The Role of Feed Screws in The Plastics Melt Stream Process

Feed screws, also known as extruder screws, play a crucial role in the melt stream process of the plastics industry. The melt stream process transforms raw plastic materials into a continuous, homogenized, and viscous molten mass, which can be further shaped and processed into various products like films, sheets, pipes, profiles, and more. The feed screw is an essential component of the extruder machine, the primary equipment used in the melt stream process.

The role of the feed screw in the melt stream process is explained in detail by understanding its different sections and their functions:

1. Solid conveying (feed) zone: The feed screw consists of a helical channel or flights with a rotating shaft that runs along its length. The screw begins with a hopper where raw plastic material, usually pellets or granules, is loaded. The rotation of the screw transports the raw material forward, creating a solid conveying zone. The screw geometry in this zone efficiently moves the plastic material toward the subsequent zones.
2. Compression (transition) zone: The depth of the screw channel decreases gradually in this zone, causing the plastic material to compress. This compression generates heat through friction, which melts the plastic along with external heating elements. At the same time, the screw design ensures proper mixing and homogenization of the plastic materials.
3. Melting (metering) zone: This zone is characterized by a constant channel depth, where the plastic material becomes fully molten. The screw's geometry creates a uniform and consistent melt flow while providing sufficient back pressure to ensure the homogenization of the molten plastic. Additional mixing elements may be incorporated into the screw design to enhance mixing and homogenization further.
4. Discharge (melt) zone: In this final zone, the screw conveys the molten plastic towards the extruder die, designed to shape the material into the desired product form. A screen pack and breaker plate are typically placed before the die to filter out contaminants and ensure a uniform melt flow.

Feed screws play a vital role in the overall efficiency and quality of the melt stream process. The design of the screw and its various geometries can significantly affect the processing conditions, output rate, and final product quality. Different types of feed screws are available, tailored to the specific requirements of the plastic materials and end products, such as single-screw, twin-screw, and multi-screw extruders. These screws may also be classified based on their compression ratio, screw profile, and mixing elements.

For more information about feed screws, contact AP Corp.

https://a-pcorp.com

(508) 351-6200

Understanding Load Cell Overload

When you're talking about load cells in process weighing, what does safe and ultimate overload mean, and how strong are load cells?

The ultimate strength relates to the function as a load cell and not the mechanical strength. The mechanical strength of the load cell is even higher. 

For a load cell, there is generally three capacity limits:  

The nominal capacity of one 100%: Let's say we have a 100-pound load cell. This is the limit or capacity of the load cell. Note the load cell should not be subjected to higher forces under regular use. If the application needs to measure higher loads, then a larger load cell should be used.

The safe load usually is 200 percent of the rated capacity: Let's say with the 100-pound load cell this would be 200 pounds. If the load cell is occasionally subjected to more than 100 percent but less than 200 percent, nothing happens to it, and it will work. If repeatedly subjected to more than 100%, the load cell can be damaged due to fatigue.

The ultimate load is usually 300 percent of rated capacity or 300 pounds for a 100-pound load cell. If the load cell is occasionally subjected to a load greater than 200 percent but less than 300 percent, the load cell will be subjected to a zero shift. However, in most cases, the load cell can be recalibrated and repaired. If subjected to more than 300 percent, the bonding of the strain gauges will most likely be damaged beyond repair. The function of the load cell is damaged, and it should be scrapped. 

As a reminder, this refers to the function as a load cell and not the mechanical part. The mechanical strength of a load cell varies but is often in the range of 400 to 1 000 percent. It should also be noted that there's a fatigue limit for a load cell that generally is 133 of capacity. 

The Dynisco LMI5500 Series Melt Flow Indexer

Of all the tests used by the plastics industry, melt flow rate testing (or melt flow index) is the most widely used. It is traditionally associated with testing polyethylene materials to determine the lot-to-lot consistency of resin lots or batches for quality control purposes. It is, however, also used for other purposes such as testing new materials, determination of material stability versus residence time within plastics processing equipment, or the assessment of regrind content within materials or moldings. It is generally a low shear rate test; however, larger weights can increase the shear rate.

A flow rate test measures a polymer’s mass flow rate (grams extruded in 10 minutes) using an orifice under specified conditions of temperature and load. Machines that determine flow rate are generally called Melt Indexers or Extrusion Plastometers. Test methods by ISO, DIN, ASTM, and others specify heat chamber and piston tip diameter such that the shear stress on the polymer is the same in all machines for a given load. In addition, material specification guidelines (by ISO, DIN, ASTM, GM, etc.) may exist, providing further constraints on how a particular material processes.

Specifically designed for the thermoplastics resin industry, the Dynisco LMI5500 Series Melt Flow Indexer has an array of features and benefits that range from ground-breaking accuracy to a unified software platform between all laboratory and online production equipment.

AP Corp.
https://a-pcorp.com

(508) 351-6200

Cost Effective, Speedy Force Calibration System from BLH Nobel

A BLH Nobel customer's manufacturing process included multiple critical tanks that required regular weight calibration. The largest, a reactor, weighs 60 tons. Traditionally, they calibrated the vessels by filling them with water, a laborious and expensive process. It took a week for each tank.  Aside from filling the tanks, each must be emptied and rinsed. Finally, calibration required thorough drying before resuming production. 

BLH Nobel developed a method to elevate the vessels and read the weight change at various stages of the process. This video demonstrates that method.

BLH Nobel's solution allows the calibration of a weighing vessel, silo, or tank in a fraction of the time compared to using flowmeter or weighbridge calibration. BLH Nobel jacks the tank using hydraulics instead of loading with weights or flowmeter. Typically they measure the result in several points and verify the weighing result. BLH Nobel's method is often carried out without modifying the existing frame or structure, as most already have a suitable jacking point at each load cell.

For more information about this weighing calibration process or any BLH Nobel products in New England, contact AP Corp. Call (508) 351-6200 or visit https://a-pcorp.com.

The Micro-Measurments Model 700B Next Generation Welder

The Micro-Measurements Model 700B Welder is the next generation of the Model 700 Welder, which has been used for decades to install tens of thousands of strain gages worldwide. This experience and customer input and support provide more capability and flexibility while remaining in a smaller, more portable package. 

This new welder combines a high-speed spot welding rate with the enhanced safety and portability features that you have come to expect from Micro-Measurements. It is designed for spot welding the Micro-Measurements line of CEA, LWK, LEA, LZN, and LZE weldable strain gages. In all types of adverse field conditions, the 7rugged 00B performs efficiently and dependably.

The 700B's use of commercially available Lithium-ion batteries, which are easily replaced in the field and can handle 1500 welds (@30 joules) on a single charge, is a significant improvement (equivalent to welding around 30 linear weldable gage). The lightweight unit weighs approximately 8.3 lb. (3.77 kg) and is ideal for field use, overcoming the main limitations of other portable spot welders on the market. The unit also welds small thermocouples and light-gauge metal  

The Model 700B enhances Micro-Measurements' broad portfolio of weldable gages suitable for all types of applications and environments. Encapsulated, sealed, and high-temperature versions of Micro-Measurements' CEA, LWK, LEA, LZN, and LZE product families are included. Weldable sensors can be easily installed in field applications under a wide range of weather conditions because they are spot-welded rather than adhesively bonded." 

The Model 700B's welding energy can be easily adjusted by the user from 10 to 60 Joules, with a weld rate of up to 60 welds per minute, making it one of the fastest tools of its kind. The 700B is simple to clip onto a harness or carry around remote job sites, whether working suspended under a structure or in a manufacturing plant. It is particularly well-suited for working from rope access, aerial lifts, or in a laboratory setting. ​

For more information in New England, contact AP Corp. Call (508) 351-6200 or visit https://a-pcorp.com.

The Druck DPI705E Series Handheld Pressure Indicators

The Druck DPI 705E Series of handheld pressure and optional temperature indicators combine tough and rugged design with accurate and reliable measurements.

Compact and robust, the DPI 705E Series is designed for single handed operation and provides many essential features required for routine maintenance and system troubleshooting.

DPI705E Series Handheld Pressure Indicator Features

• 48 pressure ranges from ±25 mbar to 1,400 bar (±1.69 psi to 20,000 psi / 2.5 KPa to 140 MPa)
• Total 1 year uncertainty down to 0.05% full scale (FS) over temperature range of -10°C to +50°C
• Integral calibration record with calibration due count-down display
• Rugged, handheld design with backlit high-contrast display
• Leak test, tare, maximum/minimum and filter
• Hazardous Area (Intrinsically safe) version available
• Optional remote plug and play pressure and Resistance Temperature Detector (RTD) sensors
• Optional pneumatic and hydraulic hand pumps

For more information in New England, contact AP Corp. Call (508) 351-6200 or visit https://a-pcorp.com.

White Paper: Introduction to Fiber Optic Sensing

Fiber optic sensing is becoming increasingly common in various industries, including manufacturing, medical, aerospace, automotive, civil, and energy. There are dozens of different types of technology on the market, each with its own set of capabilities. Because of the variety of technologies, navigating the fiber optic sensing landscape can be difficult.

This white paper, courtesy of Sensuron, intends to provide a framework for understanding multiple fiber optic sensing technologies and insights into market trends.

GET THE WHITE PAPER HERE

For decades, point sensing solutions such as strain gauges and thermocouples were  "good enough," but this mindset frequently stifles innovation. Today, many Sensuron clients have innovated beyond their ability to test with legacy technologies. New, robust sensing technologies, such as Sensuron fiber optic solutions that can monitor beyond the scope of point sensors, are required to enable the next generation of innovations.

For more information in New England and Upstate New York, contact AP Corp by calling (508) 351-6200 or visiting https://a-pcorp.com.

In-Line Color Measurement in the Molten Polymer

Color measurement is a widely used technology for ensuring the quality of color values during the manufacturing process. Typically, these measurements happen offline. The time it takes between sampling and receiving results from the laboratory can be lengthy. A significant disadvantage is that only one measurement occurs during this period, and the color quality during, before, and after the sampling point is unknown. A complete analysis is possible because inline color measurements are performed directly in the melt, but when color variations occur, immediate intervention is possible.

Inline color measurement will provide product-quality indicators for immediate and automatic adjustment of process parameters. The outcome is to maintain the highest possible product quality without waiting for sample analysis from the plant's laboratory.

Equitech International Corp. has been in business since 1995, supplying fiber-optic spectroscopic instruments for process analysis to pharmaceutical, chemical, and food manufacturers. In 2005 they entered the plastics market and began extending their technology into inline color monitoring and real-time closed-loop process control. They published a helpful Technical Paper titled In-Line Color Measurement in the Molten Polymer. You can download that paper here.

Webinar: Components of a Successful Noise Monitoring Program - June 16, 2021

AP Corp. is pleased to provide details for an upcoming webinar presented by OHD (Occupational Health Dynamics) and SVANTEK on implementing and operating a successful sound monitoring program.

In this 1-hour webinar, OHD's Certified Industrial Hygienist, Dr. Stephanie Lynch, will go over regulations, best practices, common downfalls, and much more when successfully building and enhancing your companies noise monitoring program. 

Stephanie Lynch is a Certified Occupational Hearing Conservationist and has over 15 years of Occupational Safety and Industrial Hygiene experience. Her doctoral dissertation research involved the collection of personal noise dosimetry and whole-body vibration measurements. Her research carries into the real world in manufacturing and military applications.

SVANTEK is the leading brand of sound and vibration meters for occupational health and safety, environmental noise, human vibration, and building vibration.

To register, visit this link (https://info.ohdusa.com/noisemonitoringwebinar). 

Dynisco Polyclean Fluidized Baths

Cost-Effective, Fast, and Safe Way to Clean Various Plastic Processing Components

The Dynisco PolyClean Fluidized Temperature Baths come in three models and offer a cost-effective, fast, and safe way to clean various plastic processing components. PolyClean Fluidized Temperature Baths are applied in any polymer manufacturing or laboratory facility that needs minimal operator interaction and a low risk of harm to essential design requirements of a part during the cleaning process. 

The PolyClean 6L Fluidized Temperature Bath is ideal for cleaning small tooling from laboratory extruders or injection molding machines. 

The PolyClean 12L cleans extrusion tooling and other forms of hardware, forms parts, calibrates and tests various sensors and systems, heat treats metals and heats reactors, coils, flasks, and containers. 

The  26L PolyClean has similar functions and benefits to the PolyClean 12L, but its 26" deep basket allows it to clean larger components than the PolyClean 12L

For more information in New England and Upstate New York, contact AP Corp by calling (508) 351-6200 or visiting https://a-pcorp.com.

AP Corp. Selected Druck New England Representative

AP Corp. is delighted to announce that they are now the New England Sales and  Engineering Representative for Druck piezo-resistive pressure sensors and test/calibration instruments.

Druck, a Baker Hughes business, manufactures the high-reliability piezo-resistive pressure sensors and test and calibration instruments known for performing in the most challenging environments. Their products provide customers with the highest performance, stability, quality, accuracy, and quickest response in any environment.

Druck's product line includes pressure sensors,  OEM custom sensors, PACE Pressure Controllers, handheld process calibrators, pressure indicators, test tool instrumentation, and  4Sight2 Calibration Management Software.

The addition of Druck extends AP's offering of high quality, best-in-class, engineered sensor solutions. AP Corp's application expertise and long-standing customer relationships in New England are vital to providing Druck with accelerated sales growth in this territory.

For more information, contact:

AP Corp.
One Tara Boulevard
Suite 200
Nashua, NH 03062
www.a-pcorp.com
508-351-6200 (office)

Process Weighing, Web Tension, and Force Control Systems Applications in Pulp and Paper Production

BLH Nobel is a leading supplier of specialized pulp and paper measuring devices. Over the years, they've built a strong understanding of pulp and paper manufacturers' process problems. Be assured that BLH Nobel has the best solutions to maximize productivity and performance.

DOWNLOAD THE BLH PULP & PAPER APPLICATIONS GUIDE HERE

Pulp and Paper Applications

• State-of-the-Art Instrument for Weighing and Force Measurement
• Web Tension Measurement Unit
• Dynamic Resultant Force Measurement
• Refiners Position and Pressure Control
• Paper Rolls, Pulpers and Coating Kitchen

AP Corp.

https://a-pcorp.com

508-351-6200

Micro-Measurements Strain Gage Instrumentation Catalog

Explore Micro-Measurements complete catalog of data acquisition instruments.

Micro-Measurements offers a comprehensive range of specialty instruments for data acquisition. With Micro-Measurements instruments, you can capture fully corrected, accurate engineering-unit data with minimal effort. Their special-purpose equipment, backed by highly skilled engineers' expertise and knowledge, complements strain gage installation integrity and instrument calibration.

DOWNLOAD THE CATALOG HERE

Product Range:

• High-speed data loggers
• Single-channel devices
• Portable indicators
• Multi-channel data acquisitions systems
• High-bandwidth signal conditioners
• Signal conditioning amplifiers
• Embedded analog-to-digital convertors
• Inputs for other commonly used sensors, including load cells, displacement transducers, thermocouples, and accelerometers. 

For more information about Micro-Measurements in New England and Upstate NY, contact AP Corp. Call them at (508) 351-6200 or visit their website at https://a-pcorp.com.

The QSO® Quick Shut-off Valve from Glycon Corporation

A better quick shut-off non-return valve for the Plastics Industry.

Injection molding applications require two important criteria from a non-return valve:

1. Rapid material shut off for part weight consistency
2. A smooth, high-flow profile to prevent material degradation. 

The Glycon QSO® valve is the only valve that provides you both. The result is higher quality parts, fewer rejects, improved yield, and a better return on every pound of material you run.

Compared to traditional ball and ring check valves, only the QSO® Quick Shut-off Valve delivers both high flow and raid shut-off. Plastics molders prefer the QSO® because:

• The QSO® ends short shots!
• The QSO® reduces scrap rates
• The QSO® optimize part weight consistency
• The QSO® prevents material degradation
• The QSO®is perfect for filled materials
• The QSO® eliminates need for decompression or “suck back”
• The QSO® maintains smooth material flow path
• The QSO®is designed for long lasting and durable

DOWNLOAD THE QSO® DATA SHEET HERE

AP Corp.

https://a-pcorp.com

508-351-6200

Which Melt Pressure Sensor Is Good for My Application?

So how do I choose the right melt pressure sensor for my application? 

A sensor is defined through the following specifications:

• Pressure Range
• Process connection
• Electrical output and connection
• Capillary configuration (rigid/flexible)

There are more variables come into play, but let's focus on these four since they are the most critical.

Melt Pressure Sensor Pressure Range

The pressure inside a plastics processing machine can usually be estimated well enough to determine a sensor's good pressure range. The typical working pressure should be within 20%-80% of the sensor's pressure range to balance accuracy and lifetime.

Melt Pressure Sensor Process Connection

For threaded connections in plastics processing, a standard has developed over time, which is the ½"-20UNF thread with a conical sealing face. There might be situations where different thread sizes or a flange connection is required. There are numerous options available from manufacturers, such as Dynisco, to satisfy customer needs regarding the process connection.

Melt Pressure Sensor Electrical Output

A pressure sensor is an electro-mechanical device that converts a mechanical effect (pressure deflects a thin piece of metal) into an electrical signal through a strain gauge. The strain gauge changes its resistance by following the deflection of the metal piece. In the simplest case, the strain gauge signal can be used directly to feed a read-out device to display the pressure.  In order to accommodate industry-standard equipment, such as process control equipment, manufacturers like Dynisco supplies sensors with different amplified output options such as 4-20mA or 0-10V.

Melt Pressure Sensor Capillary Configuration

A typical pressure sensor has a liquid-filled capillary that connects the process-connection diaphragm (which is deflected by the process pressure) and the measuring diaphragm (where the strain gauge is bonded). This capillary is necessary to create a heat barrier, as the strain gauge cannot withstand the typical process temperatures at plastics processing. Also, the sensor's electronics need to be kept away from heat sources as well as possible. To find a suitable mounting location for the electronics, countless combinations of the rigid stem and flexible connection lengths are available.

Other Considerations in choosing a Melt Pressure Sensor:

• Diaphragm materials
• Diaphragm coatings
• Approvals and certifications

For assistance in selecting or applying any plastics molding equipment, contact AP Corp. by calling (508) 351-6200 or visit their website at https://a-pcorp.com.

Web Tension Control in Paper Production

BLH Nobel web tension systems comprise off-the-shelf standard modules and electronics, as well as customized systems. BLH Nobel designs force measurement modules according to the customers’ mechanical requirements and forces, ranging in size from just a few Newtons to mega-Newtons. The combination of digital signal amplifiers and stable force transducers means that BLH Nobel systems can handle anything from applications with a low tare and large forces, to those with a large tare and small forces.

For more information about BLH Nobel products in New England, contact AP Corp. Call them at (508) 351-6200 or visit their website at https://a-pcorp.com.

EASYHEAT Induction Heaters from Ambrell Corporation

EASYHEAT advanced induction heating systems by Ambrell Corporation provide a flameless, non-contact, reliable, compact solution for heating your parts with a quick, clean source of heat. Available in models from 500 Watt to 10 kW, all are ideal for repeatable, energy-focused heating of your parts.

Flameless, non-contact induction heating minimizes energy waste by focusing energy only on the part and zone to be heated. Select and monitor power levels from the front panel LCD and sealed touch pad. Remote power control is available for employing contact inputs, analog inputs or optional serial data port. Easily control the length of the heating cycle with a built-in programmable digital timer.

Download the Ambrell EASYHEAT® 500 Watt to 10 kW Induction Heater Catalog here.

For more information about Ambrell products in New England, contact AP Corp. Call them at 508-351-6200 or visit their website at https://a-pcorp.com.

New Bench Top Series of Shaker Systems from Sentek Dynamics

The BT Series shakers from Sentek Dynamics are designed for demanding vibration test applications. Typical applications included structural analysis, calibration and testing of smaller assemblies. The BT-100 through BT-400 shakers utilize light weight rare earth magnets in lieu of traditional Alnico magnets. The use of these magnets decreases the total shaker mass to a third of similar size system, making these shakers easy to handle and portable. 

The systems range in size from 100 N (70 lbf) to 1000 N (224 lbf). Systems 400 N (99 lbf) and smaller are permanent magnet shakers and use lightweight rare earth magnets, making these systems easy to handle and portable. There are three versions of the BT Series of shakers: the BT, BT-M and BT-MTH.  

The BT Series is recommended for vibration testing of small assemblies and components. These shakers have armature diameters from 60 mm (2.36 in.) to 120 mm (4.72 in.). The BT-1000 is equipped as standard with Automatic Armature Centering (AAC) and Air-Isolation Feet (AIF).  

The BT-M and BT-MTH Series are our modal shakers lines. BT-M will use standard stingers while the BT-MTH is our through-hole version. On the 100 N and 200 N system the BT-MTH offers over double the displacement. The BT-MTH Series allow you to use piano-wire stingers. The BT-1000-M is ideal for the structural and modal analysis of high-mass structures. The addition of ZPR (electronic zero-point regulation and adjustable suspension stiffness) allows the user to pre-load the structure prior to applying a dynamic load.

The new Sentek Dynamics Bench Top and modal exciters are based upon years of practical experience. These systems all exhibit a high lateral stiffness and high force-to-weight ratio. They are specifically designed to help ensure the best possible performance with minimum setup time. 

Contact AP Corp. regarding any Sentek Dynamics product in New England and Upstate New York. Call us at (508) 351-6200 or visit our website at https://a-pcorp.com.

Micro-Epsilon Laser Profile Scanners: scanCONTROL LLT3000 and 2500

Micro-Epsilon scanCONTROL LLT3000

The scanCONTROL LLT3000 laser profile scanners impress in 2D/3D measurement tasks with high precision and dynamics. With a high resolution sensor matrix and high profile frequency, the scanners are designed for precise profile measurements in dynamic processes.

Micro-Epsilon scanCONTROL 2500

The scanCONTROL 2500 laser scanners are specially designed for industrial measurement tasks. Compact design, versatility and high signal stability result in an excellent price/performance ratio especially for measurement tasks involving large quantities.

Laser profile scanners from Micro-Epsilon are among the highest performing profile sensors with respect to accuracy and measuring rate. Equipped with powerful processors and highly sensitive optical components, these scanners ensure precise profile measurements on nearly any type of surface. While they can be integrated in various environments, the scanners also impress with a compact design which includes an integrated controller.

For more information about Micro-Epsilon products in New England, contact AP Corp. Call them at (508) 351-6200 or visit their website at https://a-pcorp.com.

BLH Nobel KIS Beam Load Cell Technology

The BLH Nobel KIS load cell provides unmatched efficiency, is simple to mount, and is highly accurate, even under complex process forces and extreme environmental conditions. Unlike other load cells, KIS works as defined in real-world applications, not just under laboratory conditions. 

KIS Beam technology integrates SR-4 ® strain gages connected as a full Wheatstone bridge that is temperature-compensated and optimized for precision and reliability. And since all KIS Beams are factory-calibrated, installation and set-up are simple and easy without the need for on-site calibration (unless mechanical obstructions prohibit a vessel being "freestanding"). 

The above four-minute video does an excellent job illustrating how the KIS load cell works and what distinguishes KIS from other load cells

For more information about BLH Nobel products in New England, contact AP Corp. Call them at (508) 351-6200 or visit their website at https://a-pcorp.com.