In open mold casting, the individual liquid reactants ofa system are mixed and poured into an open faced mold. the foaming reaction is allowed to progress unrestricted, resulting in rising foam with density that is controlled by the chemical foaming process (i.e. free-rise). Open mold casting produces, as well as a high density skin due to the contact and restriction occuring at the mold surface.
For composite production, open mold casting is only viable for short fiber or nanofiller reinforcement because of the free expansion of the resin during the foaming process. The use of continious fibers in an open mold process isn't advantageous because of the inability of a free rising foam to achieve proper impegnation while maintaining the control of fiber placement. ( S. Pilla, Handbook of Bioplastics and Bıocomposites Engineering Applications pg.276)
Open Mold (Older)
The distinguishing feature of this family of FRP( fiber-reinforced polymer composites) shaping processes is its use of a single positive or negative mold surface to produce laminated FRP structures. Other names for open mold processes include contact lamination and contact molding. The starting materials (resins, fibers, mats, and woven rovings) are applied to the mold in layers, builging up to the desired thickness. This is followed by curing and part removal. Common resinds are unsaturated polyesters and epoxies, using fiberglass as the reinforcement. The moldings are usually large( e.g., boat hulls). The advantage of using an open mold is that the mold costs mych less than if two matching molds wew used. The disadvantage is that only the part surface in contact with the mold surface is finished; the other side is rough. For the best possible part surface on the finished side, the mold itself must be very smooth.
There are several important open mold FRP processes. The differences are in the methods of applying the laminations to the mold, alternative curing techniques, and other variations. The family of open molf processes for shaping fiber-reinforced plastics: (1) hand lay-up, (2) spray-up, (3) automated tape – laying machines, and (4) bag molding. We treat hand lay-up as the base process and the others as modifications and refinements.
(Groover, M.P., Fundamentals of modern manufacturing: materials, processes, and systems, 4th Edition, pg.331-332)
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Electrochroming (Older) (Chemical Manufacturing Process)
Electrolysis consists of chemical decomposition due to the effects of an electric current.An anode and a cathode are placed in a tank filled with a solution , and linked to a continuous current generator.The anode is the positive terminal, and the cathode, negative.The anode undergoes reactions of oxidation, and will loose electrons, whereas the cathode undergoes reaction of reduction and gains electrons.
By electrolysis , pieces of plastic can be coated in chrome, nickel, and even gold.The metal is deposited in the solution and the plastic pieces need to be made conductive (ABS,Polypropylene,polyamide,polycarbonate, for example). The pieces , submerged in the bath, act as the cathode and will be covered in the metal on all surfaces.It is possible to make quite large pieces (for cars, for example )
(materiology by Daniel kula and elodie ternaux p.306)
Electrochroming (Newer) ( Better)
Electrochroming is one of the most effective NTMP; in this process, the metal removal is based on the anodic dissolution governed by FARADAY's principle of electrolysis (1833). According to this principle, the the anodic dissociation rate in the machining (depleting) cell is directly proportional to the dc electrolyzing current and the chemical equivalent € of the anode material (€ = atomic weight/valence)
(H. Youssef, H. Hofy, Machining Technology, pg.445)
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Precursor station (older)(beetter)
To achieve longer production runs,precursor packages will get larger and once a 'one man lift' operation is exceeded, suitable lifting gear must be provided.Creels and improved box handling facilities designed to suit the larger packages, probably with the introduction of robotics for continuous splicing, hence reducing downtime, is required. The golden rule with precursor handling is to have the least number of contact points in order to minimize filament damage.
It is possible that in the future , precursor fiber will be produced on textile beams, but these would be heavy and difficult to manipulate and would necessitate the return of the empty beams to the precursor supplier.( Carbon fibers and their composites PETER MORGAN P.194)
Precursor Station (Newer) (Carbon Processing)
Commercial carbon fibers are fabricated by using pitch or polyacrylonitrile (PAN) as the precursor. Precursor fibers are fabricated by conventional spinning techniques, such as wet spinning for PAN and melt spinning for pitch. They must be converted to a form which is flameproof and stable at the high temperatures invlovd in carbonization. Therefore, before carbonization (pyrolysis), they are stabilized for the case of the PAN precursor, or infusiblized for the case of the pitch precursor. Both stabilization and infusiblization are carried out in an oxidazing atmospheree, followed by graphitization at > 2500 degree celcius in an inert atmosphere (D. Chung, Carbon Fiber Compozites, pg.6)
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Precursor creel (older) (better)
The batch numbers of all precursor spools used on the line should be recorded and a list made of any defects found.The correct degree of braking should be applied to all spools so that they rotate freely and give a uniform band of precursor entering the oxidation oven. ( Carbon fibers and their composites PETER MORGAN P.438)
Precursor Creel (Newer) (fixture)
Precursor spool, along with its supporting structure, that holds the required number of roving balls or supply packages in a desired position for unwinding for the next processing step, that is weaving, braiding, or filament winding. (ASM, Engineering Plastics, pg.12)
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Hot marking (older)
A plastic film with metallic deposits in inserted between a heated die punch and the piece to be decorated.The pattern, machined in relief on the die, is transferred by pressure and heat onto the piece(which may be plastic, for example).This procedure is fast, simple, and economical.Hot marking is often used to obtain 'gold' and 'silver' logos on cosmetic cases or flocked packaging.Gilding(with gold leaf) when done on luxury leather objects is similar to this thechnique.
(materiology by Daniel kula and elodie ternaux p.307)
Hot Marking (newer) (better) (manufacturing)
is acommon method for applying decorations, printed material and other surface changes to plasticproducts. The process involves a selective transfer of coating material to the surface of the workpiece. A multi-layer plastic foil is placed against the surface to be decorated. Heat from a hot pad, roller or die which is pressed against thee foil, causes the coating material to be transfered to the workpiece. The foil typically consists of the following layers: 1) a carrier film, usually polyester, 2) a layer of a thin release agent that is activated when heated, 3) a layer of thee decorative coating to be transferred to the workpiece. This coating may be metallicor an ink, dye, or paint, often in several colours 4) a protecttive layer for the decorative coating and 5) an adhesive wihich is formulated to bond the desired coating to the work piece. The rubber or metal hot pad, is hot enough to melt the release coating of the foil, and to activate the adhesive coating. Often an engraved die is used. It''s made to the forrm of the decorative design or lettering to be transferred. Then the design transferred is in the form of the die, rather than form a printed design on the foil. When either the die or the pad is briefly held against the foil and workpiece, the decorative material is transferred. Upon cooling, the coating is firmly bonded to the workpiece surface, which is slightly depressed in the coated area. The protective layer is also transferred and serves to shield the decorative coating of the part from abrasion or chemical attack. (J. Bralla, Handbook of Manufacturing Process, pg.199)
Electrochroming (Older) (Chemical Manufacturing Process)
Electrolysis consists of chemical decomposition due to the effects of an electric current.An anode and a cathode are placed in a tank filled with a solution , and linked to a continuous current generator.The anode is the positive terminal, and the cathode, negative.The anode undergoes reactions of oxidation, and will loose electrons, whereas the cathode undergoes reaction of reduction and gains electrons.
By electrolysis , pieces of plastic can be coated in chrome, nickel, and even gold.The metal is deposited in the solution and the plastic pieces need to be made conductive (ABS,Polypropylene,polyamide,polycarbonate, for example). The pieces , submerged in the bath, act as the cathode and will be covered in the metal on all surfaces.It is possible to make quite large pieces (for cars, for example )
(materiology by Daniel kula and elodie ternaux p.306)
Electrochroming (Newer) ( Better)
Electrochroming is one of the most effective NTMP; in this process, the metal removal is based on the anodic dissolution governed by FARADAY's principle of electrolysis (1833). According to this principle, the the anodic dissociation rate in the machining (depleting) cell is directly proportional to the dc electrolyzing current and the chemical equivalent € of the anode material (€ = atomic weight/valence)
(H. Youssef, H. Hofy, Machining Technology, pg.445)
-----------------------------------------------------------------------------
Precursor station (older)(beetter)
To achieve longer production runs,precursor packages will get larger and once a 'one man lift' operation is exceeded, suitable lifting gear must be provided.Creels and improved box handling facilities designed to suit the larger packages, probably with the introduction of robotics for continuous splicing, hence reducing downtime, is required. The golden rule with precursor handling is to have the least number of contact points in order to minimize filament damage.
It is possible that in the future , precursor fiber will be produced on textile beams, but these would be heavy and difficult to manipulate and would necessitate the return of the empty beams to the precursor supplier.( Carbon fibers and their composites PETER MORGAN P.194)
Precursor Station (Newer) (Carbon Processing)
Commercial carbon fibers are fabricated by using pitch or polyacrylonitrile (PAN) as the precursor. Precursor fibers are fabricated by conventional spinning techniques, such as wet spinning for PAN and melt spinning for pitch. They must be converted to a form which is flameproof and stable at the high temperatures invlovd in carbonization. Therefore, before carbonization (pyrolysis), they are stabilized for the case of the PAN precursor, or infusiblized for the case of the pitch precursor. Both stabilization and infusiblization are carried out in an oxidazing atmospheree, followed by graphitization at > 2500 degree celcius in an inert atmosphere (D. Chung, Carbon Fiber Compozites, pg.6)
--------------------------------------------------------------
Precursor creel (older) (better)
The batch numbers of all precursor spools used on the line should be recorded and a list made of any defects found.The correct degree of braking should be applied to all spools so that they rotate freely and give a uniform band of precursor entering the oxidation oven. ( Carbon fibers and their composites PETER MORGAN P.438)
Precursor Creel (Newer) (fixture)
Precursor spool, along with its supporting structure, that holds the required number of roving balls or supply packages in a desired position for unwinding for the next processing step, that is weaving, braiding, or filament winding. (ASM, Engineering Plastics, pg.12)
----------------------------------------------------------------------------
Hot marking (older)
A plastic film with metallic deposits in inserted between a heated die punch and the piece to be decorated.The pattern, machined in relief on the die, is transferred by pressure and heat onto the piece(which may be plastic, for example).This procedure is fast, simple, and economical.Hot marking is often used to obtain 'gold' and 'silver' logos on cosmetic cases or flocked packaging.Gilding(with gold leaf) when done on luxury leather objects is similar to this thechnique.
(materiology by Daniel kula and elodie ternaux p.307)
Hot Marking (newer) (better) (manufacturing)
is acommon method for applying decorations, printed material and other surface changes to plasticproducts. The process involves a selective transfer of coating material to the surface of the workpiece. A multi-layer plastic foil is placed against the surface to be decorated. Heat from a hot pad, roller or die which is pressed against thee foil, causes the coating material to be transfered to the workpiece. The foil typically consists of the following layers: 1) a carrier film, usually polyester, 2) a layer of a thin release agent that is activated when heated, 3) a layer of thee decorative coating to be transferred to the workpiece. This coating may be metallicor an ink, dye, or paint, often in several colours 4) a protecttive layer for the decorative coating and 5) an adhesive wihich is formulated to bond the desired coating to the work piece. The rubber or metal hot pad, is hot enough to melt the release coating of the foil, and to activate the adhesive coating. Often an engraved die is used. It''s made to the forrm of the decorative design or lettering to be transferred. Then the design transferred is in the form of the die, rather than form a printed design on the foil. When either the die or the pad is briefly held against the foil and workpiece, the decorative material is transferred. Upon cooling, the coating is firmly bonded to the workpiece surface, which is slightly depressed in the coated area. The protective layer is also transferred and serves to shield the decorative coating of the part from abrasion or chemical attack. (J. Bralla, Handbook of Manufacturing Process, pg.199)
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