Compression Moulding is a method of moulding in which the moulding material, generally preheated, is first placed in an open, heated mould cavity. The mould is closed with a top force or plug member, pressure is applied to force the material into contact with all mould areas, while heat and pressure are maintained until the moulding material has cured. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or preforms. In compression molding there are six important considerations that an engineer should bear in mind:

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  • Compression Moulding is a method of moulding in which the moulding material, generally preheated, is first placed in an open, heated mould cavity. The mould is closed with a top force or plug member, pressure is applied to force the material into contact with all mould areas, while heat and pressure are maintained until the moulding material has cured. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or preforms. Compression molding is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements. Advanced composite thermoplastics can also be compression molded with unidirectional tapes, woven fabrics, randomly oriented fiber mat or chopped strand. The advantage of compression molding is its ability to mold large, fairly intricate parts. Also, it is one of the lowest cost molding methods compared with other methods such as transfer molding and injection molding; moreover it wastes relatively little material, giving it an advantage when working with expensive compounds. However, compression molding often provides poor product consistency and difficulty in controlling flashing, and it is not suitable for some types of parts. Fewer knit lines are produced and a smaller amount of fiber-length degradation is noticeable when compared to injection molding. Compression-molding is also suitable for ultra-large basic shape production in sizes beyond the capacity of extrusion techniques. Materials that are typically manufactured through compression molding include: Polyester fiberglass resin systems (SMC/BMC), Torlon, Vespel, Poly(p-phenylene sulfide) (PPS), and many grades of PEEK. Compression molding is commonly utilized by product development engineers seeking cost effective rubber and silicone parts. Manufacturers of low volume compression molded components include , 3D, STYS, and Aero MFG. Compression molding was first developed to manufacture composite parts for metal replacement applications, compression molding is typically used to make larger flat or moderately curved parts. This method of molding is greatly used in manufacturing automotive parts such as hoods, fenders, scoops, spoilers, as well as smaller more intricate parts. The material to be molded is positioned in the mold cavity and the heated platens are closed by a hydraulic ram. Bulk molding compound (BMC) or sheet molding compound (SMC), are conformed to the mold form by the applied pressure and heated until the curing reaction occurs. SMC feed material usually is cut to conform to the surface area of the mold. The mold is then cooled and the part removed. Mold and material behavior vary based on material types. New I-PRESS Servo Hydraulic technology provides end users with a greater degree of flexibility with press movement & pressure profiles and control of external devices such as automation to platen zone temperature control. With the latest of electronic servo motor to high pressure hydraulic pump users save considerable energy and the greatest in speed, distance, pressure, dwell time and burping movements. Materials may be loaded into the mold either in the form of pellets or sheet, or the mold may be loaded from a plasticating extruder. Materials are heated above their melting points, formed and cooled. The more evenly the feed material is distributed over the mold surface, the less flow orientation occurs during the compression stage. Compression molding is also widely used to produce sandwich structures that incorporate a core material such as a honeycomb or polymer foam. Thermoplastic matrices are commonplace in mass production industries. One significant example are automotive applications where the leading technologies are long fibre reinforced thermoplastics (LFT) and glass fiber mat reinforced thermoplastics (GMT). In compression molding there are six important considerations that an engineer should bear in mind: * Determining the proper amount of material. * Determining the minimum amount of energy required to heat the material. * Determining the minimum time required to heat the material. * Determining the appropriate heating technique. * Predicting the required force, to ensure that shot attains the proper shape. * Designing the mold for rapid cooling after the material has been compressed into the mold. (en)
  • El moldeo por compresión es un proceso de conformado de piezas en el que el material, generalmente un polímero, es introducido en un molde abierto al que luego se le aplica presión para que el material adopte la forma del molde y calor para que el material reticule y adopte definitivamente la forma deseada. En algunos casos la reticulación es acelerada añadiendo reactivos químicos, por ejemplo peróxidos. Se habla entonces de moldeo por compresión con reacción química. También se utiliza este proceso con materiales compuestos, por ejemplo plásticos reforzados con fibra de vidrio. En este caso el material no reticula sino que adopta una forma fija gracias a la orientación imprimida a las fibras durante la compresión. El moldeo por compresión se utiliza en forma común para procesar compuesto de madera y plástico, obteniendo un material económico y durable que generalmente se usa en techos, pisos y perfiles en diseño de jardines.El moldeo por compresión es el método menos utilizado en obtención de piezas. (es)
  • Formpressen ist ein Herstellungsverfahren für Kunststoffe, geeignet für leicht gewölbte oder flache Bauteile. Haupteinsatzgebiet dieses Verfahrens ist die Automobilindustrie, wo es zur Produktion größerer Bauteile mit zweidimensionaler oder einfacher dreidimensionaler Struktur, wie zum Beispiel Motorhauben, Stoßfängern, Spoilern oder Heckklappen eingesetzt wird. Es können sowohl duroplastische als auch thermoplastische Kunststoffe verarbeitet werden. Zu Beginn des Verfahrens wird die Formmasse in die Kavität eingebracht, welche aufgeheizt wird. Anschließend wird die Kavität unter Einsatz eines Druckkolbens geschlossen. Durch den Druck erlangt die Formmasse die vom Werkzeug vorgegebene Form. Bei duroplastischen Kunststoffen dient die Temperatur zur Beeinflussung des Aushärtevorgangs, bei Thermoplasten zum Schmelzen des Kunststoffs. Nach dem Abkühlen kann das fertige Teil aus dem Formwerkzeug entnommen und ggf. nach- oder weiterverarbeitet werden. Das Formpress-Verfahren eignet sich vor allem für mittelgroße Stückzahlen, da die Werkzeugkosten in der Regel geringer sind als zum Beispiel beim Spritzgiessen. Das Formpressen kann auch zur Herstellung von Faserverbundwerkstoffen eingesetzt werden, u. a. zur Herstellung von naturfaserverstärkten Kunststoffen. (de)
  • Le moulage par compression est un procédé de mise en forme par moulage de pièces en matériaux plastiques ou composites. Ces matériaux peuvent être à base des thermoplastiques et surtout des thermodurcissables. (fr)
  • Lo stampaggio a compressione consiste nella vulcanizzazione della gomma per mezzo di uno stampo in modo da conferirle una forma definitiva. Lo stampo, generalmente in alluminio o acciaio, riproduce la forma finale del manufatto da ottenere ed è suddiviso in due o più parti, a seconda della complessità del manufatto, in modo da permetterne l'estrazione a fine stampaggio. La pressa su cui è fissato lo stampo permette di aprirlo e chiuderlo con una pressione variabile da poche decine di tonnellate fino a oltre 800 tonnellate, a seconda della dimensione dello stampo stesso. La pressa inoltre permette, tramite pianali riscaldati elettricamente e termocontrollati, di mantenere lo stampo alla temperatura adatta allo stampaggio dell'elastomero che si sta processando, generalmente da 150 °C a 170 °C. La gomma da processare deve essere prima preparata: generalmente calandrata in lastre dello spessore adatto e successivamente tagliata in pezzetti delle misure e del peso voluto, oppure prima estrusa in tondi o altre forme e successivamente sempre tagliata alla misura e al peso adatto. Lo stampaggio a compressione consiste nel posizionare la gomma preparata, della opportuna forma e peso, all'interno dello stampo riscaldato e aperto, e solo successivamente chiuso in pressione per un tempo sufficiente a permettere la vulcanizzazione della gomma nella sua nuova e definitiva forma. Il manufatto generalmente è estratto manualmente e presenta sempre, in corrispondenza della chiusura dello stampo, una bava anche consistente che deve essere asportata dall'operatore. Differisce dallo stampaggio ad iniezione in quanto in quest'ultimo metodo la gomma viene iniettata calda, tramite un estrusore, direttamente all'interno dello stampo già chiuso e in pressione. Il manufatto generalmente viene estratto automaticamente e anche la sbavatura, se necessaria, viene eseguita in modo totalmente automatizzato. Le presse, anche se simili, sono prodotte specificatamente per le due tipologie di stampaggio. Lo stampaggio a compressione è molto flessibile e permette più facilmente di inglobare nel manufatto inserti tipo quelli tessili, e permette di processare elastomeri dalle caratteristiche superiori ma difficilmente processabili ad iniezione; è sicuramente più adatto per produzioni piccole e medie.Lo stampaggio ad iniezione invece garantisce l'uniformità, anche estetica, dei manufatti e consente tempi di produzione più bassi col conseguente vantaggio economico; è sicuramente più adatto per produzioni medioalte e alte a causa del maggior tempo necessario per l'approntamento della pressa e del maggior tempo richiesto per l'ammortamento del costo dello stampo. (it)
  • Formpressning är en metod för formning av till exempel keramiska produkter, trä, textil eller härdplaster. Vid formpressningen används både värme och tryck för att forma en produkt eller mönster med hjälp av ett formverktyg. (sv)
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  • February 2020 (en)
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  • Le moulage par compression est un procédé de mise en forme par moulage de pièces en matériaux plastiques ou composites. Ces matériaux peuvent être à base des thermoplastiques et surtout des thermodurcissables. (fr)
  • Formpressning är en metod för formning av till exempel keramiska produkter, trä, textil eller härdplaster. Vid formpressningen används både värme och tryck för att forma en produkt eller mönster med hjälp av ett formverktyg. (sv)
  • Formpressen ist ein Herstellungsverfahren für Kunststoffe, geeignet für leicht gewölbte oder flache Bauteile. Haupteinsatzgebiet dieses Verfahrens ist die Automobilindustrie, wo es zur Produktion größerer Bauteile mit zweidimensionaler oder einfacher dreidimensionaler Struktur, wie zum Beispiel Motorhauben, Stoßfängern, Spoilern oder Heckklappen eingesetzt wird. Es können sowohl duroplastische als auch thermoplastische Kunststoffe verarbeitet werden. (de)
  • Compression Moulding is a method of moulding in which the moulding material, generally preheated, is first placed in an open, heated mould cavity. The mould is closed with a top force or plug member, pressure is applied to force the material into contact with all mould areas, while heat and pressure are maintained until the moulding material has cured. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or preforms. In compression molding there are six important considerations that an engineer should bear in mind: (en)
  • El moldeo por compresión es un proceso de conformado de piezas en el que el material, generalmente un polímero, es introducido en un molde abierto al que luego se le aplica presión para que el material adopte la forma del molde y calor para que el material reticule y adopte definitivamente la forma deseada. En algunos casos la reticulación es acelerada añadiendo reactivos químicos, por ejemplo peróxidos. Se habla entonces de moldeo por compresión con reacción química. (es)
  • Lo stampaggio a compressione consiste nella vulcanizzazione della gomma per mezzo di uno stampo in modo da conferirle una forma definitiva. Lo stampo, generalmente in alluminio o acciaio, riproduce la forma finale del manufatto da ottenere ed è suddiviso in due o più parti, a seconda della complessità del manufatto, in modo da permetterne l'estrazione a fine stampaggio. (it)
rdfs:label
  • Formpressen (de)
  • Compression molding (en)
  • Moldeo por compresión (es)
  • Moulage par compression (fr)
  • Stampaggio a compressione (it)
  • Formpressning (sv)
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