A process for welding a first molding to a second molding. The process uses an implement including first and second external surfaces. Each external surface further includes a duct. An end of the first molding is heated by a hot gas while the end is at a distance from the duct-entry plane in the range from 3 mm outside the duct to 10 mm inside the duct. A junction area of the second molding is heated by a hot gas while the junction area is at a distance from the duct-entry plane in a range from 3 mm outside the duct to 10 mm inside the duct. The heated end and the heated junction area are then brought into contact with one another and cooled, forming a weld between the first molding and the second molding. Also disclosed is a welded molding obtainable by the process of the invention.

A process for welding a first molding to a second molding. The process uses an implement including first and second external surfaces. Each external surface further includes a duct. An end of the first molding is heated by a hot gas while the end is at a distance from the duct-entry plane in the range from 3 mm outside the duct to 10 mm inside the duct. A junction area of the second molding is heated by a hot gas while the junction area is at a distance from the duct-entry plane in a range from 3 mm outside the duct to 10 mm inside the duct. The heated end and the heated junction area are then brought into contact with one another and cooled, forming a weld between the first molding and the second molding. Also disclosed is a welded molding obtainable by the process of the invention.

A photocurable composition including metal oxide nanoparticles (X) and a photopolymerizable sulfur compound (C).

The present disclosure relates to the use of occluding fluids, such as a high-density fluid (a z-fluid) or a low-density fluid (an a-fluid), to displace resin within a vat during 3D printing. Further, an a-fluid may act as a protective boundary for a 3D printing resin wherein the a-fluid sits on top of the printing resin. Another embodiment of the disclosure provides a process of assessing which regions of a computer-aided design (CAD) model take advantage of a buoying force supplied by the occluding fluid, such that fewer support structures are needed for printing a final CAD model compared to printing the CAD model without the occluding fluid.

The embodiments relate to a polythiol composition for a plastic optical lens and a polythiourethane-based plastic optical lens prepared therefrom. In the embodiments, a first polythiol compound having an ester group and a mercapto group only as a hydrogen-bondable functional group and a second polythiol compound having an ester group and a hydrogen-bondable functional group other than a mercapto group are used in an appropriate amount. Thus, it is possible to control the viscosity of a polymerizable composition at the initial stage of polymerization at a low temperature of 5 to 15 C. and to stabilize the rate of increase in the viscosity of the composition and the reaction rate thereof, thereby preventing the generation of striae, bubbles, and the like. Further, various plastic lenses such as eyeglass lenses, camera lenses, and the like having excellent appearance characteristics (without striae and bubbles) and excellent optical characteristics can be obtained from the composition.

A respiratory protection composite facepiece is disclosed and includes a polymeric rigid facepiece body portion having a first surface and a second surface and a silicone sealing facepiece element chemically bonded at least one of the first surface or the second surface. The first and second surfaces can be opposing major surfaces. A second silicone element is chemically bonded to at least one of the first surface or the second surface. Methods of making the same are also disclosed.

Compounds and compositions are provided which are useful in additive printing, particularly additive printing techniques such as stereolithography (SLA) wherein a macromer is photopolymerized to form a manufactured article. Representative compounds comprise a polyaxial central core (CC) and 2-4 arms of the formula (A)-(B) or (B)-(A) extending from the central core, where at least one of the arms comprise a light-reactive functional group (Q) and (A) is the free-radical polymerization product from monomers selected from trimethylene carbonate (T) and ?-caprolactone (C), while (B) is the free-radical polymerization product from monomers selected from glycolide, lactide and ?-dioxanone.

Described here are multilayer tubes including a plurality of layers. The multilayer tubes include an outermost layer, including a first polyarylene sulfide (PAS) and from 5 wt. % to 30 wt. % of an impact modifier. The multilayer tubes also include an innermost layer including a second PAS and from 0.1 wt. % to 10 wt. % of an electrically conductive filler. Significantly, each layer in the multilayer tube comprises a PAS. The outermost layer is the sole layer comprising an impact modifier and the innermost layer is the sole layer comprising an electrically conductive filler. At least in part because of compatibility of PAS based materials with one another for interfacial bonding, the multilayer tube is free of tie layers.

A respiratory protection composite facepiece is disclosed and includes a polymeric rigid facepiece body portion having a first surface and a second surface and a silicone sealing facepiece element chemically bonded at least one of the first surface or the second surface. The first and second surfaces can be opposing major surfaces. A second silicone element is chemically bonded to at least one of the first surface or the second surface. Methods of making the same are also disclosed.

The present invention relates to a poly(arylene sulfide) composition including a combination of a limited amount of an antioxidant compound and of an epoxy-functional polyorganosiloxane polymer, possessing improved mechanical performances and outstanding thermal ageing resistance, to a process for its manufacturing, as well as to an article, part or composite material comprising said composition, and to the use of this composition for the manufacture of 3D objects