Browse Prior Art Database

Off- and On-Line Control for Drying Epoxy Resin Impregnated Glass Fabrics

IP.com Disclosure Number: IPCOM000041602D
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Poetsch, H: AUTHOR

Abstract

According to Fig. 1, a pretreated glass fabric web 1 is impregnated with epoxy resin in a bath 2. The web then passes through a drying tower 3 with constant temperature zones and is wound up on a drum 4. The drying process serves to ensure a substantially constant degree of polymerization or a predetermined flow. The time the web is inside the drying tower is controlled as a function of the transfer speed. To rapidly control the transfer speed, the loss angle tan w of the web dielectric is determined by a frequency scanning method for selected isothermal measuring temperatures T (T1, T2, T3 or Tx). T depends on the material behavior required. At a given isothermal measuring temperature T, the frequencies in tan w max are proportional to the transfer speeds V (V1, V2, Vg, ... Vd, Fig. 3).

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Off- and On-Line Control for Drying Epoxy Resin Impregnated Glass Fabrics

According to Fig. 1, a pretreated glass fabric web 1 is impregnated with epoxy resin in a bath 2. The web then passes through a drying tower 3 with constant temperature zones and is wound up on a drum 4. The drying process serves to ensure a substantially constant degree of polymerization or a predetermined flow. The time the web is inside the drying tower is controlled as a function of the transfer speed. To rapidly control the transfer speed, the loss angle tan w of the web dielectric is determined by a frequency scanning method for selected isothermal measuring temperatures T (T1, T2, T3 or Tx). T depends on the material behavior required. At a given isothermal measuring temperature T, the frequencies in tan w max are proportional to the transfer speeds V (V1, V2, Vg,
... Vd, Fig. 3). As a result, changes in the consistency of the epoxy resin need not be considered, and long waiting periods, incurred by determining the loss angle of the web dielectric, are avoided. The aforementioned values are used to compute a material related family of curves (Fig. 3) for the curve maxima Pmaxl and Pmax2, etc. (Fig. 2). For such a family of curves, the transfer speed is proportional to the degree of polymerization. It is known that materials of the same consistency may require different transfer speeds to obtain a particular degree of polymerization or flow. For a particular material and a particular temperature, say, T2, the transfer speed is determined at Vg (corresponding to curve maximum Pmax1 in Fig. 2), using a given frequency value, say, fg. The curve data (Fig. 3) are stored in a compu...