•Polymers are long chain giant organic molecules are assembled from many
smaller molecules called monomers.
•Polymers consist of many repeating monomer units in long chains.
•A polymer is analogous to a necklace made from many small beads
•Another common name for many synthetic polymers is plastic which comes
from the Greek word "plastikos", suitable for molding or shaping.
•Many objects in daily use from packing, wrapping, and building materials
include half of all polymers synthesized.
•Other uses include textiles, TV's, CD's, automobiles, and many other all are
made from polymers.
•A quarter of the solid waste from homes is plastic materials - some of which
may be recycled as shown in the table on the left.
Natural Gas Liquids (Ethane, Propane)
or Naphtha (from Crude Oil)
polyethylene is created through the polymerization of ethylene (i.e.,
Polyethene, Polythene, PE, LDPE, HDPE, MDPE, LLDPE
Types of Polyethylene
“Linear Low Density”
High Pressure Copolymers
(AA, VA, MA, EA)
Low-density polyethylene (LDPE) is
a thermoplastic made from the monomer
Imperial Chemical Industries first discovered
low-density polyethylene in 1933. Its first
commercial use came during World War II, when
it was used as insulation on radar cables.
•LDPE (Low Density Polyethylene) is defined by a density range of 0.910 - 0.940 g/cm3.
•It has a high degree of short and long chain branching, which means that the chains do not
pack into the crystal structure as well.
•It has therefore less strong intermolecular forces as the instantaneous-dipole induceddipole attraction is less.
•This results in a lower tensile strength and increased ductility.
•LDPE is created by free radical polymerization.
•The high degree of branches with long chains gives molten LDPE unique and desirable flow
The SPI resin identification coding system is a set of symbols
placed on plastics to identify the polymer type.
It was developed by the Society of the Plastics Industry (SPI)
in 1988, and is used internationally.
The primary purpose of the codes is to allow efficient
separation of different polymer types for recycling.
Separation must be efficient because the plastics must be
recycled separately. Even one item of the wrong type of resin
can ruin a mix.
PETE or PET
PVC or V
OTHER or O
The injection blow moulding machine is based on an extruder barrel and screw assembly which melts
the polymer. The molten polymer is fed into a manifold where it is injected through nozzles into a
hollow, heated preform mould. The preform mould forms the external shape and is clamped around a
mandrel (the core rod) which forms the internal shape of the preform. The preform consists of a fully
formed bottle/jar neck with a thick tube of polymer attached, which will form the body.
The preform mould opens and the core rod is rotated and clamped into the hollow, chilled blow mould.
The core rod opens and allows compressed air into the preform, which inflates it to the finished article
After a cooling period the blow mould opens and the core rod is rotated to the ejection position. The
finished article is stripped off the core rod and leak-tested prior to packing. The preform and blow mould
can have many cavities, typically three to sixteen depending on the article size and the required output.
There are three sets of core rods, which allow concurrent preform injection, blow moulding and ejection.
The blow moulding machine is based on a standard extruder barrel and screw
assembly to plasticise the polymer. The molten polymer is led through a right angle
and through a die to emerge as a hollow (usually circular) pipe section called a
When the parison has reached a sufficient length a hollow mould is closed around
it. The mould mates closely at its bottom edge thus forming a seal. The parison is
cut at the top by a knife prior to the mould being moved sideways to a second
position where air is blown into the parison to inflate it to the shape of the mould.
After a cooling period the mould is opened and the final article is ejected.
To speed production several identical moulds may be fed in cycle by the same
extruder unit. The process is not unlike that used for producing glass bottles, in
that the molten material is forced into a mould under air pressure.
One of the most common methods of film manufacture
is Blown Film (also referred to as the Tubular Film)
Extrusion. The process involves extrusion of a plastic
through a circular die, followed by "bubble-like"
expansion. The principal advantages of manufacturing
film by this process include the ability to:
Produce tubing (both flat and gussetted) in a single
Regulation of film width and thichness by control of the
volume of air in the bubble, the output of the extruder
and the speed of the haul-off
Eliminate end effects such as edge bead trim and non
uniform temperature that can result from flat die film
Capability of biaxial orientation (allowing uniformity of
Blown Film Extrusion can be used for the manufacture of
co-extruded, multi-layer films for high barrier
applications such as food packaging.
3 layer die head with air ring
and internal bubble cooling
Film bubble going into a
Taking an edge trim
from film web
The lay flat tube is separated
into 2 single sheets
Control panel graphic from an
automated blown film line
Blow Film Line In Action
Blown film can be used either in tube form (e.g. for plastic bags and sacks) or the tube
can be slit to form a sheet.
- Industry packaging (e.g. shrink film, stretch film, bag film or container liners),
- Consumer packaging (e.g. packaging film for frozen products, shrink film for
transport packaging, food wrap film, packaging bags, or form, fill and seal packaging
- Laminating film (e.g. laminating of aluminium or paper used for packaging for
example milk or coffee),
- Barrier film (e.g. film made of raw materials such as polyamides and EVOH acting
as an aroma or oxygen barrier used for packaging food, e. g. cold meats and cheese),
- films for the packaging of medical products, Agricultural film (e.g. greenhouse
film, crop forcing film, silage film, silage stretch film).
PE Demand by Conversion Process
• Food Packaging
• Hygiene & Medical
• Consumer & Ind. Liners
• Stretch Films
• Agricultural Films
Plastics and rubbers are used in different packaging
materials and dosing devices
These materials are in direct contact with the
The final use of the product determines the risk of
possible interactions with the product
Extractables and leachables can be harmful and can
possibly alter the pharmaceutical product
Compounds that can be extracted from
packaging (i.e. elastomeric, plastic
components or coating of the container
and closure system) when in the presence
of selected solvent or process
Compounds that leach from packaging
as a result of direct contact with the
formulation of the drug product and thus
could potentially be dosed to a patient.
Can also get interaction with a product
component to produce an impurity that
requires stability monitoring.
Potential Sources of Extractables from elastomeric or plastic
Additives and processing aids, e.g. antioxidants, stabilizers,
plasticizers, emulsifiers etc.
Trace level contaminants and reaction products contained in
Secondary reaction products from processing
Contaminants and/ or reaction products from storage/shipping
=> Conduct risk assessment based on this information regarding the
identity and amounts of ingredients
Based on Extractable study suitable test methods for
testing of potential leachables in drug product have to
Recovery of reference compounds could be optimized
by spiking into a drug product formulation matrix.
Based on Toxicological Expertise limits for potential
leachables have to be defined
Validate the analytical methods
Methods for leachables studies are specific to the
Determine shelf-life acceptance criteria for leachables
based on the toxicological risk assessment
Lubricants – Prevent sticky to machine
Slip & Blocking Agent – Prevent film & sheet
Anti Static Agent – Prevent static charges on
Coupling Agent – Improve bonding between
polymer & filler
Welty Agent – Stabilize dispersion of Fillers
Anti Fogging Agent – Disperse moisture
droplets on film
Plasticizers – Flexibility
Impact Modifier – Improves impact
Reinforcy fillers – Increase Strength
Nucleatic agent – Modify Crystalling
By virtue of their insulting nature, polymers of all types
allow static charge to build up on their surfaces, and
films have large surface area to volume ratio.
Such static charge build up leads to several undesirable
consequences in the final products.
Built up static charge can attract dust on to a food
package, which is undesirable aesthetically.
It cause several processing problems such as winding of
films, agglomeration of powders during transport,
adhesion of film during processing, etc..
It can be avoided by using masterbatches containing
anti-static agents which will used internally with
Internal antistats are
migratory in nature.
The strongly polar hydrophilic
end adsorbs water molecules
which eliminates static
charges by ionic conduction.
The long hydrocarbon chain
length constitutes the
hydrophobic group and
controls the rate of diffusion
of the antistat to the surface
of the polymer product.
1. If the other additives are also migratory, they compete
with the antistats for diffusion through the polymer
matrix & also compete with the antistats for surface
Slips are a common example of this type of additive,
which may exert adverse influenced on anti-static
2. Amine & Amide type antistats are basic(Alkaline) in
nature, which may react with some acidic flame
retardants, which can result in reduction of anti-static