Platen presses

Samples for a variety of physical, electrical, and chemical testing can be prepared by simple compression in a platen press, and thoughtful adaptation of standard test procedures allows valid... 

Pneumatic and hydraulic presses are excellent tools for applying constant pressure. Steam or electrically heated platen presses with hydraulic rams are often used for adhesive bonding. Some units have multiple platens, thereby permitting the bonding of several assemblies at one time. 

The PC window will be produced in a production cell comprising a 2420-ton Battenfeld HM two-platen press and an ABB jointed-arm... 

Select steam traps for the following five types of equipment (1) where the steam directly heats solid materials, as in autoclaves, retorts, and sterilizers (2) where the steam indirectly heats a liquid through a metallic surface, as in heat exchangers and kettles where the quantity of liquid heated is known and unknown (3) where the steam indirectly heats a solid through a metallic surface, as in dryers using cylinders or chambers and platen presses and (4) where the steam indirectly heats air through metallic surfaces, as in unit heaters, pipe coils, and radiators. 

One component contained the isocyanate and epoxy resin, and the other component contained the polyols, chain extenders, catalysts, fillers, and plasticizers. The two components were then mixed together for 30 seconds (at room temperature) using a high speed mechanical stirrer at 2000 rpm. The mixture was then quickly poured into a pre-heated mold and pressed on a laboratory platen press at 100 C. The sample was removed from the press and demolded 30 minutes after it gelled. The gel time was approximately 3-6 minutes. The post curing condition was for 5 hours at 120 0. 

The blend was mixed for sixty seconds at room temperature (RT). It was poured Into a hot mold (100°C) and cured for 30 minutes at 100 C on a platen press under a pressure of approximately 2700 KPa. The elastomers were then post-cured In an oven at 100°C for 16 hours and conditioned at 25°C and SOX relative humidity for three days prior to testing. 

To avoid repetition of our company s trade name we will, in this chapter, use a generic name to describe the equipment and its process. We will call it the "Fluid Film Process". The fluid film process permits a high speed continuous treatment of sheet, strip, panel and billet material requiring cooling, heating, pressure confinement or shape and surface control. Many products presently manufactured in molds or platen presses can now be much more rapidly produced continuously on machinery incorporating fluid film processing. 

Fig. 8.92 Hand-operated hydraulic platen press with the pressing force acting from below (courtesy Carver, Wabash, IN, USA).

Polyethylene. The effect of crystallinity on the diffusion coefficient of iso-octane at 54°C in PE was determined in a sorption experiment. Films of Sclair PE (DuPont Chemical Co., Kingston, Ontario) were compression-molded in a hot platens press at 170°C and were allowed to cool in the press. All films were 200 /xm thick. The properties of the resins are given in Table II. 

Test materials were loaded into the heated barrel and compacted with the ram plunger. After 10 minutes dwell time, the charge was ejected onto a PET sheet and rapidly queneh cooled in a room temperature platen press. Two 20 gram shots were prepared for eaeh test formulation. After cooling, the plaque samples were cut by hand into 1x1 cm pieces and submitted for DCB analysis. 

The polyethylene films with various levels of carbon black were prepared by mixing various ratios of black polyethylene (0.2 percent C) with natural polyethylene (w/w) and pressing them between Kapton films in a platen press. The film was cut, re-stacked, and re-pressed about ten times. 

ANSI Standard B65.5-1996 Safety Standard-Stand Alone Platen Presses apphes to this press, which was manufactured in 1969. The standard requires that its provisions be applied immediately upon relocation of older equipment. This press was moved to this facihty about one year prior to this incident. It had not been upgraded. 

Pneumatic and hydraulic presses are excellent tools for applying constant pressure. Steam or electrically heated platen presses with hydrauUc rams are often used for adhesive bonding. Some units have multiple platens, thereby permitting the bonding of several assembUes at one time. Large bonded areas, such as on aircraft parts, are usually cured in an autoclave. The parts are first joined then covered with a rubber blanket to provide uniform pressure distribution. The entire assembly is then placed in an autoclave, which can he pressurized and heated. This method, which is widely used in the aerospace industry, requires capital-equipment. ""... 

Compression molding—the laminate is heated beyond its softening temperature using hot air or infrared and pressed into the required shape. A heated platen press can be used to initially heat the laminate. 

Platen pressing of carbon fiber/PEEK laminate... 

Platen press n. A press which prints a single sheet by pressing the latter against an entire frame or chase of type at the same moment. 

Heated platen presses are good for bonding flat or moderately contoured panels when faster cure cycles are desired. Platens are heated with steam, hot oil, or electricity and are easily adapted with cooling water connections to further speed the bonding cycle. 

Rotary/platen press cleaning involves minimal exposure to only a few chemicals kerosene for the steel cylinder and a blanket wash for the rubber rollers. An aqueous solution of sodium hydroxide is used to clean many parts of the gravure press, whilst a typical cleanup solution will contain n-propyl acetate and toluene. Since the computerised presses now used in many larger establishments require little direct attention, solvents, inks and rubber gloves are responsible for most cases of dermatitis. 

Composite fabrication. Test laminates were prepared by coating graphite cloth (8-harness satin weave cloth) designed as a style 133 fabric with a DMF solution of bis-maleimide E and drying the prepregs in an air oven at 160°C-170°C for 15 min. The dried prepregs (4 or 9 plies) were stacked and pressed between aluminum plates covered with a tetrafluoroethylene film. The resulting laminate was then cured in a flat platen press at 232°C at a pressure... 

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