Patent GB-811844-A (GB)
Title: Improvements in or relating to the treatment of thermoplastic synthetic materials
IPC: D02J1/22
Filed: 1955-07-05
Abstract: <PICT:0811844/III/1> <PICT:0811844/III/2> <PICT:0811844/III/3> Synthetic thermoplastic material is heated by irradiation for a short time with charged particles of high beam density, e.g. accelerated electrons, and the material is subjected to physical treatment while in the heated state.  The process is especially applicable to the treatment of fibres, filaments, or bands of polyamides, e.g. nylon. Filaments may be stretched or may be coated with other material, for example dyestuffs, metal powder, graphite, water repellent materials, or synthetic or natural fibres, in order to colour the filaments or produce electrically conductive or light reflecting material.  In addition to stretching, one or more filaments may be twisted or wound into spiral form.  Heating may take place over the whole cross-sectional area of the filaments or lands or only at a part, e.g. the surface; for this purpose, beams of electrons may be composed of electrons having different velocities or the beam of electrons may be focused on to a desired part of the material. More than one filament may be heated by the electron beam or the same filament may be heated at more than one stage by the same beam.  As shown in Fig. 1, the material 31 is led through chambers 13, 14, 15, 16 which are at pressures decreasing in steps.  In chamber 16 an accelerated electron beam 12 from generator 1 (see Group XL (a)) emerges from slit 3 and impinges on the material.  The material is then led to the atmosphere through chamber 18 which contains liquid, e.g. mercury, to act as a pressure seal and as a cooling means.  In Fig. 11 the intensity of the radiation 103 is controlled according to the amount of stretching of a filament 100, as measured by the difference in the speed of the drives 104, 105.  Fig. 12 shows an arrangement for attaching flakes of material from a nozzle 145 to a filament 140. The filament surface is melted by an electron beam 148 and the flakes are transferred to the surface by an electrostatic field which is applied between the nozzle 145 and the drive 142.  In another arrangement, Fig. 13 (not shown), material is applied to the whole surface of a nylon filament of circular cross-section.ALSO:<PICT:0811844/IV (a)/1> Fibres, filaments, or bands of synthetic thermoplastic material, e.g. nylon, are heated by irradiation for a short time with charged particles of high beam density, e.g. accelerated electrons, and then stretched while in the heated state.  In addition to stretching, one or more filaments may be twisted or wound into spiral form.  As shown in Fig. 11, the intensity of the radiation 103 is controlled according to the amount of stretching of filament 100, as measured by the difference in the speed of drives 104, 105.ALSO:Synthetic thermoplastic material is heated by irradiation for a short time with charged particles of high beam density, e.g. accelerated electrons, in order to melt the surface layer and is then coated with solid material.  Fibres, filaments, or bands of polyamides, e.g. nylon, may be coated with dyestuffs, metal powder, graphite, water repellent materials, or synthetic or natural fibres, in order to colour the material or impart electrically conductive or light-reflecting properties.  The solid material may be transferred to the surface from a nozzle by means of an electrostatic field.