DE839715C - Hardening of synthetic resin laminate workpieces - Google Patents

Description

(WlGBL p. 175)

ISSUED MAY 23, 1952

A 4703 XII / 39 a

Hans Cropp, Ingolstadt

has been named as the inventor

Auto-Union G.m.b.H., Ingolstadt

Patent application published September 27, 1951

Patent issued April 10, 1952

The heating of the dies for laminates generally causes considerable difficulties, when it comes down to short cycle times in flow production, because the Workpieces require up to 15 minutes to harden. The shortening of this time is with the Heat can only be supplied with difficulty from the outside, since heat is released from the workpiece to the workpiece Heat storage capacity of the tool and the possibility of heat supply depends. the Temperature must not rise above the hardening temperature, so that on the way of External heat supply makes the curing time difficult to shorten.

It is known to dielectrically preheat synthetic resin blanks outside of the tool, the blanks then to be introduced into the actual tool and finished with additional heat input from the outside to press.

A shorter curing time than with oven or ao press curing is also achieved by the known method achieved by hardening in a high frequency field.

The invention makes use of the simultaneous use of both methods, namely by Heat supply from the outside and by heating from the inside out with dielectric heat.

In this way, the curing time is reduced quite significantly, since the now at the same time of The heat acting inside and outside brings the workpiece to the desired temperature all of a sudden brings.

After a further development of the method, the workpiece is used for particularly difficult pieces in the tool through the supply of heat from the outside

pre-dried before the dielectric heat in addition is applied.

Claims (2)

PATENT CLAIMS: I. Hardening of synthetic resin laminate workpieces by heat, characterized through the simultaneous use of the two hardening processes known per se, namely by supplying heat from the outside and by heating, from the inside out with dielectric Warmth. 2. The method according to claim i, characterized in that that the workpiece is pre-dried in the tool by conventional heating before the dielectric heat is additionally applied will. Attached publications: K. Fabel »German Yearbook for Industry der plastischen Massen 1945/1950 «, p. 87, last paragraph; Swiss Patent No. 256 044. 5020 5.