Twist Off Cap Application

GINTENDED FOR HAND Operation

Silgan White Cap's world notorious Twist Off is a protean vacuum- holding essence lug check. A quarter of a turn seals, removes and reseals it. It's air tight and liquid tight dragging the shelf life of the product.
Whilst the bulk of Twist Off caps are applied by machine it's possible to hand apply successfully. Still, particular care must be taken as follows.

THE FOLLOWING GUIDELINES SHOULD BE OBSERVED

1) Stuffing-in order to allow space to produce a vacuum don't fill the jar/ bottle to within 5 of the overflow (95 of the volume) or roughly 10 mm from the hem.

2) Circumscribing pre toast the cap if possible and in particular if cold filler. Don't heat the cap, maximum 60 c. This softens the sealing emulsion which takes the pressure off the lugs and makes for a better seal. Apply cap cutlet tight taking care not to cross thread and icing the cap lugs are engaged in the glass thread. Once cutlet tight apply necklace ( pressure) by ¼ to ½ of an inch or 7 to 12 mm. The quantum of necklace applied is presumably the most important aspect of Twist Off cap operation as this can be the difference between achieving a good vacuum, i.e. a perfect seal, and a loss of vacuum which can lead to mould, caps coming off if subordinated to shock, etc. Over tensing can also lead to high necklace junking problems.Please remember this isn't a screw cap and mustn't be over tensed.


QUALITY CONTROL CHECKS.
1) Cap seal- check necklace measures as described over on a regular base. Outside these companion lines will lead to the cap ringing or the cap coming loose when subordinated to shock performing in a loss of vacuum.

2) Emulsion print-a good seal will leave a 360 * print of the glass hem in the cap sealing emulsion. An uneven print can indicate a cross threaded cap and won't affect in a good sealN.B.Pre-heating the cap will ameliorate the emulsion print and seal.
3) Make a visual check on the depression in the centre of the cap which should be hollow. A good vacuum will pull down the centre of the cap creating a pop when the seal is broken. No vacuum will appear as a convex in the centre of the cap. This will be the case with a cold filler.