A method of bonding a first part on a second part made of composite material by an adhesive, in which the adhesive is filled with elements of shape memory alloy, is provided. A method of un-sticking the first part adhesively bonded on the composite material second part is also provided. The un-sticking method includes a step of weakening the adhesive interface that consists in subjecting the adhesively bonded parts to heat treatment performed at a temperature that is lower or higher than the martensitic transformation temperature of the shape memory alloy elements.

New adhesives and methods for preparing them are disclosed that include polylactic acid irradiated with gamma radiation, such as by a Co.sup.60 source. Irradiation times are used that improve the characteristics of the adhesive materials. Generally, the dose of radiation is from about 5 kGy to about 200 kGy of gamma irradiation. The adhesives generally have melting temperatures in the range of at least about 140 to about 148 C. such that they can be conveniently used in conventional glue guns and other glue equipment. The disclosed adhesives can provide bond strengths in the range of about 1,600 psi or more to about 2,500 psi or more. The disclosed adhesives can include a crosslinking agents. They can be used to join a wide range of substrates including wood, metal, plastic, ceramic, glass or combinations of substrates. They can be conveniently prepared by heating a polylactic acid (polylactic acid) preparation and mixing the molten polylactic acid with one or more crosslinkers when present. The molten mixture can then be and the polylactic acid can be irradiated with the desired dose of gamma radiation. Irradiation can occur before during or after mixing with the crosslinking agent and before or after shaping into the desired shape or even after use to join substrates. The adhesives can be used to join substrates by any known method once heated to a molten state.

A method of fastening a second object to a first object includes: providing the first object with an attachment surface; providing the second object; placing the second object relative to the first object, with a resin composition in between the attachment surface and the second object, wherein the resin composition has a resin having a first viscosity and being in a flowable state; pressing the first and second objects against each other and causing mechanical vibration to act on at least one of the objects until the resin composition experiences a vibration induced activation, which includes at least one of reduction of the viscosity of the resin compared to the first viscosity and activation of particles dispersed in the resin. The pressing and mechanical vibration are continued or repeated until the resin has at least partially cross-linked and the viscosity of the resin is increased compared to the first viscosity.

A process for laminating a material layer to a support including: providing the support, applying the material layer to the support, a heat-activatable adhesive being applied to s side of the material layer facing the dimensionally stable support and/or to the side of the dimensionally stable support facing the material layer, pressing the flexible material layer and the dimensionally stable support together by means of a lower dimensionally stable mold half and an upper dimensionally stable mold half, irradiating the mold halves, the support and the material layer with electromagnetic radiation, in particular with microwave radiation, high-frequency radiation or induction radiation, whereby the adhesive is activated directly or indirectly.