Quality Process

SAMPLE SIZE – 450*800

THICKNESS – 4 TO 12

PROCEDURE – A screen bearing an assembly of black and white stripes is observed through glass from a 9 m distance in a centre line of axis. The position of sample is 4.5 m from screen in a rotating frame. The glass being examined is rotated from angle 90 to 0 degree.

CRITREIA – The angle at which optical distortion occur shall not exceed 50 degree angle.

SAMPLE SIZE – ANY

THICKNESS – 4 TO 12

PROCEDURE – Glass to viewed from one side by illumating fluorescent lamps kept at 50 cm gap on black mat finished wall on other side. The glass should be placed at 1 m from lamp and to be observed from 2 and 4 m respectively.

CRITREIA –No fault to be present on visible condition.

SAMPLE SIZE – ANY

THICKNESS – 4 TO 12

PROCEDURE – Glass thickness to be measured with micrometer/ vernier caliper from 25 mm away from edge at centre of each side. The average of four measurements to be taken. .

CRITREIA – Tolerance up to +/- 0.2 to 0.5 mm is allowed for thickness 4 to 12 mm.

SAMPLE SIZE – ANY

THICKNESS – 4 TO 12

PROCEDURE – Glass diagonals to be measured using tape.

CRITREIA –Tolerance up to +/-3 to 5 mm is allowed on diagonal for thickness 4 to 12 mm.

PROCEDURE

• Cut the sample test pcs of size 360 mm x 1100 mm.
• Temper/Heat strength the glass in furnace like height must be perpendicular to roller and width parallel to roller
• Place the glass in flat surface as like logo should come on bottom side which must be contact with flat surface (ie: check should be carried out in surface with no logo)
• Place the Roller Gauge on top surface of glass as like parallel to height.
• Extrude the portion 150 mm from edges and make origin zero in gauge then note reading displayed in main digital gauge covering central area of glass while moving gauge from one end to other end
• For Over all waveness use formula Rw=Pm+Vm
• For Edge lift note the reading observe in secondary gauge covering area 150 mm from edges

KEY POINT

• Glass surface must be dust and defect free
• The overall glass waveness and edge lift must be less than 0.3 mm
• In case of abnormal trend identify the lot & inform the Production & QA incharge.

SAMPLE SIZE – 1100*360

THICKNESS – 4 TO 12

PROCEDURE – Test specimen shall impacted with centre punch having 0.2 mm tip on 13 mm from longest side edge. The particle count should be taken on fracture specimen by making a square of 50 mm in an area excluding 25 mm from edges and 100 mm radius from impact point.

CRITREIA – The minimum count of particle must be 40 for thickness 4 to 12 mm .

SAMPLE SIZE – 610*610

THICKNESS – 5 TO 12

PROCEDURE – A steel ball of about 63.5 mm dia and weighing 1040 g shall be freely dropped freely from 1 m so as to strike specimen within 25 mm from its centre.

CRITREIA – The specimen should not broken.

SAMPLE SIZE – 1938*876

THICKNESS – 4 TO 12

PROCEDURE – A twin tyre impactor of mass 50 kg is allowed to strike on specimen which clamped on frame of structure from 3 levels of height(190,450,1200) freely.

CRITREIA – The specimen should not break. If it does, collect the 10 largest particles. Their combined weight should not be more than the weight of glass having an area of 6500 mm square taken from original test piece.