Introduction to the three major foaming processes of polyurethane foam caulking agent

Polyurethane Foam caulk 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 the physical process of gas generation（i.e. volatilization or sublimation), or chemical process（That is, the destruction of chemical structure or other chemical reactions）. Let’s talk about the common polyurethane foaming agent foaming process.

1. Pre-polymerization Body method

The prepolymer foaming process is to combine(white material) and (black material) First make the prepolymer, then add water, catalyst, surfactant, other additives, etc. to the prepolymer, mix it under high-speed stirring for foaming, and then mature it at a certain temperature after solidification.

2. Semi-prepolymer method

half pre- The foaming process of the polymer method is to first make part of the polyether polyol (white material) and diisocyanate (black material) into a prepolymer, and then make the other part of the polyether polyol (white material) into a prepolymer. Add ether or polyester polyol and diisocyanate, water, catalyst, surfactant, other additives, etc., and mix under high-speed stirring for foaming.

Third, one-step foaming process

will gatherEther 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. Mix at high speed and foam.

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.

has a wide range of applications. It has the advantages of pre-foaming, high expansion, small shrinkage, etc., and the foam has good strength and high adhesion. After curing, the foam has various effects such as gap filling, bonding, sealing, heat insulation, and sound absorption. It is an environmentally friendly and energy-saving foam. ﹑Easy-to-use building materials, suitable for sealing and plugging, filling gaps, fixing and bonding, thermal insulation and sound insulation, especially suitable for sealing, plugging and waterproofing between plastic steel or aluminum alloy doors, windows and walls.