Manufacturing Methods
Transparent Laminate Lay-up Procedure(s)
The laminate lay-up process:
- Gather all of the components to be incorporated into the laminate.
- Clean all of the components to be incorporated into the laminate.
- Glass
- Glass edges should have a smooth seamed or ground edge. Avoid using glass with edge chips, shell chips or coarse seamed edges as they have a tendency to create runs in the glass.
- Wash the glass.
- Glass should be washed in accordance with industry standards. If hand washing is necessary, use a detergent solution that does not contain silicone wetting agents. Glass priming is not normally considered necessary when using adhesion enhanced interlayers. If glass surface priming is desired, contact the Thermedics™ Polymer Products group for more information.
- Polycarbonate Sheet
- Use ONLY saw cut edges for laminating.
- Inspect the masking for defects. If defects are apparent, do NOT use the sheet.
- Remove the masking from the polycarbonate sheet (unless the intended laminate is a no-spall configuration). If so wait to unmask the polycarbonate sheet (coated side) until you are ready to apply it to the assembly.
- If a polycarbonate sheet requires cleaning, consult the manufacturer's literature for information or use a 50/50 solution of isopropanol and water. Lightly mist the solution onto the polycarbonate surface, and then very gently wipe the surface clean and dry.
- If scratch and abrasion resistant coated sheet is to be used, leave the polyethylene masking on throughout the lamination.
- Acrylic Sheet
- Consult the acrylic sheet manufacturer's information prior to use.
Note: The lamination temperature of Tecoflex® polyurethane to acrylic must exceed 225°F (107°C) to acquire acceptable adhesion. Contact the Thermedics Polymer Products group for further information.
Begin the lay-up:
Step 1: Lay the initial piece of glass or polycarbonate horizontally.
Step 2: Apply the first layer of Tecoflex polyurethane interlayer covering the glass or polycarbonate sheet.
Step 3: Ensure there is enough interlayer coverage beyond the edge of the glass or polycarbonate to allow for trimming. Trim the edge 1/16" (1.5mm) to 1/8" (3mm) from the edge of the glass and/or polycarbonate.
Step 4: Continue this process until the intended composition of the laminate has been achieved.
- Polycarbonate as a no spall surface:
- If scratch and abrasion resistant coated sheet is to be used, leave the polyethylene masking (coating side) on throughout the lamination.
Note:If the masking has been removed, use in its place the red polyethylene interleaving which comes wound on rolls of Tecoflex® polyurethane interlayer. Ensure that the polyethylene film is smooth against the surface and there are no wrinkles. The polyethylene film can be easily removed after the laminate has returned to room temperature and will absorb small fiber-like contaminants rather than pressing them into the polycarbonate sheet.
- Press Plates:
- Press plates can consist of either glass or high density polyethylene. If glass is used it must be at least 1/4" (6mm) to 1/2" (12mm) thick. Thicker glass has sufficient strength to withstand thepressures of vacuum bagging and autoclaving.
Flat Line Laminating Process Troubleshooting Information
| Problem |
Solution |
| Interlayer bubbles around the edges |
-The oven ambient temperature is too high…
-Oven elements are too hot at the side(s) of the laminate… |
| The trailing edge of the glass separates from the laminate as it passes through the press |
The press roll gap is too tight (close)…increase the press roll gap opening |
| The trailing edge of the laminate exhibits a large amount of air entrapment |
The press roll gap is too tight (close)…adjust the press roll gap opening |
| There are "blow-ins" around the laminate after autoclaving |
Tacking temperature is too low…increase the oven ambient temperature |
Flat Line Laminating Process Information (symmetrical)
Process Description: Estane® AG8451 and AG8320 are polymers designed for lamination in both vacuum bag and flat line laminating processes. Various types of heat sources, whether gas or electric (convection or IR) can be optimized for polyurethane flat laminations.
Limitations: Experience has shown that glass/polycarbonate laminations via flat-line process may have size and thickness limitations. Although every process differs, these limitations may/may not apply. Typically the maximum thickness should not exceed 1" (25.40mm) and the maximum overall dimensions should not exceed 12-ft2 (1.12 m2).
Flat-Line Initial set-up Parameters: The conveyor line speed should not exceed 39.3" (1 m) per minute, through the oven, to begin. Oven ambient temperature should be initially established at 350°F (177°C). The initial press roll gap set should be approximately .040" – .080" (1 mm – 2mm) less than the nominal thickness of the laminate, as measured by the operator.
Flat-Line Laminate Positioning: Position the laminate on the line diagonally (approximately 5° from parallel).
Exit Temperatures: The surface temperature of a laminate as it exits the final press roll should be 155°F – 175°F (68°C – 79°C) and have a clear area around the outside edge of the laminate as observed through the surface. Note: The lamination temperature of Tecoflex to acrylic must exceed 225°F (107°C) to acquire acceptable adhesion.
The information contained herein to the best of our knowledge and belief, is accurate. Since the conditions of handling and of use are beyond our control, we make no guarantee of results and assume no liability for damages incurred by following these suggestions. Nothing contained herein is to be construed as a recommendation for use in violation of any patents or of applicable laws of regulations.