LIQUID/LIQUID, LIQUID/GAS OR GAS/GAS SEPARATION Method General operations by centrifugal force, using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force, using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/LIQUID OR SOLID/GAS SEPARATION Method General operations by centrifugal force using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/SOLID SEPARATION Method Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods Apparatus Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus , Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods This class does not cover the working of plastics sheet material in a manner analogous to the working of paper, which is covered by class . In this class, the following term is used with the meaning indicated: "plastics" means macromolecular compounds or compositions based on such compounds. In this class, the following rules apply: The working of plastics is, as far as possible, classified primarily according to the particular shaping technique used, e.g. in subclass . A product is not classified in this class unless it results from a technique which is covered by this class. Classification according to production of particular articles in subclass is restricted to: aspects which are characteristic for the production of a particular article, and not classifiable in subclass or ; combined operations for making the particular article which are not fully classifiable in subclass . The codes of subclass are only for use as indexing codes associated with subclasses , , or so as to provide information concerning moulding materials or materials for reinforcements, fillers or preformed parts, e.g. inserts. The codes of subclass are only for use as indexing codes associated with subclass , so as to provide information concerning the articles produced by the techniques classified in subclass . Attention is drawn to Note (3) following the title of class . Layered products or laminating methods are further classified in subclass . In this subclass: repairing of articles made from plastics or substances in a plastic state, e.g. of articles shaped or produced by using techniques covered by this subclass or subclass , is classified in group ; component parts, details, accessories or auxiliary operations which are applicable to more than one moulding technique are classified in groups ; component parts, details, accessories or auxiliary operations which are only applicable or only of use for one specific shaping technique are classified only in the relevant subgroups of groups . In this subclass, it is desirable to add the indexing codes of subclasses and . COMPONENT PARTS, DETAILS ACCESSORIES, AUXILIARY OPERATIONS Moulds or cores Heating, cooling, curing Other features , MOULDING by casting, by coating a mould , Compression moulding by internal pressure Injection moulding Extrusion moulding Blow-moulding Thermoforming OTHER SHAPING TECHNIQUES Bending, folding, twisting, straightening, flattening Stretching Liberation of internal stresses Other techniques JOINING PARTICULAR APPLICATIONS Shaping tube ends Surface shaping Lining or sheathing Shaping composites COMBINATIONS OF SHAPING TECHNIQUES AFTER-TREATMENT REPAIRING Classification is made in this group only if the details or adaptations of the heating means are of interest. In this group, the following terms or expressions are used with the meanings indicated: "reinforcement" means a structure in the form of fibres, wires, rods, bars, sections, plates or blocks, which improves the strength of an article; "filler" means a relatively inert substance in the form of particles, powder, beads, flakes or spheres, which improves the physical properties or increases the bulk or weight of an article; "preformed part" means a part made of any material, being completely shaped to have a determined form and which is not used as a reinforcement, e.g. wires or nets forced only into the surface of an article; "insert" means a preformed part incorporated in an article during moulding. This group covers: the shaping of coherent fibrous reinforcements which are pre-impregnated or without binder, or of non-coherent reinforcements of fibres placed in a mould or on a support; the impregnation or introduction of a plastics matrix in reinforcements during shaping. This group does not cover: the moulding by a single technique of plastics matrix material mixed with and containing reinforcing fibres of short length, which is covered by the appropriate place for that technique; the pretreatment, e.g. impregnation, of reinforcements per se, i.e. independently of their shaping, which is covered by group . Moulding of plastics matrix material mixed with fillers by a single technique is classified in the appropriate place for that technique. This group does not cover: incorporating, or moulding on, preformed parts by a single technique, which is covered by the appropriate place for that technique; pretreatment of preformed parts per se, i.e. independently of their shaping, which is covered by group .