SETT ATT BINDA MED ETT SKUMMAT TERMOPLASTISKT BINDEMEDELSMATERIAL

摘要

Foamed thermoplastic materials such as coatings, adhesives and structural bodies are made by a method which offers significant advantages and economies. The method involves the steps of stabilizing a dispersion of gas in a molten thermoplastic material by adding a surfactant to the molten material in a sufficient stabilizing amount and subsequently pressurizing the stabilized dispersion to form a hot solution. Thereafter, the hot solution is dispensed under lower pressure whereby the gas is released from solution to form a foamed material. The method is especially advantageous in making hot melt thermoplastic adhesives which are very useful in bonding substrates with efficiency and superior bond strengths. Continuous and reliable foaming operations are achieved with a uniform quality and output of foamed materials. Thermoplastic materials are also capable of being foamed with relatively simple mechanical apparatus and under conditions which provide considerable savings of energy. The number of thermoplastic materials which can be foamed employing the present technique in a controlled manner is unlimited. The method of stabilization is conducted at low or ambient pressures and resulting stabilized hot thermoplastic-gas dispersions may then be pumped with pressurization and dispensed with immediate foaming.