The Use Method and Principle of Polyurethane Foaming Agent

Apr 27, 2021

Polyurethane foaming agent is the product of cross combination of aerosol technology and polyurethane foam technology. There are two kinds of spongy states in the pipe type and gun type. Styrofoam is used as a foaming agent for the production of microcellular foams. It can generally be divided into physical and chemical types. This is based on whether the production of gas is a physical process (that is, volatilization or sublimation) or a chemical process (that is, chemical structure). Damage or other chemical reactions).

The full name of polyurethane foaming agent is one-component polyurethane foam jointing agent, commonly known as foaming agent, foaming glue, PU jointing agent, English PU FOAM is the product of the cross combination of aerosol technology and polyurethane foam technology. It is a special polyurethane product in which components such as polyurethane prepolymer, blowing agent, and catalyst are filled in a pressure-resistant aerosol can. When the material is sprayed from the aerosol tank, the foamed polyurethane material will rapidly expand and solidify and react with the air or the moisture in the contacted matrix to form a foam. Wide range of applications. It has the advantages of front foaming, high expansion, small shrinkage, etc., and the foam has good strength and high adhesion. The cured foam has various effects such as caulking, bonding, sealing, heat insulation, and sound absorption. It is an environmentally friendly and energy-saving ﹑Easy to use building materials, suitable for sealing and plugging, filling gaps, fixing and bonding, heat preservation and sound insulation, especially suitable for sealing, plugging and waterproofing between plastic steel or aluminum alloy doors and windows and walls.

Generally, the surface drying time is about 10 minutes (at a room temperature of 20°C). The total drying time varies with the ambient temperature and humidity. Generally, the total drying time is about 4-6 hours in summer and 24 hours in winter at around zero. It will take longer to dry. Under normal use conditions (and with a covering layer on the surface), it is estimated that its service life will not be less than ten years, and the cured foam will maintain good elasticity and adhesion within the temperature range of -10°C to 80°C. force. The cured foam has the functions of caulking, bonding, and sealing. In addition, flame-retardant polyurethane foaming agent can achieve B and C flame retardant.

Disadvantagesedit
1. Polyurethane foam caulking agent, the temperature is high, it will flow, and the stability is poor. Not as stable as polyurethane rigid foam.
2. Polyurethane foam sealant, the foaming speed is too slow, large area construction cannot be carried out, the flatness cannot be controlled, and the foam quality is too poor.
3. Polyurethane foam sealant is expensive.
typical application
Door and window installation: sealing, fixing and bonding between the door and window and the wall.
Advertising model: model, sand table production, exhibition board repair.
Sound insulation and silencing: fill the gaps in the decoration of speech rooms, broadcasting rooms, etc., which can play a role in sound insulation and silencing.
Gardening and landscaping: flower arrangement, gardening and landscaping, light and beautiful.
Daily maintenance: repair of cavities, gaps, wall tiles, floor tiles, and floors.
Waterproof plugging: repairing and plugging leaks in water pipes, sewers, etc.
Packaging and transportation: It can conveniently package valuable and fragile commodities, which is time-saving and fast, shock-resistant and pressure-resistant.
Instructions:

Before construction, oil stains and floating dust on the construction surface should be removed, and a small amount of water should be sprayed on the construction surface.　Before use, shake the polyurethane foaming agent tank for at least 60 seconds to ensure that the material in the tank is uniform.　If a gun-type polyurethane foaming agent is used, turn the tank upside down and connect it with the spray gun thread, turn on the flow valve, and adjust the flow before spraying.　If tubular polyurethane foaming agent is used, screw the plastic | test large | nozzle on the valve thread, align the plastic tube with the gap, and press the nozzle to spray.　Pay attention to the travel speed when spraying, usually the spray volume is half of the required filling volume. Filling vertical gaps should be from bottom to top; when filling gaps such as ceilings, uncured foam may fall due to the action of gravity. It is recommended to provide proper support just after filling, and after the foam is cured and bonded to the wall of the gap Then withdraw the support.　About 10 minutes, the foam will be debonded, and it can be cut after 60 minutes.　Use a knife to cut off the excess foam, and then coat the surface with cement mortar, paint or silica gel. Weigh the foaming agent according to the technical requirements, add 80 times of clear water to dilute to make a foaming liquid; then use a foaming machine to foam the foaming liquid, and then add the foam to the uniformly mixed magnesite cement slurry according to the predetermined amount Stir evenly, and finally send the foamed magnesite slurry to the molding machine or mold for molding.

Construction Notes:
The normal use temperature of the polyurethane foaming agent tank is +5～+40℃, and the best use temperature is +18～+25℃. In the case of low temperature, it is recommended to place this product at a constant temperature of +25～+30℃ for 30 minutes before using it to ensure its best performance. The temperature resistance range of the cured foam is -35℃～+80℃.
Polyurethane foaming agent is a moisture-curing foam. It should be sprayed on the wet surface during use. The higher the humidity, the faster the curing. Uncured foam can be cleaned with cleaning agents, and cured foam should be removed by mechanical methods (sanding or cutting). The cured foam will turn yellow after being irradiated by ultraviolet light. It is recommended to coat the cured foam surface with other materials (cement mortar, paint, etc.). After using the spray gun, please clean it immediately with a special cleaning agent
When replacing the material tank, first shake the new tank well (shake at least 20 times), remove the empty tank, and quickly replace the new material tank to prevent the spray gun connection port from solidifying.

The one-step foaming process is a commonly used process. There is also the manual foaming method, which is the easiest method. After all the raw materials are accurately weighed, they are placed in a container, and then these raw materials are mixed uniformly and injected into the mold or the space that needs to be filled with foam. Note: When weighing, the polyisocyanate (black material) must be weighed in last.

Rigid polyurethane foam is generally foamed at room temperature, and the molding process is relatively simple. According to the degree of construction mechanization, it can be divided into manual foaming and mechanical foaming; according to the foaming pressure, it can be divided into high pressure foaming and low pressure foaming; according to the molding method, it can be divided into pouring foaming and spraying foaming.