Both Box Screens and Scalping Screens have their place in the portable screen market. Before comparing the different technologies, let’s get acquainted with where and when these technologies became popular.

In the United States, box screens became extremely popular by a company named Read Screen- All located in Middleboro, MA.. A man named Jim Read wanted to design and manufacture an extremely heavy-duty screener that had minimal moving parts, extremely durable, highly portable, and high production. He was extremely successful achieving his goals and was a pioneer of his time. In 1978 this technology was perfected and his machines are still seen today at many job sites. 

Box Screeners

Box Screeners are popular amongst contractors as they are very portable and can be set-up in minutes. There is only an engine and a shaft for moving parts so there are no conveyors to track. As a result, the price of these machines was extremely affordable.

In recent years, small manufacturers have taken this robust design and have made variations that are extremely light-duty and inexpensive. As a result, the end result has been many equipment failures as the newer, cheaper versions cannot withstand the heavy-duty applications of their heavier counter-parts.

If you have a skid steer and light sandy material you can utilize the lighter-duty versions, but if you experience large rocks and debris in your material you wish to screen, you need a robust screener. Box screeners are particularly effective when dealing with various types of feed material, including light sandy material and larger rocks and debris.

Scalping Equipment

Scalping Screens are also designed for heavy-duty applications; however, this technology normally is equipped with a feeder and take-away conveyors. This technology became popular many years after the Box Screener as many producers wanted to have a feeder and take-away conveyors. Having conveyors to both feed and transport the other materials into piles saves the front-end loader from having to move the material into piles. As a result, the cost per yard became considerably less with the Scalping Screeners. In addition to conveying into piles, most Scalping Screeners are on tracks allowing for the machine to windrow the materials, saving time and money in moving the material. As you might expect, this technology is significantly more money than a box screen capable of handling the same material.

Scalping screens operate by utilizing vibrating meshes, or ‘screens,’ which are arranged in tiers on a screen deck. The type of screening media used can significantly impact the efficiency of the screening process. Some scalping screens also utilize finger screens, which enhance the screening process for various applications.

How Scalping Screens Work

Scalping screens are engineered to separate mixed materials into different grades based on size. These screens operate by

utilizing vibrating meshes, or ‘screens,’ which are arranged in tiers. When material is dumped onto the top tier, the screens vibrate, causing smaller particles to fall through the mesh holes while larger pieces remain on top. For fine screening applications, typically less than 6mm, the screens are inclined. This inclination allows any material that doesn’t pass through each tier to tumble onto a conveyor, which then carries it away. This process ensures efficient separation and sorting of materials, making scalping screens indispensable in various heavy-duty applications.

Applications for Scalping Screens

Scalping screens are versatile machines used across a wide range of industries, including aggregate, mining, and mineral processing. They are particularly valuable in recycling, aggregates, compost, topsoil, coal, and construction and demolition waste. For instance, scalping screens are employed to sort sand and gravel from construction waste, separate crushed stone from aggregates, and break down iron ore into a form useful for steel manufacturing. Their ability to handle diverse materials makes them a critical component in various industries, ensuring efficient processing and sorting of raw materials.

Key Differences Between Box Screens and Scalping Screens

While both box screens and scalping screens are used for screening materials, they differ significantly in design and functionality. Box screens are typically used for coarser screening applications and feature a more compact design. In contrast, scalping screens are built for the same heavy-duty scalping but can screen 3 products instead of just two of the box screens. Scalping screens also have a larger screen box, enabling them to handle more production. These differences make scalping screens more suitable for demanding applications where capacity is paramount..  

Screen Box Design and Configuration

The design and configuration of the screen box are crucial to the efficiency of a scalping screen. Factors such as the size, shape, and material of the screen box significantly impact the screen’s performance. A well-designed screen box enhances the accuracy of the screening process and boosts productivity. Additionally, the type of screen media used within the screen box plays a vital role. Different types of screen media are suited for various applications, and selecting the appropriate media can optimize the performance of the scalping screen, ensuring it meets the specific needs of the task at hand.

Mobile Scalping Screens

Mobile scalping screens are track-mounted or wheeled screening plants designed for effective onsite material screening. Often used in conjunction with mobile crushing plants, these screens can size material at a high rate, making them ideal for a variety of applications, including demolition and contracting, sand and gravel, and aggregates. Mobile scalping screens offer superior productivity, versatility, and reliability, making them a popular choice among aggregate producers. Their mobility allows for easy transportation and setup, ensuring that screening operations can be conducted efficiently and effectively, regardless of the location.

Box Screeners and Scalping Screeners Pros and Cons

There are advantages and disadvantages of both Box Screeners and Scalping Screeners. Scalping equipment, with its robust design and multiple screen decks, is essential for efficient separation of larger rocks from smaller ones.

In this conversation, the light-duty scalping screens will not be discussed as they are considered precision screeners not a heavy-duty screening technology. The advantage of robust box screeners is that they are extremely portable.

In job sites that are unionized, using this technology eliminates the need for an extra service / grease-gun employee as there are no conveyors on the screener. The loader operator is solely responsible for loading the screener and taking the fines and overs into their designated piles. In this style of screening the fines fall under the screen and the overs fall on the other side of the screener resulting in a 2-product separation.

The heavy-duty box screeners are priced significantly below their conveyor counter-part. The disadvantages of these screening machines are the advantage of the Scalping Screens which is that conveyors feed and convey the materials saving the loader operator half the time to do other things like load trucks.

The owners of Scalping Screeners will testify that the most economical way to move material from point A to point B is by conveyor. This statement is extremely true and this is why the Scalping Screeners have heavy-duty impact bed belt feeders or apron feeders and take away conveyors. This allows the loader operator to dump his material into a feeder and move on to get more. This is more favorable than having to sprinkle material onto a shaker screen.

Another advantage is that scalping screens meter the material onto the shaker screens so the material spends more time on the screen surface allowing for a cleaner separation. In addition, scalping screens yield 3 products (fines, middles, and overs) compared to 2 of the Box Screeners (fines and overs). As stated above, this technology is considerably more expensive than the box screens and are slightly more difficult and expensive to transport. Since most are on tracks, you need a tractor trailer to move from site to site.

Since both screeners have their advantages and disadvantages, what tips are there for when to purchase each technology:

Box Screeners with no conveyors are a great choice if:

1. Contractor only needs fines and overs and screening topsoil so bottom screen mesh is greater or equal to ½”.
2. Jobsite is small as this option takes up the smallest footprint
3. Raw material is boney and has large rocks / contaminants in the material.
4. Budget is limited.

Scalping Screens with 3 built-on conveyors are preferred if:

1. Contractor needs to size more than one material. Scalping screens with 3 built-on conveyors, such as a mobile scalper, are preferred if: These versatile machines can handle a wide range of materials, making them ideal for various applications. This technology does extremely well screening topsoil but will also screen concrete and rock needing crushing. In addition, after the material is crushed, it can be conveyed into the Scalping Screen and 3 products can be piled simultaneously. This technology can have a fine bottom deck like 3/16” or ¼” without difficulty screening material.
2. Jobsite is not small where the operator can windrow material as screener is on tracks.
3. This machine is equally capable of handling boney materials.
4. This machine is more expensive to purchase so purchasers must determine if advantages outweigh disadvantages.

3rd Option not discussed above: Box Screen with built-on 60” Wide Fines Conveyor

1. If a scalping screener is desirable but the thought of having to move the finished screened material is a problem, GrinderCrusherScreen Inc. has just introduced such a screener:
2. Unlike all of the above options, this screener is equipped with a 60” wide extra- high conveyor that discharges 14’-3” high so it can easily directly load a dump truck. It is a wheeled screener so easy to transport via 5th wheel.

If you need assistance in determining which screening technology is best for your application, contact the professionals at GrinderCrusherScreen Inc. They can be found at GrinderCrusherScreen.com or 770-433-2670. They have been assisting customers since 1973 and are happy to answer your specific questions.