An apparatus and method for concentrically overmolding Gutta-Percha onto a carrier. A shape, structure and dimensions of gutta-percha may be configured into cavities of a mold having more retractable pins for concentrically overmolding the gutta-percha onto one or more carriers. The apparatus may preferably be automated/self-driven to concentrically overmold gutta-percha onto the carriers in multiple stages and cycles.

The invention relates to the production of PSA in a planetary gear extruder. During filling and after passing a passage on a dispersing ring using a lateral arm extruder, the products are degassed.

The present invention relates to an MDO heat-shrinkable film of a copolymer polyester having excellent thermal resistance. In particular, the present invention provides a copolymer polyester MDO (machine direction orientation) thermoresistant heat-shrinkable film that consists of a copolymer polyester resin including isosorbide and 1,4-cyclohexanedimethanol at an optimized content ratio as a diol component copolymerized with an acid component including terephthalic acid, and having a number average molecular weight of 18,000 g/mol or more, and can be used for labels, cap seals, direct packaging, etc. of various containers due to the high shrink initiation temperature.

Pore-free rubber articles are prepared by dip-molding in a dipping medium that includes a vulcanizing agent, then partially-cured by immersing the dip former in a heated liquid bath that is chemically inert. A particularly effective liquid bath is a molten, nitrite free inorganic salt. The partially-cured rubber is then maintained at a desired curing temperature in a low/no oxygen heating oven to complete curing. Alternatively, upon removal from the molten salt bath, the latex film is quenched.

Systems and methods for managing the waste associated with the extraction of rubber from guayule shrubs are. provided. Also provided is a portable local sub-station for reducing the transportation costs associated with the processing of guayule shrubs for the extraction of rubber. Use of the disclosed systems, methods and/or local sub-station can reduce transportation costs, reduce processing costs and reduce the downstream processing complexity associated with the extraction of rubber from guayule shrubs.

An apparatus of manufacturing a rubber member includes an extruder; a mouthpiece; and a support surface which faces the mouthpiece in an opposed manner. The support surface and the mouthpiece are moved relative to each other thus molding a rubber member on the support surface. The apparatus further includes: a rubber pool portion formed between the mouthpiece and the support surface; and a closing surface having an inclined surface shape and capable of closing a moving-direction front side of the rubber pool portion. A rubber material is ejected from an ejection port in a state where the rubber pool portion is closed by the closing surface, the support surface and the mouthpiece are moved relative to each other after the rubber pool portion is filled with the rubber material, and a lamination starting end of the rubber material is pressed to the closing surface thus molding the lamination starting end into an inclined surface and, thereafter, the closing surface is moved in a direction away from the support surface.

An initial processing of natural raw rubber through an initial processing machine, comprising the steps of: (a) providing a coagulated latex which contains water and volatile compositions; (b) dewatering the coagulated latex through a screw-pressing process to remove free water; (c) forming a first pretreated latex material; (d) aging the first pretreated latex material through an aging process to remove water and volatile compositions; and (e) forming a final product of aged latex material. The screw-pressing process makes use of the temperature and pressure increase along the elongated channel structure. The aging process makes use of the further temperature and pressure increase of the rubber materials, together with the screwing effect of the screw-shaft component, the squeezing effect of the nozzle and additional heating at a particular location, which is around the mouthpiece of the nozzle to complete the aging process, which is energy saving, effective and efficient.

Impact-dissipating liners, helmets having an impact-dissipating liner, and methods of fabricating impact-dissipating liners are provided. The liners include a fluid impermeable enclosure having cavities with sidewalls and a fluid contained in the enclosure. The enclosure may have a central portion and lobes extending from the central portion, wherein the central portion and the lobes are adapted to conform to the shape of an internal surface of a helmet. The helmets may include bodies positioned within the cavities of the liner, where, under impact loading, contact between the bodies and the liner absorbs at least some of the energy of the impact loading. Aspects of the invention are particularly adapted for use for head protection, such as, helmets; however, aspects of the invention are also adaptable to provide impact-dissipation for any body or surface that would benefit from such protection.

A method for producing a polymer latex, includes a step of emulsifying a polymer solution of a synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer, in water in the presence of a rosin and/or a rosin metal salt, thereby obtaining an emulsified liquid, wherein the rosin and/or the rosin metal salt to be used have/has a total content rate of abietic acid, neoabietic acid and palustric acid, and salts thereof, of 5% by weight or less.

This invention relates to an elastomeric article with improved lubricity and donnablity and reduced stickiness/tackiness. According to the methods of the invention, the internal surface of the elastomeric article is coated with a polyisoprene coating. The coating of the invention is formed from synthetic polyisoprene rubber that may or may not contain minor amounts of other components. The coating is preferably directly bonded to the underlying elastomeric article.