Polyurethane foaming agent is a cross-combination product of aerosol technology and polyurethane foam technology. Sponge state appears on both the split-tube type and the gun type. Foam rubber is used as a blowing agent in the production of microcellular foam plastics. It can generally be divided into two categories: physical type and chemical type. This is based on whether the gas generation is a physical process (i.e. volatilization or sublimation) or a chemical process (i.e. chemical structure). destruction or other chemical reactions). BelowPolyurethane CatalystThe editor will introduce to you the polyurethane foaming agent foaming process:
1. Prepolymer method
The prepolymer foaming process is to first make the (white material) and (black material) into a prepolymer, and then add Water, catalyst, surfactant, other additives, etc. are mixed under high-speed stirring for foaming, and then cured and matured at a certain temperature.
II. Semi-prepolymer method
The development of semi-prepolymer method The foaming process is to first make part of the polyether polyol (white material) and diisocyanate (black material) into prepolymers, and then mix the other part of the polyether or polyester polyol and diisocyanate, water, catalyst, surfactant, Add other additives, etc., and mix under high-speed stirring for foaming.
3. One-step foaming process
Plastic polyether or polyester polyol (White material) and polyisocyanate (black material), water, catalyst, surfactant, foaming agent, other additives and other raw materials are added in one step, mixed under high-speed stirring and then foamed.
The one-step foaming process is a commonly used process. There is also the manual foaming method, which is the simplest method. After accurately weighing all the raw materials, place them in a container, then immediately mix the raw materials evenly and inject them into the mold or the space that needs to be filled with foam plastic. Note: When weighing, the polyisocyanate (black material) must be weighed in last.
Polyurethane rigid foam is generally foamed at room temperature, and the molding process is relatively simple. According to the degree of mechanization of construction, it can be divided into manual foaming and mechanical foaming; according to the pressure during foaming, 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 spray foaming.
The above is the introduction of the polyurethane catalyst editor, I hope it will be helpful to everyone.
