PDF Publication Title:
Text from PDF Page: 021
voids were larger than those observed in previous laminates, and exhibited elongated ellipsoidal shapes. Increasing the room-temperature vacuum hold time from four hours to eight hours eliminated the voids. These defects can be attributed to the modified pressure distribution caused by the pressure strip. The fillets corresponded to the edge of the strip, which experienced a local and steep reduction in compaction pressure. The concentrated pressure caused by the strip could also possibly decrease the air permeability of the prepreg, reducing the rate of air evacuation and, for an equivalent ambient evacuation time, causing higher void contents. The longer room temperature vacuum hold allowed more time for the evacuation of entrapped air, and consequently decreased the void content. 4. Conclusions We investigated several aspects of the OoA manufacture of VBO prepreg laminates with corner geometries. First, concave and convex corner parts were manufactured for various corner angles and laminate thickness levels and from two prepreg materials. Polished sections revealed that for both concave and convex parts, defects were concentrated in corner regions, and increasing geometric complexity led to a reduction in quality. However, defects levels were always greater in concave laminates than in convex laminates. Microstructural data indicated that two different mechanisms caused the dimensional non-uniformities. For concave laminates, corner thickening was primarily associated with resin accumulation due to reduced compaction pressure and the inability of the fiber bed to conform to the geometry of the tooling. Conversely, in convex laminates, corner thinning was caused by uneven pressure distribution but counteracted by the stiffness of the fiber bed. The void content was primarily affected by the prepreg age, with the DOI: 10.1002/pc.23773 21PDF Image | Vacuum Bag-Only Prepregs
PDF Search Title:
Vacuum Bag-Only PrepregsOriginal File Name Searched:
J224.pdfDIY PDF Search: Google It | Yahoo | Bing
5,000 BF Shipping Container Lumber Dry Kiln For Quality Lumber The 5,000 BF container kiln consists of one 40 foot high-cube aluminum shipping container... More Info
Shipping Container Lumber Dry Kilns by Global Energy Global Energy designed and developed the container kiln back in 1991. The purpose is to give access to portable sawmill owners, furniture makers, and small business the value added profit of dry kiln lumber and quality hardwoods... More Info
Vacuum Kiln Conversion Kit for Lumber and Wood Dry Kilns Convert your existing conventional dry kiln into a fast drying vacuum kiln. Similar to vacuum bagging in the boat building and aircraft industry, we have come up with a proprietary process which allows you to build a very simple vacuum kiln at a fraction of the price, and without the intensive conventional metal chamber structure... More Info
Vacuum Pump Cart System for Bagging Clamping Wood Drying and more Vacuum Cart with 2HP Pump and Dual Pistons with multiple multiplex vacuum ports and liquid reservoir... More Info
Vacuum Bagging Basics Vacuum bagging is a method of clamping, which has traditionally been used in the composites industry, but can also be used for vacuum drying materials, including wood products... More Info
| CONTACT TEL: 608-238-6001 Email: greg@globalmicroturbine.com | RSS | AMP |