Plastic blow molding processes are the most popular methods used to produce hollow products out of thermoplastic materials. Pet books blow molding advisors at apex container tech inc. Hendry built the first screw injection molding machine, revolutionizing the plastics industry. Traditionally, molds have been expensive to manufacture. A within a split mold cavity, air pressure is applied to a heated plastic material called a parison that expands similar to a balloon and is shaped against the walls of the mold cavity. In the past, blowmolding companies have largely avoided prototyping due to high cost and long lead times. Polyethylene extrusion blow molding process guide formosa plastics corporation, u. Design of flash pocket inserts in an extrusion blow mould based on. Injection molding to the material we have on hand at the time your quote is created. Formolene hl5010 the fomolene hl5010 series of resins are high load melt index resins hlmi, used to produce large containers and parts by both the blow molding or sheetthermoforming production processes. Each chapter is complete in its description of the material and has all the figures that are in the book.
The raw material in this process is a thermoplastic in the form of small pellets or granules, which is first melted and formed into a hollow tube, called the parison. It is also used for forming glass bottles or other hollow shapes. Molding in the texture is most cost effective for higher volumes. The stretch blow molding book is an ideal text to teach newcomers to the industry the basics of the material, process, and machinery. Software products can help predict molding characteristics and our engineers.
This guide focuses on the extrusion blow molding process. There are different ways of molding a plastic some of them are blow molding, injection molding, rotational molding and compression molding. Pdf design of flash pocket inserts in an extrusion blow mould. Combined effects of geometry, part, material characteristics, mold design and processing conditions on the part manufacturing is. Compared to its extrusionbased counterpart, the injection blow molding process has a lower production rate. Today bottles still represent a large share of the blow molding market with an 80 percent share. Blow molding modified extrusion and injectionmolding process characteristics hollow thinwalled parts of various sizes high production rates low cost for. Blow molding is a manufacturing process that is used to create hollow plastic parts by inflating a heated plastic tube until it fills a mold and forms the desired shape.
Extrusion blow molding can be operated as either a continuous or semicontinuous process depending on the requirement. Parison not being blown defective blow timer, clogged blow lines, or too sharp pinch. Blow mould design free download as powerpoint presentation. For additional troubleshooting information, contact your dow. The material and process sections especially give more experienced people a better understanding. Chapter 2 injection moulding process injection moulding is the most widely used polymeric fabrication process. When your project requires a specific engineered material, it becomes either a lowvolume injection molding or production injection molding project. The injection molding handbook is primarily written for engineers, processors. Pdf design optimization of the blow moulding process using a. As a result, molded parts with solid external skin and porous inner core are obtained. Under moderate rates of shear, hdpe is moderately viscous. The custompak blow molding design guide provides you with basic design tools for making engineered blow molded parts. Eastar copolyesters for extrusion blow molding are clear thermoplastic polymers with a glass transition temperature t g of approximately 8084c 176183f. No two designs are alike, so the mold and process must be adjusted to optimize each design.
Extrusion blow molding series our extrusion blow molding training programs were developed in collaboration with the society of plastics engineers spe and were designed to provide participants with a thorough understanding of whats involved in extrusion blow molding. Characterization of key process parameters in blow molding using artificial neural networks. With a molded in texture, the finish color comes from the base material and then the texture, which is etched into the mold surface, is produced on the part during the pressure forming process. Press injection blow molding sarlink is an excellent material to use in a press injection blow molding system. Blow molding explained manufacturing solutions group. Blow molding troubleshooting guide introduction this guide indicates possible causes and corrective actions for problems typically encountered in the blow molding process. A within a split mold cavity, air pressure is applied to a heated plastic material called a parison that expands similar to a balloon and. Aug 01, 2007 challenges in blow mold design blow mold design and build requirementsas well as challenges and how to overcome themthrough the use of a new rotary blow molding wheel system. The mold temperature should be set just above the dew point of the ambient air. It contains a description of the extrusion manufacturing process, compatible materials, and principles of design.
Pdf the results of heat flow simulation in a flash pocket of an extrusion blow mould, made using. Discover formolene high density polyethylene for blow molding when success is essential, formosa is your quality choice. The injection blowmolding ibm machines shown in figures 1 and 2, even though produced by different injection blowmolding machinery manufacturers, can use tooling designed for either machine with slight mold design changes be. Each sheet is then vacuum formed to its corresponding mold with the two sheets fused.
It is also used for forming glass bottles or other hollow shapes in general, there are three main types of blow molding. Modification and development of a blow molding machine. Jun 19, 2014 plastic blow molding processes are the most popular methods used to produce hollow products out of thermoplastic materials. When blow molding whether it be a container, or an industrial part, particular attention should be made to ascertain the best pinchoff design is used in the tooling. Roughly 95% of all molding machines now use screws to efficiently heat, mix, and inject plastic into molds. In addition, as for high viscosity material such as pc, because torque is big, the fatigue failure. The injection blow molding ibm machines shown in figures 1 and 2, even though produced by different injection blow molding machinery manufacturers, can use tooling designed for either machine with slight mold design changes be. The most common representation of the parison swell is. Your quote worksheet will present you with the currently available materials. Ottmar brandau has written and edited 4 books for the pet industry. Characterization of key process parameters in blow molding. The plastic extrusion design guide is intended to help you optimize your plastic profile design and drive cost out of your part. Blow mould design polyethylene organic polymers scribd.
I found the information extremely helpful allowing me to begin connecting the dots if you will of. Pdf blow moulding is the forming of a hollow part by blowing a mould. A cylindrical reservoir that is fed melted resin from the extruder. Blow molding extrusion blow molding is manufacturing process that forms hollow thermoplastics. Blow molding moulding is a specific manufacturing process by which hollow plastic parts are formed and can be joined together.
In plastic injection molding, heated plastic and is fed into the mold, which forms into the part as it cools. Parison not being blown defective blow timer, clogged blow lines, or too sharp pinchoffs replace blow timer clean blow lines stone pinchoffs to create more pinch area reset cushion clean tooling 2. Blow molding manufacturing design considerations engineers edge. In extrusion blow molding a plastic material feedstock is fed through a hopper onto a feeding transfer screw. Characteristics of the typical blow molding equipment for sarlink. Guidelines for the blow moulding of sarlink distrupol. Blow molding is performed using a wide variety of production methods.
The mold halves are oriented relative to the parison such that the parting line between the mold halves is aligned with the view stripe of the parison. Blow molding design guideline blow molding design guideline 3 radii corners material will freeze when it comes into contact with the mold, causing it to stretch into corners if parison is trapped pinched off at parting line, it must stretch into the cavity preblowing the parison prior to mold closure helps minimize stretch. There are a wide variety of textures available to select from. Troubleshooting guide for blow molding problem possible causes possible solutions 1. Guide to extrusion blow blow molding advisors at apex. This guide is meant to provide the extrusion blow mold processor with a reference document on how to design molds, process and produce product from aes. Guide to extrusion blow blow molding advisors at apex container tech inc. Instead a large force must be used to inject the polymer into the hollow mould cavity. They were usually only used in mass production where thousands of parts were being produced. In general, there are three main types of blow molding. The two most common types of blow molding are extrusion blow molding and injection blow molding with many variants related to handling of the thermoplastic melt and molds. Blowmold design and the specification of process parameters require skill and precision.
Compression molding process is followed by two step first one preheating and pressurizing compression molding is generally used for. Spmbs1605 extrusion blow molding with eastman copolyesters. The measurements were made at a weight of 21,6 kg and at a temperature close to the typical processing. This is a new book written to give engineers, operators, sales people, and managers practical and useful information in their daily business. It is not, however, intended to provide a complete listing of all blow molding challenges and problems. The topics covered in this training series include a wide range of. Extrusion blow molding an overview sciencedirect topics. A comprehensive experimental study and numerical modeling of. Ottmar brandau started as service engineer with bekum in 1978 and has since then worked on a large number of machines of various types and manufacturers besides being involved in product design, plant layout and sales. The sb 24 station monolayer system from wilmington machinery has a fourinch extruder for 90ml liquid yogurt bottles. The injection machine is constructed of a mold clamping device that opens and closes the mold tool, and.
Machines and moulds, processing 50 basic principles 50 machines and moulds 51 processing 52 design of the preform 52 injection moulding the preform 55 blowing the preform 58 general notes on processing 59 qenos blow moulding grades 60 chemical resistance 60 appendix 1 blow moulding. This will maximize cooling and minimize surface defects, including surface blemishes from. When blow air is injected into the mold to mold the parison to the desired. Therefore, the design of the flow path without dead space by taking enough r so as not to provide the corner as much as possible is expected. Viscoelastic simulation of pet stretchblow molding process. Blow molding cannot produce features that project from the surface such as ribs and bosses. Blow molding is one of the well known manufacturing. The pinchoff areas pinch the ends of the plastic parison and seal the edges together when the blow mold closes. The main concept of plastic molding is placing a polymer in a molten state into the mold cavity so that the polymer can take the required shape with the help of varying temperature and pressure. Melt index mfi values have been measured on zytel blow moulding resins and are shown in table 1. Design and manufacturing of plastic injection mould. Part geometry determines mold and equipment costs, which can. This process is also known as the ossberger process, named after the equipment manufacturer. In the injection blow molding process, custom mold and design manufacturers injectmold the starting parison instead of extrude it.
870 740 315 768 1299 655 936 367 341 1238 1461 1413 1111 122 626 849 1287 137 727 860 1046 39 1331 1445 782 322 550 31 674 1367 393 8 1104 480 1362 576 836 299 1375 886