Kdi

Figure 2.13 Stress-strain curves for various materials (a) Reinforced plastics (b) wood and most metals and (c) steel. (From Charles A. Harper, Handbook of Plastics, Elastomers, and Composites, 3d ed., McGraw-Hill, New York, 1996, p. 2.3.) Figure 2.13 Stress-strain curves for various materials (a) Reinforced plastics (b) wood and most metals and (c) steel. (From Charles A. Harper, Handbook of Plastics, Elastomers, and Composites, 3d ed., McGraw-Hill, New York, 1996, p. 2.3.) serving as the...

Info

AMaterials Engineering, Materials Selector Issue, vol. 66, no. 5, Chapman-Reinhold Publication, mid-October 1967-1968. b'Insulation, Directory Encyclopedia Issue, no. 7, June-July 1968. cH. Lee and K. Neville, Epoxy Resins, McGraw-Hill, New York, 1966. dTucker, Cooperman, and Franklin, Dielectric Properties of Casting Resins, Electronics Equipment, July 1956. eJ. H. Freeman, A New Concept in Flat Cable Systems, 5th Annual Symposium on Advanced Technology for Aircraft Electrical Systems,...

976 Polycarbonate

Polycarbonate parts lend themselves to all mechanical assembly methods. Polycarbonate parts can be easily joined by solvents or thermal welding methods they can also be joined by adhesives. However, polycarbonate is soluble in selected chlorinated hydrocarbons. It also exhibits crazing in acetone and is attacked by bases. When adhesives are used, epoxies, urethanes, and cyanoacrylates are chosen. Adhesive bond strengths with polycarbonate are generally 1000 to 2000 lb in2. Cyanoacrylates,...

533 Pipe extrusion

Pipe extrusion and its variants are used to produce pipe, hose, and tubing. As illustrated in Fig. 5.48,110 the extruder pumps molten polymer through an annular die. The tube of molten polymer is then pulled into a calibration unit where the extrudate dimensions are finalized and the melt is cooled. Finally, the puller draws the cooled product into the wind-up or stacking unit. The components of a pipe extrusion line include an extruder, annual die, calibration system, cooling system, puller,...

Carl P Izzo

Industrial Paint Consultant Export, Pennsylvania Almost from the beginning, humans have used coatings and finishes. Biblical history reports that Noah received divine instructions to paint his ark with pitch. Amber was mixed with oils to make decorative varnishes by the Egyptians. White lead was mixed with amber and with pitch by the Romans. From cave dwellers decorating their walls with earth pigments ground in egg whites to factory workers protecting products with E-coat primers and urethane...

Pullin Cylinder

Figure 5.56 Two-stage screw-plunger injection-molding machine.128 through the barrel. However, injection-molding screws, unlike extrusion screws, end with a nonreturn valve. Once molten plastic flows over or through this valve, it cannot stream back toward the feed throat during the injection phase of the molding cycle. While the melt will flow out of an open nozzle, the nozzle is typically in contact with the mold. Thus, discharge from the nozzle is blocked by the sprue of Figure 5.57...

352 Butadiene rubber BR and polybutadiene PB

Budene * solution polybutadiene (solution polymerized) is cis-1,4-poly(butadiene) produced with stereospecific catalysts which yield a controlled MWD, which is essentially a linear polymer.6 Butadiene rubber, polybutadiene, is solution-polymerized to stereospecific polymer configurations10 by the additional polymerization of butadiene monomer. The following cis- and trans-1,4-polybutadiene isomers can be produced cis-1,4-polybutadiene with good dynamic properties, low *Budene is a registered...

351 Acrylonitrile butadiene copolymers

Nitrile butadiene rubbers (NBRs) are poly(acrylonitrile-co-1,3-butadi-ene) copolymers of butadiene and acrylonitrile.23 Resistance to swelling caused by oils, greases, solvents, and fuels is related to percent bound acrylonitrile (ACN) content, which usually ranges from 20 to 46 .6 Higher ACN provides higher resistance to swelling but diminishes compression set and low temperature flexibility.6 ACN properties are related to percent acrylo and percent nitrile content. Nitrile increases...

1253 Composting

Composting of municipal solid waste in the United States is still in its infancy. According to BioCyle, 18 such facilities are currently in operation, and two are under construction.158 Some facilities process a mixed waste stream and others process source-separated organics (that is, the generators of the waste separate the compostable organics from the noncompostable wastes). Generally, the source-separated organics stream contains paper and food waste, and does not include any plastics. Some...

721 Introduction

We begin with some definitions of the acronyms used in this section. The term computer-aided drafting (CAD) is part of common language today and refers to the use of computers for drafting and modeling of product designs. In a sense, CAD is the technological backbone that provides opportunities for concurrent engineering and for the subsequent use of CAE and CAM. The CAD industry has seen tremendous growth since its inception in the 1970s and continues to grow with advances in both technology...

Carol M F Barry Stephen A Orroth

University of Massachusetts Lowell, Massachusetts McKelvey1 defined plastics processing as operations carried out on polymeric materials or systems to increase their utility. These types of operations produce flow, chemical change, and or a permanent change in physical properties.1 Plastics processing techniques can be grouped into three categories Although forming operations always involve flow, thermoplastic processes, such as extrusion, thermoplastic injection molding, thermo-forming, and...

Thermoset shapes

Compression molding, bulk molding compound (BMC), sheet molding compound (SMC), low-pressure molding compound (LPMC), transfer molding, and thermoset injection molding Since many of the thermoset processes are best suited to large parts, two pecking orders exist in this area as well. Up to 1 ft2, the next step after machining and casting would, depending on part configuration, be either compression molding, transfer molding, or injection molding. All of these are processes which require...

6

Many of these processes and applications are described in articles and handbooks on the subject. The plastic resin manufacturer is generally the leading source of information on the proper methods of joining a particular plastic. Various theories attempt to describe the phenomena of adhesion. The adhesion theories that are applicable to plastic substrates are provided in the following sections. Mechanical theory. The surface of a solid material is never...

113592 E 831

At a cooling rate of 2.5 C min at 40, 80, 120, 160, and 200 MPa with an estimation at 1 MPa. DSC cooling scan 10 C min from processing temperature to 23 C. DSC cooling scan 10 C min from processing temperature to 23 C (11357-3). DSC cooling scan 10 C min from processing temperature to 23 C (11357-3). DSC cooling scan 10 C min from processing temperature to 23 C. DSC cooling scan 10 C min from processing temperature to 23 C. DSC cooling scan 10 C min from...

D 15095

ISO IEC methods as specified by ISO 10350-1 99 (Greater thickness may be used for those materials that cannot be molded reliably at 1-mm thickness.) Ibst specimens are of suitable shape and thickness determined by the material specification or by the accuracy of measurement required, and the frequency at which the measurements are to be made. Specimen conditioning, including any postmolding treatment, shall be carried out at 23 C 2 C and 50 5 RH for a minimum length of time of 88 h, except...

Ddr

Figure 5.41 The effect of (a) BUR on tensile strength, (b) BUR on tear strength, (c) DDR on tensile strength, and (d) DDR on impact strength.96 suitable for shrink-wrap films. Impact strength is also enhanced by the biaxial orientation while any blocking tendency decreases due to the rapid cooling. Although stretching the film washes out defects, which improves optical properties and gloss, the larger, more unwieldy tube produced at higher BURs reduces bubble stability. Increasing the take-off...

Ch3

Figure 1.37 The reaction to prepare polypropylene. Figure 1.37 The reaction to prepare polypropylene. form with a melting point of 165 C. Atactic polypropylene has a very small amount of crystallinity (5 to 10 ) because its irregular structure prevents crystallization, thus, it behaves as a soft flexible material.298 It is used in applications such as sealing strips, paper laminating, and adhesives. Unlike polyethylene, which crystallizes in the planar zigzag form, isotactic polypropylene...

1252 Effects of environmentexposure conditions

As was mentioned earlier, rates of biodegradation are very sensitive to environmental conditions. One result of this sensitivity is that degradation rates in modern municipal solid waste landfills tend to be quite slow. A key factor is the amount of water. When landfills were found to often be the source of pollutants entering groundwater systems, regulations were tightened to ensure that landfills would not generate substantial amounts of liquid effluent which could make their way into water...

7281 Increased use of threedimensional modeling

Today, a lot of design is still performed in two dimensions. Decreasing costs of high-performance computers, the relatively low cost of RAM, and falling prices of solid modeling systems will combine to increase the use of solids modeling in all facets of the plastic industry. Increased use of solids modeling will lead to increased use of 3D CAE and interfacing to CAM. Figure 7.68 A gas-injected part. Such a complex shape requires three-dimensional analysis to accurately simulate the...

91

Is these material properties that must occupy the designer's early attention, and this chapter will elaborate on these. The reader should consider the individual plastic supplier as an excellent source of information on fabricating and finishing processes for specific types of plastic materials. Generally, this information is readily available because the plastic resin producers benefit by providing the most complete and up-to-date information on how their materials can reliably and...

700

In cutting threads, either by tapping with serial taps or threading with die and die stock, frequent stops should be made. The tap or die should be backed off occasionally to clear the thread and remove the chips. A coolant or lubricant is not essential, but, if available, its use is recommended to minimize heat and to flush away chips. Because of the elastic recovery of most plastics, oversized taps should be used. Oversized taps are commercially available. Taps with slightly negative rake and...

010

*Values represent weight percent of total. source From Ref. 12, p. 2.6. *Values represent weight percent of total. source From Ref. 12, p. 2.6. The press may have 24 platens making a press load of some 240 laminates each cycle. After molding, the laminates are trimmed to final size and sometimes postcured by heating them in ovens. Physical and mechanical. The use of reinforcements in combination with thermosetting resins will produce laminates exhibiting higher tensile, compressive, and...

D732

These data are based on testing of laboratory test specimens and represent data that fall within the standard range of properties for natural material. Colorant or other additives may cause significant variations in data values. source Courtesy Ticona. These data are based on testing of laboratory test specimens and represent data that fall within the standard range of properties for natural material. Colorant or other additives may cause significant variations in data...

538 Coextrusion

Coextrusion permits multiple-layer extrusion of film, sheet, pipes, tubing, profiles, wire coating, and extrusion coating. It is used mostly in packaging applications to obtain desired barrier properties. The process eliminates the need for a laminator for plastic-plastic surfaces, is less expensive, and provides property enhancement. Coextrusion is applicable to most extrusion processes. Multiple extruders feed into the process. Two techniques, feedblocks and multi-manifold dies, are used to...

203

Stalk height depends on material properties and processing conditions. Typically, low-density polyethylene has a short stalk, whereas high-density polyethylene (HDPE) has long stalk.93 When the molten tube expands, it stretches the film in the transverse direction. A measure of this transverse stretching of the bubble is the blow-up ratio (BUR) Db 0.637WLF BUR - (5.20) where Db is the stabilized bubble diameter, Dd is the die diameter, and Wlf is the lay-flat width. The BUR is...

Oo

N H2N-(-CH2 -NH2 + n HO -C -CH -C-OH Nylons are relatively insensitive to nonpolar solvents, however, because of the presence of the polar groups, nylons can be affected by polar solvents, particularly water.95 The presence of moisture must be considered in any nylon application. Moisture can cause changes in part dimensions and reduce the properties, particularly at elevated temperatures.96 As a result, the material should be dried before any processing operations. In the absence of moisture...

7283Extension of threedimensional analysis

From the analysis side, there is no doubt that the introduction of three-dimensional techniques will increase. While existing technology for 3D FEA is notable for its ability to deal with thick components, it is also a platform technology for future developments in simulation. Considerable improvement in simulation for co-injection, gas injection, and warpage are possible with a three-dimensional approach. For example, the gas-injected part shown in Fig. 7.68 is very difficult to model with...

0150

Beck, Plastic Product Design, Van Nostrand Reinhold Company, Inc., New York, 1980. source R. D. Beck, Plastic Product Design, Van Nostrand Reinhold Company, Inc., New York, 1980. Figure 8.34 Co-extrusion design examples (a) cap sheet (b) hollow bumper and (c) two-color strip. Figure 8.34 Co-extrusion design examples (a) cap sheet (b) hollow bumper and (c) two-color strip. imbalance during extrusion. Figure 8.34 depicts several examples of co-extrusion designs. 8.3.7 Gas-assisted...

100 200

Figure 7.55 Graphs of pvT data for amorphous (left) and semicystalline (right) polymer. fill patterns. The mold has two main functions in injection molding. The first is to form the shape of the part to be manufactured and the second is to remove heat from the mold as quickly as possible. Frequently the injection mold is a complex mechanism with provision for moving cores and ejection systems. This complexity influences the position of cooling channels which, in turn, can lead to variations in...

74

On terephthalic acid, p-hydroxybenzoic acid, and p,p'-dihydroxy-biphenyl, while Vectra is based on p-hydroxybenzoic acid and hydroxynaphthoic acid.176 These materials are known for their high-temperature resistance, particularly heat-distortion temperature. The heat-distortion temperature can vary from 170 to 350 C. They also have excellent mechanical properties, especially in the flow direction. For example, the tensile strength varies from 165 to 230 MPa, the flex-ural strength varies from...

300

Quantity of catalyst acting to either accelerate or inhibit the curing rate in both the production and the molding phases. Lubricants which provide a measure of flow promotion, mold release, and barrel life during molding are generally internally supplied but are occasionally provided as an external addition. All ther-mosetting molding compound colors are opaque, with the pigments or dyes heat stable within the molding process temperature range of 200 to 400 . Coloring does have a large effect...

Ii

Figure 2.10 Structural formula for poly(amide-imide) resin. (From Charles A. Harper, Handbook of Plastics, Elastomers, and Composites, 3d ed., McGraw-Hill, New York, 1996, p. 1.64.) The diversity of isocyanate chemistry, combined with the availability of selective catalysts, has made it possible to select reactions which fit desired modes and rates of processing. Table 2.1 lists some of the known polymer-forming reactions of the iso-cyanates. Chemical characteristics.9 The silicone family...

799

Flow analysis in which the flow of a material through a defined Mechanical analysis where motion of a linkage or mechanical system is determined. Regardless of the type of analysis, all CAE involves the use of a mathematical model that simulates the physical process or conditions to which the design is exposed.1 The mathematical model is typically a set of equations, usually involving partial derivatives and suitable boundary conditions to ensure a unique solution. In order to implement the...

S

Charpy rw& zhcc impact strength kjj'rr5 Charpy rw& zhcc impact strength kjj'rr5 Figure 11.15 Illustration of the scatter diagram of DTUL at 1.8 MPa against Charpy notched impact strength for selected products. Figure 11.16 Illustration of the spider diagram display feature in CAMPUS. Figure 11.16 Illustration of the spider diagram display feature in CAMPUS. for processing simulation, pvT data, and DSC curves were included in the latest version 4.1. Through close cooperation with designers...

7173 Drying time and airflow

You might think it is easy to monitor drying time. If a given material requires 4 h of drying time, the hopper capacity is 500 lb, and the machine throughput rate is 100 lb h, then keeping the hopper at least four-fifths full at all times should ensure adequate drying when the correct air temperature and dewpoint settings are maintained. Remember, though, that time in the hopper is not necessarily effective drying time. If dryer airflow is not sufficient to keep the correct amount of material...

O

Figure 1.41 General structure of a polysulfone. Polyaryl sulfones are stiff, strong, and tough polymers with very good chemical resistance. Most fuels, lubricants, cleaning agents, and hydraulic fluids will not affect the polymer.355 However, methylene chloride, dimethyl acetamide, and dimethyl formamide will dissolve the polymer.356 The glass transition temperature of these polymers is about 210 C with a heat-deflection temperature of 205 C at 1.82 MPa.357 PAS also has good hydrolytic...

537 Extrusion coating

In extrusion coating (Fig. 5.53121), a layer of molten polymer is applied to a substrate such as paper, plastic, or metal foil. When the substrate is fed into the extrusion line, it is often preheated and may be pretreated to enhance adhesion. Then an extruder pumps molten plastic onto the substrate. The coated material is then cooled by chill rolls and collected on a wind-up roll. Auxiliary equipment, such as slitters, corona discharge stations, and printing heads, may be placed between the...

04

*Tested in humidity chamber after 30 days at 70 C (158 F) and 100 relative humidity. source Directory Encyclopedia Issue, Insulation Circuits, June July 1972. *Tested in humidity chamber after 30 days at 70 C (158 F) and 100 relative humidity. source Directory Encyclopedia Issue, Insulation Circuits, June July 1972. Allylic monomers are sometimes used with alkyds to produce polyesters, with the orthophthalate resin being the most widely used because of its lower cost and very low water vapor...

12415 Carpet recycling

In the past several years, interest in the recycling of carpeting has grown substantially. Most efforts have focused on commercial carpeting. It is estimated that about 1.7 million tons of waste carpet are landfilled in the United States each year, most of it during construction or remodeling of office space. Carpet is typically formed by bonding a face fiber onto a backing fiber, most commonly using a styrene-butadiene adhesive which incorporates fillers such as calcium carbonate. The face...

70

Owing to their chemical resistance and ease of decontamination from chemical, biological, and radiological warfare agents, they are widely used for painting military land vehicles, ships, and aircraft. They are used on automobiles as coatings for plastic parts and as clear topcoats in the basecoat-clearcoat finish systems. Low-temperature baking polyurethanes are used as mar-resistant finishes for products that must be packaged while still warm. Polyurethanes are used in an...

D 286397

80 x 10 x 4 mm cut from the center of the ISO 3167 multipurpose specimen (ISO 4589-2, Form 1). Specimen conditioning, including any post molding treatment, shall be carried out at 23 C 2 C and 50 5 RH for a minimum length of time of 88 h, except where special conditioning is required as specified by the appropriate material standard. As received, unless otherwise agreed upon. Test chimney dimensions of 450 mm in height x 75 mm minimum diameter cylindrical bore. The upper outlet shall be...

165225

Cleaning will remove oily soils and mold release agents but additional pretreatment may be needed on certain plastic surfaces to ensure adhesion. Many of the plastic substrates are chemically inert and will not accept coatings because of their poor wettability. Depending on their chemical composition, they will require mechanical, chemical, and physical pretreatment or priming to enhance coating adhesion. Since mechanical pretreatment consists of abrasion, its effect on the substrate must be...

T

Figure 11.12 Type S and L tensile impact specimens (ASTM D 1822-93). relevant ISO IEC and ASTM standards are provided in Appendices 1 and 2, respectively. The most significant differences between the two approaches are the use of the Charpy impact strength instead of the Izod impact strength and melt volume rate (MVR) in addition to the melt mass flow rate (MFR). Charpy impact strength for plastics is rarely reported in the United States, and very few resin producers and almost no processors in...

724 History of Injection Molding Simulation

Injection molding was practiced a long time prior to the advent of simulation. While the observation that part quality was affected by processing was well known, due to the complex interplay of the factors mentioned earlier, injection molding was something of an art. Experience was the only means of dealing with problems encountered in the process. An overview of this approach is given in Ref. 16. The bibliography of Ref. 16 cites hundreds of empirical studies, each contributing to the...

95 Adhesive Bonding

Adhesive bonding presents several distinct advantages over other methods of fastening plastic substrates. These are summarized in Table 9.7. Solvent and heat welding may be considered, as a type of adhesive bonding process where the adhesive is actually part of the substrate itself. Bonding, as a method of assembly, is often preferred when different types of substrates (for example, metals to plastics) need to be joined, when high-volume production is necessary, or when the design of the...

24

Polymerization is performed using sequential anionic polymeriza-tion.339 The copolymers are better known as thermoplastic elastomers, but copolymers with high styrene contents can be treated as thermoplastics. The polymers can be prepared as either a star block form or as a linear, multiblock polymer. The butadiene exists as a separate dispersed phase in a continuous matrix of polystyrene.340 The size of the butadiene phase is controlled to be less than the wavelength of light resulting in...

1264 Polysaccharides

A limited amount of research has been directed at polysaccharides. Cellulose and thermoplastics derived from cellulose are members of this family, of course, as are starch-based polymers. It is well known, as mentioned earlier, that biodegradation is influenced by the degree of modification of the basic structure of the cellulose as well as by its crystallinity. In 1990, Japanese researchers were investigating the use of selected natural polysaccharides to produce biodegradable plastics with...

12412 Compatibilization of commingled plastics

As discussed previously, one approach to the use of commingled plastics is to use them in wood-substitute and similar applications where the incompatibility between the various ingredients of the mix does not present severe problems. A different approach is to make the resins compatible in some way, hence improving the performance characteristics of the blend. The compatibilization can be done by the way the blend is processed, perhaps including some degree of control over the resins in the...

120

*Parts hardener per hundred parts resin. source Bahelite Liquid Epoxy Resins and Hardeners, Technical Bulletin, Union Carbide Corporation. *Parts hardener per hundred parts resin. source Bahelite Liquid Epoxy Resins and Hardeners, Technical Bulletin, Union Carbide Corporation. TABLE 2.7 Cast-Resin Data on Blends of Cycloaliphatic Epoxy Resins TABLE 2.7 Cast-Resin Data on Blends of Cycloaliphatic Epoxy Resins

025

Rates are sought by cable manufacturers.20 Low MW (Mooney viscosity, ML), high ethylene content copolymers, and terpolymers are used in medium-voltage cable formulations.20 With ethylidiene norbornene or hexadiene, EPDMs are good vulcanizates, providing improved wet electrical properties.20 When the diene vinyl norbornene is incorporated on the EPDM backbone by a gel-free process, a significantly improved EPDM terpolymer is obtained for wire cable applications.20 Other applications are...

20

Figure 12.32 PP recycling in the United States.2,45,46 Figure 12.32 PP recycling in the United States.2,45,46 gible (under 5000 tons), and no recycling of PP from the bags, sacks, and wraps category was reported. The total of 130,000 tons recycled gives an overall PP recycling rate of 5 .2 Recycling of PP battery cases also takes place outside the United States. Germany began such recycling in 1984, yielding about 3000 tonnes year of polypropylene. The process involves crushing the batteries...

92 Machining and Finishing

This section will discuss the major machining and finishing operations commonly used in the manufacture of plastic products Filing, grinding, and sanding Routing, milling, and turning Almost all molded articles require finishing to some extent, if only to remove flash and gates from the molding operation. Machining of plastic parts is normally employed only if there is no other way of designing the functional requirement (hole, rounded edge, etc.) into the primary molded part. Some finishing...

1

H + and h- are, respectively, the upper and lower z coordinates of the frozen layer position, k is the coefficient of compressibility, and H is half the wall thickness. With the additional assumption that convection in the z direction may be ignored, the energy equation takes the form The left-hand side of the energy equation represents the rate of change of temperature and convection, while the terms on the right-hand side account for heat of expansion compression, viscous dissipation, and...

1021

Figure 5.3 Velocity profiles (a) shear flow and (b) elongational flow. (Adapted from Ref. 11.) plastic fluids does not occur immediately. At low shear rates, the polymer molecules flow as random coils and the viscosity of the polymer melt is not affected by the increasing shear rate. The constant viscosity of this lower Newtonian plateau is called the zero shear-rate viscosity ( 0). As the shear rate continues to increase, the polymer chains begin to align in the direction of flow. Since less...

7271 Setting up the molding machine

This module, called Setup Xpert, enables systematic mold setup independent of operator and location. Mold setup can be done via A setup wizard that takes the user though a defined set of questions to generate the initial velocity and pressure profiles. Profiles obtained by CAE analysis. These are velocity versus screw displacement or time for the filling phase and pressure versus time for the holding phase. The module determines the best optimization route for each setup process, then starts...

7241 Early simulation of filling

In 1978, Moldflow introduced commercial software on a worldwide computer time-sharing system. This software enabled users to determine process conditions (melt temperature, mold temperature, and injection time) and to balance flow in cavities and runner systems. Although accepted at the time, this software was difficult to use as it required the user to produce a layflat.24 The layflat was a representation of the part under consideration that reduced the problem of flow in a three-dimensional...

7182 Mobile drying systems

An excellent alternative to machine-mounted drying, mobile systems (Fig. 7.47) are comprised of a dedicated dehumidifying dryer and hopper, mounted on a sturdy frame with casters for mobility. This system has Figure 7.47 Mobile drying-conveying systems like this one feature a dedicated dehu-midifying dryer and hopper, and vacuum or compressed air loader, mounted on a sturdy frame with casters for mobility. Figure 7.47 Mobile drying-conveying systems like this one feature a dedicated...

H 3w

Figure 8.14 Standing rib design (a) R 0.25W and (b) R 0.5W. (Source Jordan I. Rotheiser, Joining of Plastics Handbook for Designers and Engineers, Hanser Publishers, Munich-Hanser Gardner Publications, Inc., Cincinnati, 1999.) Figure 8.14 Standing rib design (a) R 0.25W and (b) R 0.5W. (Source Jordan I. Rotheiser, Joining of Plastics Handbook for Designers and Engineers, Hanser Publishers, Munich-Hanser Gardner Publications, Inc., Cincinnati, 1999.) minimum. If the rib is used for locating...

100 212

Dudgeon in Engineering Materials Handbook, vol. 1, Theodore Reinhart, Tech. Chairman, ASM International, 1987, p. 91. SOURCE Charles D. Dudgeon in Engineering Materials Handbook, vol. 1, Theodore Reinhart, Tech. Chairman, ASM International, 1987, p. 91. 2.62 Chapter Two TABLE 2.32 Epoxy Resin Selection Factors Adhesion to fibers and to resin No by-products formed during cure Solvent and chemical resistance High or low strength and flexibility Resistance to creep and fatigue...

0002

NOTE Does not include cavity tolerance. *Plus 0.250 cm for parting-line variation. source Glenn L. Beall, Rotational Molding Design, Materials, Tooling, and Processing, Hanser Publishers, Munich-Hanser Gardner Publications, Inc., Cincinnati, 1998. note This table refers to Fig. 8.37. NOTE Does not include cavity tolerance. *Plus 0.250 cm for parting-line variation. source Glenn L. Beall, Rotational Molding Design, Materials, Tooling, and Processing, Hanser...

7242 Simulation of packing cooling and variations of injection molding

Over the past decade, development has been rapid with simulation now available for the packing and cooling phases of the injection-molding process. Also, in the 1990s some variants of injection molding have been introduced. These include Co-injection, in which a charge of material is first injected and then followed by a second charge. This results in the second material forming the core of the part which is encapsulated with the first material. Gas injection, in which after introduction of...

1900

It is also used in safety helmets, riot shields, aircraft canopies, traffic light lens housings, and automotive battery cases. Design engineers take care not to design with tight radii where PC's tendency to stress crack could be a hindrance. PC cannot withstand constant exposure to hot water and can absorb 0.2 of its weight of water at 33 C and 65 relative humidity. This does not impair its mechanical properties but at levels greater than 0.01 processing results in streaks...

Tmc

Figure 2.20 Thick molding compound process (TMC). polyethylene bag. These compounds are also available in a rope form in any length or diameter specified by the customer. The shape is attained by feeding the doughy material through an extruder, with the extruder nozzle providing the desired shape and length. Quality assurance. Thermosetting compound production uses comprehensive quality assurance programs to ensure that the customer receives products that meet their specific specifications,...

346

This material is biaxially oriented into films and while it is mechanically weaker than PET, it offers superior water resistance and weather resistance.189 As seen in the introductory Table 1.4, PCT differentiates itself from PET and PBT by its high heat-distortion temperature. As with PET and PBT, PCT has low moisture absorption and its good chemical resistance to engine fluids and organic solvents lend it to under-the-hood applications such as alternator armatures and pressure sensors.190...

Pc

Beall, Rotational Molding Design, Materials, Tooling, and Processing, Hanser Publishers, Munich-Hanser Gardner Publications, Inc., Cincinnati, 1998. source Glenn L. Beall, Rotational Molding Design, Materials, Tooling, and Processing, Hanser Publishers, Munich-Hanser Gardner Publications, Inc., Cincinnati, 1998. undercut. If the undercut is too deep to be stripped, a side core which must be removed before demolding can be used. Holes can be molded-in rotational molded parts by...

196

*Heat-distortion temperature, C (stoichiometric amount of curing agent except BF3 MEA cured 15 h at 180 C). fNovolac resin, Dow Chemical Co. Epi-bis resin, Dow Chemical Co. The mixture reacts too quickly to permit proper mixing by hand. source Dow Epoxy Novolac Resins, Technical Bulletin, Dow Chemical Company. *Heat-distortion temperature, C (stoichiometric amount of curing agent except BF3 MEA cured 15 h at 180 C). fNovolac resin, Dow Chemical Co. Epi-bis resin, Dow Chemical Co. The mixture...

D

Crystallization is the competition between two processes nucleation and crystal growth. Nucleation is the formation of small sites (nuclei) from which crystallites can grow. Primary nucleation creates the initial nuclei. Crystallites develop around these nuclei. Then in secondary nucleation, the surfaces of the crystallites are nucleated. More polymer chains diffuse to the crystallite surfaces and growth continues. Crystallization is influenced by cooling rate, pressure, shear and orientation,...

Wz

CALIBRE* ZOO aerlea ses oai rel puifioae, l't listed PDascfectoritci teaiia ri> rouinrpii Tfl wmp'-y vifl arP f Mi T'A or.1 Bai dp pot Ei> gulaslc ifl goveEQi Ccod ecntaci111. lA-IEiRE DD series isain exh ali en excellent physical property balance c-C heat resistance., rcar-spicency ants 1143.51 t stcer-'Xth 'JLe LjU,ilU< - ' Oil series cai t- supplied vltfc t dcIO pmJsajje.- i IT steoi . . p .Jsay oc botju CALIBRE* ZOO aerlea ses oai rel puifioae, l't listed PDascfectoritci teaiia ri>...

175

Containing side branches of 1-butene most commonly, with 1-hexene or 1-octene also present. Density ranges of 0.915 to 0.940 g cm3 are polymerized with Ziegler catalysts which orient the polymer chain and govern the tacticity of the pendant side groups.222 High-density polyethylene (HDPE). HDPE is one of the highest-volume commodity chemicals produced in the world, in 1998 the worldwide demand was 1.8 X 1010 kg.223 The most common method of processing HDPE is blow molding, where resin is turned...

N H2C O CH2

Figure 1.4 Polymerization of formaldehyde to polyoxymethylene. above 270 C. It is important that processing temperatures remain below this temperature to avoid degradation of the polymer.5 Acetals are highly crystalline, typically 75 crystalline, with a melting point of 180 C.6 Compared to polyethylene (PE), the chains pack closer together because of the shorter C O bond. As a result, the polymer has a higher melting point. It is also harder than PE. The high degree of crystallinity imparts...

Hdpe Lldpe

Weight Polyethylene PC Polycarbonate HDPE High Density Polyethylene Figure 8.2 Classification of thermoplastics. (Source Laura Pugliese, Defining Engineering Plastics, Plastics Machining and Fabrication, January-February, 1999, Courtesy DSM Engineering Plastic Products.) The next level are the Engineering plastics which can be used for applications ranging up to 250 F. ABS is often considered an engineering plastic for its other properties although it cannot withstand this temperature level....

1261 Bacterial polyesters

One of the early truly biodegradable polymers was polyhydroxybu-tyrate valerate (PHBV). This is a member of the polyester family which is produced by certain types of bacteria when they have a diet which is carbon-rich but poor in some essential nutrient. Under these conditions, they produce polyhydroxybutyrate (PHB) as a food store to be called upon when carbon sources are less available. With manipulation of the diet, the bacteria can be induced to form a copolymer, PHBV, which has more...

Temperature Zones

Figure 5.21 Barrel temperatures for selected materials.51 While most melting or plastication occurs in the transition zone, the polymer can melt in the feed zone and may not be fully molten until well into the metering zone. Although the heater bands and cooling fans maintain the barrel at a set temperature profile, conduction from the barrel walls provides only 0 to 30 percent56 of the energy required to melt the resin. The remainder of the energy is generated from the mechanical motion of the...

Modern Plastics And Charles A Harper

1.2 Polymer Categories 1.4 1.3 Comparative Properties of Thermoplastics 1.79 1.6 Polymer Blends 1.83 References 1.85 Chapter 2. Thermosets, Reinforced Plastics, and Composites 2.1 2.2 Thermosetting Resin Family 2.2 2.3 Resin Characteristics 2.10 2.5 Liquid Resin Processes 2.13 2.7 Molding Compounds 2.38 References 2.88 Chapter 3. Elastomeric Materials and Processes 3.1 3.2 Thermoplastic Elastomers (TPEs) 3.1 3.3 Melt Processing Rubbers (MPRs) 3.24 3.4 Thermoplastic Vulcanizates (TPVs) 3.26 3.5...

7252 Cooling analysis

The cooling of the mold is a key factor in efficient production and quality. Generally, cooling systems are given too little priority in the mold design process. This is unfortunate as careful attention to cooling system design can reduce cycle time and so increase the productivity of the mold machine combination. Injection-molding cooling systems can be analyzed quite readily today. Generally, two analyses are done. The first concerns the flow of the coolant in the cooling system the second...

125 Overview of Plastics Degradation

Until the early 1970s, attention to plastics degradation, including biodegradation, was focused primarily on ensuring that the plastic materials being used were resistant to such degradation so that they could maintain their usability. Biodegradation and other types of degradation, such as photodegradation, were not always clearly differentiated. Further, the extent of degradation was frequently measured based on loss of useful properties, such as tensile strength, rather than on chemical...

Ath

Martin Marietta Martinswerke (Lonza) Melamine Chemicals Mikuni Smelting & Refining Mines de la Lucette Mitsubishi Gas Chemicals Morton International Nabaltec Nihon Seiko Nippon Chemicals Nyacol Products Occidental Laurel Sherwin Williams Showa Denko Soci t Industrielle et Sumitomo Chemical Sumitomo Metal Mining Teijin Chemicals Tosoh U.S. Borax & Chemical United States Antiomy Sales Velsicol Witco gen-based products where it can. Look for some rapid growth in the other flame-retardant...

Time

Figure 2.21 Typical thermosetting curve. In all of the following flow tests, with the exception of the Brabender, three elements are always kept constant during the testing procedure Amount of compound. Charge weight Mold temperature. Usually 300 F Molding pressure. Usually 1000 lb in2 Cup closing (test and mold) (Fig. 2.22). With the mold set at 300 F (148 C) and a molding pressure of 1000 lb in,2 a room temperature charge of compound is placed in the lower half of the mold and the mold is...

974Fluorocarbons Ptfe Ctfe Fep etc

Because of the lower ductility of the fluorocarbon materials, snap-fit and press-fit joints are seldom used. Rivets or studs can be used in forming permanent mechanical joints. These can be provided with thermal techniques on the melt processable grades. Self-tapping screws and threaded inserts are used for many mechanical joining operations. In bolted connections some stress relaxation may occur the first day after installation. In such cases, mechanical fasteners should be tightened...

180

Phenolic molding compounds have found worldwide acceptance in such diverse market areas as. Automotive (as seen in Figs. 2.14a, b, and c) Cytec Fiberite Occidental Chemical Plastics Engineering Company Plaslok Corporation Rogers Corporation Cytec Fiberite Occidental Chemical Plastics Engineering Company Plaslok Corporation Rogers Corporation Figure 2.14 (a) Transmission stator and reactor. Figure 2.14 (a) Transmission stator and reactor. Figure 2.14 (Continued)...

122 Overview of Recycling

For plastics recycling (or recycling of other materials) to occur, three basic elements must be in place. First, there must be a system for collecting the targeted materials. Second, there must be a facility capable of processing the collected recyclables into a form which can be utilized by manufacturers to make a new product. Third, new products made in whole or part from the recycled material must be manufactured and sold. While the end uses differ substantially for different plastics, there...

1998

Alliance of Foam Packaging Recyclers, EPS Recycling What's Next, Molding the Future, October, 1998, p. 1. 91. Eastman Kodak Recycles 50 Million Cameras, Plastics News, August 14, 1995, p. 10. 92. Snapshot of Recycling, BioCycle, June 1996, p. 88. 93. Myers, S., Recyclers of Appliances, Durables Looking to Germany's Proposals, Modern Plastics, March 1995, pp. 14-15. 94. A Noncatalytic Process Reverts Polystyrene to Its Monomer, Chemical Engineering, February 1993, p. 19. 95. Battery Council...

Pot Type Transfer Moulding

Pot Type Transfer Moulding

Figure 6.5 Schematic showing four steps in the vacuum potting process. with matched molds (that is, with two mold halves closed after the reinforcing material has been impregnated with the liquid to produce a smooth uniform surface on both top and bottom of the part) and with conveyors, curing ovens, etc. Figure 6.6 Hand lay-up process for producing highly reinforced parts with fiber matting and polyester, epoxy, or other thermosetting liquid resin systems. Figure 6.6 Hand lay-up process for...

359Polychloroprene neoprene CR

Polychloroprene is produced by free-radical emulsion polymerization of primarily trans-2-chloro-2-butenylene moieties.23 Chloroprene rubber possesses moderate oil resistance, very good weather and oil resistance, and good resistance to oxidative chemicals.10 Performance properties depend on compound formulation, with the polymer providing fundamental properties. This is typical of any polymer and its compounds. Chloride imparts inherent self-extinguishing flame retardance. *Acron is a...

124 Recycling of Major Polymers

The amount of plastics entering the municipal solid waste stream in the United States in 1996 is estimated at 19.7 million tons. The amount which was recycled was 1.1 million tons, or 5.4 of plastics generation (see Figs. 12.5 and 12.6). The remaining 18.7 million tons amounted to 12.3 by weight of total MSW discards.2 Recycling rates are significantly higher for some plastic materials than for others, and for some types of plastic products, as will be discussed in more detail in the following...

1 1

Figure 5.77 Orientation developed during filling. (a) Across the cavity thickness (b) along the length of the cavity.175 the screw rotates and builds up a new shot. Cooling is usually the longest part of the molding cycle because the part is cooled until it can be ejected from the mold. The ejection temperature is estimated using the heat deflection temperature or Vicat softening temperature, but parts are ejected as soon as the ejection process does not damage the part. Parts ejected at high...

Sae

J 1686 Classification System for Automotive Polypropylene (PP) Plastics10 J 1687 Classification System for Automotive Thermoplastics Elastomeric Olefins (TEO)11 J 2250 Classification System for Automotive Poly(Methyl methacrylate) (PMMA) Plastics12 J 2273 Classification System for Automotive Polyester Plastics13 J 2274 Classification System for Automotive Acetal (POM) Plastics14 J 2323 Classification System for Automotive Polycarbonate Plastics15 J 2324 Classification System for Automotive...

961 Thermal welding

Welding by application of heat or thermal welding provides an advantageous method of joining many thermoplastics that do not degrade rapidly at their melt temperature. It is a method of providing fast, relatively easy, and economical bonds that are generally 80 to 100 the strength of the parent plastic. The thermal welding process can be of two kinds direct and indirect. With direct welding, the heat is applied directly to the substrate in the form of either a heated tool or hot gas. Indirect...

Adhesive Completely Fills Irregularities

Figure 9.15 Illustration of poor (top) and good (bottom) wetting by an adhesive spreading over a substrate surface. adherend. The diffusion theory is primarily applicable when both the adhesive and adherend are polymeric. For example, bonds formed by solvent or heat welding of thermoplastics result from the diffusion of molecules. Weak boundary layer theory. According to the weak boundary layer theory, when bond failure seems to be at the interface, usually a cohesive break of a weak boundary...

Ethylene Propylene Diene Monomer Impact Modifier Sippliers

*PVC Polyvinylchloride. **PE polyethylene. fPP polypropylene. PA polyamide. PET polyethylene terephthalate PBT polybutylene terephthalate. *PVC Polyvinylchloride. **PE polyethylene. fPP polypropylene. PA polyamide. PET polyethylene terephthalate PBT polybutylene terephthalate. Methacrylate-butadiene-styrene (MBS). Methacrylate-butadiene-styrene represents the highest volume of the styrenic type impact modifiers. This modifier is used in transparent packaging applications due to its clarity....

329

Figure 3.9 Dynamic mechanical properties for different hardness grades over a range of temperatures. (a) 55 Shore A grades (b) 50 Shore D grades. (Source Ref. 8, pp. 12-13.) Figure 3.9 Dynamic mechanical properties for different hardness grades over a range of temperatures. (a) 55 Shore A grades (b) 50 Shore D grades. (Source Ref. 8, pp. 12-13.) bags, pharmaceutical packaging, wound dressings (U.S. Pharmacopoeia Class VI rating for biocompatibility). Special-purpose Santoprene grades meet flame...

356 Ethylene propylene copolymer EPM and ethylene propylene diene terpolymer EPDM

EPM poly(ethylene-co-propylene) and EPDM can be metallocene catalyst polymerized. Metallocene catalyst technologies include (1) Insite, a constrained geometry group of catalysts used to produce Affinity polyolefin plastomers (POP), Elite * PE, Nordel f EPDM, and Engage polyolefin elastomers (POP) and (2) Exxpol ionic metal-locene catalyst compositions used to produce Exact plastomer octene copolymers.24 Insite technology produces EPDM-based Nordel IP with property consistency and...

983 Plating

Electroless, electrolytic plating, and vacuum metallizing are processes used to deposit metal surfaces on plastics materials. However, metal surfaces can also be provided by adhesives or hot-stamp methods. Some finished plastic parts must have shiny metallic surfaces. Besides providing a decorative finish, metal coatings may provide an electrical conducting surface, a wear- and corrosion-resistant surface, or added heat deflection. Many plated plastics have drastically altered physical...

Contributors

Anne-Marie Baker University of Massachusetts, Lowell, Mass. (chap. 1) Carol M. F. Barry University of Massachusetts, Lowell, Mass. (chap. 5) Allison A. Cacciatore TownsendTarnell, Inc., Mt. Olive, N.J. (chap. 4) Fred Gastrock TownsendTarnell, Inc., Mt. Olive, N.J. (chap. 4) John L. Hull Hall Finmac, Inc., Warminster, Pa. (chap. 6) Carl P. Izzo Consultant, Murrysville, Pa. (chap. 10) Louis N. Kattas TownsendTarnell, Inc., Mt. Olive, N.J. (chap. 4) Peter Kennedy Moldflow Corporation, Lexington,...

942 Mechanical fasteners

A large variety of mechanical fasteners can be used for joining plastic parts to themselves and to other materials. These include machine screws, self-tapping screws, rivets, spring clips, and nuts. In general, when repeated disassembly of the product is anticipated, mechanical fasteners are used. Metal fasteners of high strength can overstress plastic parts, so torque-controlled tightening or special design provisions are required. Where torque cannot be controlled, various types of washers...

1 2345

Spiral Flow Test

Figure 2.24 Disk flow test and mold (II). Figure 2.24 Disk flow test and mold (II). circles numbered 1 to 5. A disk matching the 1 circle on the target will be designated as 1S flow, whereas a disk matching the 5 circle will carry a 5S flow. The higher the number, the softer the flow. Orifice flow I (test and mold) (Fig. 2.25). This flow test involves the use of a mold with a lower plate containing a cavity into which a measured quantity of room temperature compound is placed. The upper plate...

60

Laminates using thermosetting resins are superior in stability, thermal resistance, and electrical properties, with dimensional stability the most important due to stresses incurred within the laminate during the molding and curing process. Laminate thickness is limited by the thermal conductivity of the polymerizing resin and the thermal conductivity of the cured laminate. The laminate derives its heat from the press platens to begin the curing action, and the resin, as...

98 Decorating Plastics

Several decorating processes can be accomplished with plastic parts either during processing of the part, directly afterward, or before final assembly and packaging. The most inexpensive method of providing decorative designs on plastics is to incorporate the design into the mold or to apply the decoration as part of the molding operation. However, often this is not possible either because of mold complexity, the need to apply decorations to customers' specifications, or other reasons. This...

325 Polyamides

Polyamide TPEs are usually either polyester-amides, polyetherester-amide block copolymers, or polyether block amides (PEBA) (see Fig. 3.7). PEBA block copolymer molecular architecture is similar to typical block copolymers.10 The polyamide is the hard (thermoplastic) segment, while the polyester, polyetherester, and polyether segments are the soft (elastomeric) segment.10 Polyamide TPEs can be produced by reacting a polyamide with a polyol such as polyoxyethylene glycol or polyoxypropylene...

822 Shrinkage and the use of draft in plastic parts

The shrink rate is the amount the part will reduce in size as it cools from processing temperature to room temperature. It is described in terms as the amount of shrinkage per inch of part size. Thus, a piece part 1 in long made of a material with a shrinkage rate of 0.005 in in will require a mold 1.005 in long if the final part is to wind up a true 1 in in length. Mold dimensions for other sizes would be determined by using 1.005 as a multiplier. Thus, the mold for a 1.500-in dimension would...