Structural Foam Molding – Working with Complicated Designs

Structural Foam Molding – Working with Complicated Designs

For products which require a softer inner core and a hard outer surface, Structural foam molding guarantees tough and reliable wall sections. This type of molding process is generally used for medium to high volume production and produced on injection molding machines where a foaming agent is used to produce thick internal wall sections.

Depending on the processing method and the application, there are wide varieties of Polycarbonate plastic available in the market. There are different blends of Polycarbonate PC like ABS, Polyesters etc. which are normally used in the automotive industry. There are various processing methods associated with Polycarbonate which includes Injection molding, Vacuum forming, Extrusion, Structural foam molding and Blow molding.

Typically used for applications or products where the goal is to reduce the component weight and tension in the material needs to be avoided, Structural foam molding allows the designer to work easily with complicated designs because the material thickness can be varied between 4 and 10 mm, allowing for diverse designs. A high level description of the structural foam molding process includes use of an injecting propellant which creates the material structure with consistent shape and design throughout the product.

Among several advantages associated with Structural foam molding, one of the most interesting aspects is its ability to make lightweight yet extremely durable and strong products. However, one also needs to be aware that the product surface needs to be painted for a better visual appearance. The superior strength to weight ratio and the use of low pressure allows a wide range of flexible and complex designs, thereby making this process extremely popular.

The process involves use of a small amount of chemical blow agent inside the plastic material which makes the internal walls thicker. When the melted plastic gradually enters the mold cavity, foaming would create a plastic wall that solidifies into a great molding wall. This versatile process can be easily used with any thermoplastic which can be injection molded. The large plastic products have a solid skin and a cellular inner structure while keeping the weight lower which makes it a favorite for vehicles, sports equipment and aircraft.

The Process

Structural foam molding needs Nitrogen to be injected into the melt before it is injected into the mold. Once the solid wall is created, the core is retracted so that the pressurized gas can expand and create a uniform cellular structure. Used with most thermoplastic materials, the process allows for weight reduction without compromising on its high rigidity features. The molded material doesn’t warp and also there are no sink marks because of the dense skin and rigid core.

The dimensional stability and high impact strength allows for great processing flexibility. The structural foam molding process creates molded parts with a smooth and solid surface on the outside and a foam structure on the inside.

Thermoplastic Injection Molding – An Engineer’s Guide

Thermoplastic Injection Molding – An Engineer’s Guide

High quality products manufactured with great accuracy, quickly and in large numbers – Thermoplastic injection molding is definitely one of the most popular manufacturing methods. The use of thermoplastic materials has seen an upsurge due to the growing demands of manufacturing quality plastic products for diverse industries.

Thermoplastic, made from polymer resins becomes a homogenized liquid when heated and gets hardened when cooled. The materials used for Injection molding process brings in its own unique features while guaranteeing best performance. Apart from thermoplastic polymers, one can also use thermosetting plastic or Elastomer which provides equally great results with Injection molding.

Advanced injection molding techniques and molds have offered better prospects, reduced costs and better appearance of the end product. There are different types of thermoplastic materials which are used in the molding process like

  • ABS – With high impact strength, scratch resistance and durability Acrylonitrile Butadiene Styrene is in great demand for a wide range of applications. ABS is mostly used by the automobile industry for manufacturing radiator grilles, instrument panels, wheel covers and mirror housings. There are several consumer electronic goods like laundry irons, hair dryers, vacuum cleaners and many more which are manufacturing by thermoplastic injection molding process.
  • Polypropylene – This type of thermoplastic is generally preferred in industries where one needs high flexibility, lightness, great shape and longevity. Mostly used in the manufacturing and packaging industry because of its good chemical resistance and attractive shape, Polypropylene is used for manufacturing washing machine drums, automotive parts, plumbing equipment etc.
  • Acrylic – The hardness of Polymethyl Methacrylate is comparable to Aluminum and it finds great use in the manufacture of lenses, control panels etc. Last few years have seen a growing demand for thermoplastic injection molding manufacturing process.
  • Polyethylene – The high density material exhibits diverse characteristics like chemical resistance, high heat distortion temperature and stiffness making it ideal for manufacturing fuel tanks, refrigerator containers, food storage boxes etc.
  • Polystyrene – Characterized by high gloss, transparency and high strength, this type of thermoplastic polymer is used for manufacturing products of diverse colors. Ideal for use in packaging and toys industries due to its crystal clear quality. There is a higher impact variety of the same material which is used in the manufacture of toilet seats, refrigerator linings etc.

The thermoplastic injection molding process starts with the addition of pellets to a hopper. Thereafter, the material is passed through a heated barrel where the rotation of the screw initiates a shearing action causing the pellets to melt. The molten plastic is then pushed through the barrel towards the mold. The material is pushed at high pressure such that the mold cavities are completely filled. Once the cooling cycle ends, the mold is opened to release the molded parts manufactured by thermoplastic injection molding process.

There are few subcategories under injection molding process which includes mold labeling, foamed injection molding or gas assisted injection molding etc. Mass production without compromising on quality and price makes thermoplastic injection molding one of the most sought after engineering process of large scale manufacturing. It is important to understand that each of the thermoplastic processing technique is unique and can be tailored to suit your requirements. There are various diverse industries which benefits from the myriad advantages offered by thermoplastic injection molding process like Aerospace industry, Toy manufacturing, Household goods manufacturing, construction and many more.

Polyurethane Resin Impregnation

Polyurethane Resin Impregnation

In a variety of manufacturing and industrial processes, there’s a need for polyurethane resin impregnation – an easy process of filling porous material using polyurethane resins, as well as making it impervious. The process assists in addressing issues associated with micro porosity in powder-metal parts, metal castings, plastic composites, electronic components, welds, and additional porous substrates – if gone untreated, it might result in poor quality of surface finish and pressure leakage. It brings an immediate necessity of an in-demand resin impregnation technology which will treat any kind of porous issues and improves their potential, while simultaneously ensuring performance that is free of leaks.

Before exploring any further, let us understand more on Polyurethane Resin Impregnation technology. It’s amongst the most typical methods utilized to seal the voids and cavities between the wire windings, which result in improved electrical insulation. Also, the impregnation assists in decreasing vibrations by repairing the wires surroundings the windings. In plain terms, it’s a standard method of avoiding component leakage, and upgrading the surface treatment.

Polyurethane (PU and PUR) polymers, in this approach, are utilized as resin blend in order to seal open pores. There isn’t any secret that it’s a ‘resin of choice’ as it will come to surface coatings, electrical potting compounds, high performance adhesives, and surface sealants. They’re valued for their resin properties. Pressure, vacuum, and temperature include the main parameters utilized in Polyurethane impregnation processing. Make sure you provide maximum attention to the correct viscosity; otherwise incorrect viscosity might lead to stress cracks and incomplete saturation.

Polyurethane impregnation approach possesses numerous benefits. Let us examine look some major advantages of the same:

  • Boost in thermal conductivity
  • Better electrical insulation with minimal vibrations
  • No resin residuals on laminations and shafts
  • High bond strength
  • Develops a bonding effect upon the lamination
  • No presence of bubbles within the resin-winding mass
  • Accurate penetration of resin deep inside a variety of existing gaps

The most broadly utilized equipment for Polyurethane Resin Impregnation include vacuum potting, Hot Dipping, Roll Dip, and Trickling. You easily can discover numerous available choices in the marketplace for them. But, what’s important is that you select the proper machine from the proper dealer.

While planning to purchase an impregnation machine, you ought to provide utmost importance to factors such as yield of resin, energy optimization, programmable auto shut down and start, automatic flushing of drippers and pumps, automatic system lubrication, automatic failure diagnostics, ease of operation, low maintenance, low thermal dissipation, and much more. Do not forget to check the manufacturer’s warranty, specifications, and quality prior to making a final purchase.

For more information on this process contact Polymer Resources at 1-860-271-0497.

Compounding Resin Productions to Peak with Shale Gas Boom

Compounding Resin Productions to Peak with Shale Gas Boom

The plentiful supply of shale gas in North America has prompted the emergence of the US as an important center for worldwide petrochemical production. Thanks to the abundance of cheap shale gas as a feedstock, petrochemical production costs have gone down dramatically. The shale gas boom could potentially result in a surge in compounding resin production.

The increase in natural gas availability due to the shale gas boom has resulted in a plentiful supply of ethylene. This in turn has led to a dramatic increase in polyethylene production via the process of ethylene cracking. Lower polyethylene prices and increased production capacity could potentially have a substantial impact on resin prices.

Opinions vary as to what extent plastics processors stand to gain from the shale gas boom. On the one hand, the reduction in polyethylene production costs ought to be beneficial for plastics processors as their material expenses stand to decrease considerably. However, it is unclear just how far the price of polyethylene could fall. It has been suggested that the price of polyethylene corresponds to the cost of production from crude oil, rather than from natural gas. Furthermore, polyethylene prices are dictated by the inventory of the supplier.

In addition to ethylene, shale gas also contains a large amount of propylene. The new abundance of shale gas therefore has implications for polypropylene production. Most of the benefits the petrochemicals industry has derived from shale gas thus far have come from ethylene cracking. However, recent advances in propylene dehydrogenation (PDH) technology mean that this is expected to change. With resin producers set to begin polypropylene production as early as 2015, the full force of the shale gas boom may soon be felt in the polypropylene sector. While polypropylene prices are unlikely to fall to the extent of polyethylene prices, the increased availability of propylene is expected to result in a less volatile polypropylene market.

The extent to which the shale gas revolution will drive compounding resin production may not yet be fully understood; however, it is clear that these are exciting times for the US petrochemicals industry. The advantage of shale gas is local to North America, and opportunities abound for both domestic business and export.

ABS Resin Plastic – Features, Limitations and Variations

ABS Resin Plastic – Features, Limitations and Variations

One of the best resins of the styrene family, ABS (Acrylonitrile Butadiene Styrene) is widely used in the automotive industry and in the manufacture of electrical and electronic equipment. The increased utilization of ABS Resin plastic means that there would be substantial volumes of material which would need to be recycled at the end of life of these products. Research studies focused on the impact of reprocessing on the physical and mechanical properties of ABS products have shown minimal impact therefore establishing the benefits of ABS Resin plastic as an easy to recycle material.

ABS is a common thermoplastic resin which guarantees high rigidity, durability, dimensional stability and excellent chemical resistance. The high quality features of ABS resin can be attributed to its composition where it brings in the strength and durability of Acrylonitrile along with the toughness of butadiene rubber. It also allows a wide range of modifications to its composition which allows to improve its impact resistance, heat resistance and toughness.

Some of the most common and well known features of ABS Resin includes:

  • Excellent ductility
  • High Impact strength
  • Extremely tough and rigid
  • Dimensional stability
  • High tensile strength
  • Heat and chemical resistance
  • Electroplatable
  • High and low temperature performance

Although there are several benefits associated with the use of ABS Resin, there are certain limitations as well like its poor solvent resistance, poor weather ability and heavy generation of smoke when burnt.

There are huge variations possible with ABS Resin, however the most common variations of ABS material includes General Purpose ABS, High Impact ABS, Low Viscosity ABS, Plate-able ABS, ABS FR and many more. The modifications of its properties is possible with the use of additives, modifiers and reinforcing agents.

ABS plastics are largely used for mechanical purposes and in the automotive industry, however it also boasts good electrical properties which show minimal impact with temperature and humidity changes.

The two most common reprocessing or recycling process used for ABS products include mechanical recycling and solvent based process. Several research studies and experiments have proved that the microstructure of ABS resin is not affected by the recycling process. For painted parts, it is usually recommended to use the solvent based recycling process to ensure minimal butadiene loss.

Known for its medium strength and performance at affordable pricing, ABS Resin is commonly used for injection molding applications. The mechanical properties of ABS Resin plastic makes it ideal for drilling, turning, die-cutting and shearing. It also possesses excellent creep resistance, abrasion resistance and electrical properties, thereby making it one of the most widely used resins ever. Because of its great versatility, ABS Resin is used in a wide variety of applications. The three components used in the manufacture of ABS resin are combined by different methods which involves polymerization, combinations and physical mixtures.

Amorphous Thermoplastics – Characteristics of Non-crystalline materials

Amorphous Thermoplastics – Characteristics of Non-crystalline materials

Plastics are loaded with macromolecules which are made under the action of heat and pressure such that it can be processed into the desired shape. There are two broad classifications of a thermoplastic i.e. amorphous thermoplastics and semi-crystalline thermoplastics. When the thermoplastic is shaped at a temperature over the glass transition temperature Tg, then it is classified as Amorphous Thermoplastics. Whereas, when the temperature is over the melting temperature Tm, it is classified as Semi-crystalline thermoplastics.

Completely amorphous thermoplastics are generally brittle, stiff and quite clear in their unprocessed state. Temperature and pressure can cause the molecular arrangement to change along with the properties of the polymer. Tg or the glass transition temperature is defined as the point when the molecular rotation about single bonds becomes favorable. There are different varieties of Amorphous thermoplastics which includes materials like polystyrene, acrylics, polycarbonate, Acrylonitrile-butadiene styrene and polyvinyl chloride.

The molecules in case of amorphous thermoplastics are entangled in solid state. Most of them are transparent in their natural form, however ABS is an exception. In general, amorphous thermoplastics are known to have lower chemical resistance and lower stiffness and strength when compared with crystalline materials. However, the amorphous thermoplastics have uniform shrinkage rates which means that their shrinkage can be calculated easily.

There are additives and fillers used with both amorphous and semi-crystalline thermoplastics to alter the physical, electrical, thermal and mechanical properties of the base resin. Amorphous thermoplastics can be used in a wide variety of applications because of its diverse range of properties. With state of the art molding machine controls and latest material formulation methods, Polymer Resources guarantees high quality and consistent molded parts.

There are different varieties of crystalline materials which includes Nylon, polypropylene, polyacetal, and thermoplastic polyesters. In case of semi-crystalline thermoplastics, the size of the crystals is larger than the wavelength of visible length, thereby making the materials translucent. Depending on the branching and cooling rate, there are different degrees of crystallinity. Close to 85% of the resins produced are thermoplastics which are further classified as amorphous thermoplastics and crystalline thermoplastics. The amorphous regions of the thermoplastics contributes to the elasticity of the thermoplastic whereas the crystalline regions contribute to the strength and durability of the thermoplastic.

The cost saving opportunities associated with the use of injection moulding technology of thermoplastics need to be ensure proper material usage and cycle time to achieve optimized results. Amorphous thermoplastics exhibit lower mold shrinkage and lower tendency to buckle under pressure when compared with semi-crystalline materials. They lose their strength and rigidity very quickly once above the glass transition temperature Tg. The randomly ordered molecular structure allows amorphous thermoplastics to soften gradually as the temperature increases.