Nylon flexure

Effects of Filament Diameter, Nylon Flexural Modulus, psi x 10 - ... 

Nylon Flexural Strength Filament Diameter Strand Solids Chopped Strand Length Glass Content Filament Diameter-Strand Solid Interaction... 

Nylon-6-clay nanocomposites were also prepared by melt intercalation process [49]. Mechanical and thermal testing revealed that the properties of Nylon-6-clay nanocomposites are superior to Nylon. The tensile strength, flexural strength, and notched Izod impact strength are similar for both melt intercalation and in sim polymerization methods. However, the heat distortion temperature is low (112°C) for melt intercalated Nylon-6-nanocomposite, compared to 152°C for nanocomposite prepared via in situ polymerization [33]. 

PBT will absorb very little water (0.08 %), and its mechanical properties are not affected in the short term. Polyamides, on the other hand, may absorb up to 12% of water. In nylon resins, the water acts as a plasticizer it lowers the Tg, decreases the flexural modulus, and may cause part growth. Based on these criteria alone, polyesters are often a better choice than nylons for many applications (less variation of properties). 

Although glass spheres are classified as nonreinforcing fillers, the addition of 40 g of these spheres to 60 g of nylon 66 increases the flexural modulus, the compressive strength, and the melt index of the polymer. The tensile strength, the impact strength, the creep resistance, and the elongation of these composites are less than those of the unfilled nylon 66. 

Heat-cleaned fiberglass cloth was treated with 0.5% carboxysilane J (Table 1) and compression-molded into a laminate with nylon 6,6 polymer. Laminates were compared to state-of-the-art silane H. Table 9 shows that silane H provided a significant improvement in flexural strength over the control, expecially after a 2 h water boil, but a carboxysilane/zinc ion ionomer system gave an even better strength improvement. 

The contribution of the crystalline high melting nylon 6 blocks and soft-block hard-phase separation are also reflected in the resistance to heat sag exhibited by NBC. Table IV shows the heat sag at 163°C as these values are related to the flexural modulus. Even at the very low end of the modulus spectrum, sag values were quite low. 

For most applications, in particular in the automotive industry, the toughness of nylon is insufficient. The most successful method developed for modifying brittle polymers is rubber-toughening. By incorporation of a minor amount of a dispersed rubber phase (Impact modifier) the fracture resistance is improved significantly and the impact strength can be increased severalfold. There is an unavoidable decrease in flexural modulus and tensile strength, but the balance of properties of the rubber modified nylon is much better than that of unmodified nylon. Several kinds of morphology which... 

From the table It appears that the Izod Impact strength Improves as the Interfacial adhesion increases. This Is also concluded In a recent publication about nylon 6.6 compounded with polyethylene-g-maleic anhydride polymer (15). Addition of more rubber In system 3 (30 %) affords hardly any addltonal Improvement In toughness, but the flexural modulus, which In ABA block copolymers Is already lower than In a dispersed rubber system, Is more than halved. 

Several authors have given a basic theory for the prediction of the modulus of a composite (16-18). The line In Fig, 4 shows the theoretical curve for the reduction of the modulus (E/Eo) due to Incorporation of a soft rubber phase In a hard matrix at a temperature above the transition region of the soft phase and below the transition region of the hard phase (E > flexural modulus of the modified nylon and E0 flexural modulus of the unmodified nylon). The experimental points of systems 1 and 2 fit fairly well onto the theoretical curve. This proves that they are well-dispersed systems without Inclusions. The difference In Impact strength between system 1 and system 2 Is mainly due to the better lnterfaclal adhesion of system 2, by which crazes are stabilized and/or the formation of small shear bands Is Initiated. 

Improvement of the Impact strength of RIM nylon can be achieved by incorporation of a polyol. Of the various kinds of morphology shown, the ABA block copolymers possess the highest toughness, although this is accompanied by a great loss in flexural modulus. 

Results of some of these short-term tests are shown in Table II. A comparison is given between PPS and five other plastics nylon (Zytel 101), polycarbonate (Lexan 141), polysulfone (Bakelite Polysulfone), polyphenylene oxide (Noryl), and polyetherimide (Ultem 2300). The data presented are based upon retention of tensile strength for all plastics except the Ultem 2300, which is based upon retention of flexural strength. Unsuccessful attempts were made to injection mold ASTM Type IV tensile bars out of the Ultem compound, but flexural strength bars could be made. Experience has shown that chemical resistance tests monitored by flexural strength retention are comparable to those monitored by retention of tensile strength. 

Flexural strength of Nylon 6 is from 9700 to 14,000-16,500 psi, that is higher than for all other thermoplastics considered in this book, except PVC, which generally has a similar flex strength (6000 to 10,000-16,000 psi). For a comparison, flex strength of HDPE is around 1400 psi (when can be measured), PP 6000-7000 psi, ABS 4300-6400 psi, sometimes to 12,000 psi [18],... 

Flexural modulus of Nylon 6 is 100,000-464,000 psi, which is in the same range with that of PVC and ABS, and generally higher than that of HDPE and polypropylene. 

Reinforcing effect of cellulose fiber on Nylon is shown in Table 3.7 Often (but not always), the higher the aspect ratio of wood fiber, the higher the flexural strength and flexural modulus of filled WPC (Table 3.8). 

Flexural modulus for Nylon is in the range of 140,000-410,000 psi for different types of Nylon. For Nylon 6/10 it is in the lower range, 160,000-280,00 psi for Nylon 6 and 6/6 flex modulus reaches 390,000 and 410,000 psi, respectively. For rigid PVC flex modulus is in the range of 380,000-540,000 psi [2]. For PVC-based composite (Boardwalk, Table 7.34), flex modulus equals to 175,000 psi, and it is one of the lowest on the market. Thus, for the PVC-based composite (Table 7.34), both flex strength and flex modulus are much lower than those for neat PVC, that is, one half to one third for flex modulus, and one fourth to one sixth for flex strength. 

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