A joining method using heat fusion includes layering a first joining body and a second joining body having a smaller plane area than the first joining body; and performing heating and pressurization with a heater from a side of the second joining body. The method further includes a resin dam interposed between the second joining body and the heater. The resin dam includes a base body having one of front and back surfaces in contact with the heater and the other of front and back surfaces in contact with the second joining body; and a dam main body extending from a circumferential edge of the base body in a direction away from the base body and having a shape control surface facing a side surface of the second joining body.

An array of resilient floor tiles is assembled into a continuous sheet after being laid down. An array of included, sacrificial resistive wires is buried along the edges of the tiles and is controllably heated in order to cause welding of the edges of tiles across the paths of the wires to neighboring tiles. Subsequently the wires may be used to give the array integral tensile strength. The welded array is provided with greater strength for resisting use, expansive and contractile forces caused by environmental heat and cold and also long-term tile contraction owing to loss of plasticizer as may be seen with PVC-based tiles.

High-frequency welding method for welding an accessory to a substrate by high-frequency welding machinery which includes a female mold, having a cavity formed by a profile having substantially the same shape and dimensions as the accessory, and a male mold, having a relief formed by a profile having substantially the same shape and dimensions as the accessory. The method includes: mounting the female mold on a movable upper plate of the machinery and the male mold on a fixed lower plate of the machinery, or vice versa, such that the profile of the cavity is aligned in a closure direction of the molds with the profile of the relief. The method further includes: positioning the accessory on the relief or in the cavity; positioning the substrate above the accessory; moving the upper plate towards the lower plate; supplying high-frequency welding energy to the upper plate and/or to the lower plate.

High-frequency welding method for welding an accessory to a substrate by high-frequency welding machinery which includes a female mold, having a cavity formed by a profile having substantially the same shape and dimensions as the accessory, and a male mold, having a relief formed by a profile having substantially the same shape and dimensions as the accessory. The method includes: mounting the female mold on a movable upper plate of the machinery and the male mold on a fixed lower plate of the machinery, or vice versa, such that the profile of the cavity is aligned in a closure direction of the molds with the profile of the relief. The method further includes: positioning the accessory on the relief or in the cavity; positioning the substrate above the accessory; moving the upper plate towards the lower plate; supplying high-frequency welding energy to the upper plate and/or to the lower plate.

The invention relates to a chamber for steam moulding expanded or cellular materials or foams comprising an enclosure comprising at least two parts (3a, 3b), at least one part being movable to allow it to be opened and closed, and the surfaces of which are partially covered with an insulating coating, in particular the inner surface of the enclosure or the outer surface of the steam inlets.

A plant produces plastic films subjected to stretching. The plant includes a flat extrusion head made of polyethylene-based plastic material, first and second rollers forming a rolling press, and a third cooling/stabilizing roller. Molten plastic material/melt exiting the flat head passes through the first and second rollers before being directed onto the third cooling/stabilizing roller. The extrusion head has a width of 1,000-5,000 mm, the first and second rollers each have a diameter of 200-800 mm. The third roller has a diameter of 400-1,000 mm. The first and second rollers are made of ferrous material, with a conductive heat transfer coefficient of at least 15 W/(mK). The ferrous material is a construction steel with a chrome-plated and mirror-polished surface, having a roughness (Ra)<1 m, copper coatings, or coatings having thermal-conductivity and surface-roughness values corresponding to the rollers. The first and/or second roller has a deformable and non-stick coating.

An injection mold insert includes a housing of a first material and an inner core of a second material sealed in the housing of the first material. A mechanical strength of the first material is greater than that of the second material. The thermal conductivity of the second material is greater than that of the first material. The inner core is formed by filling a molten liquid of the second material into an inner cavity of the housing.