Abstract: The present invention is a method for real-time controlling a resin transfer molding process, which is used to control a filling pressure of a resin in a resin transfer molding (RTM) apparatus. In a pre-control RTM process, the current filling pressure, the current permeability and the wave front position at the current time point is input into a prediction-control model to acquire a predicted filling pressure at the next time point. The predicted filling pressure is used as the filling pressure to make the resin flow to the expected position of the wave front at the next time point, whereby to achieve stable quality of RTM products.

Abstract: A light irradiation molding apparatus 1 includes a pair of rubber die units 2A and 2B, which are formed of a rubber material having a property of transmitting light X therethrough and form a cavity between facing sides which face each other, and a light irradiation means 4, which applies light X to a particulate or solid thermoplastic resin 6 arranged in the cavity 20 through surfaces of a pair of the rubber die units 2A and 2B. The light irradiation molding apparatus 1 is constituted so that a pair of the rubber die units 2A and 2B are made to come close to each other while the thermoplastic resin 6 arranged in the cavity 20 is molten by the light X applied from the light irradiation means 4, and a molded article 7 of the thermoplastic resin 6 is formed in the cavity 20 having a reduced volume.

Abstract: The invention provides: a method for applying a liquid to the rim of a container by transfer from a roller whose surface is composed of a tubular warp or weft knit of 2×1 rib construction; a glass jar or equivalent container whose rim has a coating of varnish, adhesion promoter or heat-sealing primer formed by an application method; a jar or equivalent container comprising a seal heat-sealed to the rim.

Abstract: The present invention relates to a device that installs in-line in the fuel supply line of fuel usage equipment such as a HVAC system or a large commercial natural gas or diesel generator. The device is suitable for use with liquid or gas hydrocarbon fuels such as gasoline, diesel, propane, or natural gas. The device consists of a hollow cylinder with male ends and that contains a tightly packed copper wire core. The copper wire serves as a catalyst to crack the fuel's carbon chain molecules as the fuel flows through the device. The resulting fuel contains more and shorter fuel molecules, has a higher vapor pressure and burns more efficiently in the vehicle's engine. The copper wire is held in place by perforated copper keepers and the keepers are secured within the cylinder by snap rings that engage circumferential grooves provided internally at the ends of the cylinder.

Abstract: An imprint apparatus of the present invention that molds and cures an imprint material on a substrate using a mold to form a pattern on the substrate. The imprint apparatus includes a supply unit configured to supply a gas into a gap between the imprint material on the substrate and the mold. The supply unit is configured to supply a mixed gas in which a permeable gas, which permeates at least one of the mold, the imprint material and the substrate, and a condensable gas, which is liquefied under a pressure generated by the molding, is mixed with each other.

Abstract: Method for coagulating an aqueous polymer dispersion, where the aqueous polymer dispersion comprises at least one polymer in dispersion in aqueous phase, and also comprises thermally expandable, thermoplastic microspheres, the polymer dispersion is coagulated by energy input, and the coagulated composition is delivered via an outlet aperture, preferably in the form of a nozzle.

Abstract: Methods and tools for forming contoured composite structures are disclosed. Methods include positioning a sheet of composite material relative to a structure of shape memory alloy, heating the structure of shape memory alloy to deform the structure of shape memory alloy to a deformed conformation and thereby conform the sheet of composite material to a desired contour corresponding to the deformed conformation of the structure of shape memory alloy. Tools include a structure of shape memory alloy and a heat source for heating the structure of shape memory alloy to conform a sheet of composite material to a desired contour corresponding to the deformed conformation of the structure of shape memory alloy.

Abstract: The invention relates to an apparatus and a process for producing pigment-containing, in particular carbon-black-containing, polymer mixtures comprising polycarbonates and optionally elastomers, and/or other components, where the mouldings produced therefrom have, after the shaping process via injection moulding or via extrusion, improved surface properties and improved mechanical properties.

Abstract: A method and apparatus for manufacturing a composite structure. The apparatus comprises a base section and a locking section. The base section of a mandrel has a channel with an opening that receives a portion of a bagging material wrapped around an exterior surface of the base section. The locking section of the mandrel engages the channel such that the portion of the bagging material in the channel is held inside the channel.

Abstract: A method of shaping plastics material pre-forms into plastics material containers with the steps: introducing a plastics material pre-form into a blow mold; conveying the blow mold with the plastics material pre-form along a pre-set conveying path; acting upon the plastics material pre-form with a gaseous medium during a pre-set period of time for the expansion thereof, wherein the supply of the gaseous medium is carried out in a controlled manner; and releasing the container from pressure at a pre-set point in time. According to the invention the pre-set point in time (t2) is variable.

Abstract: A pressure-maintenance device for a resin injection system including an injection network connected to an injection mould, includes a pressurisation device adapted to inject a pressurised gas into a channelling; a first connector adapted to be connected to the resin injection network and adapted to be connected to the channelling; a second connector adapted to be connected to the injection mould of the injection system; the first connector being connected to the second connector by a pressure-maintenance channelling adapted to receive the gas injected under pressure.

Abstract: A tooling system may include an outer mold line (OML) tool and one or more inner mold line (IML) tools. The OML tool may have an OML tool surface. Each one of the IML tools may have an IML tool surface and may be receivable within the OML tool 202. Each IML tool may be formed of expandable material. Each IML tool may apply an internal compaction pressure to a composite assembly positioned between the OML tool surface and the IML tool surface when the expandable material is heated.

Abstract: A method of RTM molding includes placing a reinforcing fiber substrate in a mold, placing resin distribution media exhibiting a resin flow resistance lower than a resin flow resistance of said reinforcing fiber substrate on both surfaces of said reinforcing fiber substrate, and after pressure in said mold is reduced by evacuation, injecting a resin into said mold through said resin distribution media to impregnate said reinforcing fiber substrate with said resin injected, wherein resin flow resistance of a first resin distribution medium placed on a first surface of said reinforcing fiber substrate is lower than resin flow resistance of a second resin distribution medium placed on a second surface of said reinforcing fiber substrate, and said evacuation is carried out through said second resin distribution medium while said resin is injected into said first resin distribution medium to impregnate said reinforcing fiber substrate with said resin injected.

Abstract: The present invention provides a seawater resistant grout material composition and a method for constructing an offshore wind turbine structure using the same, the seawater resistant grout material composition comprising: 2˜10 wt % of high strength admixture; 25˜35 wt % of type I Portland cement; 30˜45 wt % of silica sand having a particle size of 30˜60 mesh; 5˜15 wt % of silica sand having a particle size of 60˜100 mesh; and 5˜10 wt % of silica sand having a particle size of 100˜200 mesh, wherein the high strength admixture is obtained by mixing and pulverizing 45˜99 wt % of slag and 1˜55 wt % of anhydrite, thus the present invention has excellent seawater resistance, excellent strength development characteristics at a low temperature, and increased compressive strength and durability to allow withstanding cyclic loads due to wind and wave pressure.

Abstract: A carrier for carrying a semiconductor layer having a growth surface and at least one nano-patterned structure on the growth surface is provided. The at least one nano-patterned structure on the growth surface of the carrier has a plurality of mesas, a recess is formed between two adjacent mesas, in which a depth of the recess ranges from 10 nm to 500 nm, and a dimension of the mesa ranges from 10 nm to 800 nm.

Abstract: Apparatus for resin transfer molding (RTM) and an RTM process for producing integral components. The apparatus has a closable mold (W) with a mold cavity (F), and an injection unit (10) coupled to the mold such that a resin is introducible into the mold; the mold has at least one resin outlet (3) connected to the mold cavity through which resin escapes after the mold is filled; a measuring unit situated at or downstream from the outlet detects escaping resin flow is and is coupled to a resin flow closing unit (5) such that the unit closes the outlet when escaping resin is detected. In the process a control system (11) transmits a signal for closing the resin flow closing unit to the closing unit when resin flow is detected such that the resin flow closing unit is closed and the flow of resin escaping the mold is interrupted.

Abstract: An impregnated fiber tow comprising multiple unitary graphene-based continuous graphitic fibers impregnated with a matrix material, wherein at least one of the continuous graphitic fibers comprises at least 90% by weight of graphene planes that are chemically bonded with one another having an inter-planar spacing d002 from 0.3354 nm to 0.4 nm as determined by X-ray diffraction and an oxygen content less than 5% by weight, wherein the graphene planes are parallel to one another and parallel to a fiber axis direction and the graphitic fiber contains no core-shell structure, has no helically arranged graphene domains or domain boundary, and has a porosity level less than 5% by volume.

Abstract: The invention relates to a composition Z comprising a component B1, a component B2, a component D, a component E and a component P, wherein the component B1 is a polyethylene glycol having a hydroxyl number of from 25 to 600 mg KOH/g and an average molecular weight of 200 to 4000 g/mol; the component B2 is a polyethylene glycol having a hydroxyl number of from 0.1 to 24 mg KOH/g and an average molecular weight of higher than 4000 to about 10,000,000 g/mol; the component D is an earth alkali carbonate, the component E is a phyllosilicate, and the component P is a polystyrene and/or an alloy thereof. Composition Z is suitable to increase the hydrophilic properties of processed solid or foamed polystyrene material, especially for making a film, sheet or food tray.

Abstract: A method produces a molded part from carbon containing carbon fibers in an amount of less than 20% by weight. The method includes comminuting waste parts or scrap parts formed from a carbon fiber-reinforced synthetic material, a carbon fiber reinforced carbon or a carbon fiber reinforced concrete. A mixture is produced from the comminuted product, a binder such as pitch, a carbon material such as coke and optionally one or more additives, wherein the mixture contains less than 20% by weight of fibers. The mixture is molded into a molded part and the molded part is carbonized. Optionally, the molded carbonized part is impregnated with an impregnating agent. Finally and optionally, the molded carbonized part or the molded part impregnated part is graphitized.

Abstract: A method for fabricating a repair laminate for a composite part having an exposed surface includes applying a release film to the exposed surface and forming an uncured ply stack assembly on the release film. The uncured ply stack assembly is formed by forming and compacting a series of uncured ply stacks. The release film and ply stack assembly is then removed from the exposed surface. A bonding material is then applied to the exposed surface, and the uncured ply stack assembly is applied to the bonding material. The ply stack assembly and bonding material are then cured.

Abstract: The invention relates to a heat transmission system based on electromagnetic radiation, which heat transmission system comprises an oven cavity and a foil with at least two layers, said at least two layers of the foil comprising a radiation-absorbing layer, wherein the wavelength spectre of the electromagnetic radiation of the radiation-absorbing layer and wavelength spectre of the electromagnetic radiation of the oven cavity are attuned to each other. The invention also relates to a foil for use in a heat transmission system, said foil comprising at least two layers, and wherein the wavelength spectre of the electromagnetic radiation of the foil is attuned to that of a heat source, eg the wavelength spectre of the electromagnetic radiation of an oven. The foil may be provided with a radiation-absorbing surface that may be configured both as a flexible foil and as an inflexible foil that may be of either metal or of a polymer, paper, cardboard or other materials that are based on wood.

Abstract: The present disclosure relates to optical elements and coatings comprising rare-earth element (REE) compounds for light wavelength attenuation of light emitting diode (LED) elements and lamps. More particularly, the present disclosure relates to LED elements and lamps comprising wavelength attenuating elements comprising REE compounds having at least a portion of non-crystalline, non-hydrate form, methods of preparing such elements, and LED elements, LED arrays, LED packages, optical elements, lamps and systems made with same.

Abstract: Disclosed is an infusion method for the manufacture of a fiber-reinforced composite component with a flow promoter, wherein the flow velocity of the matrix material in a component to be infiltrated is modified by means of the flow promoter. Also disclosed is a flow promoter, which has an integral body section for the modification of the flow velocity.

Abstract: The current inventive technology includes improved methods, apparatus and material applications for the fabrication of seamless helium-free balloons and display systems. Specific embodiments of the invention include rotational molding techniques to produce seamless helium-free balloons having, in some cases seamless integral attachment supports that may secured to external displays. Additional embodiments of the invention include techniques for the fabrication of seamed, as well as seamless polyurethane (PU) and/or thermoplastic polyurethane (TPU) helium-free balloons that may be integrated with external display systems.

Abstract: The present invention regards a fiber-reinforced composite molding with an outer (102) structure and an inner structure (106), wherein the outer structure (102) is formed from at least one layer of fibrous reinforcing material and a cured first resin material, and the inner structure (106) is formed from a plurality of layers of fibrous reinforcing material and a second cured resin material, wherein the viscosity of the uncured first resin material is lower than the viscosity of the uncured second resin material and wherein in the composite molding the two cured resin materials are at least partially mixed with each other. It also regards a process for the production of such a fiber-reinforced composite molding.

Abstract: A foamed polyester extrusion process and equipment can be used in plants for producing sheets, boards or tubes of foamed polyester, preferably of the type operating continuously which has a thermoregulated frame provided with a feeding inlet of pure and/or recycled polyester material inside the frame. Two co-rotating screws are arranged inside the frame, the co-rotating screws defining, with the internal walls of the frame, a first degassing zone interposed between a feeding zone placed at the feeding inlet and a first tight zone. A second degassing zone is placed downstream from the first degassing zone and is separated from the latter through the first tight zone. A foaming agent inlet zone is placed downstream from the second degassing zone and is separated from the latter through a second tight zone and a pumping end zone of the melted material is placed downstream from the foaming agent inlet zone.

Abstract: A loudspeaker diaphragm includes a diaphragm portion and an edge portion, which is molded integrally with the diaphragm portion and made of a material different from a material for the diaphragm portion. The edge portion contains at least one thermoplastic polymer (I), in combination with a block polymer (II). The at least one thermoplastic polymer (I) is selected from a block copolymer (I-a) which contains a polymer block (A) having a repeating structural unit derived from an aromatic vinyl compound and a polymer block (B) having a repeating structural unit derived from a conjugated diene, and an addition hydrogenated block copolymer (I-b) of the block copolymer (I-a). The block copolymer (II) contains a polymer block (C) having a repeating structural unit derived from an olefin compound and a polymer block (D) having a repeating structural unit derived from a (meth)acrylic compound.

Abstract: In the case of a fiber composite component for energy absorption in the event of a crash for an aircraft or spacecraft, the fiber composite component is formed as a laminate construction made of CFRP layers and at least one integrated metal foil portion which is corrosion-resistant with respect to the CFRP layers. A fuselage structure portion of an aircraft or spacecraft is formed using at least one fiber composite component of this type. An aircraft or spacecraft comprises a fuselage structure portion of this type.

Abstract: A method and apparatus for manufacturing a composite material part from a preform of fibers pre-impregnated with resin. The method includes laying the preform on a laying surface of a tool with a peripheral shoulder, covering the preform with a conforming plate delimited by a peripheral edge which extends beyond the peripheral flank of the preform over the entire periphery of the preform, using shims calibrated to position the conforming plate, the shims being arranged between the support surface of the peripheral shoulder and the peripheral edge of the conforming plate, removing the calibrated shims, arranging a seal connecting the conforming plate and the tool all around the preform, and polymerizing the preform.

Abstract: Layers of unidirectional (UD) fiber prepreg are formed into a pre-plied, multi-directional, continuous fiber laminate that is used as a molding compound to form three dimensional structures. Cut-outs from the laminate are slotted and folded along fold lines to provide near-net-shaped preforms that may be compression molded to form fiber-reinforced composite structures having complex shapes.

Abstract: A problem is to provide a production method by which a high-strength concrete formed body can be obtained. The problem can be solved by a method for producing a concrete formed body including a defoaming step [1] of holding a concrete composition having a water-cement ratio adjusted to from 14 to 20%, in a reduced pressure atmosphere to obtain a defoamed concrete; a defoaming step [2] of holding a carbon fiber immersed in a cement solution having a water-cement ratio adjusted to 14% or more, in a reduced pressure atmosphere to obtain a defoamed fiber; and a forming step of placing the defoamed concrete and the defoamed fiber within a shuttering, followed by curing to obtain a high-strength concrete formed body.

Abstract: A method for fabricating a repair laminate for a composite part having an exposed surface includes applying a bonding material to the exposed surface and forming an uncured ply stack assembly on the bonding material. The uncured ply stack assembly is formed by forming and compacting a series of uncured ply stacks. The ply stack assembly and bonding material are then cured.

Abstract: A system for making PET objects including a means for reacting a first PET precursor and a second PET precursor to produce a PET melt; a means for flowing the PET melt to a valve having at least two outlets; a means for flowing the PET melt from at least one of the at least two outlets to at least one die forming line and one pelletizing (cutter) line. A means for controlling individually the mass flow of the PET melt in each of the at least two system lines independently of the other and a means for forming the PET objects from the PET melt. The control scheme is a combination of a feed forward system as well as a feedback loop. The entire control scheme is part of the overall system PLC. The fine tuning of the pressure at the outlet of the die forming loop is controllers to less than +/?1 bar to obtain maximum control of formed part.

Abstract: Methods for making high quality polyimide fibers suitable for continuous industrial production are described. Polyimide fibers are continuously prepared from a polyamic acid solution through sequentially spinning the polyamic acid solution by either a wet or a dry-wet process, coagulating, drying or drying after washing, thermally treating and stretching the resulting polyamic acid fibers to obtain polyimide fibers, and winding polyimide fibers as prepared into rolls.

Abstract: A method of manufacturing a component having first and second layers, the first and/or second layers including one or more depressions provided on a surface of the respective layer. The method including: arranging the first and second layers so that they face one another and with the depressions on inner facing surfaces of the layers; diffusion bonding the first and second layers together about their edges; applying a first differential pressure across each of the first and second layers to evacuate an inner space defined by the layers, thereby forming one or more depressions on an outer facing surface of the first or second layer; and applying a second differential pressure across each of the first and second layers to expand the inner space defined by the layers.

Abstract: This invention describes a composite molded material consisting of granular ceramic or ceramic coated material and liquid epoxy or urethane resin or vinyl ester resin or polyester resin or mixtures thereof in various ratios by weight and the processes by which the invention is produced. This invention results in a composite material of two or more dissimilar materials which improves the characteristic properties, such as wear, stain and abrasion resistance, oxidation resistance, corrosion resistance, heat resistance, electrical and thermal conductivity, and mechanical strength for which a monolithic material is not satisfactory.

Abstract: An apparatus and method for fabricating a stator of a super-high-speed induction motor, in which the process of loading a stator on which a coil is completely wound into a mold, injecting a functional resin into a chamber, converting the inside of the chamber into the vacuum state, and pressurizing the inside of the chamber is carried out so that bubbles are removed from the inside and the surface of the functional resin and the functional resin is completely filled between the inner circumference of the stator and the inner circumference of the mold, thereby maximizing heat conductivity and insulation, preventing the stator from deteriorating, and improving the performance and endurance of the super-high-speed induction motor.

Abstract: The present disclosure provides polyimide fibers with kidney-shaped cross-section and their preparation methods thereof, falling within the technical field of polyimide fiber. Polyimide fibers with kidney-shaped cross-sections are prepared by a continuous, integrated approach, starting from a polyamic acid solution prepared by reacting an aromatic dianhydride with an aromatic diamine. PAA nascent fibers with kidney-shaped cross-sections are obtained by adopting a spinneret having circular orifices under wet spinning process. The kidney-shaped cross-sections are obtained by varying the processing condition, including spinning speed, coagulation bath composition, coagulation temperature, and depth of coagulation bath. After washing and drying, polyamic acid nascent fibers are converted to polyimide fibers with kidney-shaped cross-sections under thermal curing. The integrated preparation methods are suitable for mass industrial production.

Abstract: A method for forming a cover assembly on an electrical power transmission cable includes: mounting a tubular cover member around the cable such that a portion of the cover member defines a cavity surrounding the cable; providing a flowable electrical stress grading material in the cavity; and applying a vacuum to the cavity to evacuate air from the cavity and compact the electrical stress grading material in the cavity.

Abstract: A production process includes introducing the material to be moulded into a mould, placing the mould in an envelope comprising a vacuum port; creating a low pressure in the envelope by formation of a gas flow through the vacuum port; deforming the mould; stopping the gas flow; and applying pressure on at least a portion of the mould, optionally with interposition of the envelope, at least after the gas flow is stopped.

Abstract: A method of manufacturing a semiconductor includes providing a mold defining a planar capillary space; placing a measure of precursor in fluid communication with the capillary space; creating a vacuum around the mold and within the planar capillary space; melting the precursor; allowing the melted precursor to flow into the capillary space; and cooling the melted precursor within the mold such that the precursor forms a semiconductor, the operations of melting the precursor, allowing the precursor to flow into the capillary space, and cooling the melted precursor occurring in the vacuum.

Abstract: In a method for coating a molded part (1), in particular a molded part produced by injection molding, the molded part (1) is arranged in a cavity (2) of a molding tool (3), wherein a partial cavity (4) between the molded part (1) and a first molding-tool half (5) of the molding tool (3) remains when a closing force (F) is applied to the molding tool (3) at a first closing-force level. A coating mass (6) is introduced into the partial cavity (4) and the coating mass (6) is cured/cross-linked. The closing force (F) of the molding tool (3) is increased during the curing/cross-linking of the coating mass (6), wherein the increase in the closing force (F) causes a volume reduction of the partial cavity (4) due to elastic deformation of the molding tool (3) and/or elastic deformation of the molded part (1).

Abstract: A method includes placing a package structure into a mold chase, with top surfaces of device dies in the package structure contacting a release film in the mold chase. A molding compound is injected into an inner space of the mold chase through an injection port, with the injection port on a side of the mold chase. During the injection of the molding compound, a venting step is performed through a first venting port and a second venting port of the mold chase. The first venting port has a first flow rate, and the second port has a second flow rate different from the first flow rate.

Abstract: An apparatus and a method of conforming a blank onto forming surface sections of a forming tool by drawing a first vacuum against an elastic forming medium for transmitting forming forces from the elastic forming medium to the blank. The elastic forming medium is evacuated with the first vacuum for allowing the elastic forming medium to stretch and conform the blank to the forming surface sections. The elastic forming medium includes at least one void. A second vacuum is applied to the void for achieving a stiffened section of the elastic forming medium corresponding with the location of the void and corresponding with, when the elastic forming medium after the completion lies against the forming tool having the blank in between, a forming surface section of the forming tool where the blank requires a forming force being larger than that of surrounding sections of the elastic forming medium.

Abstract: Cast polyurethane parts for shoes or other items may be formed in an automated fashion. A dispensing mechanism may dispense a predetermined amount of a liquid phase polyurethane mixture onto a flat surface face of a mold. A dispersal mechanism may distribute the liquid phase polyurethane mixture over the flat surface face of the mold to fill at least one cavity in the form. A vacuum may be applied to remove air bubbles from the liquid phase polyurethane mixture. Excess liquid phase polyurethane mixture may be removed from the flat surface face of the mold using a flexible blade that contacts and moves across the flat surface face. One or more conveyance mechanism may transport molds through the desired stages of a system and/or method in accordance with the present invention.

Abstract: A method for making a vacuum insulated glass window assembly is provided in which an exposed end of a pump-out tube of a vacuum insulated glass window assembly is sealed using a laser that is applied to the end of the pump out tube in controlled sequential manner as opposed to a short duration, high-powered application of a laser. In particular, a method is disclosed in which a multiphase sequential variable power application of laser energy to an exposed end of a pump-out tube for controlled exposure times and decreasing laser trace diameters produces a more controlled melting of the tube glass to reduce or eliminate undesirable outgassing that may occur during a high-power short duration exposure of laser energy to the end of the pump-out tube to seal the tube.

Abstract: The present invention provides compositions and methods that may be used to form low thermal distortion molds. The composition may include a curable elastomeric silicone composition formed using a de-volatilized polymer and at least one de-volatilized cross-linker. One embodiment of the method may include forming a pattern on a first side of an elastomer that is impregnated with a fibrous material proximate a second side of the elastomer.

Abstract: Certain example embodiments of this invention relate to apparatuses for sealing the tips of pump-out tubes of vacuum insulating glass (VIG) units, and/or associated methods. In certain example embodiments, a laser source used in sealing the pump-out tube is thermally insulated from the VIG unit and emits a laser beam through one or more windows in an oven towards a mirror located therein. The mirror is located so as to redirect the laser beam onto the pump-out tube to thereby seal it. For instance, a substantially horizontal laser beam emitted from a laser source located outside the oven enters into the oven through one or more windows and is reflected by a mirror towards the pump-out tube to be sealed. The repositioning of the laser source advantageously can change its effective focal length and/or the location of the laser beam, e.g., because of the fixed location of the mirror.

Abstract: A method of attaching a composite member to a structure. The method including forming a laminate of fabric impregnated with resin; applying heat at a first temperature to the impregnated laminate; applying vacuum at a first pressure to the impregnated laminate to degas the resin and form a degassed, impregnated laminate; positioning the degassed, impregnated laminate on a structure; and curing the degassed, impregnated laminate on the substrate by applying heat at a second temperature and by applying vacuum at a second pressure.

Abstract: A mold includes a first core and a second core matched with the first core. The first core includes a first die parting surface defining the molding cavity. The second core includes a second die parting surface facing the first die parting surface. A plurality of first exhaust grooves are defined in the first die parting surface. A plurality of transverse second exhaust grooves are defined in the second die parting surface. When the mold is closed, the first core and the second core cooperatively form at least one molding space. The first exhaust grooves are machining marks formed during the machining of the first core. The second exhaust grooves are machining marks formed during the machining of the second core.