Bottle Blowing Research Articles

In situ adjustment of a visco hyper elastic model for stretch blow molding process simulation of poly‐ethylene terephthalate bottles

AbstractSimulation of the stretch blow molding (SBM) process necessitates to develop a model able to reproduce the material behavior at high strain rate, large deformation with temperature gradient. On the other hand, both the need to understand polyethylene terephthalate (PET) material characteristics and the final bottle performance requirements continue to get higher. That necessitates a regular update of the identification of the model. Bottle producers are interested by managing this identification without a specific complex apparatus not available in an industrial context. The work presented here describes an in‐situ adjustment process for upgrading all parameters of a visco‐hyperelastic (VHE) model from a small number of blowing tests that do not necessitate complex equipment. The accuracy of the adjustment process is validated through the ability of the updated VHE model to reproduce the final shape, the pressure evolution and the tension of the rod during an industrial blowing of PET bottles.

Injection‐stretch blow molding of poly (lactic acid)/polybutylene succinate blends for the manufacturing of bottles

AbstractThe stretch blow molding process of plastic preforms is widely used for the manufacturing of bottles in numerous market sectors, with high production volumes and low unit costs. In the sector of alcoholic beverages and, in particular, of wine, plastic bottles are used sporadically. Glass bottles or other economic solutions such as laminated cardboard containers or so‐called bag‐in‐boxes are regularly preferred. However, the high ease of use, lightness, recyclability and low cost of plastic materials are the main reasons that are fueling interest especially in wine producers. Poly (ethylene terephthalate) bottles have recently been introduced to the market, although their success has been limited by poor gas impermeability and above all by their recognized high environmental footprint. Barrier can be improved by oxygen scavenger and plasma coating. Environmental footprint is rather low when recycled but that is not well possible with scavenger. Bioplastic materials offer an interesting alternative to fossil‐based plastics, combining most of their technical advantages with a lower environmental impact. However, they are more expensive and complex to process. In addition, mechanical and barrier properties are often less than for conventional polymers. In this work, therefore, the development of bioplastic bottles with low gas permeation by stretch blow molding was studied. Poly (lactic acid)‐polybutylene succinate blends have been modified by adding additives that obstruct the passage of gaseous molecules through the wall of the bottle. The studies have in particular concerned the extrusion and characterization of bioplastic compounds, the injection molding of preforms, and the blowing of bottles. The results obtained showed that it is possible to obtain low permeation bioplastic bottles, which are an ecological alternative to conventional solutions for packaging.

Development and Experimental Study of the First Stage in a Two-Stage Water-Flooded Single-Screw Compressor Unit for Polyethylene Terephthalate Bottle Blowing System

The oil-free compressor is a key component in fabricating polyethylene terephthalate (PET) bottles for beverages and water. At present, the main compressor type used for blowing PET bottles is the reciprocating compressor. However, compared to screw compressors, reciprocating compressors have shortcomings of high energy consumption and too many consumable parts. Many manufacturers of PET bottles in Asia are seeking to replace reciprocating compressors with screw compressors, as we know. Screw compressors can be classified as single-screw compressors (SSC) and twin-screw compressors. Since the load in a twin-screw compressor is far larger than that in an SSC, SSCs are more suitable for being developed for high-pressure applications such as PET bottle blowing. This paper presents a performance study on an oil-free single-screw compressor as the first stage of the PET compressor unit. A 5.4 m3·min−1 prototype and its test rig were developed. The thermophysical process of the moist air is theoretically analyzed. The pressure loss on the flow path and the influence of the important parameters are experimentally investigated. It is found that water vapor cannot be separated during the adiabatic compression process. The results also show that the pressure loss from the discharging duct to the check valve accounts for the largest percentage of the total pressure loss. The experimental results further show that the discharge capacity and shaft power increase almost linearly with the motor speed. The efficiency declines with increasing injected water temperature. The discharge capacity and shaft power all increase with the injected water flowrate, and an optimum flowrate is found to ensure a highest isentropic efficiency. With the increase in discharge pressure, the discharge capacity decreases, and the shaft power increases. The isentropic efficiency is found to have its maximum value at a certain discharge pressure.

Pet Şişe Şişirme Makinelerinde Fırın Optimizasyonu

In this study, we have consulted the information of Pet Bottle Machine manufacturers and end users; Located in a limited number of Pet Bottle Blowing Machines in Turkey has been conducted on ovens. After the preform moves around its axis since it enters the machine and reaches the required heat by passing through the oven sections, bottles are obtained by giving 40 bar high pressure in the blowing unit. The quality of the obtained bottles is very important. The reason for this is that the labeling, filling and palletizing machines are also included in the continuation of Pet Bottle Blowing Machines. If the bottles are of poor quality, the entire line stops. The most important way to ensure that the bottles are produced in a robust manner is the efficient heating of the preforms, the raw material of the bottle. This study provided more efficient application of heat treatments of prefoms. In the heat treatment of the preform, to optimize the oven zone; PLC, HMI, temperature controls, thermal heat meter, thermocupl and thermal camera are used. The instantaneous temperature values obtained from the thermal heat meter, thermocupl and temperature controls are processed to the PLC as a reference and necessary adjustments are made available to the user via HMI. The reference values imported to PLC were developed using ST language in Codesys based software. In this study, instant values are shown on the panel. By using these data, heat optimization of infrared lamps in Pet Bottle Blow Molding Machines despite variable weather conditions is provided. The heat taken from the oven, the preform which is the raw material of the bottle, which has been optimized by the software, is observed with the thermal camera; The results were compared with the standard oven. In the context of the data obtained, it was observed that the software positively affected the preform and caused the production of bottles of better quality and cost-effective which are not affected by the changing climate conditions.

Strain induced crystallization in biobased Poly(ethylene 2,5-furandicarboxylate) (PEF); conditions for appearance and microstructure analysis

Poly(ethylene 2,5-furandicarboxylate) (PEF) is an emerging biobased thermoplastic polymer that may replace PET for stretching applications such as bottle blowing, thermoforming, or film extrusion. The stretch ability and strain induced microstructure in PEF have not been fully addressed in the literature despite being the key issue for industrial processing. In this study, it is demonstrated that PEF can develop an organized crystalline-like microstructure under uni-axial stretching above its glass transition and can exhibit behavior close to that of PET with drastic strain hardening and coupled sensitivities to strain rate and temperature. The time-temperature superposition principle appeared to make it possible to map stretch ability in terms of strain rate and temperature, and to develop conditions for strain-induced crystallization (SIC). The periodic microstructure of stretched PEF was highlighted by means of wide-angle X-Ray scattering and analyzed with stochastically modulated temperature DSC (TOPEM). Depending on the stretching conditions applied to PEF, different morphologies of crystals are developed. The heat capacity (ΔCP), crystalline fraction (XC), mobile amorphous fraction (XMAF), and rigid amorphous fraction (XRAF) for stretched and non-stretched PEF samples were evaluated.

Stress monitoring of PET beverage bottles by Digital Photoelasticity

Polyethylene Terephthalate (PET) is used in many packaging applications. PET is especially important in the carbonated soft drink industry, where the pressure of carbonation and the imposed and residual stresses in the bottle bases can sometimes lead to cracking, and failures. In the process of bottle blowing, residual stresses are created and remain in the bottle base as a result of the uniaxial and biaxial stretching in these regions. It is advantageous to measure these residual stresses and the mode of stretching, which may be related to the failure characteristics of the bottle bases. Photoelasticity can be used to examine these residual stresses in the sidewalls and bases of bottles. This work reports on a residual stress measurement tool for the bottle blowing industry.

Kinematics Analysis of the Wedge Clamping Device of PET Bottle Blowing Machines

In the current pin clamping device of bottle blowing machines, the design datum can’t coincide with mold datum. So it not only needs a pressure compensation device, but requires clamping holes to meet high precision. It makes the clamping device manufacturing and maintenance cost high. On the other hand, the producing plastic bottles have obvious mold lines. It affects products quality. For the above shortcomings, this paper designs a wedge clamping device, and then analyzes the kinematics modeling of planar moving cam mechanism and plane linkage mechanism. The results show that the device has smooth operation and small impact. So the new wedge device can meet the job requirements of high-speed rotary bottle blowing machines.

The material property basis of bottle blowing: Stable axisymmetric aneurisms

In the free axisymmetric blowing of hollow axisymmetric forms, a stable anuerism often develops which then travels through the form. This paper presents a procedure for carrying out experiments where by stresses and strains can be measured during axisymmetric free blowing. This paper explores the relation ship between material properties and this behaviour to explain the conditions under which stable anuerisms can occur.

The material property basis of bottle blowing and balloons: stable axisymmetric aneurisms

In the free axisymmetric blowing of hollow axisymmetric forms, a stable anuerism often develops which then travels through the form. This paper presents a procedure for carrying out experiments where by stresses and strains can be measured during axisymmetric free blowing. This paper explores the relation ship between material properties and this behaviour to explain the conditions under which stable anuerisms can occur.

Product Quality of Recycled Food Grade PET from a Bottle to Bottle Recycling Process

Retaining food grade quality is essential for a bottle to bottle PET recycling process. A PET recycling process comprising reactive extrusion of bottle flakes under vacuum followed by solidstate polycondensation to again increase the viscosity to the required value of bottle blowing has been investigated in detail applying a comprehensive reaction model. Quality parameters like viscosity and content of carboxyl end groups and vinyl end groups (potential acetaldehyde) have been calculated for different process conditions. The recycling process is assessed under consideration of the requirements of the food packaging industry.

Causes of Cracks in Petaloid Bottom of Carbonated PET Bottle

Abstract Petaloid design in bottom for carbonated PET bottles is wide spread. Crack problems exist in the bottom of the bottles. Through this paper we investigated the causes of bottom crack. We examined the physical properties of material and tensile yield stress variations according to the stretch ratio of PET. Then we analyzed stretch ratio and strength in the bottom of blown bottles. We also performed crack tests to observe crack phenomena. The distributions of effective stress and maximum principal stress were examined by computer simulation to seek the influence of bottom design on crack. We concluded that the bottom crack occurs because of not only insufficient strength of material due to the insufficient stretch of PET but also coarse design of petaloid bottom. The stretch ratio at bottom in bottle blowing should be higher than strain hardening point of PET to have enhanced mechanical strength. The crack in the bottom of PET bottles occurred through crazing. The maximum principal stress at valleys in the petaloid bottom of bottles was higher than the other area in the bottom and this maximum principal stress strongly affected the crack in the bottom of bottles.

Prediction of PET container properties using film data

In this work, PET films were stretched on the long extensional tester at various temperatures, stretch speeds, and stretch ratios. The stretched films were then characterized using various techniques. Prediction of container properties using the data generated for films was undertaken and three different approaches were used. The first method involves the use of time–temperature superposition to extrapolate the film data to the extension rate and extension ratio encountered in bottle blowing. In the second method, correlations developed between functional properties and average orientation functions for films were used for prediction of properties of blown containers. The third method was a combination of the first two methods. The birefringence was obtained by superposition and other properties were predicted using the correlation between functional properties and birefringence. With the exception of tensile energy absorption, it has been shown that mechanical properties of blown containers can be predicted from film data using any of the three methods previously described. A quantitative measure of property variation through thickness can also be obtained. Using the methods developed in this work, a map of properties and processing conditions encountered in stretch blow molding can be generated and this information can be used for designing preforms and containers. © 1998 John Wiley & Sons, Inc. Adv Polym Techn 17: 217–235, 1998

Prediction of PET container properties using film data

In this work, PET films were stretched on the long extensional tester at various temperatures, stretch speeds, and stretch ratios. The stretched films were then characterized using various techniques. Prediction of container properties using the data generated for films was undertaken and three different approaches were used. The first method involves the use of time–temperature superposition to extrapolate the film data to the extension rate and extension ratio encountered in bottle blowing. In the second method, correlations developed between functional properties and average orientation functions for films were used for prediction of properties of blown containers. The third method was a combination of the first two methods. The birefringence was obtained by superposition and other properties were predicted using the correlation between functional properties and birefringence. With the exception of tensile energy absorption, it has been shown that mechanical properties of blown containers can be predicted from film data using any of the three methods previously described. A quantitative measure of property variation through thickness can also be obtained. Using the methods developed in this work, a map of properties and processing conditions encountered in stretch blow molding can be generated and this information can be used for designing preforms and containers. © 1998 John Wiley & Sons, Inc. Adv Polym Techn 17: 217–235, 1998

Relations Between Heat Losses of Glass, Forming Times, and Bottle Production in Blowing Machines

The critical review of production numbers and forming times of different glass‐container machines is a problem of technical and economic importance that is recognized in nearly all glassworks. An exact technical and scientific investigation of these forming times is not possible because of (a) the limited knowledge of the heat transfer and flow of glass, (b) the great difficulties encountered in making measurements of the process, and (c) the influence of ordinary variations in the plant. Some simple relations between the timetable of operations and heat losses of glass during the forming process are given. Quite exact data for heat losses and operating times permit the assignment of standard values which characterize the special properties of the glass during forming.V. SummaryCritical judgment of the capacities and forming times of various glass‐processing machines is a task that has to be carried through almost daily in glassworks, since it is closely‐related to the necessity of finding out the best way of operation. An exact technical and scientific evaluation of the forming times is hardly possible for the following reasons: (a) the meager knowledge of heat transfer and flow during forming, (b) the great, nearly insurmountable difficulties with respect to the technical problems of measurement, and (c) the variety of the manifold operational influences. Therefore an attempt has been made to describe in simple relations the chronological sequence of the individual operations of the forming process, and the cooling of the glass during the process. On the basis of exact time studies of the individual operations, and with the aid of many calorimetric measurements of the heat rates in the individual forming stages, which were made on numerous fully automatic blowing machines, one can, by means of classification and comparison of the findings, set up approximate operational values. It is hoped that such an analysis has afforded some new ideas and suggestions concerning the technical principles of fully automatic bottle blowing.

EMPYEMA

A survey of the treatment for empyema by continuous tidal irrigation 1 and supplementary suction for the past eighteen months 2 has shown that this method can be used in the presence of practically any type of organism; that it is satisfactory for patients of all ages; that it works best with a trocar thoracotomy but can be adapted for use with patients having a resection of the ribs; that many patients with chronic empyema can be cured without mutilating operations; that bronchial fistulas close within a few days; that the period of convalescence is shortened; that the mortality is relatively low, and that no patient has left the hospital with a draining sinus. The treatment has also simplified the postoperative care, eliminated the difficult and painful dressings, removed the necessity for special exercises and blowing of bottles to give expansion of the lung and chest, and decreased the amount