Video Parts (3)
This clip is Part 1 of a 3-part film.
SAFETY GLASS Part 1
Description
The original catalog description provided by the Ford Motor Company reads as follows: Safety Glass, Part One. “This picture is from the film library of The Bureau of Mines of the United States Department of Interior, Washington, D.C.” “Presentation of this film was made possible through the co-operation of the Ford Motor Company.” Two cars moving down country road - one car throwing rock against windshield of other - man and boy looking at cracked windshield. “‘Gee, dad, the window at home would have broken into a million pieces.’” “‘It surely would, but we have a safety glass windshield.’” Man and boy getting back into car. “‘Dad, how is safety glass made.’” View through windshield of moving car. “By cementing a transparent, flexible sheet of cellulose acetate, which is a kind of celluloid, between two pieces of plate glass.” View through windshield of moving car. “The first step in making plate glass is quarrying the silica sand, which is the main ingredient.” “The overburden is stripped.” Steam shovel loading dump truck. “The sand rock is blasted --” Dynamite blasting hill, “-- loaded --” Steam shovel scooping sand. “-- and transported to the mill.” Steam shovel loading hopper cars - cars going up incline to top of tipple - men dumping sand onto conveyor. “It is then screened.” Sand passing under sprayer. “The coarse lumps are broken in a chaser mill --” View of chaser mill. “-- and some of the water is removed in drag and screw classifiers.” Water being removed by machinery. “The sand goes on a belt conveyor --” Sand on conveyor. “-- to rotary drying kilns.” Worker tending kilns. “When dry, it is discharged --” Sand pouring from kiln. “-- into freight cars --” Freight cars being loaded - view of loaded cars. “-- and transported to the glass plant.” View of plant - freight train entering plant. “The sand is sampled upon arrival --” Man taking sample of sand - pouring it into paper bag. “-- dumped --” Sand pouring through trough. “-- and conveyed to the silo.” Sand on conveyor. “Plate glass is made from the following materials: Sand - 44.8 per cent Limestone - 13.4 ” ” Soda Ash - 14.3 ” ” Salt Cake - 3.3 ” ” Charcoal - 1.25 ” ” Cullet (cut glass) - 22.7 ” ” Rouge - .05 ” ” Sodium Silicate - 1.2 ” ” “Each batch is accurately weighed --” Views of scales, “-- thoroughly mixed --” Sand in mixer, “-- and pressed into briquettes --” Machine in operation - briquettes on conveyor. “-- which are conveyed to a furnace.” Views of furnaces. “The melting end of the furnace.” Man poking furnace. “Inside the furnace.” View in furnace. “The briquettes are evenly spread.” Man poking furnace. “Temperatures are automatically recorded --” Views of gauges. “-- and gas and air for combustion are carefully controlled.” Views of valves and gauges. “Another view of melting.” View inside furnace. “Temperatures are checked with a radiation pyrometer.” Man taking reading with pyrometer. “Each batch is sampled at the refining end before pouring.” Man taking sample. “A sample bulb is blown to make sure the glass is free from air bubbles and streaks.” Man blowing “The hot glass is roiled in a continuous ribbon --” Glass in rolling machinery. “-- which is inspected before entering the annealing lehr.” Man inspecting glass on conveyor. “It is inspected again after annealing --” Marking glass. “-- cut into strips --” Machine cutting glass. “-- and then into sheets.” Glass on conveyor. “The edges of the sheet are trimmed.” Men trimming edges. “It is then turned over --” Machine turning sheet over, “-- and conveyed to the grinding floor of the plant.” Glass on conveyors and elevators. “The sheets are lifted automatically by suction cups and placed on the grinding table.” Machine picking up sheet of glass. “Each sheet is laid on a bed of plaster --” Men spreading plaster-of-Paris, machine depositing glass on plaster. “-- and pressed evenly in place.” Machine pressing glass into plaster. “Cast iron mullers are used for grinding.” Close-up of underneath side of muller. “They are electrically driven.” Views of control panel. “The glass passes under the mullers --” Mullers in operation. “-- which are fed with sand and water.” Mixture of sand and water pouring into muller. “As the glass progresses, finer sand is fed from the tanks above.” Views of tanks and mullers. [1937]
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