Resin Inventory Questions Answered

Simplified Solutions Using Sensors & Software

Who: Plastics manufacturers and molders. Plant managers and plant engineers. Purchasing and finance. Everyone wants something.

People want inventory data for different reasons. Production doesn’t want to slow, interrupt, or stop processing. Plant engineers want to optimize storage and movement of resins through the plant. Finance wants higher inventory turns, accurate data for financial reporting, and to reduce the cost of carrying safety stock. Purchasing needs to buy and schedule deliveries to keep everyone else happy.

What: Real-time inventory data. A change agent.

Production needs change. Resin prices change. Customers change their orders and delivery dates. Synchronizing the needs of the plant with the customer can be achieved when inventory data is current and accurate. Timing is everything to optimize processes and profit margins in the competitive plastics business.

When: Now – and updated any time.

Inventory now and readiness for tomorrow is crucial. Manual inventories, clipboards, and spreadsheets can be eliminated with the use of sensors and software. Sensors can measure continuously or take readings at timed intervals and immediately update inventory.

Where: Anywhere they happen to be.

In the plant, the office, an airport, at headquarters, on the road … even on the beach. Anywhere there’s internet, inventory data can be accessed by everyone that needs the data. People from different plants, offices, or vendors can be granted access to the data they need most.

Why: Eliminate outages and increase inventory turns

Production slowdowns and shutdowns can delay shipments, erode profit margins, and disappoint customers. Carrying just the right amount of safety stock, ordering with confidence, and scheduling timely deliveries can reduce carrying costs and make for happy customers and suppliers.

How: Keep reading …

Wait! Before we talk about sensors and software. Does any of this sound familiar?


  • My current systems don’t provide real-time information.
  • We don’t have any instrumentation. We still do manual checks.
  • The equipment we have doesn’t work. It’s either unreliable, inaccurate, or outdated.


  • I’m tasked with producing more, better, and faster to increase margins.
  • Figuring out ways to reduce resin inventory or increase inventory turns.
  • The storm of spreadsheets and emails that complicate my job.


When it comes to automated monitoring software there are a couple of options. One is software installed on a local network or individual computers, with inventory data stored on the company’s system. The other is a software as a service, commonly referred to as a SaaS, where automated monitoring programs are accessed from the internet and inventory data is stored securely in the cloud.


Alerts and Notifications

Receiving alerts when silo inventory reaches low levels is one of the greatest assets of an automated system. Level thresholds are entered into the system and an automated email or text message is sent when the resin in the silo reaches that level. Additionally, silos change color on the dashboard for an at-a-glance status.

For History Buffs

Reporting is one of the most powerful features of an automated system. Current tank readings can be viewed in chart or tabular form. Reports can be run for one or all locations and can be sorted by vessel, material, or alert status. Specific date ranges can be selected to view historical usage trends over time. Each authorized user can generate the reports they need themselves, so there is no reliance or waiting on others to get data.

Share the Love

Some plastics operations share their inventory with vendors and suppliers and work in tandem to ensure resins are ordered and delivered when they are needed. In some cases, resin inventory is owned by the customer until the time it is processed. In this scenario, an automated system can ensure the plant and the customer are viewing the same information.



The BinView SaaS takes data from a wide variety of level sensors and sends it to the cloud for processing. Users log in to a website, enter credentials, and are presented inventory data instantaneously. Any device with internet access can be used to view data including a smartphone, tablet, or PC. Users don’t need to be on site to use it. They can be anywhere in the world as long as there is internet access.

Dashboards present inventory information in a simple, easy-to-use graphical interface. Depending on the level of access granted by an administrator, users can see inventory by location, silo, and the type of resin. With one click, they can view details for each silo such as the time of the last measurement, how much headspace remains, its percentage full, or volume. Each user can customize their views to display just the information that is important to them.

The BinView SaaS is an annual subscription with a modest cost based upon the number of silos and gateways.


For plastics operations that want to install software locally, BinVentory is a robust and affordable option. This software is a one-time purchase for the base software with viewer software sold separately. Periodic upgrades are generally issued every few years at a nominal cost.

Easy-to-use with a simple graphical interface, Binventory can monitor inventory for up to 255 silos at one or multiple sites using a company’s LAN, WAN, or VPN. It allows viewing of all vessels, sorting by a select group of vessels, or zeroing in on an individual vessel. Users can also activate an instant reading if needed. Binventory offers wireless options and is a great alternative to using a PLC, HMI, or SCADA system as it requires no special programming or added costs.

Binventory is most often used with SmartBob cable-based sensors but is compatible with other continuous levels sensors.


Level sensors measure the level of resins in a silo very accurately with repeatable results of within 0.2”.

Typically, resin silos are smooth walled—about 12 feet in diameter and 40 to 60 feet tall. Plastic pellets generally flow well and generate little dust, making them easy to measure. Popular sensor selections among plastics processors include: 

Meet Bob

Also, known as weight and cable or yo-yo type sensors, SmartBob simply acts as an automated tape measure. It drops a weight to the surface of the material and instantly retracts upon impact. It measures the amount of cable dispensed on its descent and double-checks the measurement upon retraction. SmartBob takes measurements at scheduled intervals or on demand from Binventory software or a console.

Can’t Touch This

Non-contact radar has quickly gained popularity in plastics since the introduction of 80 GHz radar. This powerful frequency cuts through dust, focusing the beam in a narrow 4° angle making it ideal for tall, narrow silos often used for resin storage. A 1-1/2” NPT mounted option is ideal for maintenance engineers who want a sensor that is easy to install in an existing opening.

Now Hear This

With its distinctive chirp, the 3DLevelScanner uses sound waves to measure pellets, powders, and flakes accurately. Instead of measuring a single point like other sensors, it measures multiple points to provide accuracy in materials that might pile in a silo. The 3DLevelScanner reports low, high, and average levels detected in the silo, and the top MV model offers a 3D image of the material. Its unique MultiVision software provides data about every sensor in the system.

No Power, No Problem

The new kid on the block is the SPL-100 laser level sensor. As it doesn’t require wiring, it is easier and less expensive to install. With a three-year replaceable battery, it is also maintenance free. The SPL-100 has a built-in transceiver that is easily connected to an internet gateway that sends measurement data to BinView.


Being alerted to high and low levels can be a real benefit to production managers. Point level indicators do exactly that–alert when resins meet a certain point. A high-level alert prevents overfilling silos. No more wasted plastics spilled on the ground when filling silos!

Rockin’ Rotaries

A rotary, or paddle-wheel, level indicator works by continuously rotating a paddle. When used for detecting high levels, the rotary paddle stops turning and sends an alert as resins are loaded into the silo and reach the paddle. Conversely, when used as a low-level alert, the paddle starts to turn when resins fall to a level below the paddle. Fail-safe rotaries such as the MAXIMA+ are ideal for circumstances where the operation of the sensor is critical to a process operation.

Good Vibrations

Vibrating rods are top-pick in plastics. They are unobtrusive and very reliable in plastic pellets when installed in either silos and hoppers. They can be used in light or powdered resins with a bulk density as low as 1.25 per cubic foot. They work by vibrating until the vibration is dampened by a covering of resin. When the rod stops vibrating, it sends an alert via a relay. When the vibration begins again as material falls away from the rod, the relay switches back̅—indicating a low or near empty level. The VR-Series of vibrating rods feature a sword-shaped rod that resists buildup and bridging and three sensitivity settings.

Both rotaries and vibrating rods come in affordable mini and compact versions for hoppers or to fit in small spaces.

Also Popular in Plastics
Digital Panel Meters

For plants that want real-time data on the ground near the silos, a digital panel meter gives instant data access to production personnel at the push of a button. Multiple silos can be networked to a single meter to save time walking from silo-to-silo to get readings. Meters can be programmed to display in pounds, tons, headspace, or level. They are a popular addition among users of NCR-80 non-contact radars and 3DLevelScanners.



As the saying goes, “Our inventory goes down the elevator every night.” Despite the increase in automation, plastics manufacturers ultimately rely on employees to make good decisions. Giving employees the tools and a system that supports their data needs helps them help the company’s bottom line.

A real-time solution combining software and sensors saves time and helps employees do their jobs better. To learn more about Inventory Management Systems for your silos, visit our website. Better yet, call one of our people for a personalized demo.

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