Abstract: This invention concerns a method of marking articles having a polyolefin surface by exposure to a laser beam. The polyolefin contains a sufficient amount of a laser radiation absorbing substance for decomposing the polyolefin, so that a black mark of decomposed polyolefin will be formed.The laser radiation absorbing substance is a silicon compound, preferably a metal silicate, e.g. calcium-metasilicate or kaoline.The invention also comprises an article having a polyolefin surface, provided with a black mark of decomposed polyolefin formed by a laser beam.

Abstract: A pipe member having at one end a socket for the insertion of a further pipe member and a corrugation in the wall of the socket containing a packing ring of resiliently deformable material, and a retaining ring received in an internal recess in the packing ring has its packing ring formed with an outer peripheral portion to fit the contour of the corrugation and annular front and rear projections situated respectively axially in front of and to the rear of the retaining ring to co-operate with the inserted pipe member to form pressure shoulders between which the retaining ring is disposed in the central region of the packing ring, the pressure shoulders transmitting compressive forces to the outer peripheral portion of the packing ring, the outer peripheral portion of the packing ring extending over the two pressure shoulders and over the retaining ring to bear against the corrugation under compressive load.

Abstract: The invention relates to a process for manufacturing an inner tube element made of synthetic resin for a double tube coring apparatus provided for deep boring. The tube element is provided with coupling nipples for connecting it to other inner tube elements. Fibers coated with synthetic resin are wound helically onto a cylindrical mandrel so as to overlap each nipple. This process gives the tube element a higher strength than that of glued nipples.

Abstract: A sealing body for a pipe connection bonded chemically and/or mechanically to a fixation part being attachable to an end portion of a socket pipe. The fixation part consists of plastic material or of reticulated elastomer.

Abstract: A web of interconnected plastic bags produced by providing a tubular foil of plastic material with gusset folds with bottom fold part seals at both sides of the tubular foil. Each fold part seal connects a gusset fold part with an opposite part of the outer foil layers. Immediately after having moved the tubular foil over a predetermined distance the tubular foil is provided with a first transverse bottom seal by heatsealing opposite first fold part seals and outer foil layers to each other.

Abstract: A plastic glazing profile for mounting a glass pane in an existing wooden frame comprises a supporting face having at one end thereof an element for fixing a glass pane by means of projections. At its other end the profile comprises a glass pane abutment and opposite thereto a profile abutment edge. The profile abutment edge being the bottom of an abutment edge chamber, is provided with apertures forming outlets for water flowing from a gutter space through bores into said chamber. The profile abutment edge is able to engage a sealing strip through a projecting portion.

Abstract: A method and device for cooling molds circulating in a horizontal plane, in which siphon action is used to pass cooling liquid from a top gutter through the molds. In this way the whole cooling system is becoming constructively simplified, such that production speeds can be increased, with the consequent greater length of the cooling system, but without its becoming unduly complicated. This effect is realized irrespective of the nature of the machine or the number of molds.Method and device are especially advantageous when applied with the manufacture of plastics tube, more particularly yet with the manufacture of plastic corrugated tube.

Abstract: Method of and device for making perforations in the inner gusset portions of a tubular web of plastics foil which is provided with side gussets. Such perforations serve to remove air from the interior of bags to be manufactured from the tubular web. According to the invention the gussets are opened over a distance sufficient to introduce, in the interior thereof, a punching member, which is activated by exerting a pressure from outside the tubular web. A device adapted to perform this method comprises a separate carrier provided at either one of its ends with rolls and adapted to be introduced into the interior of the tubular web where it is supported and maintained in its place lengthwise of the web, by two sets of rolls which are situated at the exterior of the tubular web. The carrier is provided with perforating units and the machine frame outside the tubular foil is provided with means to exert through the web material, a force and to activate the perforating units.

Abstract: A plastic tubular heat exchanging element consists of a tube or tubular element comprising an inner wall and an outer wall interconnected by partitions, thereby forming longitudinal channels.The channels are connected with a fluid supply chamber and a fluid outlet chamber for feeding and removing a heating fluid. Preferably a supply chamber and outlet chamber are formed by a tubular sleeve, sealingly engaging a wall of the heat exchanging element by applying sealing rings.The supply chamber and outlet chamber may be located near the ends of the tubular heat exchanging element. The chambers may also be opposite each other while the other end of the tubular element is closed by a covering cap forming a chamber for passage of heat absorbing fluid from the supply chamber toward the outlet chamber, located at the same end.

Abstract: Coloring composition for colouring polyvinylchloride comprising at least 40% by weight of coloring pigment and at most 60% by weight of glycerolmonostearate. The composition may be added directly to extruder for extruding polyvinylchloride, the amount of glycerolmonostearate in the moulded article as obtained being restricted to at most 5%.

Abstract: In a non-destructive method the state of ageing of plastic products is determined by means of infrared radiation, which is passed through the product.The invention is based upon the discovery that there is a clear relationship between certain physical and/or chemical changes occurring during the course of time in the interior of plastic materials, detectable by infrared analysis, and the mechanical properties of the product. On the basis of this relationship, the method may be used to decide whether products can be safely used or whether they must be disqualified and removed.The method is particularly well suited with crates which are to contain bottles; the radiation is then passed through a crate wall.Apparatus for performing the method may be arranged in a line such as a conveyor belt bottling line.

Abstract: A plastic bag 1 with gusset fold parts 7, 8; 7a, 8a bounded by a central gusset fold edge 3, 3a and outer gusset fold edge 4, 5; 4a, 5a, is provided with a transverse seal 6 and first fold part seals 9, 10, 11, 12 at either side of the bag. Perforations 14 are present in the first and second gusset fold parts 7, 7; 7a, 8a in the area bound by said first fold part seals 9, 10, 12, 12, imaginary lines 15, 15a and the central gusset fold edges 3, 3a. The imaginary lines 15, 15a extend parallel to the transverse seal 6 and through the intersection of the first fold part seals and outer gusset fold edge 4, 5; 4a, 5a. Similar perforations 14 may be present at the other side of the bag in the region of the gusset fold parts bound by the central gusset fold edge 3, 3a, second fold part seals 16, 17, 18, 19 and imaginary lines 26, 26a extending parallel to the transverse seal 6 and through the intersection of second fold part seals 16, 17, 18, 19 and outer fold edges 4, 5; 4a, 5a.

Abstract: An insulating pipe part of thermoplastic material comprises two opposite sections and one third section disposed at an angle with respect to the former sections, the wall portion of said sections being provided with a continuous wall cutting slit. The pipe part may comprise thicker parts of a polyurethan foam.For forming an insulated branch pipe joint, said insulating pipe part is pushed over a branch pipe and subsequently plastic sleeves with beveled front ends are heatshrunk on to said sections, thereby closing said slit in a moisture tight manner.In order to obtain a reliable moisture tight closing, the sleeves are provided with beveled front ends so that the lower sleeve ends overlap each other.

Abstract: A plastic pipe part 1 is pushed across a head part 3 of a sealing sleeve 4, being supported by a support 8, thereby providing the plastic pipe part with a widened end 7. Subsequently the widened end is surrounded by an outer mold 11 with three successive widenings 12, 14, 15 and by means of a fluid pressure in the interior of the widened end 7, sealed by the head part 3, the widened end is provided with three socket end widenings 28, 22, 29. After removal of the support 8 the end portion 6 of the socket end is inwardly rebent around the head part 3 thus forming a groove chamber 5 retaining the head part 3 of sealing sleeve 4. Pushing the plastic pipe part across the head part is facilitated by applying a fluid pressure.

Abstract: Method for uniting a plastic fixation part with a sealing body comprising a head end and a sealing sleeve, by first molding the sealing body and subsequently molding the plastic fixation part around the head end of the sealing body, thereby protecting the sealing sleeve. The fixation part is provided with corrugations for connecting said fixation part with a socket pipe provided with corrugations on its outer side.The method may be carried out in an apparatus comprising a first mold part, a second mold part and a third mold part forming together a molding space for forming the sealing body and a forth mold part replacing the first mold part, forms a molding space for molding the fixation part.

Abstract: The invention relates to a coupler for insulated plastic pipe ends and a branch pipe end, the insulation being covered with tubular casings. The coupler is provided with anchoring means comprising one or more ribs or cams extending laterally from the central coupler 1 and with means for transmitting pressure forces from the anchoring means and the central coupler to the tubular casings.

Abstract: A device and method for recovering heat from the soil and groundwater, comprise heat-exchanging means consisting of an inner tube, an outer tube and partitions forming longitudinal channels between said inner and outer tube.An inlet for heat-exchanging fluid and an outlet for heat-exchanging fluid are present for conveying a heat-exchanging fluid through said longitudinal channels.The heat-exchanging means are preferably placed in a perforated casing allowing passage of liquid but not of soil particles. The casing consists preferably of an outer casing tube and an inner casing tube, casing partitions providing longitudinal casing channels. For allowing passage of groundwater the outer casing tube and the inner casing tube are provided with perforations.Heat is recovered by passing a heat-exchanging fluid through the casing channels.

Abstract: A method of making seals in tubular web provided with side gussets, in which method, after making the seals, sensors for the inner gusset edges are withdrawn outwardly over a certain distance, the position of the sealing devices remaining unchanged, and after transport of the tubular web, the sensors are moved inwardly again and the new position of the inner gusset edges is observed, subsequently, when a difference is observed as compared with the previous time, the position of the sealing devices is brought into correspondence with this observation before making the next seal.

Abstract: A plastic crate or tray comprises a bottom and vertical side walls. A side wall comprises inner and outer side wall parts.Injection molding points are present in the lower edge of the outer side wall parts.

Abstract: Apparatus for making profiled plastic tube and comprising two circulating endless chains, each making a plurality of mold halves move along with a tube coming from an extruder, these mold halves pairwise constituting a mold cavity in which the tube is being given its profile. According to the invention the molds are movable relative to the chain links in a direction perpendicular to the direction of movement of the links. The machine frame is provided with guides for the mold halves, some located interiorly, others exteriorly, with respect to the chain loop, such that once closed, the cavity formed by the pairs of mold halves will remain closed and undisturbed up to the end.Preferably the transitions between curved portions and the operative portion of the path of the mold halves at the entrance and the exit ends are bending points of mathematically calculated paths and the operative straight path tangentially joins said transitional portions.