PET-->Ionomers

PET production

An ester - organic acid and base

Ethylene glycol and terepthalic acid

A condensation reaction

Includes a dibasic acid or glycol in the polymerization reaction

PCTA brilliant clarity, good toughness and high tear strength

CPET, highly crystallized form for dual ovenable tray, PETG little tendency to crystallize high melt strength for thermoforming or ebm

PET films are biaxially oriented

High tensile strength, low elongation, high melting point, excellent grease/oil barrier, low gas and moisture permeability, good printing characteristics, high use temp range, high impact strength, high scuff resistance, excellent dimensional stability

PET Films limitations

Lack of heat scalability, poor machine performance, a propensity for generating static and poor package openability

Low melt strength (very fluid at melt temp) hard to ebm, often isbm

PVC Production/processing

Suspension or emulsion polymerization of vinyl chloride, gas from ethylene base

Alone, pvc is hard brittle and low thermal stability

Often mixed with slip agents, plasticizers pigments, waxes, fillers, processing aids, impact modifiers, and liquid epoxy stsbilizers

Less-plasticized PVC films are Stiffer and possess better barrier properties than heavily plasticized

Highly plasticized PVC films have excellent Stretch properties and cling

PVC and other halogen bearing (chlorine fluorine bromine)

Self extinguishing and burn with difficulty

PVC properties

Good clarity, excellent stiffness, and resistant to oils and alcohols good for Blow molded bottles

PVDC (saran)

Extrusion casting or blown tube process

Good grease oil and chemical resistance

Can be used as coating to make a better barrier and heat seal

PVAC

White glue

Highly polar and resilient thermoplastic

Broad range of emulsion adhesives

EVA -pvac copolymer of pe

Similar to ldpe, high clarity, good flex crack resistance puncture resistance and cold temp performance

Used in adhesive production

Polyamide (nylon) strengths

Tough, abrasion resisting, impacts, puncturing and cracking when repeatedly flexed

Good barrier to aromatics, oxygen, niteogen, CO2

Polyamide weaknesses

Not resistant to strong inorganic acids and not heat sealable, poor slip properties, more expensive packaging films

Poor vapor barrier properties

PA film

By extrusion casting, mono or bi axially oriented for strength and barrier properties

Type 6 for meat and cheese vacuum pack for ozygen barrier and grease resistance

Nylon

Used in laminated structures

As an abrasion resistant base material for vacuum brick packages

For bulk bagging of frozen primal cuts due to abrasion resistance and toughness

PVAL

Water soluble, superior oxygen barrier

Limited to dry products like tide pods

EVOH/EVAL

Highest useable oxygen barrier

Adversely affected by water, can be used as core then coated with water barrier properties

Ethylene acid copolymers and EEA = pe copolymers

Reduces crystallinity, lowrr heat seal temp, good adhesion to polar substrates

Ionomers (surlyn)

To make tough clear films suitsble for skin packaging, excellent heat seal bonds, ezcellent aluminum foils