Introduction to Other Polyurethane Flexible Foams

1. Flame-Retardant Flexible Foam

Flame retardants are introduced into the foaming system.

There are two types of flame retardants: additive flame retardants and reactive flame retardants.

*Additive flame retardants:

Inorganic flame retardants: antimony compounds, boron compounds, aluminum hydroxide, water, chromium chloride, etc.

Organic flame retardants:

①Phosphorus-based: phosphate esters, polyphosphate esters, etc.

②Halogen-based: chlorides, bromides, etc.

③Nitrogen-based: melamine, melamine phosphate, triazine compounds, etc.

*Reactive flame retardants: isocyanates containing phosphorus and other elements; polymer polyols containing phosphorus, nitrogen, silicon; polymer polyols with aromatic and aromatic heterocyclic structures, etc.

2. Anti-Yellowing Flexible Foam

Light

(Quinonoid structure)

Light stabilizers:

① UV absorbers (benzotriazole type, salicylate type, benzophenone type)

② Hindered amine light stabilizers (HALS)

Heat and chlorine

Chlorine degradation and high heat → free radicals and peroxides

Antioxidants: free radical chain terminators (hindered phenol type, aromatic secondary amine type)

peroxide decomposers (phosphite type, thioester type)

Water and bacteria → hydrolysis and mildew

Hydrolysis stabilizers: carbodiimides and their derivatives, epoxy compounds

Mildew prevention agents

3. Surface-Modified Flexible Foam

Hydrophilic flexible foam

Oleophilic flexible foam

Antistatic flexible foam

4. Polyurethane Semi-Rigid Foam and Microcellular Foamed Adhesives

Polyurethane semi-rigid foams are mostly used for molding.

Microcellular foamed adhesives are mainly used for shoe soles.

Modified general-purpose foam mimicking semi-rigid block foam

High-hardness foam — source of hardness

High-Hardness Foam Production Example

5. On-Site Applied Flexible Foam

On-site packaging uses ultra-low-density semi-rigid foam; spray-applied soft foam is rarely used.

Formulation

Foaming Process Conditions