Laminates definition

Aesthetic properties are of greatest concern in decorative laminates. These include gloss, appearance, cleanabiUty, wear resistance, stain resistance, and other surface properties. Physical properties are of most importance for industrial laminates. These include strength, electrical and thermal properties, expansion coefficient, and punchabiUty. The definitions of the laminate grades in these standards foUow. 

The stress-strain relations in arbitrary in-plane coordinates, namely Equation (4.5), are useful in the definition of the laminate stiffnesses because of the arbitrary orientation of the constituent laminae. Both Equations (4.4) and (4.5) can be thought of as stress-strain relations for the k layer of a multilayered laminate. Thus, Equation (4.5) can be written as... 

Knowledge of the variation of stress and strain through the laminate thickness is essential to the definition of the extensional and bending stiffnesses of a laminate. The laminate is presumed to consist of per-... 

The term quasi-isotropic iaminate is used to describe laminates that have isotropic extensionai stiffnesses (the same in all directions in the plane of the laminate). As background to the definition, recall that the term isotropy is a material property whereas laminate stiffnesses are a function of both material properties and geometry. Note also that the prefix quasi means in a sense or manner. Thus, a quasi-isotropic laminate must mean a laminate that, in some sense, appears isotropic, but is not actually isotropic in all senses. In this case, a quasi-isotropic... 

Although the word balanced is ambiguous and not definitive, the common meaning for a balanced laminate is a laminate in which all equal-thickness laminae at angles 0 other than 0° and 90° to the reference axis occur only in 0 pairs. The individual -n O and - 0 layers are not necessarily adjacent to each other. Note also that balanced laminates are required to be symmetric about the laminate middle surface, so there must be two + Q laminae and two - 0 laminae for each 0 pair. The behavioral characteristics of a balanced laminate are that shear-... 

The basic nature of composite materials was introduced in Chapter 1. An overall classification scheme was presented, and the mechanical behavior aspects of composite materials that differ from those of conventional materials were described in a qualitative fashion. The book was then restricted to laminated fiber-reinforced composite mafeffals. The basic definitions and how such materials are made were then treated. Finally, the current and potential advantages of composite materials were discussed along with some case histories that clearly reveal how composite materials are used in structures. 

The effect of the specific values of the B j can be readily calculated for some simple laminates and can be calculated without significant difficulty for many more complex laminates. The influence of bending-extension coupling can be evaluated by use of the reduced bending stiffness approximation suggested by Ashton [7-20]. If you examine the matrix manipulations for the inversion of the force-strain-curvature and moment-strain-curvature relations (see Section 4.4), you will find a definition that relates to the reduced bending stiffness approximation. You will find that you could use as the bending stiffness of the entire structure,... 

Reinforced plastics (RPs) hold a special place in the design and manufacturing industry because they are unique materials (Figs. 6-11 and 6-12). During the 1940s, RPs (or low-pressure laminates, as they were then commonly known) was easy to identify. The basic definition then, as now, is simply that of a plastic reinforced with either a fibrous or nonfibrous material. TSs such as polyester (Table 6-19) and E-glass fiber dominated and still dominates the field. Also used are epoxies. 

Sheets of a substrate that have been impregnated with a curable polymer, curable polymers, or liquid reactants, or a thermoplastic, and are ready for fabrication of laminates. Note 1 See Definition 1.16 notes 2 and 3. 

A definition of high-pressure laminate ( HPL ) is given in BS EN 438 19911 as follows ... 

The British Standard for decorative continuous laminate ( DCL ) is BS 7332 1990,3 which gives the following definition ... 

On the other hand, the resistance of laminates with printed decor papers depends very much on the substance weight of the overlay paper used to protect the ink layers. There is a tendency, unfortunately, for an overlay to impair the definition of print and brightness of colour—which can be undesirable, or, particularly with more exotic designs such as metallized and pearlescent effects, even unacceptable. 

Figure 2 Definition of parameters for the lamination of N prepreg layers.

Many characterized INM proteins have been shown to interact with lamins (Ye et al. 1998). For the subset of putative NETs that share this characteristic, a more definite result can be achieved. As previously discussed, the lamin polymer is insoluble to extraction with detergent and salt therefore retention of NETs in cells extracted with detergent (e.g. 0.5% Triton X-100) prior to fixation for microscopy confirms their direct, or indirect, association with the lamin polymer and NE localization. However, loss of the protein to a pre-extraction with detergent would occur for proteins not tethered to the lamin polymer whether they are normally localized to the INM, ONM, or ER. All eight of the putative NETs originally tested targeted to the NE, but only five remained at the NE after the detergent pre-extraction (Schirmer et al. 2003). 

This section is devoted to the definition of the vessel dimension as long as the material properties. Typically, the dimension of the prototypes which are mannfactnred in onr Laboratory is a 1 litre bottle of 250 mm long for a 75.3 mm inside diameter. The thickness of the aluminium liner is 1.85 mm and the thickness of each layer of the laminate is 0.27 mm. The stacking sequence of the laminate is the following [+30] + [+50]4 + [90]3. This sequence means the liner is reinforced with 13 layers of composite 2 layers with a 30° angle, 8 layers with a 50° angle and finally 3 layers with a circumferential winding. 

The comparison of the different initiation points in the three laminate types (Tables 2-4) raises the question which definition shall be used for initiation in the cross-ply laminates. Since visual initiation (VTS-point) and probably also non-linearity of the load-displacement plot (NL-point) yield values similar to initiation values in the corresponding unidirectional laminate, the maximum load or 5% offset in compliance (MAX/5%-point) seems to reflect the higher delamination resistance of cross-ply compared with unidirectional laminates better. Further analysis of additional data from the 3" round robin may allow a better assessment of this question. 

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