The chemistry of ink

Generally there are two kinds of ink
*Inorganic e.g.: TiO2(white), FeO(red)
* Organic e.g.Phthalocyanine blue
Advantage and disadvantage
Inorganic:* color strength not good, Longer life time, Processability not good
Organic :*good color strength, Shorter Life Time, Better Processability

Base Cylinder

The base cylinder is a steel unwelded tube, 12 to 20 mm thick (for practical use 6-10 mm is common)
* It is grinded outside
* It is turned inside
* It is balanced statically or dynamically
There are two categories of cylinder
*Shaftless
*Shafted
The Cylinder dimensions are
*Width=horizontal length
* Develop=circumference ( n replicate)
Shaftless cylinders are mounted to the printing machine with a set of cones with 10 cone angle and 90 mm diameter

The Colour Sequence

When materials have to be printed inside, the colour sequence has to start from the darkest colour to the lightest one
*Black
*Cyan
*Magente
*Yellow
This technique is used to keep the chromatic result at the end of the process close to the original
For outside printing, colour starts from the lightest to the darkest one
* Yellow
* Magente
* Cyan
*Black

UV STABILIZERS

3 Clases of Light Stabilizers-HALS (Hindered Amine Light Stabilizers); Absorbers(UVA) e.g. benzophenones and benzotriazoles;Quenchers e.g. Ni(Energy transfer)
HALS chemically scavenge free radicals and decompose peroxides;usually more effective.
UVA's need high concentrations and thick polymer governed by Beer Lambert Law
[Absorbance=Ext'n Coeff x Path Length x Concentration]

Homopolymers and Copolymers

Polymers made solely from one kind of monomer are called homopolymers
Polymers made from two monomers (or co-monomers) are called copolymers
Ethylene only=homopolymer
LDPE,HDPE
Ethylene & octene = copolymer
LLDPE
Ethylene & Vinyl acetate = copolymer
EVA,EAA

Fundamentals of Polyethylene

Types of Polyethylene
Polyethylene is composed of only carbon and hydrogen(with some exceptions) which can be combined in number of ways to make many different polyethylenes including:
LDPE, Low Density Polyethylene
EVA, Ethylene Acrylic Acid Copolymers
HDPE, High Density Polyethylene
LLDPE,Linear Low Density Polyethylene
ULDPE,Ultra Low Density Polyethylene(a.k.a. very low Density PE, VLDPE)
Single-site polyethylenes

Laminating Process

Normally during laminating process two or more layers of materials will be laminated together using adhesive. They are different types of Adhesives, example solventbased Adhesive, solventfree Adhesive and also waterbased Adhesives. Each typed of Adhesives have their advantage and disadvantage, depends on Usage and Application. For economically and health issue nowadays food Industry prefer to use waterbased Adhesives or solventfree Adhesives. The Laminating Process is simple, in which Unwinder A will unwind the Material A through the transferring rolls and the then through the coater and then drying chamber at the same time the Unwinder B will also unwind Material B, normally the position of Unwinder B are at behind of the Laminating Maschine. Then the both Material A+B will go through Niprolls, so that both Material can be laminated together. At the same time the Rewinder will rewind the laminated Material as finish goods. After that the laminated rolls will be stored inside Agingroom for certain time so that Adhesive can really be cured perfectly, especially Adhesives with solventbased.

Flexible Packaging Process

In this modern & dynamic world everybody expect instant product. So the food industry must work together with packaging company to solve this problem especially in flexible packaging. The packaging company must make a breakthrough with innovation. I would like to share with everybody how this process from beginning until finish product. First from choosing the right material suitable to pack the food and the design the customer want. It's quite complex. First the material must be printed as customer's wish. For that the designer must prepare the rolls for printing department. The rolls must be engrave first like the customer's design. Then will test print be done for to see if the design already suitable like customer's wish. If so, then the mass production can be done. Printing technology normally be use is rotogravure. After printed, then will go to laminating process. After that go to slitting process as finish product and then can deliver to customer.