constructed, use the special coating for the reinforcement layer developed by our company to paste a piece of reinforcement coil, and the edge should be extended outward for 50- 60mm, the thickness is about 1mm.

4.4 Steel substrate

(1). Inspection: burrs, welding slag, corrosion, oil stains, cracks, old paint film.

(2). Surface treatment: A. Degreasing: solvent, lye, emulsification, ultrasonic.

B. Rust removal: sandblasting (shot), manual, mechanical.

(3). Primer: If it is used as the outer wall, it is not necessary to apply the primer if it has been sandblasted. If it is used as the inner wall, it needs to be painted with primer to enhance the adhesion.

(4). Spray polyurea.

(5). Check: thickness, leakage, adhesion.

4.5 Construction of SPUA materials

Try to apply the SPUA material within 12 hours of the construction of the reinforcement layer. If it exceeds 12 hours, the reinforcement layer should be polished, brushed or sprayed with an interlayer adhesive, and the SPUA coating should be applied after 20 minutes. When applying SPUA coating, the next one should cover 50% of the previous one, commonly known as "pressure gun", only in this way can the coating be uniform.

For places with high anti-slip requirements, artificial granulation or manual spreading of anti-slip particles (such as rubber particles, emery, etc.) can be done on the wet coating.

The collective operation of artificial granulation is as follows: using the principle of rapid solidification of SPUA technology, through the control of the spray angle and flow by the builder, before the last coating is completely cured, open the spray at a certain distance from the construction site. Spray gun, let the mixed and atomized spray paint freely fall on the construction site, so as to form particles of a certain size, and obtain a rough non-slip particle surface, which is anti-slip and matting (mainly used in film and television, entertainment and indoor lighting stadiums, etc. occasion) function. During artificial granulation, attention should be paid to the wind direction and wind force. The builder should be at the upper air outlet, and the wind force should be below level 3 to reduce the falling of atomized particles to the construction personnel and equipment.

Hand-spreading anti-slip particles is carried out in this way: Before the last coating is completely cured, the anti-slip particles are evenly sprinkled on the construction site by hand. Anti-slip particles sweep clean.

4.6 Topcoat Construction

Aromatic SPUA materials will appear yellowing after being irradiated by ultraviolet rays, which is unfavorable for occasions with light color requirements. Therefore, it is recommended to apply the corresponding yellowing-resistant topcoat. The topcoat should be applied within 12 hours of SPUA coating application. If more than 12 hours, the SPUA coating should be sanded, painted or sprayed with a coat of intercoat adhesive, and then topcoated.

4.7 Patching

The mechanical properties of the SPUA material itself are very good, and it will not be damaged in normal use. In the event of accidental damage (such as falling heavy objects, impact, etc.), the SPUA-202S repair material developed by our company can be used for partial repair. Specific steps are as follows:

(1). Grind the surface to be repaired, and the polished edge should extend 150mm outward from the surface to be repaired.

(2). Adhesive between construction layers.

(3). Apply repair materials to the polished parts. Care should be taken to ensure a smooth transition of the coat of repair compound to the surrounding coat.

(4). For special applications, apply a matching topcoat.

【Introduction to special equipment for construction】

Special construction equipment for spraying polyurea elastomers, "If a worker wants to do a good job, he must first sharpen his tools"

The perfect combination of spraying polyurea elastic technology and unique spraying equipment reflects the "revolutionary" breakthrough;

Equipment suppliers: GUSMER, GRACO, GLOS-GRAFT;

The comprehensive performance of SPUA material is very outstanding, and the construction technology is very advanced. However, if there is no suitable spraying equipment to effectively control the rapid chemical reaction of polyurea, it is difficult to achieve excellent physical properties and smooth appearance. Polyurea professional spraying equipment is a very important link in the entire polyurea process, which requires the stable and precise coordinated operation of the entire equipment system.

The spray polyurea system is composed of two components with extremely high chemical activity. After mixing, the rapid reaction causes the viscosity to increase rapidly. If there is no proper equipment for conveying, metering, mixing, atomizing and cleaning, this reaction is different from the previous ordinary Paint construction. The specialized equipment required by SPUA must have a stable material conveying system, an accurate material metering system, a uniform material mixing system, a good material atomization system and a convenient material cleaning system.

equipment system

American high-pressure airless spraying equipment, the equipment is mainly composed of five systems:

◎Stable material conveying system;

◎Accurate material measurement system;

◎Uniform material mixing system;

◎Good material atomization system;

◎Convenient material cleaning system.