1、 FORD LABORATORY TEST METHOD BO 007-01 Date Action Revisions 2000 11 09 Revised Editorial no technical change A. Cockman 1992 07 13 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Technologies, Inc. SOFTENING POINT OF RESINS - BAR-BRUSH METHOD Application This procedure is us
2、ed to determine the softening point of resins used in the shell molding process. Apparatus Required Dennis Parr Melting Point Apparatus This apparatus, shown in the attached sketch, consists of a silver plated copper bar 1 inch square and 17 inches long. A temperature gradient is established along t
3、he entire length of the bar by means of a cartridge type electric heater in an aluminum block and an adjustable thermoregulator. The operating range of the instrument is 0 - 482 F. A sliding contact copper Constantan thermocouple is connected to a calibrated potentiometer to indicate the temperature
4、 at any point on the bar. Shown in the illustration but not supplied with the ap paratus is a brush - holding fixture which bridges the thermal gradient bar and enables the operator to brush the resin from the bar with a uniform pressure. Also shown is a hopper with a U.S. Standard #80 mesh screen a
5、cross the bottom. The hopper is used to distribute the resin uniformly over the thermal gradient bar. The hopper has the following approximate dimensions: Bottom - 1 1/16 inches wide x 10 inches long; top - 5 inches wide x 14 inches long; height - 5 1/2 inches; screen - approximately 1 inch from the
6、 lowest part of the hopper. Both the brush fixture and hopper must be fabricated as these items are not manufactured. Source: Central Scientific Co. Melting Point Apparatus - Catalog No. 23111 Potentiometer - Catalog No. 23114 Brush A soft, ca mel hair brush 1/4 inch in diameter and cut flat across
7、the bottom is used for dusting the unattached resin from the thermal gradient bar. The brush is inserted in the brush fixture as shown so that the end of the brush is 1/8 inch below the heated bar. Stop Watch A stop watch or timing device is required. FORD LABORATORY TEST METHOD BO 007-01 Page 2 of
8、3 Copyright 2000, For d Global Technologies, Inc. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/ - 2 C and 50 +/ - 5 % relative humidity for not less than 24 h p rior to testing and tested under the same conditi
9、ons unless otherwise specified. Procedure 1. Regulate the temperature of the thermal gradient bar to cover the softening point range (203 - 221 F for M4R34 resin) of the resin to be tested and allow to c ome to equilibrium. 2. Place the hopper over the thermal gradient bar so that it covers the soft
10、ening point range of the resin under test. Pour a sample of the resin over the screen in the hopper, wipe across the screen twice with the end of a spatula to dislodge an even coating of resin on the bar, remove the hopper and start the stop watch. 3. At the end of one minute, begin brushing the res
11、in from the bar, starting at the cool end. Move the brush fixture along the length of the bar while brushing twi ce over each area covered by the width of the brush. The sliding brushing action should be done as uniformly and rapidly as possible until that point on the bar is reached where the resin
12、 adheres. 4. Move the sliding contact thermocouple to the point where the resin sticks to the thermal gradient bar and read the temperature on the potentiometer. This temperature is reported as the softening point of the resin. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BO 007-01 Page 3 of 3 Copyright 2000, For d Global Technologies, Inc. MELTING POINT APPARATUS (Dennis Parr)
