The main characteristics or the properties which determine a plastics processability are molecular weight, uniformity, additive type, content and plastic feed rates. Any particular plastics performance across these criteria can vary widely. Just like other forms of plastic molding, after the molten plastic is injected into the mold, the mold is cooled and opened to reveal a solid plastic part. Variations may occur as far as cases and technical parts are concerned. An overview of the plastic material selection process for medical devices february 20 the d. Typical reactions for chain assembling are polyaddition continuous or step wise and condensation polymerization polycondensation 1 figure 1.
Thats why youre able to reheat your leftovers in tupperware without worrying about it melting. An overview of the plastic material selection process for. These two definitions of true strain are equivalent in the plastic range where the material volume can be considered constant during deformation as shown below. Therefore, to determine the exact density of plastic, it is. Many complex plastic compounds require a rigorous spectral or destructive chemical analysis for a positive identification. A simple guide to plastic molding processes, best uses. Such a material iselastic accordingtothedescription ofelasticity given earlier immediate response,fullrecovery, andit is also linear in its relation between stress and strain or equivalently, force and deformation. This paper presents an overview of the plastic material selection process, with specific emphasis on the unique requirements of. It is available in the form of liquid at room temperature.
Pvc type 1 typical properties property units value 1 astm method physical properties density gcm3 1. Items such as disposable coffee cups, plastic food boxes, plastic cutlery and packing foam are made from ps. Definitions of plastic material types adapted from the. This information will help you sort plastic materials more effectively for recycling.
Plastics are essential materials of modern day life. Polymethylmethacrylate pmma plastic sheet it is a versatile material. Each type of filler lends a unique property set to the host polymer. Although the information and statements herein are believed to be accurate, no guarantee of their accuracy is made. Some of them are reusable, the others produce hazardous material after several uses. These numbers and labels identify both the type of resin used to make the plastic and the products recyclability. This property of plasticity, often found in combination with other special properties such as low density, low electrical conductivity, transparency, and toughness, allows plastics to be made into a great variety of products. Material type acronym pet hdpe lope eps other plastic identification code full polymer names po,hyetnylene terepntnalate high density polyethylene potpinyl chloride unplasticised. It is important to note that density varies with temperature. The ultimate objective of a failure analysis is to ascertain the mode and the cause of the failure, regardless of the material from which the part was fabricated. It is calculated by dividing the mass of the material by the volume and is normally expressed in gcm 3. The two principle types extruded and cast have similar properties, but extruded sheet can be vacuum formed whereas cast sheet can be pressed. The plastic properties on pages 222223 are exclusively applicable for the specified standard test pieces.
For chemically resistant plastic, view our chemical resistance of plastics chart. The density of a plastic sample may change due to change in crystallinity, loss of plasticizers, absorption of solvent, etc. This quiz is comprised of multiplechoice questions designed to test your level of understanding of the material covered in the continuing education article, frame materials. This type of plastic is strong and can usually withstand higher temperatures. Plastic material is a term that refers to a large class of polymers, separated into various groups and subgroups. Fillers are an extremely diverse group of materials. What is a major cause of getting static electricity shocks. A resin is judged by any number of criteria strength, toughness, aesthetics, etc. Within manufacturing technology there is a very high degree. While most elastomers are thermosets, thermoplastics are in contrast relatively easy to use in manufacturing, for example, by injection molding.
Types ofmaterial used in food packaging material use appearance i properties temperature cost toler. Any particulate material added to a plastic will behave like a filler. Characterization of plastics in failure analysis jeffrey a. Smart plastics guide plastic products are typically labeled with a number surrounded by the recycling symbol. Frame materials you must be an aoa associate member and answer seven of ten questions successfully to receive one hour of continuing education credit.
Code 7 is used to designate miscellaneous types of. The plastic and packaging material used by okw are on the whole harmless and, apart from some exceptions, can easily be recycled and reutilized. Injection molding is the process of making custom plastic parts by injecting molten plastic material at high pressure into a metal mold. Caused by the macromolecular structure and the temperaturedependent physical properties plastic materials are distinguished into different. Greene, csu 7 medical plastics and composites use containers bottles, bags drug delivery iv bags, syringes tubing and tools for surgery implants, artificial skins the use of plastic materials in the medical field, about. Use our interactive properties table below to explore by property group, sort, or compare two or more plastic materials.
Plastic marked with an spi code of 6 is made with polystyrene. A plastic with good processability possesses the properties necessary to make it easy to process the plastics into desired shapes. Engineering plastics are a group of plastic materials that have better mechanical andor thermal properties than the more widely used commodity plastics such as polystyrene, pvc, polypropylene and polyethylene being more expensive, engineering plastics are produced in lower quantities and tend to be used for smaller objects or lowvolume applications such as mechanical parts, rather than. The investigation is performed in generally the same manner, whether the failed component was. Also, you may want to use our plastic material selection guide or interactive thermoplastics triangle to assist with the material selection process based on your application requirements. Caused by the macromolecular structure and the temperature dependent physical properties plastic materials are distinguished into different.
Thermoplastic polymers are represented by a large range of plastic materials. Associated with the different types of resin are potential health risks. A buildup of charges due to dry skin rubbing on clothes. Since the previous edition, several new materials have been. A material that can burn is described as flammable. The society of the plastics industry spi established a classification system in 1988 to allow consumers and recyclers to identify different types of plastic. Usually a chemical reaction involves a transformation of the sample into a different. Both types of plastic materials are recyclable and it is possible to produce bio degradable plastics with both types of feedstocks.
Acrylics are available in a range of colours and can be opaque, translucent or transparent. Before starting the chapter on the uses and subsequent recycling of plastic, let us establish a general classification of these thermosetting resins or thermoplastics the two big groups into which we include elastomers by detailing their properties, their makeup, their. They are available in sheet, rod, and tube for use in injection moulding, extrusion and vacuum forming. Plastic material properties table mechanical, physical. Bridging the gap between theory and practice, it enables scientists to understand the commercial implications of their work as well as providing technologists with a theoretical background. Polystyrene is commonly recycled, but is difficult to do. The seventh edition of this classic reference work once more provides a comprehensive overview of commercially available plastics materials. The properties of thermosetting plastic material are as follows. See a full breakdown of each kind of plastic, along with its. To initially determine whether a material is thermoset or thermoplastic, heat a stirring rod to about 5000f2600c, the material is a thermoplastic. S flexible packaging market by material plastic film.
1587 748 510 1100 693 636 805 254 498 1555 952 663 564 918 1099 899 1191 1507 1251 1317 1244 602 271 1413 326 5 848 459 991 1321 74 1469 1228 1012 124 1425