Bottomless Conveyor: Top Questions Buyers Ask Before Choosing One
A bottomless conveyor is a side-grip conveyor that holds a product from both sides while leaving the bottom surface exposed. This makes it useful when a production line needs to print, label, inspect, or transfer products without blocking the underside. In packaging lines, it is often used for bottom coding, label verification, inkjet marking, vision inspection, and smooth transfer between machines.
Based on common buyer searches around bottomless conveyors, side-grip conveyors, bottom coding conveyors, and packaging conveyor selection, the questions below are the ones most often asked before purchase.
Most Asked Questions About a Bottomless Conveyor
1. What is a bottomless conveyor?
2. How does a bottomless conveyor work?
3. What is a bottomless conveyor used for?
4. Can it print or code on the bottom of bottles, jars, cartons, or containers?
5. What products can run on a bottomless conveyor?
6. What product shapes are not suitable?
7. How fast can a bottomless conveyor run?
8. Can it connect with an inkjet printer, laser coder, labeler, or vision system?
9. How do you adjust it for different product sizes?
10. What belt material should be used?
11. What safety features are needed?
12. How much maintenance does it require?
13. How do you choose the right bottomless conveyor supplier?
What Is a Bottomless Conveyor?
A bottomless conveyor uses two synchronized side belts to grip and move products. Unlike a standard belt conveyor, the product is not supported from underneath during the working section. Because the bottom is open, another device can access the underside of the package.
Standard conveyor systems are widely used in packaging, bottling, food, pharmaceutical, chemical, electronics, and manufacturing lines because they move products efficiently from one process to the next. A bottomless conveyor is a more specialized version for operations that need underside access while the product stays controlled.
How Does a Bottomless Conveyor Work?
Two parallel belts run at the same speed and hold the product by light side pressure. The belts carry the item across an open gap, allowing equipment below the conveyor to apply a code, scan a mark, inspect a seal, or transfer the product to another section of the line.
The most important design points are:
- Belt speed synchronization
- Stable side pressure
- Correct belt height
- Product width adjustment
- Smooth infeed and discharge transfer
- Enough open space for the printer, camera, sensor, or reject device
If the belts are too tight, they may deform labels or containers. If they are too loose, the product can slip or rotate. A good setup keeps the product stable without damaging the package.
What Is a Bottomless Conveyor Used For?
A bottomless conveyor is most commonly used when the bottom of a package must stay visible or accessible. Typical applications include:
- Bottom coding with thermal inkjet, continuous inkjet, or laser marking systems
- Printing batch codes, lot numbers, expiry dates, QR codes, or barcodes
- Inspecting bottom labels, seals, date codes, or molded marks
- Transferring containers over a printer, sensor, scale, or inspection station
- Holding products steady between filling, capping, labeling, and case-packing equipment
For factories that need traceability, underside coding can keep required information visible while preserving the main label design.
What Products Can Run on a Bottomless Conveyor?
A bottomless conveyor works best with products that have enough side surface for the belts to grip. Common examples include:
- Bottles
- Jars
- Cans
- Cartons
- Tubs
- Trays
- Rigid pouches with stable side edges
- Cosmetic containers
- Pharmaceutical bottles
- Food and beverage packages
The product should usually have a consistent width, reasonable rigidity, and enough height for side contact. Round containers can run well if the side belts are aligned and the transfer is controlled.
What Products Are Not Suitable For Side Conveyor Belt?
A bottomless conveyor may not be the best choice for very soft, very short, very slippery, unstable, or irregularly shaped products. Packages with weak sidewalls can deform under belt pressure. Very small products may not have enough contact area. Heavy products may need extra transfer support before and after the open section.
Before buying, test the real product, including filled weight, empty weight, label material, cap shape, and any size variation.
Can It Integrate With Printers, Labelers, and Vision Systems?
Yes. One of the main reasons buyers choose a bottomless conveyor is integration. It can be paired with:
- Thermal inkjet printers
- Continuous inkjet printers
- Laser coders
- Print-and-apply labelers
- Barcode scanners
- Vision inspection cameras
- Sensors and reject systems
For reliable integration, confirm the working distance, mounting space, trigger sensor position, encoder requirements, conveyor speed range, and communication signals between machines.
How Fast Can a Bottomless Conveyor Run?
Speed depends on product stability, belt grip, machine length, printer or inspection exposure time, and upstream line speed. Many applications are limited less by the conveyor motor and more by whether the product stays stable enough for accurate coding or inspection.
When comparing machines, ask for the usable speed with your actual product, not only the maximum belt speed. A stable line at a realistic speed is usually more valuable than a high-speed rating that works only with ideal samples.
How Do You Adjust It for Different Product Sizes?
Most bottomless conveyors offer manual or powered adjustment for width and height. For lines with frequent changeovers, look for:
- Handwheel width adjustment
- Digital position indicators
- Tool-less guides
- Repeatable setup scales
- Adjustable belt pressure
- Quick mounting slots for printer and sensor brackets
If your line runs many SKUs, changeover repeatability can affect daily output as much as top speed.
What Belt Material Should Be Used?
The right belt depends on the product surface, environment, cleaning method, and grip requirement. Common considerations include:
- Food-grade or pharmaceutical-grade contact requirements
- Friction level for glass, plastic, metal, or paperboard
- Resistance to ink, oil, moisture, cleaning chemicals, or abrasion
- Belt hardness to avoid marking the package
- Static control if the line handles electronics or dust-sensitive products
For sensitive labels or soft containers, a gentler belt surface can reduce scuffing.
What Safety Features Matter?
Because a bottomless conveyor uses moving belts and nip points, safety should be considered during both design and daily operation. Useful features include emergency stops, guarded moving parts, clear access points, stable machine feet, lockable controls, and safe procedures for cleaning or maintenance.
In the United States, OSHA machine guarding and lockout/tagout rules are common reference points for industrial equipment safety. Always follow local regulations and your plant's safety policy.
How Much Maintenance Does It Need?
A bottomless conveyor is usually straightforward to maintain, but it still needs routine attention. Build a simple checklist around:
- Belt tracking
- Belt tension
- Side belt wear
- Pulley and bearing condition
- Motor and reducer inspection
- Sensor alignment
- Fastener tightness
- Cleanliness around printer or inspection stations
Regular inspection is especially important because small changes in belt tension or alignment can affect print quality and product stability.
How to Choose a Bottomless Conveyor
Before requesting a quotation, prepare the information a supplier needs:
- Product dimensions and weight
- Product material and sidewall strength
- Filled and empty product samples
- Required line speed
- Coding, labeling, or inspection device model
- Available floor space
- Infeed and discharge conveyor height
- Electrical requirements
- Washdown, food-grade, or cleanroom requirements
- Changeover frequency
The best supplier should ask about your full packaging line, not only the conveyor size. A bottomless conveyor must match the upstream and downstream machines to prevent unstable transfers, missed codes, and unnecessary downtime.
Bottomless Conveyor FAQ
Is a bottomless conveyor the same as a side-grip conveyor?
They are closely related. Many suppliers use terms such as bottomless conveyor, side-grip conveyor, side-belt conveyor, hugger belt conveyor, or bottom coding conveyor depending on the application.
Can a bottomless conveyor print on the bottom of a bottle?
Yes, if the bottle has enough side surface for stable gripping and the printer has the correct working distance below the open section.
Can it handle round bottles?
Yes, but round bottles need careful belt pressure and guide adjustment to prevent rotation during coding or inspection.
Does it replace a normal conveyor?
Usually no. It is normally installed as a short specialized section within a longer packaging line.
What information should I provide to get an accurate quote?
Send product drawings or samples, line speed, product weight, available space, conveyor height, power requirements, and details of the printer, labeler, or inspection device.
Conclusion
A bottomless conveyor is a practical solution when the bottom of a package needs to stay open for coding, labeling, inspection, or transfer. The right machine should grip products securely, protect the package surface, integrate cleanly with nearby equipment, and adjust easily for your production range.
If you are planning a new packaging line or upgrading a coding station, start by testing real product samples and confirming the exact working space required under the conveyor. That will make the final system easier to install, tune, and maintain.
