Breathing New Life into Aging Machinery: Reconditioning and Modernizing Your Plastic Injection Molding and Extrusion Equipment

Reconditioning of plastic injection mold and extrusion machines is a process that involves restoring or upgrading the machine to improve its performance, efficiency, and lifespan. This process can include replacing worn-out or outdated components, updating control systems, and enhancing the overall functionality of the machine. Key elements to consider for reconditioning are control systems, HMI (Human-Machine Interface), pressure sensors, temperature sensors, and feed screws. Here's a list of items to consider when reconditioning these machines:

1. Inspection and assessment: Begin by thoroughly examining the machine to identify worn-out or damaged components, as well as outdated control systems and sensors. This assessment will help you determine the necessary upgrades and replacements needed.
2. Disassembly: Carefully disassemble the machine, taking note of the locations and orientations of each component for reassembly later. Clean each part to remove accumulated debris and contaminants.
3. Control system replacement: Remove and replace the existing control system with a modern, programmable system that offers improved performance and efficiency. This new system should be compatible with existing hardware and allow for seamless integration with the machine.
4. HMI upgrade: Replace the old HMI with a modern, user-friendly interface that simplifies machine operation, monitoring, and control. This new HMI should be compatible with the updated control system and provide enhanced visualization and data-logging capabilities.
5. Pressure sensor replacement: Replace outdated or damaged pressure sensors with new, high-precision sensors calibrated appropriately and integrated with the control system, ensuring accurate pressure measurement and monitoring throughout the injection and extrusion process.
6. Temperature sensor replacement: Install new temperature sensors that provide accurate and reliable measurements. These sensors should be compatible with the control system and HMI, allowing for real-time monitoring and control of temperature during the injection and extrusion process.
7. Feed screw replacement: Inspect the feed screws for wear, damage, or reduced efficiency. Replace them with new, high-performance screws designed for optimal material mixing and flow. Ensure proper alignment and installation to minimize wear and improve overall machine performance.
8. Lubrication and maintenance: Lubricate all moving parts and replace worn-out seals or gaskets. Perform routine maintenance tasks such as filter changes and cleaning to ensure the machine operates smoothly.
9. Reassembly: Reassemble the machine, ensuring all components are correctly installed and aligned. Double-check connections and wiring to ensure proper communication between sensors, control systems, and the HMI.
10. Testing and calibration: Power the machine on and conduct a series of tests to verify proper function and performance. Calibrate the control system, sensors, and HMI to ensure accurate readings and control.

With these core steps, you can successfully recondition a plastic injection mold or extrusion machine, ensuring it operates efficiently and reliably for years.

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(508) 351-6200

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

Commissioning a Dynisco Pressure Sensor Using the Dynisco 1490 Panel Indicator

Polymer manufacturing equipment such as extruders and injection molding machines are outfitted with various sensors, which allow the operators to monitor process variables, maintain safety, and avoid downtime and product output.

Dynisco manufactures precise pressure measurement and control devices that allow operators to monitor process variables, maintain safety, and avoid downtime during product output. This video will demonstrate each step of the pressure sensor commissioning process, including unpacking and wiring the sensor and setting parameter requirements for system operation.

For over 60 years, Dynisco has provided precision pressure measurement and control devices for all manner of plastic manufacturing equipment, which end-users rely on.

This video will teach you how to commission a pressure sensor with a Dynisco model 1490 indication device. The technician will offer guidance through each step of the pressure sensor commissioning process, from taking the sensor out of the box to wiring the sensor with the instrument and finally setting the parameter requirements for system operation.

This Video Covers:

• Introduction
• Unpacking and Examining the Pressure Sensor
• Selecting the Cable Assembly
• Unpacking and Wiring the Instrument
• Connecting the Sensor Cable Assembly to the Instrument
• Connecting the Cable Assembly to the Pressure Sensor
• Supplying Power and Setting Parameters on the Instrument
• Calibration of the Pressure Sensor with Instrumentation 

For more information about Dynisco products in New England and Upstate New York contact:

AP Corp.

https://a-pcorp.com

(508) 351-6200

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.

Plastics Industry Feed Screw Classification White Paper

The feed screw is used in plastics extrusion to force melting plastic resin through a die into a mold to form a desired shape. As screw designs have evolved through the years, there are several generic categories.

Glycon Corporation, the industry leader manufacturer of high performance and innovative feed screws, has put together this white paper describing the classifications of feed screws used in the plastics industry.

DOWNLOAD THE FEED SCREW CLASSIFICATION WHITE PAPER FROM THE AP CORP WEB SITE HERE

AP Corp.
https://a-pcorp.com
(508) 351-6200

Why Plastics Industry Feed Screws are Designed the Way They Are

Download the white paper here.

The selection of the proper screw for a given injection molding or extrusion application can be critical to its success.

Screw geometry — length-to-diameter ratio, profile, channel depth, compression ratio, helix angle and a host of special design features — has everything to do with how well the screw performs in a given application.

There are documented applications where customers have improved production rates or reduced cycle times by 30 or 40% simply by switching to an improved screw design. Similarly, reject rates have been lowered from more than 4-6% to less than 1% by incorporating a custom designed mixing screw.

And experience shows that the amount of color concentrate required to achieve optimum color mix can be typically reduced from 4% (of the total blend) to 2%, just by using an optimized screw design. When considering resin and concentrate costs, payback for an optimized screw and non-return valve design can be almost immediate.

This white paper, published by Glycon Corporation, provides an in-depth look into plastics industry feed screw design.

DOWNLOAD THE WHITE PAPER FROM THIS AP CORP WEB PAGE