Laminates Constructions

TABLE 25-20 Dual-Laminate Construction and Lining Properties... 

The methodology presented is generic and can be applied to other types of materials, laminate constructions, and processing methods. In all cases a characterization of the cure state is needed first. As a result, models must be developed to predict the mechanical response as a function of the cure state. Mechanics models can then be developed for the specific application of interest. 

Fig. 8. Flexural properties at elevated temperatures. Laminates constructed from alternating plies of 46.7-g (1.5-oz) mat and 746-g/m2 (24-oz/yd2) woven roving at a nominal glass content of 45%. A represents bisphenol fumarate (Tg = 130° C) B, novolak epoxy methacrylate ( T = 130° C) C, epoxy dimethacrylate (Tg = 100° C) D, isophthalic resin (Tg = 100° C) and E, 0/ 0-phthalic resin (Tg = 80° C).

A composite, flexible package in broad use throughout much of the world today is the aseptic Tetra Brik a rectangular package of laminate construction containing six or seven components with paper as the primary one. Juices are distributed and retailed in parts of Europe, Asia, South aid North America in 200-and 250-ml and in 1-liter Tetra Brik packages, normally at ambient temperature. 

The laminate construction in FRP parts can have an effect on flame spread and smoke test results. A study was conducted by Stevens15 and published in the proceedings of Composites 2007 conference. This study looked at how glass fiber content and panel thickness affected the ASTM E-84 flame spread index (FSI) and smoke developed index (SDI). The effects of fiber content and thickness on cone calorimeter results were also evaluated. Another study was conducted by Dempsey16 looking at the effect of glass content in several fire tests, and in this paper, he also found a correlation between the FR performance and glass content. 

Two resins were used to do the first study on laminate construction. The first was a brominated epoxy vinyl ester resin with antimony pentoxide and the second was a brominated unsaturated polyester resin. They were both promoted to cure at room temperature with methyl ethyl ketone peroxide catalyst. The panels were then postcured at 250°F (121°C) for 8 h. Panels were prepared that varied in glass content from 25% to 70% and panel thickness varying from 0.05 in. to 0.25 in. and were tested at the same testing facility. A summary of the FSI test data for the first set of panels tested are shown in Figures 23.1 and 23.2. This graph in Figure 23.1 plots the FSI value versus the panel thickness. This data would indicate that the thickness of the test panel has no effect on the measured... 

Stevens, M., How does laminate construction affect fire performance of FRP composites, Proceedings of Composites and Polycon, Tampa, FL, October, 2007. 

Indirect tooling methods are many. Examples include cast aluminum, investment metal cast, cast plastics, cast kirksite, sprayed steel, spin-castings, plaster casting, electroforming, room temperature vulcanizing (RTV) silicone elastomer (Chapter 2 Silicone Elastomer), elastomer/ rubber, reaction injection, stereolithography,338 344 (Table 17.4), direct metal laser sintering, and laminate construction. 

In the last decade several novel types of gas-filled polymers appeared which belong to the second generation integral (structural) plastic foams syntactic foams reinforced polymer foams multilayer foams (foamed laminates), metallized plastic foams mineral and metallic foamed materials obtained on the basis of foamed polymers laminated constructions on the basis of foamed polymers and monolithic (unfoamed) plastics, metals, paper, leather, etc. 

The rapid decrease of emission in one of the floorings seems to be due to the hardening of the acid curing laquer layer and not to the ageing of the UF-resin in the laminated construction. Acknowledgment... 

Laminates constructed from 12 plies of Style 7628, 1-399 finish glass cloth prepreg press cured one hour at 350°F. and 150 psi were tested versus NEMA FR-4 specification limits. Results are listed... 

The principle of dual laminate construction is to line an FRP vessel or column with a fluoropolymer lining. However, the sequence of construction is to first make the liner out of fabric-backed sheets the same as in the adhesively bonded construction. The FRP structure is then laminated on the liner to pro-... 

Figure 8.22 Machine butt welding of fluoropolymer prior to dual laminate construction. (Courtesy CPF Dualam, Montreal, Canada.)...

Figure 8.24 Supply chain and Job sequence for dual laminate construction.

Nesting Also called nested cloth. Placing plies of fabric so that the fibers of one ply lie in the valleys between the fibers of the adjacent ply developing laminated constructions... 

In industry, for almost a century these laminates are used for their electrical properties, impact strength, wearing qualities, chemical resistance, decorative panels, or other characteristics depending on laminate construction used with or without a surfacing material. They are used for printed circuit boards, electrical insulation, decorative... 

Table 6.5 Mechanical properties of various laminate constructions...

A chlorofluoroethylene also possesses excellent chemical resistance to almost all acids and alkalies at temperatures up to about 176.66°C (350°F). It too is difficult to bond to itself and other materials, but the use of tape-bonded laminated construction has widened the use of the material. It can be extruded readily and so is available in the form of solid pipe and also as a lining material for steel pipe. 

A widely used method of laminate construction is by the contact moulding process or hand lay-up . In this, a layer of catalysed unreinforced resin, known as the gelcoat , is brushed or sprayed onto the mould and allowed to cure and then layers of reinforcing-fibre impregnated with resin are built up behind (Fig. 6.3). Variations of this include resin injection and vacuum-assisted resin injection in closed moulds. After removal of the cured moulding from the mould, the gelcoat forms the outer skin and as such performs the two functions of decoration and protection ... 

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