732 results about "Rotational molding" patented technology

A golf club having a hollow golf club head which is filled with a gas under pressure. The interior surface of the golf club head is coated with a solidified layer of plastic material. The pressurized gas permits the use of thinner face plates by compensating for forces generated when the face plate strikes a golf ball. The plastic layer is preferably applied through the process of rotational molding using a thermoplastic material.

A blend of a macrocyclic polyester oligomer and a polymerization catalyst as a one component ready-to-use material with a long shelf life enables production of parts from macrocyclic polyester oligomers without the modification of existing equipment, thereby reducing time and cost of manufacture while expanding the application of macrocyclic polyester oligomers. In this blend material, the macrocyclic polyester oligomer remains intact in solid state at ambient conditions. Upon melting, the blend material initially forms low viscosity fluid, and then rapidly polymerizes to form high molecular weight polyesters which subsequently solidify to form crystalline polymers. In the case of certain macrocyclic polyester oligomers, for example, poly(1,4-butylene terephthalate), demolding can take place at the polymerization temperature, e.g., at about 180° C. to 200° C., because the resulting polyester polymer solidifies fairly rapidly at that temperature without cooling. In one aspect, the invention generally features a blend material that includes a macrocyclic polyester oligomer, a polymerization catalyst, and optionally, a filler. In another aspect, the invention generally features a process for preparing a blend material. In yet another aspect, the invention features processes such as rotational molding, resin film infusion, pultrusion, resin transfer molding, filament winding, making and using powder-coated or hot melt prepreg, compression molding, and roll wrapping, which use the blend material.

A system and method for reinforcing at least a portion of a structural member, including at least one hollow carrier, having an exterior shell and an interior portion, which substantially conforms to the dimensions and geometry of the structural member being reinforced; and a lightweight, low density material for filling the interior portion of one or more of the carriers. The material filling one or more of the carriers of the present invention can be a reinforcement material, self-curing material, or a heat activated expandable material. The carrier can be produced by blow molding or rotational molding and has an adhesive material disposed along at least a portion of the exterior shell used to place, adhere, and affix the carrier to a targeted portion of the structural member selected to be structurally reinforced.

An elastomeric gel-filled prosthetic implant having a shell made of a single gel barrier layer. The barrier layer is formed of a homogeneous silicone elastomer capable of sterically retarding permeation of the silicone gel through the shell and having a bleed rate that is less than about 40% of the bleed rate of current shells which use a sandwiched construction with an internal barrier layer. Further, the barrier layer shell is made of a material that exhibits a wet strength that is comparable to or greater than current shells. The silicone elastomer may be a polydimethyl siloxane, and the substituted chemical group is a diphenyl group with a minimum mole percent of at least 13%. The implant may be designed for breast reconstruction or augmentation such that the shell is accordingly shaped. The shell wall thickness is at least 0.254 mm (0.010 inches), and desirably about 0.456 mm (0.018 inches). The implant shell may be made by dip-forming, spray-forming, or rotational molding. The exterior may be smooth or textured.

The application discloses a method of making a balance spring (100) from continuous fibres or ceramic by winding them around a cylindrical former (90), interspaced with a releasing agent (110). Also disclosed is a method of making a balance spring, preferably of a ceramic material (60), by applying it to a rotating former (70) mandrel or plate and subsequently heat treating. Balance wheels (30) having a moment of inertia which decreases with a rise in temperature due to a special arrangement of components (8, 9, 10) having different coefficients of thermal expansion are also disclosed. A mechanical oscillator system comprising a non-magnetic ceramic or continuous fibre balance spring (50) and a non-magnetic balance wheel (30) formed of a material having a coefficient of thermal expansion of less than 6×10⁻⁶K⁻¹ and having a plurality of non-magnetic poising or timing appendages (5) is also disclosed.

The invention discloses a rotational molding wear-resistant polyolefin resin and a preparation method thereof. In the rotational molding wear-resistant polyolefin resin, raw materials commonly used in the rotational molding process, namely linear low-density polyethylene, high-density polyethylene or polypropylene is taken as a matrix material; and by adding components of an inorganic filler, ultrahigh molecular weight polyethylene and a lubricant, the wear resistance of the matrix resin is improved. The rotational molding wear-resistant polyolefin resin consists of the following components in percentage by mass: 70 to 80 percent of matrix resin, 10 to 15 percent of inorganic filler subjected to surface treatment, 4 to 13 percent of ultrahigh molecular weight polyethylene and 1.5 to 2 percent of lubricant, wherein the matrix resin is the linear low-density polyethylene, the high-density polyethylene or the polypropylene; and a range of a melt flow rate of the matrix resin is between 2g/10min and 15g/10min.

A multi-component lacrosse stick head, made of at least two materials, including a base lacrosse head structure of one material and one or more overlays made of one or more other materials strategically located on the base structure. The base structure and overlays provide particular performance characteristics for the lacrosse head. An embodiment of the invention includes a base lacrosse head structure, and at least one of a ball stop overlay, a sidewall overlay, an edge overlay, a thread opening overlay, and a scoop overlay. The overlays are affixed to the base lacrosse head structure by, for example, insert molding, over molding, reaction injection molding, spray application, rotational molding, dual extrusion, casting, or an interference fit.

A plastic molded, sit-on-top kayak of unique size and shape is disclosed with various components which provide multi-purpose usage. the kayak is especially useful for multi-purposes such as sailing kayak surfing, scuba diving, paddling, touring and electric motorized usage. The kayak has attachment points integrally molded that provide for these multi-purposes. An important component of the invention includes a removable backrest that additionally provides secure waterproof storage of the operator's personal items. The backrest can be easily removed and reattached securely in place when desired. The ability to easily remove a backrest or backpack option also enables a desirable compact capability for transportation and storage by a user. Additional benefits of this feature provide for a smaller profile for packaging and commercial transportation. The kayak as disclosed may be formed for the most part, typically by blow molding, rotational molding, injection molding, rim molding, fiberglass and thermoforming, and by using a wide variety of polymer materials that may be suitable.

Disclosed are processes for rotational molding of thermoplastic polyesters and for hollow articles produced therefrom. The thermoplastic polyesters have a crystallization half time of at least 10 minutes and an inherent viscosity of 0.55 to 0.70 dL/g. Additional thermoplastic polymers may be used to produce multilayered articles.

The invention relates to a high-impact high-stiffness polypropylene rotational molding material and a preparation method thereof. The rolling plastic rotational molding material comprises the following raw materials: by weight, 100 parts of polypropylene, 0-30 parts of polyethylene, 0-0.1 part of a crosslinking agent, 0-0.15 part of an auxiliary crosslinking agent, 1-10 parts of an elastomer, 0.1-0.5 part of an antioxidant, 0-10 parts of a nano filler, 0.1-0.5 part of a dispersing lubricant and 0-0.4 part of a surface treatment agent. According to the invention, the crosslinkable polyethylene is added in a polypropylene melt mixing process for melt curing to obtain the high-impact high-stiffness polypropylene modified rotational molding material with a semi interpenetrating network structure, and the high-impact high-stiffness polypropylene modified rotational molding material can meet the material requirements of vehicles and other different fields. The curing reaction of the polyethylene belongs to the in situ curing, the material has the unique semi interpenetrating network structure, different components are mutually bitten or buckled, the compatibility between the polyethylene and polypropylene resin can be improved, and the performance advantages of the both are full played.

A method of producing a plastics article having solid skin and a foam core by a rotational moulding process, comprises charging a mold with a skin-forming component and substantially simultaneously with a foam core-forming component of bulk density greater than 0.5 g/cc, providing a first heating stage in which the mold is heated to a first temperature and is rotated for a first predetermined time to form a substantially impervious skin within the mold, and providing a second heating stage in which the mold is heated to a higher second temperature and is rotated for a second predetermined time to cause foaming of said foam core-forming component, thereby forming a foam core within said substantially impervious skin.

A method for applying a radio frequency identification tag to an object, e.g., a container, by means of an insert molding process or in-mold decorating process. Such a method can be utilized to simplify the manufacturing processes for applying a radio frequency identification tag to an object, e.g., a container. The molding process can be a conventional molding process, such as, for example, injection molding, blow molding, compression molding, transfer molding, and rotational molding. However, the conventional molding process is modified by inserting a radio frequency identification tag into the cavity of the mold prior to forming the molded article. The modified molding process results in a molded article having a radio frequency identification tag encapsulated by the polymeric material of the molded article.

The invention relates to a forging aluminum alloy wheel forging-rotational molding method, which combines the forging and rotational compressing techniques. In forging, molding part of spoke of wheel, and pre-molding the rim; then in rotational compressing, rotationally compressing the rim to complete the molding. Wherein, the rim is molded by forging, and the rim is mainly molded by rotational compression. The invention can combine the forging and rotational compression to express their advantages. And the inventive aluminum alloy wheel has better quality, high accuracy, less finish allowance, higher strength, and reduced material consumption.

The invention relates to a crosslinked polyethylene single-purpose material for rotational moulding which comprises (by weight percent) linear low density polyethylene 70-90%, low density polyethylene 10-30%, cross linking agent 0.5-5%, anti-oxidant 0.1-1%. The invention also relates to the process for preparing the special-purpose material. The rotational moulding product prepared by the single-purpose material has good processing characteristics, fine impact strength, thermal creep resistance and low-temperature flexibility, good penetrability resistance and chemical environmental resistance.

One embodiment of a molded fuel tank includes a fuel tank molded from a synthetic material, such as a composite polymer. One embodiment may include molding a fuel tank with metal component fastening structures positioned within the fuel tank as it is molded. One embodiment may include molding a fuel tank and integral component fastening structures simultaneously from synthetic materials. One embodiment of a molded fuel tank may include a fuel tank formed by a rotational molding process.

A method for producing a valve holder assembly for an automatic gas shutoff valve in a pressurized gas coupling comprises mounting a compressible annular gasket on a cylindrical portion of the valve holder adjacent an enlarged flange that abuts an outer side of the gasket; mounting a retaining washer on the cylindrical portion adjacent an outer side of the gasket, the cylindrical portion extending outwardly past the retaining washer and terminating at a shoulder; and flaring the shoulder radially outwardly so as to form a retaining cap on an outer side of the retaining washer, thereby locking the gasket on the valve holder, by applying a rotary forming tool against the shoulder on the cylindrical portion. The coupling desirably includes shutoff valves in male and female components, with identical valve holder assemblies being used in both coupling components. A powdered metal guide can be used for a stem on the valve holder.

A variety of pet related products are provided formed initially of plastic and finalized with a metallized surface finish. The pet product is molded using injection molding, rotational molding, vacuum forming, blow molding, compression molding, thermoforming or other plastic forming techniques that can provide a structure having a shape that cannot be readily or economically shaped by metal stamping or other conventional metalworking method. The semi finished plastic part is then subjected to a metallizing process in an individualized non-contiguous manner, where a thin metallic layer is deposited on at least one of the product surfaces. The resultant pet product item simulates the appearance metal, and may provide the durability, cleanability and the general antimicrobial nature resulting metal surfaces.

The invention discloses a rotational molding grade cross-linked polyethylene wear-resistant composite and a preparation method thereof. The rotational molding grade cross-linked polyethylene wear-resistant composite is prepared by the steps of mixing a base material, which is linear low-density polyethylene (granular or powdery) commonly used in a rotational molding process, with a cross-linking agent and an assistant cross-linking agent uniformly, absorbing for 80-120 minutes at 85 DEG C, and then adding ultra-high molecular weight polyethylene, an inorganic filler and other components for improving the wear resistance of the base. The rotational molding grade cross-linked polyethylene wear-resistant composite disclosed by the invention comprises the following components in percentage by weight: 76.7-79% of linear low-density polyethylene, 0.15-4% of cross-linking agent, 0.15-1% of antioxidant, 4-19% of ultra-high molecular weight polyethylene and 4-12% of inorganic filler subjected to surface treatment.

The cycle time of polymer compositions subjected to a rotomolding process is improved (i.e., reduced), while the processing window is simultaneously enlarged through the use of a polymer-stabilizing amount of a processing stabilizer system having at least one chroman-based compound according to Formula V:

Toughened thermoplastic compositions comprising a thermoplastic polymer toughened by the inclusion of a thermoplastic elastomer derived from a particulate rubber dynamically vulcanized in the presence of a matrix polymer. The toughened thermoplastic composition exhibits properties including toughness, improved impact resistance, and improved hardness. The compositions are utilized wherever toughened, high performance polymers are desired. A method for forming the toughened polymer compositions is also described. Processing methods, such as rotational molding, utilizing the toughened polymer compositions are described.

The invention provides a rotational molding process of a three-layer plastic automobile shell, which belongs to the field of rotational molding of automobile shells and solves the problem of poor performances of the automobile shell in the prior art. The rotational molding process for the three-layer plastic automobile shell comprises the following steps: manufacturing an external die and an internal die according to an automobile type; fixedly connecting the external die with the internal die through a locking device and forming an accommodating space by the external die and the internal die; adding a rotational molding powder material and a foaming granule material with different melting points in a cavity formed by the external mold and the internal mold; and performing rotational molding after closing the dies, so as to form an internal layer and an external layer of the automobile shell by the rotational molding powder material and form a foaming layer in the middle of the internal layer and the external layer by the foaming granule material. According to the invention, the three-layer plastic automobile shell is molded one time through the rotational molding process, so that the molding period of the automobile shell is shortened; and as a three-layer structure is adopted, the strength, the rigidity and the heat-insulating property of the three-layer plastic automobile shell are all increased compared with those of the automobile shell with a two-layer structure.