Abstract: A die and method for impregnating at least one fiber roving with a polymer resin are disclosed. In one embodiment, the die includes an impregnation section including an impregnation zone configured to impregnate the roving with the resin, the impregnation zone including a plurality of contact surfaces. The die further includes a perturbation positioned on at least one of the plurality of contact surfaces, the perturbation configured to interact with the roving. In one embodiment, the method includes coating a fiber roving with a polymer resin. The method further includes traversing the coated roving through an impregnation zone to impregnate the roving with the resin. The impregnation zone includes a plurality of contact surfaces. The method further includes interacting the coated roving with a perturbation positioned on at least one of the plurality of contact surfaces.

Abstract: The invention relates to polymer compositions comprising PCT (poly((cyclohexylene-dimethylene) terephthalate)) polymer and a fibrous glass filler having a non-circular cross-sectional aspect ratio of greater than at or about 4.

Abstract: A wholly aromatic thermotropic liquid crystalline polymer and compositions including the liquid crystalline polymer are described. The polymer composition can include the liquid crystalline polymer and a fibrous filler, e.g., a chopped glass or milled glass fibrous filler. The compositions are capable of exhibiting excellent mechanical properties. The liquid crystalline polymer provides desirable characteristics with the incorporation of little or no naphthenic acids in the polymer backbone.

Abstract: A composite core for use in electrical cables, such as high voltage transmission cables is provided. The composite core contains at least one rod that includes a continuous fiber component surrounded by a capping layer. The continuous fiber component is formed from a plurality of unidirectionally aligned fiber rovings embedded within a thermoplastic polymer matrix. The present inventors have discovered that the degree to which the rovings are impregnated with the thermoplastic polymer matrix can be significantly improved through selective control over the impregnation process, and also through control over the degree of compression imparted to the rovings during formation and shaping of the rod, as well as the calibration of the final rod geometry. Such a well impregnated rod has a very small void fraction, which leads to excellent strength properties. Notably, the desired strength properties may be achieved without the need for different fiber types in the rod.

Abstract: Polymer compositions are described that are well suited for producing reflectors for light-emitting devices, such as light-emitting diodes. In one embodiment, the polymer composition contains a polymer resin and a stabilizer comprising a phosphonate compound and/or a phosphate compound and optionally a white pigment. The polymer resin may comprise, for instance, a poly(1,4-cyclohexanedimethanol terephthalate). The phosphate stabilizer has been found to significantly improve the stability of the polymer composition without interfering with the ability of the composition to bond to other polymer materials, such as silicone resins. Silicone resins, for instance, are typically used as an encapsulant for light-emitting diode assemblies.

Abstract: Pipe sections and methods for forming pipe sections are disclosed. A pipe section includes a hollow body, the hollow body having an inner surface and an outer surface, the inner surface defining an interior. The pipe section further includes a barrier layer surrounding the hollow body, the barrier layer having an inner surface and an outer surface. The barrier layer is formed from a polyarylene sulfide composition. The polyarylene sulfide composition includes a polyarylene sulfide and a crosslinked impact modifier. Such pipe sections exhibit high strength characteristics and flexibility as well as resistance to degradation, even in extreme temperature environments, while maintaining desirable processing characteristics.

Abstract: Blow molded articles are made from a polymeric composition containing a mixture of polyphenylene sulfide resins. For instance, the polymeric composition may contain a linear polyphenylene sulfide resin combined with a branched polyphenylene sulfide resin. The composition can further contain a reinforcing agent, such as glass fibers, a polytetrafluoroethylene polymer, a polyphenylene oxide polymer, a silane coupling agent, and/or an impact modifier. Compositions made according to the present disclosure can have relatively high near zero shear rate melt strengths while also having high shear rate melt viscosities and high engineering stresses at a high percent elongations, making the compositions amenable to extrusion and molding processes. Compositions made according to the present disclosure are particularly well suited to molding articles with a complex shape.

Abstract: An aromatic polyester that contains one or more aromatic ester repeating units and one or more biphenyl repeating units is provided. While a wide variety of aromatic ester repeating units may be employed, the polymer is nevertheless “low naphthenic” to the extent that it contains a minimal content of repeating units derived from naphthenic hydroxycarboxylic acids and naphthenic dicarboxylic acids. Despite the absence of a high level of conventional naphthenic acid repeating units, the present inventors have discovered that selective control over the type and relative concentration of the biphenyl repeating units can lead to “low naphthenic” polymers that are not only soluble in certain solvents, but also capable of exhibiting good mechanical properties. Thus, the ability of the resulting polymer to be dissolved or dispersed in various solvents can be enhanced without sacrificing performance.

Abstract: A crosslinkable aromatic polyester that is formed by polymerizing certain precursor monomers in the presence of a biaromatic crosslinking agent is provided. The crosslinkable aromatic polyester can have a relatively high melting temperature. For example, the melting temperature of the crosslinkable polyester may be from about 200° C. to about 370° C. While having a relatively high melting temperature, the crosslinkable polyester can maintain a relatively low melt viscosity so that it can be readily removed from the polymerization reactor without solidifying therein.

Abstract: A method for injection molding a thermoplastic composition that contains a polyarylene sulfide and an aromatic amide oligomer is provided. Due to the improved crystallization properties imparted by the oligomer, the present inventors have discovered that the thermoplastic composition can be molded at lower temperatures to still achieve the same degree of crystallization. In addition to minimizing the energy requirements for the molding operation, such low mold temperatures may be accomplished using heating mediums that are less corrosive and expensive than some conventional techniques.

Abstract: An injection molded housing for a portable electronic device is provided. The housing contains a thermoplastic composition that includes a polyarylene sulfide melt processed in the presence of a disulfide compound and a filler. Without intending to be limited by theory, it is believed that the disulfide can undergo a chain scission reaction with the starting polyarylene sulfide to lower its melt viscosity, which can lead to decreased attrition of the filler and thus improved mechanical properties. Due to this ability to reduce viscosity during melt processing, the present inventors have discovered that relatively high molecular weight polyarylene sulfides can be fed to the extruder with little difficulty.

Abstract: A polymer composition that contains at least one high performance polymer and at least one aromatic amide oligomer is provided. The oligomer can serve as a flow aid that lowers the overall viscosity of the polymer matrix under shear.

Abstract: A liquid crystalline polymer composition that contains a liquid crystalline polymer and an aromatic amide oligomer is provided. The oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix under shear. The oligomer is also not easily volatized or decomposed during compounding, molding, and/or use, which minimizes off-gassing and the formation of blisters that would otherwise impact the final mechanical properties of a part made from the polymer composition. While providing the benefits noted, the aromatic amide oligomer does not generally react with the polymer backbone of the liquid crystalline polymer to any appreciable extent so that the mechanical properties of the polymer are not adversely impacted.

Abstract: A prepreg that contains a plurality of unidirectionally aligned continuous fibers embedded within a thermoplastic polymer matrix is provided. In addition to continuous fibers, the prepreg also contains a plurality of long fibers that are combined with the continuous fibers so that they are randomly distributed within the thermoplastic matrix. As a result, at least a portion of the long fibers become oriented at an angle (e.g., perpendicular) relative to the direction of the continuous fibers. Through such orientation, the long fibers can substantially increase the mechanical properties of the prepreg in the transverse direction (e.g., strength) and thus achieve a more isotropic material. Although unique isotropic prepregs are one aspect of the present invention, it should be understood that this is not a requirement.

Abstract: Thermally conductive thermoplastic resin compositions are provided containing thermoplastic resin and thermally conductive filler and fibrous filler, along with articles made therefrom. In certain instances when the thermally conductive filler and fibrous filer are more restricted, and other ingredients are present, the thermally conductive composition exhibits an improved volume resistibility and is suitable for fabricating a chassis for LCD display. Also described are the thermally conductive resin compositions, especially when the polymer is LCP. Such compositions are useful for items such as electrical and electronic housings requiring highly thermally conduciveness.

Abstract: Polymer compositions are described that contain at least two different immiscible phases for producing molded articles having a swirl-like or marble-like appearance. The first phase, for instance, may contain one or more polyoxymethylene polymers. The second phase, on the other hand, contains one or more polymers that together have a melting point that is from about 5° to about 30° different than the melting point of the polyoxymethylene polymer. In one embodiment, the second phase may contain a thermoplastic elastomer, a glycol-modified polyethylene terephthalate, or a polyamide and may have a melting point that is higher than the melting point of the polyoxymethylene polymer. The second phase is present in the polymer composition in relatively low amounts, such as in amounts less than about 5% by weight. The second phase can contain a high concentration of colorants that creates a contrast of colors when the molded article is produced.

Abstract: A nucleating system for a thermoplastic composition that contains a polyarylene sulfide is provided. The nucleating system includes a combination of an inorganic crystalline compound and an aromatic amide oligomer. The present inventors have discovered that the combination of these different types of nucleating agents result in excellent crystallization properties (e.g., rate of crystallization). Due to the improved crystallization rate, the thermoplastic composition can be molded at lower temperatures to still achieve the same degree of crystallization. In addition to minimizing the energy requirements of the molding operating, the use of lower temperatures can also decrease the production of “flash” normally associated with high temperature molding operations. The composition may also possess good viscosity properties that allow it to be readily molded into parts of a variety of different shapes and sizes.

Abstract: A thermoplastic composition that contains a unique combination of a thermotropic liquid crystalline polymer, dielectric material, laser activatable additive, and a fibrous filler is provided. The nature of the components and/or their concentration are selectively controlled in the present invention to maintain a high dielectric constant, good mechanical properties (e.g., deflection under load), and good processibility (e.g., low viscosity), yet still be laser activatable. Thus, the thermoplastic composition can be readily shaped into a thin substrate and subsequently applied with one or more conductive elements using a laser direct structuring process (“LDS”).

Abstract: A thermotropic liquid crystalline polymer melt polymerized in the presence of a viscosity modifier that can help increase the “low shear” viscosity of the resulting composition is provided. The increased “low shear” viscosity can minimize drooling of the polymer composition during processing and also allow it to possess a greater melt strength, which facilitates its ability to be processed in a wide variety of applications without losing its physical integrity. Despite having a relatively high “low shear” viscosity, the present inventors have discovered that the viscosity modifier does not substantially increase the “high shear” melt viscosity of the polymer composition. In this regard, the ratio of the “low shear” viscosity to the melt viscosity is generally very high, such as within a range of from about 50 to about 1000.

Abstract: Polymer compositions are described containing a white pigment for increasing the reflectance properties of the resulting material. In this regard, the material is well suited for being used as a reflector, such as a reflector for light-emitting diode assemblies. In accordance with the present disclosure, the white pigment comprises chalk resistance particles. The particles can also display a basic pH when placed in distilled water.