Laminates compression molding

Important processing methods coating, injection molding, blending, compression molding, lamination, thermoforming... 

By means of compression molding, laminates were prepared from the commercially drawn LDPE/PET bristles. Their tensile strength is higher by about one order of magnitude than that of the compression or injection molded neat LDPE. 

PC/SAN blends have been found to exhibit maximal properties at 25-27 wt% AN. This was evidenced by the improvanent in lap shear adhesion of compression-molded laminated sheets of PC and SAN copolymers, and in tensile modulus and elongation at break, improved notched impact Izod strength, and inward shifts of the glass transition temperatures of PC and SAN blend components with respect to their homopolymer values. PC and SAN were found to be partially miscible. The 25-27 wt% AN was found close to the azeotropic composition of SAN. 

Methods of fabricating gears involve cutting/hobbing from processed blocks or sheet plastics, compression molding laminated (RP) material, or the most popular injection molding. Use is made of unfilled and... 

Manufacture of friction elements includes the impregnation of fabrics and subsequent lamination, the wet-dough process, and the dry-mix process. Elements from the last two are prepared by compression-molding the formulation for up to an hour at 150—175°C. Thick brake elements require a carefully controUed heating-and-cooHng cycle to minimize stresses created by expansion and contraction (see Brake linings and clutch facings Fillers). 

Phenolic resins Good acid resistance, good electrical properties (except arc resistance), high heat resistance Compression molding, continuous lamination... 

A thin molding of an acetylene-terminated phenylquinoxaline, fabricated by compression molding at 316°C for 26 hr and at 371°C for 5 hr, gave tensile strength of 103 MPa (15,000 psi), tensile modulus of 2.62 GPa (380,000 psi) and elongation of 5% (46). Preliminary unidirectional graphite fiber laminate properties are reported in Table VI. 

An important step in the manufacture of any plastic product is the fabrication or the shaping of the article. Most polymers used as plastics when manufactured are prepared in pellet form as they are expelled from the reactor. These are small pieces of material a couple of millimeters in size. This resin can then be heated and shaped by one of several methods. Thermoset materials are usually compression molded, cast, or laminated. Thermoplastic resins can be injection molded, extruded, or blow molded most commonly, with vacuum forming and calendering also used but to a lesser extent. 

The Li-Loos intimate contact model was verified for compression molded unidirectional graphite-polysulfone and graphite-PEEK (APC-2) laminae and graphite-PEEK (APC-2) cross-ply laminates. The degrees of intimate contact of the unidirectional and cross-ply specimens were measured by optical microscopy and scanning acoustic microscopy, respectively. The predicted degrees of intimate contact agreed well with the measured values for both the unidirectional and cross-ply specimens processed at different temperature and pressures. 

The intimate contact data shown in Figure 7.16 were obtained from three-ply, APC-2, [0°/90o/0o]7- cross-ply laminates that were compression molded in a 76.2 mm (3 in.) square steel mold. The degree of intimate contact of the ply interfaces was measured using scanning acoustic microscopy and image analysis software (Section 7.4). The surface characterization parameters for APC-2 Batch II prepreg in Table 7.2 and the zero-shear-rate viscosity for PEEK resin were input into the intimate contact model for the cross-ply interface. Additional details of the experimental procedures and the viscosity data for PEEK resin are given in Reference 22. 

Heat-cleaned fiberglass cloth was treated with 0.5% carboxysilane J (Table 1) and compression-molded into a laminate with nylon 6,6 polymer. Laminates were compared to state-of-the-art silane H. Table 9 shows that silane H provided a significant improvement in flexural strength over the control, expecially after a 2 h water boil, but a carboxysilane/zinc ion ionomer system gave an even better strength improvement. 

During the press operation, which is actually a form of compression molding, the resin-treated laminate plies are heated under pressure and the resins cured. The initial heating phases cause the resin to melt and flow into voids in the reinforcing ply and bond the individual plies together. The applied heat simultaneously causes the resin to polymerize and eventually to cross-link or gel. Therefore, resin viscosity reaches a minimum during the press cycle. This is the point at which the curing process becomes dominant over the melt flow process. Dynamic mechanical and dielectric analyses (11) are excellent tools for study of this behavior. 

Polystyrene, 20% by weight glass, 32% for fabric laminate, epoxy silane compression molded at 500°F. 

Acrylics Good gloss, weaiher resistance, optical clarity, and color excellent electrical properties injection molding Vacuum forming Compression molding Continuous laminating... 

Compression Molding Flexible Plunger Flexible Bag Molding Laminate Hand Lay-Up Vacuum Bag Molding Vacuum Bag Molding and Pressure Pressure Bag Molding Autoclave Molding Autoclave Press Clave Wet Lay-Up... 

Melt compression molding identifies in-mold laminating and in-line molding of carriers, decorations, etc. The basic technique has been used for over a century. There has been an increased application of textile cover stock and leather substitutes both preferably with a soft touch. This type development was primarily initiated by the automotive industry with the objective to be prepared for future trends. Other industries such as furniture and packaging manufacturers use this process. 

Also used is the injection-compression cycle where after a preforming stroke for the cover stock, the carrier material is injected in a partially open mold (Chapter 4). By closing the gap the part is formed and laminated. The mold corresponds to a back injection mold. The method has similarities with melt flow compression molding. 

Back compression is a process based on compression molding (Chapter 14) of a melt strip deposited in an open mold. It describes the process during which a cover stock cutting is placed on a melt strip for simultaneous compression molding and lamination of parts. Melt strip deposition also includes fiber reinforced thermoplastic stock with subsequent compression molding of non-laminated structural parts. 

Schematic diagrams of (top) stacked dried PF resin-soaked kraft paper (brown) plus a metal foil (optional), a pattern or veneer sheet (red) and a translucent sheet (blue) (middle) compression molding between highly pol-ished heavy steel platens under high temperature and pressure (bottom) a sheet of Formica laminate.

Laminate panels were fabricated by means of compression molding in its molten state from a sheet of pre-forming by lay-up of sixth plys before and after thermo-chemical treatment and EB irradiation, respectively. 

Type 5 For flat injection molded or compression molded thin sheets materials. Glass fiber reinforced laminates. 

The interfacial adhesion effect of the HB PAMAMs on fibers in epoxy composite systems was investigated with laminates prepared by compression molding. 

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