Proper screen tension is crucial for effective screening

Proper screen tension is crucial for effective screening and longer screen life. Proper screen
tension helps spread material across the full width of the screen. Uniform tension must be
also maintained on the screen surface to prevent whipping and to maintain contact between
the screen surface and the capping rubber (also called channel rubber, bucker-up rubber,
etc.) on the longitudinal support (camber) bars for preventing damage to (breakage of)

screen cloth.

As shown in above figure, for proper screen tensioning; tension plates (also called tension
bars, tension rails, clamp down rails, side hold down, etc.) and tension bolts with swivel nuts
(or swivel/spherical/taper washer and hex nut) are commonly used for heavy wire cloth or
perforated plate (screen cloth) with edge hooks (hook strips) on side tensioned vibrating
screens. Tension plates, tension bolts, etc. are called screen accessories.
During operation, as the screen may become loose due to stretching (as the screen cloth
wire wears thin) and loosening of the hooks, it is important to periodically check the screen,

and retighten the hooks.

Above figure shows the most common type of tensioning device for fine and medium weight
cloth consisting of tension wedge and rubber spring. This tensioning device has the
advantage of quick tightening or easy release, while at the same time providing constant
tension through the action of the molded rubber spring. Because the wedges are held firmly

in place by spring action, constant attention (retightening) is not required.

Above figure shows other automatic tensioning device for fine and medium weight wire cloth
or light weight perforated plate consisting of steel spring assembly. As the screen cloth gets
stretched, the springs automatically keep the cloth in constant tension.


The main obstacles to efficient screening

The main obstacles to efficient screening are plugging/pegging, blinding and carryover. Each can be minimized with a variety of solutions.


Plugging/pegging happens when near-size particles become lodged/wedged, blocking the openings. Generally, if loose particles/rocks (“Carrots” Shape) get stuck in the media holes it is called plugging whereas if particles get jammed in the openings, it is called pegging. Solutions may include increasing stroke, changing opening shape (using long-slotted openings instead of standard square openings), using urethane or rubber media, using selfcleaning (non-blinding) screening surfaces having wires that are crimped to form openings but individual wires are free to vibrate and using ball trays (also called bouncing ball decks).

As shown in above figure, the ball trays consist of compartments with perforated plate or wire cloth with relatively large openings placed beneath the screen cloth. Generally, rubber balls are placed in each compartment that freely bounce during the operation of the screen. They strike the underside of the screen surface and therefore randomly knock out the clogged material. The secondary vibration generated in the screen cloth due to striking of the balls also prevents fine particles from sticking and building up on the wires. In most cases, a ball tray will be effective with material containing as much as 5% moisture. The material that passes through the screen cloth passes through the perforated plate or wire cloth at the bottom of the ball tray where it can be collected.
Ball trays are generally used for coarse meshes which can withstand higher impact energy from the balls. Balls are not recommended for fine screen meshes because they may damage the screen cloth.


As a rule of thumb, screening at less than around 5 mm aperture size must be performed on perfectly dry or wet material, unless special measures are taken to prevent blinding. Blinding occurs when moisture causes fine particles to stick to the surface and gradually cover the openings. In this case, changing stroke and increasing speed may help. Use of different surface media also may be considered. The other options are to consider ball trays and heated decks. Heated decks have an electric current in the wire that heats and dries the material so that it easily knocks itself loose as the screen vibrates. Heated deck is a more effective method of preventing blinding in damp materials (1.5 to 6% moisture) than the ball tray.
Heating transformers, consuming from 2 to 3 KVA per foot of screen length, can be used with any screen cloth weighing less than about 1.5 lbs. per square foot. The current flows at a low voltage (1 to 12) and a high amperage to produce temperatures on the screen wires ranging from 80 to 150°F. This heat is not intended to dry the material being screened, but only to dry the interface between the wire and adhering particles (e.g. clay particles) sufficiently to break the adhesive bond holding the particles to the wire. The screen vibration does the rest.
Wet screening allows finer sizes to be processed efficiently down to 250 μm and finer.
Adherent fines are washed off large particles, and the screen is cleaned by the flow of pulp and additional water sprays. Carryover occurs when excessive undersize particles fail to pass through the openings. Solutions may involve changing stroke, speed or reversing screen rotation; changing wire diameter or the shape of the opening to increase open area; changing the angle of inclination and changing feed tonnage.

Vibrating Screen Installation, Start up and Adjustments

Installation
The supporting steel structures on which the screen and drive motor are mounted must be sufficiently strong and braced to accept without deflection the dynamic loads caused by the
vibration of the screen.
Adequate clearances must be allowed between the screen and the fixed structure, chutes etc., to allow enough space because the movement of the screen is large in the so-called resonance areas when starting and stopping the screen.
Check that the height difference of separate springs pedestals (in the same end of the screen) are not more than ± 3 mm. Transparent water hose and water may be used to check the height difference. Pedestals surface must be horizontal.
Tighten all bolts in the recommended sequence if any and to the recommended torque.



  • Check the screen’s installation angle.


  • Check that all of the spring axes are vertical.


  • Check rotation directions of the motor/s.
In case of screen driven by motor and cardan shaft, the vertical position of the motor must be fixed so that the centre line on the screen’s shaft is approx. 5 mm higher than the centre line of the motor shaft. During running with material, cardan shaft should be close to horizontal. In case of belt drive, tension the belts as per manufacturer’s recommendation.
Make sure that all guards are properly fastened and all the safety devices are installed and they are working properly.
Earth the motor connection at the mains.
Have qualified electrician install overload, short-circuit and ground-fault protection.
If unbalance motor is installed onto a vibrating screen, leave slack in electrical cable so that cable does not become taut during vibration cycle and cause stress on wire connection.
In case of a linear motion vibrating screen, interlock the two unbalance motors rotating in opposite directions and install separate overload protection. The screen’s control circuit must be arranged so that if one unbalance motor becomes de-energized, the other unbalance motor will automatically and immediately become de-energized. Failure to properly interlock screen’s unbalance motors could result in damage to the screen if one unbalance motor fails (if only one unbalance motor of a pair is powered, the bearings in the unpowered unbalance motor will get damaged within a very short time).
If the unit is going to be stored before start-up, once a month, the shaft should be rotated several times to re-lubricate the upper bearing portion.


Start up
After start (first 1-2 minutes) make sure that screen is starting and running properly.
Check the feed of the material. It must spread to whole width of the screen.
Check screening result.

Above figure shows three potential screening scenarios. Screening finishes early on the
deck at (A), which results in a loss of production; screening not completed (B), which results
in carryover and contaminated material; and optimal screening (C), which provides for higher
production with less contamination.
Check stroke length and stroke angles in each corner. Stroke length must be within one mm to each other in the same end of the screen!
Check for oil/grease leaks in the mechanism.
After 4 to 6 hours, check that bearing temperature is even in each bearing. Normal running temperature can be about 70°C when ambient temp is 20°C.
After running the screen for about 50 hours, check the following:

  • Fastening / tightness of mechanism bolts.
  • Fastening / tightness of counterweight.
  • Fastening of screening medias.
  • Alignment / tightness of V-belts.
Mechanism has tendency to leak a little bit after few operation hours or days. This leak is mainly extra grease coming out of sealing. Leaking should stop in few hours or days.
The first oil change for the mechanism must be done as per manufacturer’s recommendation
(in case of gears, after about 100 hours of operation).


Screen Adjustments
If the screening performance is not satisfactory, check first that the screen meshes are correct for the application and that the feed and discharge arrangements are satisfactory. Feed to the screen must be arranged so that the material is fed uniformly across the entire width of the screen.
As feed material is a mixture of varying sizes, oversize material will restrict the passage of undersize material, which results in a build-up, or bed depth, of material on the screen surface. Bed depth diminishes as the undersize material passes through the screen openings. For efficient screening, the material bed should not reach a depth that prevents undersize from stratifying before it is discharged. Hence for maximum screening efficiency depth of bed should be proper. As stated earlier, depth of bed (in dry screening) should not
exceed four times the opening size at the discharge end of the screen. Depth of bed can be
changed by adjustments in speed, stroke length, rotation (or throw) direction and angle of
inclination. However, always make only the minimum adjustments necessary to achieve the
desired result.
If adjustments are necessary, they should be made in the order given below.


  • Stroke frequency adjustment

  • Stroke length adjustment

  • Adjusting the inclination of the screen body

Try the action of each measure separately and singly. Try one action at a time and observe
the result before taking on the next one.
Adjustment of the stroke length is done by adding or removing counterweights. At both ends of the same shaft there has to be exactly the same number of counterweights. Higher stroke delivers a higher carrying capacity and travel rate, while reducing plugging, blinding and enhancing stratification. Always check the screen speed/stroke length combination so that the maximum allowed acceleration (G-force) of the screen is not exceeded.
Stroke frequency adjustment can be done by changing V-belt pulleys or inverter parameters.
Higher frequency/speed may decrease depth of bed. Rotation speed affects the G-forces.
More speed, more G-forces with same counter weights.
Always ask manufacturer before changing rotation speed. Wrong speed can run the screen near to its natural frequency leading to screen body failure.
Also remember that increased G-forces shortens the bearing life time!
Adjusting the inclination of the screen body is done by lifting or lowering other end of the screen or feeder. Increasing the angle of inclination causes material to travel faster, which can be advantageous in certain dry screening applications. Although, there may be a point where too much incline will hinder efficiency as fines may roll over the media rather than passing through.
Do consult the manufacturer for advice on the selection of the optimum speed, stroke length, angle and frequency, if mesh sizes are changed or different material is fed to the screen.



Vibrating Screening size control

Size control is the process of separating bulk material into two or more products on basis of
their size. In mineral processing practices, two methods dominating size control processes
are: screening and classification. As shown in the following figure, while screening uses a
geometrical pattern for size control, classification uses behavior of particle’s (finer than 1
mm) motion in air or liquids (water) for size control.


Sizing is extensively used for size separations from 300 mm down to around 40 μm (micron),
although the efficiency decreases rapidly with fineness. Dry screening is generally limited to
material above about 5 mm in size, while wet screening down to around 250 μm is common.
Although there are screen types that are capable of efficient size separations down to 40
μm, sizing below 250 μm is also undertaken by classification. Selection between screening
and classification is influenced by the fact that finer separations demand large areas of
screening surface and therefore can be expensive compared with classification for high
throughput applications.

520 Vertical Filling Forming Sealing Packing Machine Your Smart Packaging Solution

  In today's increasingly competitive global manufacturing landscape, the efficiency and stability of the packaging process directly impact an enterprise's market competitiveness. Many businesses have encountered troubles such as downtime maintenance due to difficult equipment cleaning, production delays from complex operations, and frequent replacements caused by poor compatibility. Here, we introduce UUPAC's 520 Vertical Filling Forming Sealing Packing Machine, which delivers intelligent packaging solutions through its smart design and high-efficiency performance.

 520 vertical filling forming sealing packing machine

1. Intelligent Design

Arc-shaped glass door for seamless cleaning: The thickened arc glass door with 304 stainless steel frame eliminates cleaning dead corners. Combined with quick-release hinges, it reduces cleaning time by 50% compared to traditional models. The transparent window enables real-time process monitoring.

20° inclined touchscreen for effortless operation: The 10.1-inch HD touchscreen with 20° inclination and anti-glare coating adapts to standing operation, minimizing light interference. Its simplified 3-level menu logic allows new users to master operations within 10 minutes.

 

2. High-Efficiency Performance

Optimized film drive for stable output: Designed for 520mm film width with 400mm pull stroke, it supports 250×400mm bags with neat sealing. Servo-driven film pulling (±0.1mm accuracy) ensures stable 10-60 BMP speed, 20% faster than traditional models.

Safety-first design: Illuminated buttons ("Single Cycle" and "Run") prevent accidental activation. Pneumatic components in a soundproof box reduce noise (<65dB) and dust intrusion, extending maintenance to every 2000 hours.

 

3. Durability and Flexibility

Industrial-grade stainless steel body: Made of 304 stainless steel, the brushed surface resists scratches and corrosion.

Multi-format bag compatibility: Processes pillow bags, stand-up pouches, and perforated bags within 50-350(L)×50-250(W)mm, enabling efficient small-batch production.

 

4. Versatile Applications

Food Industry: Ideal for powders/granules (milk powder, nuts, etc.). The FDA-compliant arc glass door enables quick cleaning for product changes.

Chemical Industry: Corrosion-resistant design with optional explosion-proof components for fertilizers, detergents, and other corrosive materials.

Pharmaceutical Industry: Smooth, GMP-compliant surface for easy disinfection, perfect for sterile packaging of tablets and powders.

 

  For businesses looking to enhance their packaging capabilities, improve operational efficiency, and maintain a competitive edge in today's fast-paced market, the 520 machine offers a comprehensive solution that delivers measurable results. To explore how this advanced packaging system can be customized for your specific production requirements or to request a demonstration, our specialists are ready to assist you——contact us to start your journey toward smarter packaging solutions.

 

Boost Production Efficiency with Our Typical Weighing, Packing and Detecting System

    In modern production lines, accurate weighing, efficient packing, and precise detecting are essential components. Any inaccuracies or inefficiencies in these areas can lead to increased costs, product quality issues, and loss of customer satisfaction. Hence, UUPAC is proud to present our Typical Weighing, Packing and Detecting System, a revolutionary solution designed to optimize production processes.

 Typical Weighing, Packing and Detecting System

7 Key Components of Our Weighing, Packing and Detecting System

1. Bucket Elevator: It can smoothly lift materials to an appropriate height, ensuring a continuous supply of materials .

2. Multihead Weigher: Using advanced technology, it can weigh products of different weights with high precision in a short time, meeting diverse weighing requirements.

3. Supporting Platform: The sturdy supporting platform ensures the stability of the system structure, reducing weighing errors caused by vibration and ensuring the accuracy of operations.

4. Vertical Packing Machine: It is capable of quickly packaging products in various forms, such as bags, boxes or other containers, handling them efficiently and greatly improving packaging efficiency.

5. Finished Product Conveyor: It is responsible for smoothly conveying the packaged finished products, avoiding damage to the products during transportation and ensuring the smooth flow of the production process.

6. Check Weigher: It accurately detects the weight of the packaged products and promptly screens out products that do not meet the weight standards, ensuring the weight consistency of the shipped products.

7. Metal Detector: It can sensitively detect metal foreign matters in products, guaranteeing product quality and consumer safety.

 

Why Choose UUPAC's Weighing, Packing and Detecting System?

1. Intelligent Automated Control

The system coordinates product feeding via fully automated mechanisms, cutting labor costs by 40% and energy consumption by 25% compared to traditional setups.

2. Precision-Engineered Work Platform

Reasonable design and soild structure of working platform to ensure the weighing accuracy is not affected.

3. Versatile & Stable Operation

Simple and scientific design of the complete line with stable running and large weighing range and high weighing accuracy features.

4. Cross-Industry Adaptability

Suitable for snack foods, puffed goods, hardware, plastics, and rubber, the system features hygienic stainless steel for food sectors and anti-static modules for industrial use.

 

Three Core Benefits of Our Weighing-Packing-Detecting System

1. Cost-saving

By minimizing measurement errors, reducing packaging waste, and decreasing the need for manual inspection, our system helps customers save significant costs. Over time, these savings can have a substantial impact on the bottom line.

2. Quality Assurance

The system's precise weighing and detecting capabilities ensure that only high - quality products are packaged and shipped. This helps customers maintain their brand reputation and meet strict quality standards imposed by regulatory bodies.

3. Increased Productivity

With faster packing speeds and automated quality control, the production line can operate at higher efficiencies.

 

Conclusion

    The Typical Weighing, Packing and Detecting System is more than just a piece of equipment—it's a strategic investment for companies looking to enhance production efficiency, reduce costs, and ensure consistent product quality. We invite potential customers to contact us for more information, schedule a product demonstration, or discuss how our system can be tailored to your specific production needs. With our solution, you can elevate your production line to new levels of performance and competitiveness.

How to Ensure Food and Industrial Safety—The Role of Metal Detectors

In food, pharmaceutical, and chemical industries, metal contaminants pose a silent but critical threat. From tiny stainless steel shavings in processing equipment to accidental metal impurities in packaging, even a single undetected particle can lead to product recalls, brand damage, and regulatory penalties. UUPAC's High Precision Horizontal Conveyor Metal Detector will become an indispensable safeguard against these risks in your production line.

 High Precision Horizontal Conveyor Metal Detector

Our high precision horizontal conveyor metal detectors are ideal for packaged, loose, or fragile products that require gentle handling. The product has the following features:

1. Balanced Coil Principle: Utilizes a balanced electromagnetic field design for enhanced stability and detection reliability.

2. Advanced Phase Compensation Technology: Dynamically adapts to product characteristics to effectively eliminate product effect and minimize false rejects.

3. Dual-Core Processing Architecture: Employs a combination of Digital Signal Processing (DSP) and a dedicated Microprocessor for real-time signal analysis, significantly improving detection sensitivity and efficiency.

4. Intelligent Signal Processing & Calibration: Features automatic transmission error compensation and simplified one-touch parameter calibration for quick setup and minimal operational errors.

5. Multilingual HMI Interface: Equipped with a large LCD touchscreen supporting bilingual (Chinese/English) operation and customizable settings for user preference.

6. Automatic Product Learning: Incorporates self-learning algorithms to digitally capture, store, and optimize product-specific parameters without manual intervention.

7. Extensive Data Storage: Capable of storing over 100 unique product profiles and corresponding detection data for rapid recall and process analysis.

8. Automatic flap rejection system can improve production efficiency and save labor costs.

 

A high-precision horizontal conveyor metal detector is an essential investment for food manufacturers prioritizing safety and quality. By integrating advanced detection technology with hygienic design and reliable rejection systems, it minimizes contamination risks while maintaining production efficiency. For optimal performance, choose a model tailored to your product type and production speed, and follow strict testing and maintenance protocols. Your consumers' safety—and your brand's reputation—depend on it.

 

Need a metal detector for your production line? Contact us for more information!

5 Axis CNC Waterjet The Future of Precision Machining

5 Axis Waterjet, known as the ‘universal knife’, it has ultra-high precision and unlimited creative potential, can provide intelligent solutions for stone mosaic , relief and art decoration and other scenarios, its unique cold cutting characteristics and excellent three-dimensional machining capabilities make it irreplaceable in the field of high-end manufacturing, is the future of precision machining.



What is CNC five-axis waterjet cutting machine?



CNC 5 Axis waterjet cutting machine is an advanced CNC machine tool that uses ultra-high-pressure water flow (usually mixed with abrasives) to cut materials. 5 Axis Waterjet can cut almost any kind of material such as steel, alloy, stone, ceramic, tile, glass, aluminium. Compared with the traditional 3-axis waterjet, the 5-axis system uses X/Y/Z linear axes + A/C rotary axes, which allows the cutting head to achieve more complex angle changes in 3-dimensional space, resulting in more precise cutting tasks. The water jet head can oscillate in any direction, which allows for three-dimensional cutting of complex shapes, such as chamfering and chamfering, and cutting of high-precision conical surfaces, arc surfaces and other complex spatial surfaces.



Core components include: ultra-high-pressure water pump system (usually up to 60,000 psi or higher), five-axis linkage CNC system, precision cutting head, abrasive delivery system, water treatment system, table and positioning system.


Technical Advantages

No thermal deformation cutting: the waterjet's ‘cold cutting’ technology eliminates thermal stress cracks caused by traditional laser or blade processing, ensuring smooth, chip-free stone edges.

Wide material adaptability: can cut metal (including titanium alloy, stainless steel), composite materials, stone, glass, ceramics, plastics and almost all materials.

High-precision processing: five-axis linkage can achieve ±0.05mm cutting accuracy, to meet the needs of aerospace and other demanding fields.

Complex geometry processing: capable of completing complex three-dimensional contour cutting that is difficult to achieve with traditional three-axis machines.


Environmental protection advantage: with the water recycling filtration system and sludge recycling device, 95% of water reuse can be achieved, in line with green manufacturing standards.


What is the best machine to cutting stone veneer?

Thin Stone Veneer Saw is a highly efficient machine designed for the precise cutting of thin natural stone slabs for wall decoration, interior and exterior projects. It is lightweight and equipped with diamond blades to easily cut thin stone veneer flats and corners, ensuring flat edges and reducing material waste. Easy to operate, safe and durable, this machine is ideal for the stone processing and construction industries.



Designed for efficient operation:

Integral compact structure for easy installation and transport.

International brand control components to ensure stable performance.

Stepless speed regulation of the main cutting motor and conveyor belt to adapt to different needs.

Versatile cutting capability:

Continuous cutting mode, efficiency increased by more than 50%.

Can be equipped with double 1200mm saw blade system.

Unique V-shaped cutting surface design, perfect for handling cracked surfaces.


This professional thin veneer saw is especially suitable for dealing with: natural finished sandstone, all kinds of bricks, limestone, pebbles and other irregular oval stones. Easy to operate, reducing labour skill requirements. Safe and durable, reducing maintenance costs. High precision cutting to enhance project quality.



What is the Fastest Splitting Machine for Natural Stone ?

In the stone processing industry, stone splitting is a key link in stone processing. Its speed directly affects: overall production efficiency, labor cost control, order delivery cycle, equipment return on investment.


The traditional manual splitting or mechanical splitting methods are not only inefficient, and the quality of the finished product varies. Hydraulic rock splitter have revolutionized the situation. Equipped with a replaceable blade system that provides smooth, repeatable splitting, reducing waste and eliminating the need for over-finishing.


The hydraulic stone splitting machine superior performance is reflected in the following areas:

1. Revolutionary Rapid Lift System
Hydraulic rock splitter adopts optimized hydraulic circuit design, which makes the knife teeth lifting speed 30-40% faster than the traditional equipment, greatly reducing the non-working travel time, and realizing the high-speed cycle of “splitting - resetting - splitting again”.

2. Retractable floating teeth design
Each knife tooth works independently and can be locked automatically, adapting to various uneven stone surfaces.

3. Wedge Chisel Balancing System
This innovative design ensures that the splitting force is evenly distributed, resulting in a neater stone edge line, reducing the need for secondary processing and improving productivity overall.

Hydraulic stone splitter is mainly used as a splitting line for the production of split stone and other finished products, such as building stone, wall stone, curbstone, paving stone. It can also be used as the main machine for semi-finished split stone, for small stone crusher and thin veneer saw.

Hydraulic stone splitter can not be the fastest natural stone splitter without its solid technical foundation:

High-quality materials: the use of high-strength cast iron body and heat-treated hardened high-carbon steel cutter teeth, to ensure the stability of the equipment in high-speed operation.

Open frame design: not only easy to maintain, but also optimize the heat dissipation performance, so that the equipment can maintain efficient operation for a long time.

Intelligent hydraulic system: precisely control the splitting strength and speed to realize the fastest processing under the premise of quality assurance.

In the pursuit of efficiency in the modern stone processing industry, hydraulic splitter it not only has excellent splitting speed and stable performance, but also through the reduction of waste and improve the rate of finished products for you to create more profit margins.