Mechanical cast polyurethane 

Cast polyurethane is widely used in all walks of life and is a good helper for social production and construction. The following is the production process of cast polyurethane.

Step 1

Processing of materials

1, take a certain amount of N material in the kettle, the temperature rises to 130 °C, vacuum at this temperature for 4 hours (vacuum> 0.07MPA);

2,Cast polyurethane lower the temperature to 55°C, add phosphoric acid, stirring for more than 10 minutes;

3, and then slowly add T material, stirring while adding (10 minutes to add the end), at this time the natural exothermic, only stirring without vacuum, let the natural reaction for an hour, and then keep the temperature at 85 °C, stirring vacuum for an hour, the above reaction is made into a pre-polymer; pre-polymer sealing to maintain 24 hours, before pouring and use.

Step 2

Pouring

1, the pouring type polyurethane prepolymer temperature to 85 °C, while stirring and vacuum defoaming 45 minutes;

2, put the mold into the drying box temperature to 120 °C, keep more than half an hour;

3, To be 1, 2 steps completed take a certain amount of MOCA on the electric furnace after melting and pour into the calculated prepolymer, quickly stir, stir, pour into the mold has been preheated, to be a few minutes after curing, put into the oven, with a constant temperature of 120 ° C maturation for one hour, you can get out of the mold, this is a one-time maturation;

4, a number of pieces of once cooked work into the oven, temperature 85 °C, and then cooked for four hours that is the finished product.

Polyurethane hand pouring process

 1st step,Preparation

1. Select suitable raw materials, including polyurethane resin, hardener, filler, etc., and select different material ratios according to specific requirements.
2. Prepare the required tools and equipments, including stirrer, weigher, sprayer, ruler, scraper and so on.
3. Clean up the work site and make sure the ground is level, free of debris and dust.

2nd step ,Mixing materials

1. Put the polyurethane resin, hardener and filler together in the mixer according to the material proportion and mix them thoroughly until it becomes a uniform mixture.
2. The color of the mixture should be even and consistent, if there is any different color, solidification, lumps, etc., the mixing should be stopped and the material ratio should be readjusted.

3rd step,Pouring

1. Use sprayer or scraper to pour the mixture onto the ground to be treated, pay attention to pouring should be smooth and even, ensure that the surface is smooth and bubble-free.
2. Control the thickness and area of the mixture according to the needs, you can use a ruler and scraper to adjust.
3. Put a number of pieces of once cooked work into the oven, warm up 85 °C, and then cooked for four hours that is the finished product.

4th step, maintenance

1. After the mixture is poured, it needs to be fully maintained to ensure its curing and firmness.
2. Conservation time depends on the type of material and environmental conditions, generally need 24 to 48 hours to reach the design strength.

Precautions

1. Polyurethane materials are flammable, explosive and other hazards, and relevant safety measures should be taken before pouring.
2. The mixing ratio of the material is very important for the pouring effect, and should be strictly controlled according to the specific work requirements.
3. During the maintenance period, attention should be paid to maintaining the temperature, humidity and other conditions to ensure the maintenance effect.

In short, the polyurethane hand pouring process requires serious and rigorous operation, and at the same time need to pay attention to safety and environmental protection issues, should be in strict accordance with the process of operation, in order to ensure the quality and stability of the work effect.