Nylon extrusion

Nylon blends, dyeing, 9 204 Nylon block copolymer, 19 762 Nylon carpet fibers, stain-resistant, 19 764 Nylon-clay nanocomposites, 11 313-314 Nylon extrusion, temperatures for, 19 789t Nylon feed yarns, spin-oriented, 19 752 Nylon fiber(s), 24 61 production of, 19 740 world production of, 19 7654 Nylon fiber surfaces, grafting of polymers on, 19 763-764... 

Nylon 6/9, molding and extrusion Nylon 6/12 Nylon 11, molding and extrusion Nylon 12, molding and extrusion Aromatic nylon (aramid), molded and unfilled ... 

Maranyl Nylon Compounds, Extrusion, N103, Du Pont De Nemours Int. SA, Geneva, Switzedand, 1987. 

MSTM D4066-93, Standard Specification for Nylon Injection and Extrusion Materials (PM), ASTM, Philadelphia, Pa., 1993. 

Injection moulding and extrusion may be carried out at temperatures in the range of 300-380°C. The polymer has a high melt viscosity and melt fracture occurs at a lower shear rate (about 10 s ) than with low-density polyethylene (about 10 s ) or nylon 66 (about 10 s ). Extruders should thus be designed to operate at low shear rates whilst large runners and gates are employed in injection moulds. 

The particular features of the nylons should also be taken into account in extrusion. Dry granules must be used unless a devolatilising extruder is employed. Because of the sharp melting point it is found appropriate to use a screw with a very short compression zone. Polymers of the lowest melt viscosity are to be avoided since they are difficult to handle. Provision should be made to initiate cooling immediately the extrudate leaves the die. 

Other, more recently developed, uses include microwave oven parts, transparent pipelines, chemical plant pumps and coffee machine hot water dispensers. One exceptional use has been to produce, by an extrusion moulding process, very large rollers for textile finishing for use where cast nylons cannot meet the specification. Also of growing interest are medical equipment applications that may be repeatedly steam-sterilised at 134°C, filtration membranes and cartridges for ink-jet printers. 

Blends based on polyolefins have been compatibilized by reactive extrusion where functionalized polyolefins are used to form copolymers that bridge the phases. Maleic anhydride modified polyolefins and acrylic acid modified polyolefins are the commonly used modified polymers used as the compatibilizer in polyolefin-polyamide systems. The chemical reaction involved in the formation of block copolymers by the reaction of the amine end group on nylon and anhydride groups or carboxylic groups on modified polyolefins is shown in Scheme 1. 

RCM. See Ring-closing metathesis (RCM) Reaction by-products, removing, 83 Reaction extrusion, 204 Reaction index, 237 Reaction injection molding (RIM), 205 Reaction-in-mold (RIM) nylon, 149 Reaction kinetics, 76, 77 Reaction mechanisms, polyesterification, 66-69... 

Using co-extrusion it is possible to make fibres with a nylon 6,6 inner core (Tm 264°C) and a nylon 6 outer shell (Tm 215°C). By applying pressure and heat between these two temperatures to bundles of these two fibres, a non-woven mat can be made. 

Nylon film, extrusion of, 19 789-790 Nylon flocking, 19 755 Nylon food packaging, 18 43 Nylon hollow fibers, 16 21-22 Nylon-MXD6... 

ISO 1874-2 1995 Plastics - Polyamide (PA) moulding and extrusion materials - Part 2 Preparation of test specimens and determination of properties ISO 15987 2003 Plastics - Film and sheeting - Biaxially oriented polyamide (nylon) films. 

After the polymer is formed, the filament is produced by extrusion. The nylon can be taken directly from the polymerization process while it is still molten. Alternatively, previously dried nylon chips can be heated and melted. The molten nylon is pressed through a spinneret, which is like a showerhead with 10—100 holes. (A spinneret with a single hole produces a monofilament. Nylon monofilaments are used for fishing line and sheer... 

Microfibers are also made by simple extrusion through a spinneret with a smaller hole than normally employed for fiber production. The third method involves spinning a bi-component fiber and using a solution to split the fiber into smaller pieces. Initially, bi-component fibers in the range of 2-4 denier are spun and then split into microfibers. If a 32-segment pie of nylon-polyester fiber is used, the final fineness is on the order of 0.1 denier. Brushing and other techniques can be used to enhance the effects. Hollow fibers are also being used... 

Some of the main uses [33,34] of polyamides or nylons are for synthetic fibers for the tire, carpet, stocking, and upholstery industries. Use of polyamides as molding and extrusion resins for the plastics industry is also of increasing importance [38]. 

Based on knowledge of relative properties and costs, it appeared to us that Celcon had some advantages to offer in the application. We quickly learned that people making tubing from nylon were extruding at rates up to 150 feet per minute. At the time, our company had very little experience with the extrusion properties of Celcon and we learned that under conditions which were being used... 

Extrusion accounts for about 30% of nylon produced and is used in various processes (24). Nylons can be extruded on conventional equipment having the following characteristics. The extruder drive should be capable of continuous variation over a range of screw speeds. Nylon often requires a high torque at low screw speeds typical power requirements would be a 7.5-kW motor for a 30-mm machine or 25-kW for 60-mm. A nylon screw is necessary and should not be cooled. Recommended compression ratios are between 3.5 1 and 4 1 for nylon-6,6 and nylon-6 between 3 1 and 3.5 1 for nylon-11 and nylon-12. The length-to-diameter ratio, L D should be greater than 15 1 at least 20 1 is recommended for nylon-6,6, and 25 1 for nylon-12. 

Capron Nylon Homopolymers forMolding and Extrusion, CL-100-884, Allied Corp., Morristown, N.J. 

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