Why sticker label not properly affixed on glass bottles.
This depends upon your requirement .no guidelines for labeling.as per Gmp norms every items should be properly labeled for its intended purpose.
Labels depending upon your requirement ie
For a shorter time usage, Water sampling
For the day, biological analysis
For week, regents
or more as per storage requirements.
Also depends how much time your glass bottle has been used in process, washing procedure.
For example, in injectable facility some of bottle required Sterilized,Depyrogenated, or acid treatment.so you can’t fix it permanently.
before labeling bottles outer surface should be dry.
Sticker paste should be of good quality.
after afixation of sticker proper pressing should be applied.
before labeling of glass bottles they should be properly dried.
sticker used should be of good quality.
gum present on the label should be of good quality.
after affixing label labels should be properly pressed so that no empty space left on the vial without gum.
One more reason that I have often observed is the labels are having more gsm.whether bottles are dry properly the labels are found not sticking to the bottles from sides.
All above aspects should be considered for proper labelling of bottles.
One most important aspect I would like to highlight is the “Knurlling” direction of paper to be used for labelling. The Knurlling direction can be determined by making a paper piece wet with water. And allow the paper to rest on a flat surface. Slowly the wet paper piece will start rolling (curving) in one direction.
The pasting of gum to the label should be done on the surface of paper which is ‘inside’ the roll (curve) so that there is a good grip of label to the glass bottle after pasting. If we paste it on opposite surface (outer surface of papre curve) the label will have tendency to come out of bottle after pasting.
Therefore, “Knurlling- direction” of paper label is very importnat aspect to be considered for pasting of lpaper abels.
There is an error in the test name in the above answer given by me… Please read as following,
This aspect is known as “Grain- direction” of paper and NOT “Knurlling”. Please make necessary correction and read above message as “Grain-direction” of paper.
Paper has a ‘grain direction’ . … “Grain direction” is very important and makes a huge difference as to how the paper will react when attempting to fold, score and bind it. Therefore, knowing the grain direction and how it will affect the layout of a project makes a big difference in the quality of the finished piece.
There are a variety of ways of determining the grain direction in a particular sheet of paper.
One test is to moisten one side of a paper square. It will curl toward its dry side, and the two opposite
edges that curl up will be parallel to the grain direction.
Sir good morning .you have very nicely explained all but does this procedure is for automatic sticking of labels also.here the labels are already having gum.
What I have explained is one important aspect to be considered along with all other suggestions given by others.
Proper selection of Grain direction should be considered by the printer of sticker labels. The printer should select appropriate surface / side of the paper for printing and applying gum to the sticker labels. We will have to inform this aspect to the label printers.