THE purpose of this manual is to provide a practical guide for glue users, to help in eliminating waste and improving the quality of product.
That there is an enormous waste due to improper preparation and use of glue is well known to all who are in touch with the subject.
Some authorities estimate that 70% of the glue used in the United States is improperly handled. The actual waste is said to be in excess of 25% of the amount of glue used; to say nothing of the loss due to imperfect condition of the completed work.
The writer knows from actual experience that many glue users are ignorant of the proper methods to be employed; and that many others are careless, or indifferent.
TABLE OF CONTENTS
IMPORTANCE OF THE INDUSTRY
Glue industry founded in America by Peter Cooper -increase in capital invested -increase in production – variety of uses -increase in requirements
THE MANUFACTURE OF GLUE
Sources from which glue is made – boiling the stock – drying – preparation in commercial form
TESTING AND GRADING GLUE
Grades established by Peter Cooper- the tests -viscosity or fluidity test- the jelly test- apparatus for making jelly test – the finger test-a simple, practical test for glue users- sampling bubbles – surface indications – color indications- alkaline or acid quality- break i lig quality – foam — grease – keeping properties-odor-laboratory test.
CORRECT METHODS IN THE GLUE ROOM
Much waste through faulty methods – importance of correct practice – soak glue in cold water before melting- test glue by water absorption – appliance for water absorption test- melting or dissolving glue – do not heat higher than 150°F. – apply heat indirectly – live steam ruins glue- use thermometer – heat glue slowly – cleaning the melting pot – importance of using copper, brass or aluminum utensils – guard against evaporation – melt only the amount required – importance of cleanliness – keeping the glue room warm – use by weight – storing – applying glue -securing workers’ co-operation.
MODERN GLUE ROOM EQUIPMENT
Modern appliances now available for all users only copper, brass or aluminum should come in contact with glue- the scientific glue heater-the automatic temperature controller – keep steam away from glue-glue spreaders – clamps and presses – distributing glue in large plants.
WHICH GLUE TO USE
Accurate records important the best glue for wood joints – veneers- sizing – paper boxes – belting and other leather goods – bookbinding – emery purposes – how much to pay – waterproof glue-vegetable glue- quick setting glue-flexible glue.