PETes AA Analyzer
Measuring Acetaldehyde (AA) content in PET preforms
Among the key acceptance tests that preform producers are to perform is the measurement of acetaldehyde content generated in the PET transformation process.
In order to guarantee superior quality of the product and verify that the AA content is kept within strict and controlled limits, Piovan offers the PETes AA Analyzer instrument, a patented method of analysis that allows measuring the Acetaldehyde (AA) contained in PET preforms fully automatically.
The use of PETes AA Analyzer is so simple that even non-specialized operators can carry out the online measurement in just 30 minutes, without any preparation of the preform.
PETes AA Analyzer can be used for different types of preforms, always using the same de-absorption cell, without the need to change the parameters:
- the preform is placed into the de-absorption cell
- the conditioning phase starts
- when the heating phase is completed, a flow of purified air (zero air) picks the gas released by the preform and carries it to the analysis loop
- the carrier gas (hydrogen) brings the sample from the loop through to the packed column where, by using a FID (flame ionization detector), the measurement takes place
- the chromatogram, all analytical data, and production references are displayed on the monitor
All data are printed and clearly summarized in analytical report forms.
- Constant control of the process: the possibility to detect the AA content in real time facilitates certification of every single production lot. The connection with the company’s network offers the possibility to access the process data constantly and elaborate on them
- High accuracy and repeatability of the measurement, ensured by the instrument based on the “Fast Head Space Gas chromatography” technology, secures a correct analysis, independent of any of the many variables that characterize the traditional methods
- Reduction of cost and time required to perform the tests. The PETes unit, which can be installed in the production department or in the company’s quality control laboratory, enables the operator to carry out the AA analysis at any time, without requiring the support from third-party specialized technicians
The PETes method advantages
PETes AA Analyzer Vs. the traditional method
The traditional method of measuring acetaldehyde in PET preforms is based on a gas chromatography analysis of the acetaldehyde present in the head space, desorbed from the ground material placed into a sealed vial after thermal treatment. This process is very labor intensive, time consuming and expensive.
The means to determine the ppm of residual AA in a PET preform is gas chromatographic analysis, a specific technique used for concentration and analysis of volatile organic elements in solids. In headspace GC, a sample is diluted and sealed in a closed container that is large enough to allow some headspace in the vial where vapors can accumulate. The sample is then kept at high temperature for a period of time to allow the solvents in the matrix to volatilize, enter the gas phase, and reach equilibrium with the remaining solvent(s) in the vial.
Precision and accuracy of the traditional method are heavily affected by:
- sample pre-treatment procedure – such as milling conditions, different sieves/screens, cryogenic treatment, part of sample under testing
- GC instrument variables – such as incubation time, different sample conditioning temperatures, column and head space systems
- any possible human error
The key for reliable and reproducible results in AA analysis is to limit the sample pre-treatment steps, to automate the process, to reduce overall time and effort and to prevent possibilities for imprecision and accuracy errors.
Using gas chromatography technology, but with no need for sample preparation, milling and processing by expert lab technicians, PETes instrument analyze the entire preform in a fully automatic way. It is simple to use, rapid, and it provides reliable and repeatable results.
PETes in drying process
AA is a colorless volatile with a fruity smell which arises as a by-product of PET thermal degradation by oxidation of the vinyl end group of the polymer chain. In PET bottles, AA is usually present in a concentration of a few ppm, which is slowly desorbed to the bottle content, altering its taste and aroma. This may not be a relevant issue for fruit juices or strong-tasting soft drinks.
But for bottled water, especially still water, low Acetaldehyde content is imperative: even AA concentrations in the water as little as 10-15 ppm can convey an undesirable off-taste.
While raw resin typically has a concentration of 1 ppm acetaldehyde before drying, at the end of the molding process its content rises up to 3-4 ppm. AA is normally generated in the plastic processing phase for two main reasons: shearing/friction in IMM screw and thermal degradation of the resin due to high temperature. At each step of the production process it is possible to control final AA content in preforms by:
- limiting the barrel residence time of raw material
- using the correct processing parameters during the drying phase
- reducing the screw back pressure effective melt-out, shortening the cycle time and limiting the injection pressure at the IMM
- adding AA blockers (anti-oxidant), erucamide or similar to the resin
Measuring AA content in PET preforms provides an index of the actual quality of the molding process. To keep the process at its best and to avoid the subsequent phases of blowing, filling, distributing and putting on shelves bottles with a content exceeding the allowed AA level in the market, AA is best measured before the blowing and filling stage: in the PET preforms. Piovan optimizes the PET drying process in order to reduce the original PET resin AA content.
Feeding & Conveying
Drying & Dehumidifying
Dosing & Blending
Acetaldehyde measurement in PET preforms
Worldwide leader in supplying ancillary equipment to the plastics industry
PIOVAN Group is a world leader in the development and production of ancillary systems for the automatization of storage, transport and processing of polymers, plastic and food products, engineering solutions and services. From open-air silos to centralized feeding systems: they design and manufacture integrated and flexible solutions for all kinds of plastic materials. Committed to their customers and to innovations, development and future trends, they are striving to direct their professionalism towards the fulfillment of customers’ requirements. The fact that differentiates PIOVAN from their competitors is that almost all of their elements and sub-assemblies are manufactured by their own mother company. This concept of the development strategy is the reason why PIOVAN stands for quality, reliability and efficiency.
About PIOVAN (PDF 6.89 MB)
Energy efficiency is a concept that in our part of the world became important towards the end of 2008 and the beginning of 2009, at the outset of the world economic crisis. Most business people had, until then, mostly declaratively considered power consumption as a significant element of the total cost analysis. In these considerations, the impact of energy efficiency on the environment pollution had hardly been tackled at all.
Neofyton was among the first companies in Serbia and the region to start actively demonstrating the importance of energy efficiency, both by cutting production costs and therefore increasing profit rates and building awareness of the resource shortage and broader ecological principles.
Energy savings through the use of Neofyton's machines
In comparison with our direct competitors in the field of plastics injection machines, and with the utilization of standard hydraulics with integrated so-called "smart" pumps, our machines consume as much as 50% less energy. The use of servo-hydraulics opens up the potential of savings as high as 70%. We have a very precise power consumption measuring device to prove this.
The company Engel was the first plastics injection machine manufacturer back in 2009, which introduced the power consumption page as a standard component of the control assembly – "Ecograph", where - next to the weight of each product (molded part) in every cycle - total hourly consumption is shown, as well as the specific power consumption per one kilogram of processed plastics (kWh/kg).
The equipment we represent contributes to ENVIRONMENT PROTECTION in several ways.
When it comes to ancillary equipment, above all water chillers by our supplier Eurochille, used for temperature control of both hydraulics and machine servo motors and molds (tools) in which finished products are made, the chiller systems we sell facilitate the use of a new cooling system based on the so-called "adiabatic effect".
In summer, the hydraulics and servo motors of the injection molding machines call for cooling with water at a maximum of 28°C. Using the so-called "free cooling" device with the "adiabatic effect", cooling of process water is performed without cooling compressors (which use freon as the heat exchanger). Heat exchange, i.e. cooling happens exclusively by the use of ventilators, which translates into six- to eightfold savings compared to traditional chillers that use freon-based compressors.
One of our customers has reduced the required cooling energy by 1.400.000 kWh per year, i.e. by about 70.000 EUR, using the "adiabatic" cooling devices. An additional benefit is the elimination of major pollution risks which might arise from emissions of freon into the atmosphere due to tube puncture or breakage.
A similar calculation can be applied to our Engel injection molding machines, as well as to the Piovan granulate dryers.
The Company Neofyton as PIOVAN’s partner
Neofyton is PIOVAN’s partner for the markets of Serbia, Bosnia and Herzegovina, Macedonia, Nigeria, and Cameroon. Piovan is a large international group founded in 1934 and has more than 70 years of experience and expertise in the production of ancillary equipment in the injection molding industry. Their service and sales of equipment are available on four continents (Europe, North and South America, Asia).
One of the features of PIOVAN is constant communication with their clients, through ongoing technical support and assistance. The client is included in the solution from the designing stage to the installation and start-up of the facility.
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