Packaging is faulty?
Find a cause suit the remedy to the case!
Packaging is faulty?
Find a cause suit the remedy to the case!
Bags of the contents of a peculiar smell can directly cause odoour, serious when can also affect the product quality or even affects their health.
Together will also deteriorating operating environment, caused by the operator.
In recent years, the packing bag of odor problems are now increasingly attention by the relevant enterprise and has obtained many open.
Constitute the bags there is peculiar smell the primary elements of residual solvents, raw and auxiliary materials itself with the peculiar smell, odor occurred in the process of processing and environmental pollution, etc.
Below a professional flexible packaging producers packaging on these elements makes an analysis respectively.
A, residual solvent printing ink transferred to the membrane, printing ink film first appearance of solvent evaporation, and in the inside of the printing ink film must first be slack to infiltrate the ink solvent evaporation film appearance before the retrograde drab.
When boring into the final stage, the printing ink film surface has been cured, this constraint internal solvent slack, then constitutes the residual solvents.
The residue solvent in print is the leading cause of the peculiar smell of the plastic gravure flexible packaging.
Its residue can use chromatograph was briefly measure, the end of the qualitative or quantitative.
Abnormal value, the print will have a problem to meet up to use the senses to sniff out and to be able to conclude that.
Printing ink layer of organic solvent in most instant monotonous, monotonous in the remaining traces of solvent curing closed residue composition in the printing ink film.
1, join resin for solvent free let's know, for the sake of habits in printing needs or considering the economy, when printing in ink to participate in the mixed solvent.
Each connection is expected to have their own true solvents, time, solvent, solubility, the better, just indicate the connection is the greater the affinity between the resin and solvent molecules;
Solvents on resin snake better solubility, resin for solvent free sex is the worse, release the worse the brief constitute the residual solvents.
In terms of some kind of ink, solvent free sex is largely to its inherent nature, so in the beginning make an advance by using a kind of ink printing ink makers understand its residual solvents, in order to make corresponding processing.
Printing ink layer in the solvent to mixed solvent, each kind of solvent evaporation speed is different: the change in this case, the evaporation of the solvent, evaporation of strong sex first escape, solvent evaporation of weak components to stay down, the composition of the solvent has had the change, not perhaps as a single solvent in stable rate under a single rate of evaporation, evaporation of the solvent will gradually slow down.
Assume that the purity of solvent (blatantly
But such as too many compounds containing high boiling point)
Or too much use of the slow drying solvent, then will occur under normal conditions the grim problem of residual solvents.
2, monotonous conditions conditions including air temperature, air velocity (monotonically
And monotonic equipment structure, etc. , it selected the drab power.
Drab bad, solvent residual amount will be added, and therefore should be invented perhaps good monotone conditions.
Moving air temperature, air velocity,
No doubt can strengthen the monotone conditions, but should be careful of is under the condition of the printing ink layer thick, assume that monotonous too fast, can make the ink layer appearance adjustable conjunctiva and make the internal solvent can't escape, it will lead to higher residual solvent, peculiar smell.
3, printing speed of the fast printing speed, choose the length of the boring time.
So should be under the condition of guarantee the printing ink layer of energetic monotonous gradually advancing speed.
The speed too fast, monotonous cannot get full guarantee after film printing, especially after what color printing from the short interval between winding unit (
And for large ink)
, very brief form excessive residual solvents.
4, monotonous medium (
The humidity and the concentration of organic solvent drab medium (
Humidity on residue has a great influence.
One is the moisture in the air into the ink, constitute the generalizability of solvent evaporation variation.
The second is monotonous medium (
Many exist in water, also contain the evaporation of the solvent.
Add double moisture, ink drab speed will slow nearly twice as much.
Thus under the condition of high humidity, should try to slow down and cut ink printing speed and the touch of the air, to ensure the full of ink is monotonous.
Together shall promptly adjust the formula of the solvent, make special formula is suitable for the climate.
Printing workshop air humidity generally should not be over 70%, of course also cannot too drab, otherwise a brief cause electrostatic problems.
Five different materials, printing film membrane of solvents have different absorption tendency.
Such as aluminum foil, polyester film as the absorbent film, less residual solvents in general;
Polypropylene class film short residual hydrocarbon solvent, water film (
Such as nylon, cellophane)
Is a brief residual alcoholic solvents.
There are some plastic film to add additives affect evaporation of the solvent, thus increased the amount of residual solvents.
6, other 1.
Aging treatment by aging treatment of the molecular structure of the residual solvent evaporation, robust abundant after finalize the design into the next process.
About multicolor printing is in the picture is planning don't fold color too much, perhaps can use of special color to avoid some ink layer too thick.
Use paper to assume that using high sealing plastic film packaging products to packaging, is equal to the product in the process of storage of energy that is released by smell all stored, once opened the package will be gone with the wind out of breath,
Open place smell after a period of time will obviously decrease)
So use breathable paper can make the smell residue and evaporation, also have must be to reduce the odor.