SPE Library

Fulcrum Technology Boosts Thermoplastic Pultrusion Process

Prithu Mukhopadhyay, June 2000

Composites are fabricated in a variety of processes. However, pultrusion process is favoured when high volume production of composite materials is demanded. Its ability to produce constant cross-section of profiles with little waste materials makes pultrusion one of the most cost-effective processes. For equivalent strength, pultruded finished products can be 50% lighter than aluminum and 80% lighter than steel. This is only part of the story.

It Seals, Feels, Flexes, and is Called Thermoplastic Elastomer

Prithu Mukhopadhyay, May 2000

Slowly but surely, new developments in thermoplastic elastomers (TPEs) are providing alternatives to traditional rubbers. They can provide cost-effective, high performance replacements to EPDM, neoprenes and polyurethanes. Parts or items can be designed ergonomically with TPEs. Who can refuse a plastic part that offers good feel, comfort and easy control? TPEs' popularity is understandable since they are processed like thermoplastics, yet perform like rubbers. That's no surprise. TPEs are two-phase blends system: a hard thermoplastic phase combined with a soft rubber phase. As Advanced Elastomer Systems (AES) puts it, "with TPEs like Santoprene, you can flex your imagination". No exaggeration indeed! Whether the soft-grip handle of MACH3 razor or the velvety, tactile feel of colourful Contura staplers - TPEs are taking the centre stage.

Z-Fiber Process: It Means a Better Composite Reinforcement

Prithu Mukhopadhyay, April 2000

Decades ago, Charles Macintosh embedded two layers of cotton fabric in natural rubber to make a raincoat. Not only he made a good raincoat, he opened-up future for fibre composites (FCs). Since FCs are made from layers of fabric glued together with resins, resins tend to break apart when stressed. Technically, this is known as delamination. It is possible to avoid delamination by adding extra thickness or by riveting. But these add cost and compromise strength. Resistance to delamination holds the key to a successful application.

If Your Mold Change is Quick, You Can Earn More Than You Think!

Prithu Mukhopadhyay, March 2000

As cars are manufactured to be on the road, moulding machines are built to run. Not to sit idle on the production floor. But this happens. Moulds changes are necessary to make parts of different sizes and shapes. This means mould set-up time is crucial to the production. Are we able to reduce the set-up time? Surely, we can by changing the mould quicker.

Cost and Mixing Keeps the Screw Rivalry Up & Going

Prithu Mukhopadhyay, February 2000

Screw is the heart of an extruder. It is fact that mixing capability of a single screw is poorer than of a twin screw. More precisely, the dispersive action (breakdown) of a twin screw extruder is always better than of a single screw extruder. For producing new blends or alloys, as well as for mixing powdered feedstock or regrinds -- twin screw extruders give unparalleled dispersion. No surprise that twin screw extruders cost more than single screw extruders.

Tyre Recycling brings Plastic and Rubber Together

Prithu Mukhopadhyay, January 2000

Making an useful product from a nearly useless item is never an easy task. When it comes to combining rubber crumb from used tires to plastics - the task is even tougher.

Aesthetics and Low-Cost Assembly Favour Film Insert Moulding

Prithu Mukhopadhyay, October 1999

It's the package that sells in the market. Decoration of injection moulded parts are no exception. Commonly known decorative methods are screen printing, pad printing, hot stamping or painting. However, to enhance productivity and achieving design freedom, new decorating methods such as Insert Moulding (IM) is gaining popularity.

Windows of Opportunities for Single Site Catalyst

Prithu Mukhopadhyay, September 1999

What makes company A produce 50,000 tons/year more of the same PE or PP than company B at the same cost? Catalyst, catalyst and catalyst. Very quietly, catalyst research has brought revolution in the plastics industry. So-called single-site catalysts (many of which are metallocenes) are closely guarded secret of alpha-olefin "big guys". A single metal atom held between two carbon rings builds metallocenes. They might look naive but provide greater control over molecular chain length and structure of polyolefins. These polymers are stronger, purer, and clearer. Upon utilizing these catalysts, material suppliers can accurately design tailor-made resins for specific applications.

Nanocomposite - Technology for the Future

Prithu Mukhopadhyay, April 1999

Researchers from Montell and General Motors call it "Nanocomposite" - a combination of smart fillers (clay) and a proven process (Catalloy). Whether you are in automotive business or you intend to put new developments/ideas in your business - the news is good.

Recycling: Giving a Second Life to Plastic Scrap

Prithu Mukhopadhyay, April 1999

Recycling is not as easy as it sounds. Scrap plastics are usually mixed. Before giving them a second chance - they need to be sorted by resin type and/or colour. Otherwise, if 1 wt % PP gets into HDPE stream through bottle caps or by mistake, the toughness of regenerated HDPE bottle decreases. Similarly, as little as 1 ppm PVC in PET can discolour the PET item. Now, sorting can be done manually which is labour intensive and not infallible. When done in an automated system (infrared or X-ray), it becomes expensive. Researchers at SpectraCode of West Lafayette, Ind., have recently invented a point-and-shoot device that can distinguish majority of plastics in 10 microseconds. This translates into 500 tons of plastics/day in a typical recycling operation. Can't we eliminate sorting step and yet produce value added recycled plastics?

A Breakthrough in Foaming Technology

Prithu Mukhopadhyay, March 1999

MuCell process by Trexel Inc. has been touted as a breakthrough technology. The process offers new foaming capabilities. If your business belongs to the categories such as Extrusion (PP, PS sheet & PVC profiles), Blow (HDPE bottles) or Injection moulding (PP, PS, Nylons, PC/ABS and TPEs) then you will profit from MuCell process. The process produces microcellular foams (5-50 micron ranges) using supercritical fluids (SCFs). These fluids like carbon dioxide or nitrogen mix thoroughly in plastic melt since they have the viscosity of gases and the density of liquids. Being environmentally benign, SCFs eliminate the need for chemical or hydrocarbon-based blowing agents. CO2 or N2 are in fluid state as opposed to gas (in gas assist injection moulding); the process generates evenly distributed microscopic cells throughout the plastic. This makes MuCell technology to foam very thin sections (0.5mm/0.20inch).

Carbonate Users: Attention Please

Prithu Mukhopadhyay, February 1999

There is no sure road to success. But search for new products or processes can make the difference in today's market place.

Blow it Right or You Blew it

Prithu Mukhopadhyay, January 1999

Blow moulders are whispering these days: "Staying ahead of the competition is the key" or "Growing quietly behind the scenes". Are we ready to take the plunge? Psst …

Mix & Match: New Developments Offer New Applications

Prithu Mukhopadhyay, November 1998

Injection molding process imparts a complex thermal deformation history to polymer melts. The complexity rises with multiphase blend systems. How about development in areas of new materials? Can we not get new resins that would give faster cycle times, high ultimate strength and elongation values combined with a wide spectrum of shore A and shore D hardness grades?

Plastic Facts

Plastic Facts book reviews.