Nylon resins


Fig. 1. (a) World production of nylon fiber (11) (b) world consumption of nylon resins (12).  [c.220]

Blow Molding. Blow mol ding of nylons has become more important as a means of making large hoUow mol dings. As well as high molecular weight nylon, resins modified to increase melt strength and containing glass fiber have been introduced. Blow mol ding of nylons is usually carried out by extmsion blow mol ding, whereby melt is produced in an extmder and formed into a tube called a parison (26). The molten parison is captured in a mold that pinches and seals the ends, and the rigid hoUow part is formed by inflation under air pressure. Intermittent extmsion blow mol ding is most common, which involves the storing of melt in an accumulator die head until requited to form the next parison. Melt storage with a reciprocating screw or accumulator pot with ram is also used, as is continuous blow mol ding. Injection blow mol ding can also be carried out for small parts. This involves the mol ding of a preform around a core, which is transferred to another mold for inflating or blowing to the final part shape. The design of the manifold and accumulator head should be such as to avoid material hold-up locations (giving degradation and gel formation), and should also incorporate even, carefully controlled heating. Adequate venting of the head is necessary to avoid buildup of gas.  [c.274]

Moulding of Zytel 6,6 Nylon Resins, TRZ 30, E-39416, Du Pont de Nemours Int. SA, Geneva, Switzedand, May 1992.  [c.277]

Nylon. Nylons comprise a large family of polyamides with a variety of chemical compositions (234,286,287). They have excellent mechanical properties, as well as abrasion and chemical resistance. However, because of the need for improved performance, many commercial nylon resins are modified by additives so as to improve toughness, heat fabrication, stabiUty, flame retardancy, and other properties.  [c.421]

Nylon Resins. Nylon engineering thermoplastic resins have the foUowing polyamide stmctures  [c.266]

Nylon resins are made by numerous methods (53) ranging from ester amidation (54) to the Schotten-Baumann synthesis (55). The most commonly used method for making nylon-6,6 and related resins is the heat-induced condensation of monomeric salt complexes (56). In this process, stoichiometric amounts of diacid and diamine react in water to form salts. Water is removed and further heating converts the carboxylate functions to amide linkages. Chain lengths are controlled by small amounts of monofunctional reagents. The molten finished nylon resin can be dkectly extmded to pellets.  [c.266]

The preparation of nylon resins from lactam precursors involves ring opening, which is facihtated by a controlled amount of water in the reaction mixture. The salt complex condenses internally to produce the polyamide (57). The synthesis of nylon-6 [25038-54-4] from S-caprolactam is as follows  [c.266]

Physical properties of commercial nylons are shown in Table 5. Crystalline nylons are white and chemically and hydrolytically stable. FlammabiUty, as measured by laboratory tests, varies with composition the higher the aUphatic carbon content, the mote flammable the resin. Both filled and unfilled nylon resins exhibit lubricity. Mineral- and glass-filled crystalline nylons are creep resistant heat-deflection temperatures approach the crystalline melting points in dry resin. With good melt flow and rapid crystallisation rates, nylons are easy to process. On the other hand, they exhibit high mold shrinkage, and dimensions and properties vary with the amount of absorbed water, which can be as high as 10% by weight an increase in water content reduces the glass-transition temperatures. The lower the glass-transition temperature, the greater the creep under load. Mineral filling reduces but does not eliminate these problems. Thus part and mold designs have to compensate for dimensional changes and warpage.  [c.267]

Amorphous nylons are transparent. Heat-deflection temperatures are lower than those of filled crystalline nylon resins, and melt flow is stiffer hence, they are more difficult to process. Mold shrinkage is lower and they absorb less water. Warpage is reduced and dimensional stabiUty less of a problem than with crystalline products. Chemical and hydrolytic stabiUty are excellent. Amorphous nylons can be made by using monomer combinations that result in highly asymmetric stmctures which crystalline with difficulty or by adding crystallization inhibitors to crystalline resins such as nylon-6 (61).  [c.267]

Crystalline nylons are processed by injection molding and extmsion. The extmsion products are mostly films. Coated or laminated with moisture-barrier resin, eg, PVDC or PE polymers, they are used for meat wrappings and shaped food containers. For injection mol dings, extmded pellets are used, available in neat, mineral-filled, glass-reinforced, pigmented, and impact-modified grades. Notched Izod impact resistance can be increased from the usual 100—150-J/m (1.9—2.8-fflbf/in.) (under ambient moisture conditions) to the 1000-J/m (19-fflbf/in.) range (62). Injection-molded parts are used for small mechanical, electrical, and building constmction appHcations. In the automotive area, nylon resins are used for interior, exterior, and under-the-hood appHcations. Parts include filter bowls (amorphous nylon resins), window cranks, electrical coimectors, fuse boxes, and speedometer gears. The electrical and electronic industries use various nylon resins for coimectors, switches, and clamps. Mechanical appHcations include metal replacement in parts such as gears, sprockets, and wedges. The constmction industry uses injection molded parts for fasteners, hardware, and power tools. For many appHcations, nylons compete with polyester and PC resins. Small volumes (about 5% of total nylon engineering appHcations) of nylon-11 [25035-04-5] and nylon-12 [24937-16 ] are used for solvent resistant parts such as automotive fuel line components.  [c.267]

Currently, over 110,000 t/yr of engineering resin blends are consumed worldwide, primarily in the transportation, business-machine, hardware, electrical, and appHance industries. Annual growth is projected to be ca 17%/yr. New blends based on PC, terephthalate, and nylon resins are experiencing the greatest expansion (122). These projections could be surpassed if large-volume metal appHcations such as automotive panels are replaced by engineering resin blends which are currently being field-tested.  [c.277]

Nylon resins are important engineering thermoplastics. Nylons are produced by a condensation reaction of amino acids, a diacid and a diammine, or by ring opening lactams such as caprolactam. The polymers, however, are more important for producing synthetic fibers (discussed later in this chapter).  [c.336]

Mechanical Properties. Stiffness, resistance to deformation under constant appHed load (creep resistance), resistance to damage by cycHcal loading (fatigue resistance), and excellent lubricity are mechanical properties for which acetal resins are perhaps best known and which have contributed significantly to their excellent commercial success. General purpose acetal resins are substantially stiffer than general purpose polyamides (nylon-6 or -6,6 types) when the latter have reached equiUbrium water content. The creep and fatigue properties are known and predictable and very valuable to the design engineer.  [c.56]

With water-solubilizing groups, eg, —SO H as in (2a) [4434-38-2] (22), these types of compounds are suitable for whitening ceUulosic materials or nylon from soap and detergent baths. In solution and on the substrate these compounds show good fastness to hypochlorite and to light. Water-insoluble derivatives of this family, eg, compounds having the nitrile group as in (2b) [5516-20-1] (23), are suitable for brightening synthetic fibers and resins.  [c.115]

A fracture toughness test, where unstable britde fracture occurs at a critical appHed load, leads to a load—displacement curve like that shown schematically in Figure 7a, having an essentially linear loading curve and a catastrophic drop in load at fracture. Gross nonlinearity in the loading curve generally indicates that excessive yielding is occurring, although it may also indicate slow stable crack growth prior to unstable fracture. Because it is the fracture toughness at the initiation of crack growth that is desired, the load at this point must be deterrnined. The ASTM standards suggest drawing a line through the straight part of the loading curve and then drawing a second line MB with a 5% lower slope, as shown in Figure 7b. If the maximum load falls between these lines, then this load is used to calculate the toughness of the material. If the maximum load is outside these lines, then a reduced load at the point where the 95% slope line crosses the loading curve should be used. Other conditions must also be met, as described in the standards. If the reduced load is less than 90% of the maximum load, or if britde fracture does not occur, then the test is invaUd and a /-integral test must be considered. Some typical values in units of are steel, 40—90 titanium, 38 aluminum, 30 30% glass-reinforced nylon-6,6, 6.0 nylon-6,6, 3.5 ABS resins, 2.0  [c.545]

Table 11 shows U.S. production and sales of the principal types of plastics and resins. Some materials are used both as plastics, ie, bulk resin, and in other apphcations. For example, nylon is used in fibers, urethanes as elastomers. Only their use as plastics is given in Table 11 their uses in other apphcations are Hsted with those apphcations.  [c.369]

Almost all of the cyclohexane that is produced in concentrated form is used as a raw material in the first step of nylon-6 and nylon-6,6 manufacture. Cyclohexane also is an excellent solvent for cellulose ethers, resins, waxes (qv), fats, oils, bitumen, and mbber (see Cellulose ethers Resins, natural Fats AND FATTY OILS Rubber, NATURAL). When used as a solvent, it usually is in admixture with other hydrocarbons. However, a small amount is used as a reaction diluent in polymer processes.  [c.409]

The development of new resins, plastics, fibers, elastomers, etc, which are processed at progressively higher operating and curing temperatures has created a need for pigments that stand up for relatively long periods of time to a hostile environment. They must remain essentially unaltered when incorporated into plastics such as polypropylene, ABS, or nylon at relatively high temperatures. In reaUty, in high temperature plastics most organic pigments partially dissolve and undergo particle ripening or growth thus changing color without chemical destmction. Some pigments can change to thermodynamically more stable polymorphic forms with consequent color change, and others simply decompose.  [c.23]

The packaging (qv) requirements for shipping and storage of thermoplastic resins depend on the moisture that can be absorbed by the resin and its effect when the material is heated to processing temperatures. Excess moisture may result in undesirable degradation during melt processing and inferior properties. Condensation polymers such as nylons and polyesters need to be specially predried to very low moisture levels (3,4), ie, less than 0.2% for nylon-6,6 and as low as 0.005% for poly(ethylene terephthalate) which hydrolyzes faster.  [c.136]

In addition to the semicrystalline nylons, which comprise the vast majority of commercial resins, nylon is also available in an amorphous form that gives rise to transparency and improved toughness at the expense of high temperature properties and chemical stress crack resistance. Table 2 shows the properties of some different polyamide types.  [c.267]

Generally, nylon is notch-sensitive and the uimotched impact strength is dramatically reduced when a notch or flaw is introduced into the material. This needs to be considered when designing parts so that sharp angles are avoided where possible. This notch sensitivity can be considerably reduced by incorporating impact modifiers. For the most effective of these materials, the notched impact strength approaches the uimotched impact performance of the unmodified resin. The increased ductility of the material that accompanies impact modification does, however, reduce stiffness and strength. Moisture conditioning of mol dings is often used to increase impact strength and flexibiUty before such operations as snap fitting or assembling cable ties, which can be avoided in some cases by using impact-modified resins. The effect of impact modifier on the properties of nylon-6,6 is shown in Table 3.  [c.269]

In the melt the material is in a dynamic situation and only at a certain (equihbrium) moisture content does the rate of hydrolysis equal the rate of polymerization. This equihbrium moisture content (in a sealed system) depends on the polymer, the temperature, the molecular weight, and the end group balance of the polymer. Below this moisture content, the melt increases in viscosity (polymerizes) and above it hydrolysis occurs with reduction in viscosity and molecular weight. For nylon-6,6, the equihbrium moisture content is close to 0.15% for most standard injection-molding resins however, the figure is less for reinforced materials as less nylon is present per unit weight. For high molecular weight nylons used for extmsion apphcations, the equihbrium moisture content is less as the concentration of end groups is less therefore, these materials need to be processed at lower moisture contents to avoid lowering the molecular weight. Nylons also polymerize in the sohd form (sohd-phase or sohd-state polymerization) if heated significantly above 100°C in the absence of water. The equihbrium also means that nylons can hydrolyze when parts are exposed to aqueous environments for long periods at high temperatures, lea ding to loss of properties. However, this depends on the conditions of exposure. Nylon-6,6 has long been used successfully for automobile radiator end tanks and is used in washing machine valves. Nylons that absorb lower amounts of moisture have improved hydrolysis resistance.  [c.270]

The markets for nylon resins, on the other hand, have shown consistent growth since the mid-1980s (13), with only minor fluctuations owing to the slowing of the world s economies (Fig. lb). As a result of the differences in relative growth rates of nylon plastics and fiber, production of the former as a percent of the total production is expected to continue to increase well into the twenty-first century. The position of polyamides as the lowest cost engineering resins or the highest cost (but arguably the highest performing) commodity resin has led to this continuous growth. Although the nylon resin markets, like those for fibers, are dominated by nylon-6,6 and nylon-6, there are many alternative polyamides and copolyamides in this end use. Table 7 gives the price range of many polyamides for various product types. Specialty products and appHcations can command prices two times higher or greater.  [c.220]

The principal worldwide manufacturers of nylon resins are given in Table 6. Total sales of nylon plastics in the United States and Canada in 1993 were 331,000 metric tons (37). West European sales were 352,000 t and Japanese sales 220,000 t (37). Figure 7 shows how sales in the United States have steadily increased since 1967 (38) and also how the price of nylon-6,6 has changed (39). The effect of the oil price rises, the boom of the mid-1980s, as well as the oil price reduction and the recession that followed are clearly evident. Table 7 shows the variation of price across different polyamide types.  [c.275]

Commercial engineering thermoplastic nylons are mainly crystalline resins. Nylon-6,6 [32131 -17-2] is the largest volume resin, followed by nylon-6 (48). Other commercially available but much lower volume crystalline nylons are -6,9, -6,10, -6,12, -11, and -12. The crystallinity of the molded part decreases with chain size (49). A few truly amorphous commercial nylon resins contain both aromatic and ahphatic monomer constituents (50). For example, Trogamid T resin is made from a mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamines and terephthahc acid (51).  [c.266]

Over 565,000 t/yr of nonftber crystalline nylons is sold worldwide (63). Since markets are controUed by the economy, a modest growth of 5—8%/yr is expected. Although currently only ca 900 t/yr of amorphous nylons is sold worldwide (64), a growth rate of 10% is expected because of increased research activity. Currently, the amorphous nylon resins compete with PEI and polyesters in many appHcations.  [c.267]

Modified nylons are blends of nylon resins and specially grafted nylon resins. In the Du Pont family of Zytel resin, certain blends have been designated Supertough to emphasize the improvement in impact that blends provide over standard resins. General Electric s Noryl GTX resins consist of a nylon matrix resin and a PPO resin in dispersed form. A highly sophisticated blend, it maintains a filled nylon s HPT with no sacrifice of impact resistance.  [c.277]

Uses. The principal use of adiponitrile is for hydrogenation to hexamethylene diamine leading to nylon-6,6. However, as a result of BASE s new adiponitrile-to-caprolactam process, a significant fraction of ADN produced may find its way into nylon-6 production. Adipoquanamine, which is prepared by the reaction of adiponitrile with dicyandiamide [461-58-5] (cyanoguanidine), may have uses in melamine—urea amino resins (qv) (see "Benzonitrile, Uses"). Its typical Hquid nitrile properties suggest its use as an extractant for aromatic hydrocarbons.  [c.221]

Significant growth in acrylonitrile end use has come from ABS and SAN resins and adiponittile (see Acrylonitrile polymers). ABS resins are second to acryflc fibers as an outlet for acrylonitrile. These resins normally contain about 25% acrylonitrile and are characterized by thein chemical resistance, mechanical strength, and ease of manufacture. Consumption of ABS resins increased significantly in the 1980s with its growing application as a specialty performance polymer in constmction, automotive, machine, and appliance applications. Opportunities stiU exist for ABS resins to continue to replace more traditional materials for packaging, building, and automotive components. SAN resins typically contain between 25 and 30% acrylonitrile. Because of thein high clarity, they are used primarily as a substitute for glass in drinking cups and tumblers, automobile instmment panels, and instmment lenses. Together, ABS and SAN resins account for about 20% of domestic acrylonitrile consumption. The largest increase among the end uses for acrylonitrile over the past 10 years has come from adiponittile, which has grown to become the third largest outlet for acrylonitrile. It is used by Monsanto as a precursor for hexamethylenediamine (HMDA, CgH N2 [124-09-4]) and is made by a proprietary acrylonitrile electrohydrodimerization process (25). HMD A is used exclusively for the manufacture of nylon-6,6. The growth of this acrylonitrile outlet in recent years stems largely from replacement of adipic acid (C H qO [124-04-9]) with acrylonitrile in HDMA production rather than from a significant increase in nylon-6,6 demand. A non-electrochemical catalytic route has also been developed for acrylonitrile dimerization to adiponittile (26,27,80,81). This technology, if it becomes commercial, can provide additional replacement opportunity for acrylonitrile in nylon manufacture. The use of acrylonitrile for HMD A production should continue to grow at a faster rate than the other outlets for acrylonitrile, but it will not approach the size of the acryflc fiber market for acrylonitrile consumption.  [c.186]

Polyamides. In 1988, 77% of U.S. demand for adipic acid was for nylon-6,6 fiber, while 11% was used in nyon-6,6 resins (195). In Western Europe only about 66% was for polyamide, because of the stronger competition from nylon-6. The fiber appHcations include carpets (67%), apparel (13%), tire cord (7%), and miscellaneous (13%). Nylon-6,6 resins were distributed between injection mol ding (85%) for such appHcations as automotive and electrical parts and for extmsion resins (15%) for strapping, film, and wire and cable.  [c.247]

In more complex combinations, HDPE, LDPE, and EVA resins are coextmded to produce stiff, heat-sealable films to be used as liners in cereal, cookie, and cracker cartons. Films of EVA and white-pigmented LLDPE are used for packaging of fro2en vegetables and fmits. In these appHcations, one layer imparts toughness, opacity, or stiffness, and the other layer adds heat sealabiUty. Coextmsions of nylon with polyethylene in five layers are used for thermoforming where high gas and water-vapor barrier are required, eg, medical packaging.  [c.453]

Industrial Uses. Tartaric acid is used ia photography, and its iron salts are used ia blue copy paper. The diethyl and dibutyl esters are used ia paints as lacquer solvents. In the textile industry, tartaric acid acts as a stabilizer in nylon dyeing and in ceUusosic fiber bleaching with peroxide. It is used as a chelating agent for boron and other micronutrients in fertilizers. In the plastics industry, tartaric acid is used as a polymerization agent of methyl methacrylate, phenol—formaldehyde resins, PVC, and acrylonitrile. In metals, it is used as a complexing agent in metal cleaning for copper and alloys, aluminum, and ferrous metals. It is used in ceramics as a component in special clays. In the electronics industry, tartaric acid is used in the anodization of semiconductors of gallium arsenide.  [c.528]

Benzene, toluene, and xylene are made mosdy from catalytic reforming of naphthas with units similar to those already discussed. As a gross mixture, these aromatics are the backbone of gasoline blending for high octane numbers. However, there are many chemicals derived from these same aromatics thus many aromatic petrochemicals have their beginning by selective extraction from naphtha or gas—oil reformate. Benzene and cyclohexane are responsible for products such as nylon and polyester fibers, polystyrene, epoxy resins (qv), phenolic resins (qv), and polyurethanes (see Fibers Styrene plastics Urethane POLYiffiRs).  [c.216]

Nylon-6,9, Nylon-6,10, and Nylon-6,12. These related polyamides ate produced in a process similar to that used for nylon-6,6, where a salt of hexamethylenediamine and the appropriate diacid is formed in water. The solution is heated in an autoclave until polymerisation is complete. Processing times, pressures, and temperatures are adjusted for the slightly different melting points and viscosities of these polymers. Because of the lower melting points, ie, nylon-6,9 (T = 210° (7), nylon-6,10 (T = 220 (7), and nylon-6,12 (T = 212" (7), and the perhaps greater chemical stabihty of the diacids, these polymers generally experience less thermal degradation in processing than nylon-6,6. They ate generally used as engineering resins for specialty appHcations where reduced moisture regain and chemical resistance are important. Nylon-6,12 [24936-74-1] and its copolymers are also used in the manufacture of toothbmsh btisties and fishing line.  [c.236]

Because of the capacity to tailor select polymer properties by varying the ratio of two or more components, copolymers have found significant commercial appHcation in several product areas. In fiber-spinning, ie, with copolymers such as nylon-6 in nylon-6,6 or the reverse, where the second component is present in low (<10%) concentration, as well as in other comonomers with nylon-6,6 or nylon-6, the copolymers are often used to control the effect of sphemUtes by decreasing their number and probably their size and the rate of crystallization (190). At higher ratios, the semicrystalline polyamides become optically clear, amorphous polymers which find appHcations in packaging and barrier resins markets (191).  [c.238]

An emerging development is the introduction of high temperature polyamide resins for automotive, under-the-hood use and in some electrical end uses, such as cores for transformer windings. At first glance, nylon-6,T appears to be an excellent candidate, because it has a very high melting point (365°C) and its components, hexamethylenediamine and terephthaUc acid, are low in cost and readily available. However, its high melting point requires even higher processing temperatures, which in turn lead to substantial thermal degradation. The attempt to produce copolymers with nylon-6 or nylon-6,6 in a melt process is thwarted by the formation of macroscopic portions of high melting blocks of nylon-6,T that can act as nucleating agents for sphemUte (microscopic particles) formation, as particulate contamination (visible particles), and as nonmelting reactor fouling (bulk material). In addition, when nylon-6,6 is blended with nylon-6,T, the required higher processing temperatures accelerate the rate of branching and gel formation to such an extent that the process is inoperable above 300°C. Since nylon-6,T and nylon-6,6 are isomorphic, they maintain a high degree of crystallinity in the copolymer, but when nylon-6 is used, its copolymer with nylon-6,T demonstrates the usual eutectic-like drop in melting point. Thus, a high ratio of nylon-6,T to nylon-6 is required to attain a significant increase in melting point. At high ratios, the copolymer can lose much of its crystallinity, but at a lower ratio it is stiU semicrystalline, and a satisfactory nylon-6,T/6 copolymer has been introduced by BASF. Amoco has introduced a proprietary process that allows the production of terephthaUc acid-based copolymers which also contain isophthaUc acid (192). These materials have been named polyphthalamides and show many desirable properties, such as a high melting point, high T, and low moisture regain (193).  [c.238]

Another approach to the production of high melting terephthalate-based copolyamides is first to make a low molecular weight prepolymer and then sohd-phase the material to higher molecular weight this process is similar in principle to that used in the manufacture of nylon-4,6. A variation of this process is used by Mitsui to produce its nylon-6,T/6,6 product, a copolymer of nylon-6,T and nylon-6,6 via a two-step process. First, an oligomer of the copolymer is made in an autoclave and spray-dried. The particles are then fed into an extmder, where the final copolymer is produced. A third approach, used by Du Pont, is to add a second diamine, 2-methylpentamethylenediamine (trade name Dytek A) rather than a second diacid to reduce the melting point (194,195). This nylon-6,T/D,T copolymer is produced via an all-melt phase process in an autoclave. Although the resulting polymer has a high melt point, the process avoids the added cost of special process equipment and handling. Table 11 presents information on most of the high temperature resins that have been introduced into the marketplace nylon-6,6 and nylon-4,6 are included for comparison.  [c.238]

It is difficult to estabhsh the exact breakdown of the world demand for PET as a mol ding resin from the open Hterature. The total toimage is small compared with the vast amounts used for fibers and bottle resin. Some estimates are given of total compounded thermoplastic polyester use in the United States, but this includes both PET and PBT (126). The bulk of the U.S. market for PET mol ding resin is the automotive industry. The heat distortion temperature and of PET are higher than the corresponding values for PBT and its low moisture uptake and dimensional stabiUty with respect to changes in humidity make it superior to nylon. Both PET and PBT engineering resins have good resistance to chemicals, and because they are crystalline do not suffer from the solvent stress cracking problems that plague amorphous materials. Polyesters in general are only attacked by severe chemicals such as powerful acidic or phenoHc solvents hot, strong aqueous alkaU and certain bases, such as hydra2ine.  [c.297]

PGT Molding Resins The latest prominent thermoplastic polyester, p oly (cycl oh exyl dim ethyl en e terephthalate) (PCT), was first produced by Eastman Kodak in the 1950s as a polyester fiber (5). PCT was introduced as a mol ding resin in 1987 in glass-filled and flame-retarded grades with specific end uses (7). Eastman is the sole polymer suppHer from the plant in Kingsport, Teimessee, although some polymer is beheved to have been suppHed to General Electric, who marketed it as part of their Valox range of thermoplastic polyesters. The targeted end uses appear to be connectors for both the electronic and automotive markets. A development in the electronic market associated with miniaturization is the so-called surface mount technology (SMT) (145). This has already taken over about 50% of the electronic connector market and the trend is expected to continue. There is a much lower level of penetration of this technique in the automotive connector market but its use is also expected to grow. The SMT process uses a solvent vapor-heated reflow soldering process in which the whole electronic component is immersed in hot vapor to melt the solder alloy and allow it to flow. The vapor temperature is usually about 215°C (420°E) for 60/40 tin—lead solder. This puts greater thermal demands on the thermoplastic parts and as a result the blistering temperature of these components has to be above the soldering bath temperature. This is beyond the capabiUty of PBT and most nylons, except nylon-4,6. Interestingly, the heat-deflection temperature (HDT) is not a very precise guide to performance in the blistering test, although obviously the higher the HDT, the better. PCT has a HDT around 260°C (500°E) and its blistering performance under vapor reflow soldering conditions is very good. PCT is significantly less expensive than the ultrahigh performance Hquid crystalline polymer (LCP) engineering resins. One specific advantage of PCT is that it has similar flow characteristics (although at higher temperatures) during mol ding to both PET and PBT which means that extensive mold redesign is not necessary which makes it attractive to molders.  [c.299]


See pages that mention the term Nylon resins : [c.79]    [c.336]    [c.304]    [c.217]    [c.478]    [c.37]    [c.144]    [c.274]   
See chapters in:

Chemistry of Petrochemical Processes  -> Nylon resins


Chemistry of Petrochemical Processes (2000) -- [ c.336 ]