Layer-laminate process

Layer Laminate Processes Layer laminate manufacturing (LLM) is not frequently used for Prototype and Indirect Tooling. It does not deliver good surface qualities. Fine details should be avoided, as they tend to break. The parts need extensive post-processing. The build process is fast if massive parts are made. 

FIGURE 4.136 Layer-laminate process, on the example of laminated object manufacturing... 

Preferably components made from paper and plastic, but also metal and ceramics, can be manufactured with the layer laminate process. Sheet products can be pur-... 

Direct Tooling So-called lamellar molds are made from steel with the layer laminate processes. They quickly create volume, but must be machined due to the surfaces, and are also very limited in their complexity. For metal parts, spreading film will also be used without reworking. 

CAMLEM Layer Laminate Process (Metal, Ceramic) WWW. camlem. com... 

Cubic Technologies Layer Laminate Process WWW. cubictechnologies. com... 

Solidica Metal Layer Laminate Process www.solidica.com... 

The process can be used to recover scrap or low quaUty resins by using them as the core layer, and using outer layers of virgin resins designed for the specific functional needs of the product such as sHp or gloss and appearance. The inner core may be a foamed resin with surface layers of supedor finish resins. Coextmded films often eliminate the need for cosdy lamination processes. 

The evaluation of the load-carrying capacity of a specific laminate (including the load-deformation behavior) is a straightforward deterministic process and is described in Section 4.5. For example, a 20-layered laminate has a certain load-carrying capacity tor one type of loading (and a different capacity tor a different type of loading). 

Thus, any laminate may consist of plies selected from paper, polyester, numerous other plastic films, foils, coatings, adhesive layers, metalization, etc. The choice of laminate structure is usually governed by technical requirements, cost of base materials, cost of lamination processes, cost of printing cylinder and process, and the amount of laminate required (quantity), the yield from which the cost per area of laminate is derived. 

The texturing sheet may also contain a plastic coating that transfers to the laminate surface during the laminating process to provide special surface properties. The caul plate itself may be smooth or textured and act directly as the release. Immediately beneath this release sheet, there may be a decorative layer or a ply that imparts special properties such as a metallic foil for electrical conductivity or a static dissipating layer. If the decorative layer is a printed... 

Multi-layer films can be produced, composed of different polymers. For each polymer a separate extruder is applied the extruders discharge into an accumulator, in which the separate streams are guided to their own position in the film. A laminated film can thus be made, in which one of the layers provides the strength, another one acts as a gas barrier, other layers promote adhesion and weldability, etc. This laminating process is applied with flat film extrusion as well as with film blowing. 

In chapter 7, section 7.2.8 an example of permeation through a functional barrier is described. Three-layered coextruded PET films were produced in which the core layer (P) was contaminated with chlorobenzene and the outer barrier layers (B) were made with virgin material. During the coextrusion process a partial contamination of the virgin layer occurred. The symmetrical structure of this film leads to a simplified treatment of it as a two layer laminate with the thickness d = a + b = 160 + 40 = 200 pm. For the modeling of this problem with numerical mathematics all parameters given in Section 7.2.8 are used. 

One of the most often used production procedures for fabricating a high-performance structural laminate is the Autoclave/Vacuum Degassing (AC/VD) laminating process. In this process, individual prepreg plies are laid up in a prescribed orientation to form a laminate. The laminate is laid against a smooth tool surface and covered with successive layers of glass bleeder fabric, Mylar or Teflon sheets, and finally a vacuum... 

In a vacuum lamination process, the steeper the melt viscosity/temperature curve for sheet pottant material, the better. The layers need to be dry and non-tacky during the initial evacuation step so as not to trap air between them. At the same time, the pottant must then melt to as fluid a state as possible in order to effectively penetrate and wet all the irregularities of the cell circuit. 

---