Collar Type Liquid Packing Machine
SW-420F
Vertical form-fill-seal machine for liquid and semi-liquid products — ketchup, sauce, milk, soy sauce, and more. Forms bags directly from roll film, seals and fills in one continuous motion at up to 70 bags per minute.
Quality
CE Certified
Source
Factory Direct · Guangdong
Customization
OEM · Voltage · Language
After-Sales
2-Year Warranty · Lifetime Remote Support
SW-420F: Vertical Form-Fill-Seal for Liquids
The SW-420F is a collar type vertical form-fill-seal (VFFS) machine designed specifically for liquid and semi-liquid products. Unlike premade bag machines that rely on pre-manufactured pouches, the SW-420F forms each bag in-line from a roll of packaging film — wrapping it around a triangular forming collar into a tube, sealing the back seam vertically, filling through a volumetric liquid pump, then sealing and cutting each bag at the bottom.
The result is a compact, continuous-motion machine that handles anything from thin liquids like milk and vinegar to medium-viscosity sauces like ketchup and salad dressing. All product-contact surfaces are SUS304 stainless steel. A Siemens PLC and touch screen control every parameter — fill volume, bag length, sealing temperature — from a single interface. Servo-driven film pull ensures consistent bag length across the full speed range.
Packing Speed
15–70 bags / min
Fill Range
50–1,000 g
Total Power
3.5 kW
| Parameter | SW-420F |
|---|---|
| Roll Film Width | ≤420 mm |
| Bag Length | 80–300 mm |
| Bag Width | 80–200 mm |
| Fill Weight Range | 50–1,000 g |
| Packing Speed | 15–70 bags / min (25–40 bags/min typical for viscous products) |
| Bag Format | 3-Side Seal (back-seal pouch from roll film) |
| Filling System | Volumetric liquid pump (40 L standard tank; auto-feed pump optional) |
| Sealing Type | Back side sealing (vertical) + horizontal cross-seal |
| Control System | Siemens PLC + Siemens HMI touch screen |
| Servo Motor | Yichuan (film pull servo) |
| Contact Material | SUS304 Stainless Steel |
| Total Power | 3.5 kW · 220V · 50/60 Hz |
| Air Consumption | 0.6–1.2 m³/min |
| Machine Weight | ~700 kg |
| Dimensions (L×W×H) | 1,200 × 1,400 × 2,500 mm |
SW-420F key components: Siemens PLC control system, volumetric liquid pump, forming collar, double-belt film pull, and heat-sealing jaws.
Recommended Configurations by Product
The SW-420F handles a broad range of liquid and semi-liquid products. Speed and output depend on viscosity, fill volume, and film type — contact us with your product specification for a tailored estimate.
Tomato Ketchup & Chili Sauce
200–500 g sachet for catering and retail
- Model
- SW-420F
- Filling
- 40L volumetric liquid pump
- Speed
- ~30 bags/min
- 8 h Output
- ≈ 14,400 bags
- Clients
- Sauce manufacturers, condiment brands, catering suppliers
Salad Dressing & Mayonnaise
100–1,000 g pouch for food service
- Model
- SW-420F
- Filling
- Peristaltic or piston pump (for thick sauce)
- Speed
- ~25 bags/min
- 8 h Output
- ≈ 12,000 bags
- Add-ons
- Hopper agitator for high-viscosity products
Milk & Dairy Products
200–500 mL pouch for institutional supply
- Model
- SW-420F
- Filling
- Volumetric pump with CIP-compatible circuit
- Speed
- ~60 bags/min
- 8 h Output
- ≈ 28,800 bags
- Clients
- Dairy processors, school meal contractors, co-packers
Soy Sauce & Vinegar
10–100 g single-serve sachet for restaurants
- Model
- SW-420F
- Filling
- Volumetric pump, small-volume nozzle
- Speed
- ~55 bags/min
- 8 h Output
- ≈ 26,400 bags
- Clients
- Seasoning brands, restaurant supply, hotel amenities
For liquid products requiring stand-up or zipper pouches, see the SW-Y premade bag liquid packing machine. For high-end spouted packaging (juice, cooking oil), see the SW-CCS6 spout pouch filler.
Output Bag Type: 3-Side Seal Pouch
The SW-420F forms bags in-line from roll film using a triangular forming collar. The output format is a three-side-seal sachet — a back seam runs along one side, horizontal cross-seals close the top and bottom. This is the most common format for liquid portioning worldwide: low material cost, tight seal integrity, and compatibility with a wide range of film materials.
Ketchup Pouch — 200 g to 1 kg, single or multiple use
Milk Sachet — 200–500 mL, single-serve
Salad Sauce Pouch — up to 1 kg, food service format
3-Side Seal (Standard Output)
Fin Seal (Back Seal)
Gusset Pouch (Optional Add-On)
Compatible film materials: PE, CPP, PET/PE laminate, aluminum foil composite, nylon laminate. For high-temperature products or UV protection requirements, specify your film grade when requesting a quote.
Note: The SW-420F does not support stand-up pouches, zipper bags, or flat-bottom bags. If these formats are required, see the SW-Y premade bag liquid machine.
How the SW-420F Forms, Fills, and Seals
The SW-420F runs as a continuous-motion machine — each step flows into the next without stopping, producing a finished, sealed pouch in one integrated cycle.
01
Roll Film Loading
A roll of packaging film (PE, CPP, or laminate) mounts on the film frame at the back of the machine. Film threads through a series of dancer rollers that maintain constant tension as the servo motor pulls the film through the forming station. An automatic film-end stop halts the machine when the roll is depleted, preventing unsealed bags.
02
Bag Forming & Vertical Sealing
The flat film wraps around a precisely machined triangular forming collar, which folds it into a continuous tube. A pair of heated vertical sealing rollers presses and seals the overlapping film edges to create the back seam of each bag. Changing bag width requires only swapping the forming collar — a 15-minute tool-free adjustment.
03
Liquid Filling
A volumetric liquid pump draws from a stainless steel tank (40 L standard capacity) and dispenses a precisely measured dose into the open bag tube through a filling nozzle. Fill volume is set digitally on the Siemens touch screen and adjustable in real time without stopping production. An optional auto-feed pump replenishes the tank automatically from a larger reservoir when the fill level drops.
04
Horizontal Sealing, Coding & Cutting
After each fill, horizontal sealing jaws clamp across the tube to create the top seal of the filled bag and the bottom seal of the next bag simultaneously. Jaw temperature, dwell time, and pressure are independently adjustable per film type via the HMI. A date printer (standard) codes batch number and expiry date. A cutting knife then severs the finished pouch, which drops onto the output conveyor.
Gallery & Video
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SW-420F collar type liquid packing machine — full front view showing stainless steel frame and control panel
Complete Liquid Packaging Line
The SW-420F operates as a standalone unit or as the core of a complete liquid packaging line. ShengWei supplies the main machine plus all peripheral equipment — liquid tank, feed pump, date printer, and output conveyor — and provides a custom line layout drawing with every quotation.
SW-420F Main Machine
Core vertical form-fill-seal unit. Forms bags from roll film, fills via volumetric pump, seals, codes, and cuts in one continuous cycle.
40 L Liquid Filling Tank & Pump
Standard 40-litre SUS304 stainless steel hopper with volumetric pump. Maintains fill accuracy across the full speed range. Contact surface fully cleanable.
Date Printer (Standard)
Inkjet or thermal ribbon date printer integrated into the sealing station. Prints batch number, production date, and expiry date on every bag automatically.
Output Conveyor
Belt conveyor receives finished pouches from the cutting station and carries them to the downstream collection or secondary packing area. Speed adjustable to match main machine output.
Optional Add-Ons
All options are factory-installed and integrated with the Siemens PLC control system. Request a configuration when you inquire.
Branded Components You Can Verify
Every critical electrical and pneumatic component on the SW-420F is sourced from established industrial brands. Part numbers are listed on the quotation sheet — you can verify pricing and availability before you commit to an order.
Siemens SMART 700 HMI
7-inch colour touch screen. Controls fill volume, bag length, sealing temperature, and speed. Supports multiple languages on request.
Siemens PLC
Programmable logic controller coordinating film pull, pump timing, sealing jaws, and cutter in real-time. Fault diagnostics display on HMI panel.
AirTAC Solenoid Valve
Controls the pneumatic sealing jaw and cutting cylinder actuation. High-cycle rated for continuous multi-shift production.
Omron Rotary Encoder
Precision film position feedback for accurate bag length control. Ensures consistent cut position even as film tension varies during production.
SMC Guide Cylinder
Anti-rotation guided cylinder for sealing jaw actuation. Consistent jaw alignment maintains seal quality across the full bag count.
Schneider Circuit Breaker
CE-compliant thermal-magnetic protection for main electrical cabinet. Overcurrent and short-circuit protection for motor and control circuits.
Collar Type VFFS vs Premade Bag: Which Is Right for Your Liquid?
Both the SW-420F (collar type) and the SW-Y series (premade bag) fill liquids into pouches automatically. The right choice depends on your bag format requirements, production volume, and material cost sensitivity.
Choose SW-420F When:
- Your product is a liquid — water, juice, milk, sauce, detergent, shampoo — and you need a dedicated pump or piston filler
- Viscosity-aware filling matters — the SW-420F is configured with the appropriate pump (gear / lobe / piston) and tubing for your product's flow profile
- An anti-drip nozzle is required — the standard cut-off nozzle prevents stringing or drip onto the sealing jaws between cycles
- ml-precision liquid dosing is the goal — volumetric piston / pump filling achieves consistent ±1% volume fill across the bag run
- For dry granules use the SW-420A weigher, SW-320C linear weigher, or SW-320D cup; for powders use the SW-420E auger; for spouted pouches see the SW-CCS6
Choose Collar Type SW-420F When:
- You need simple 3-side seal sachets at high daily volume
- Lower per-bag film cost is a priority — rollstock film costs significantly less than pre-manufactured pouches
- Your product is consistent in viscosity and does not require frequent SKU changes
- Compact floor footprint is important — the SW-420F is 1,200 × 1,400 mm versus a typical premade bag line at 2,000+ mm wide
- You are packing institutional volumes: dairy, sauce, condiment sachets for catering or food service
Choose Premade Bag SW-Y Series When:
- You need stand-up pouches, zipper bags, or flat-bottom bags — formats that collar type cannot produce
- High-quality pre-printed graphics are important for retail shelf presentation
- You run multiple SKUs and switch bag sizes or formats frequently within a shift
- Your production volume is lower (under 50,000 bags/day) and film cost per bag is less critical
When Neither Is the Right Fit
For liquid products in spouted pouches (cooking oil, juice, shampoo), the SW-CCS6 spout pouch filler is the correct choice. For very high-viscosity pastes (peanut butter, thick chili paste above ~30,000 cP), contact us to discuss a custom dosing configuration — the standard pump may require modification.
Why Choose ShengWei Machine
Factory Direct from Guangdong
Designed and manufactured in our own 11,000 m² factory in Shantou, Guangdong. No trading companies or middlemen — you communicate directly with the production engineers who build and test your machine before shipment.
Built-to-Order Configuration
Voltage (220V 50/60 Hz), HMI language (English, Spanish, Arabic, Russian, Portuguese, and more), pump type, tank capacity, and accessories are all configurable per order. OEM branding is available for distributors.
Lifetime Remote Support
Free remote video technical support for the life of the machine — not only during the warranty period. Common spare parts typically ship from our Guangdong factory within 3 working days. On-site installation is available on request.
80+ Export Countries
ShengWei liquid packing machines are deployed in the UAE, Saudi Arabia, Nigeria, Indonesia, Mexico, Colombia, and 70+ additional markets across food processing, dairy, condiment, and beverage industries.
Tested Before Shipment — How We Prove the SW-420F
72-Hour Run Test on Your Recipe
Every SW-420F goes through a structured Factory Acceptance Test before it ships: a 72-hour continuous run with actual packaging film and product material, with speed, seal quality, fill accuracy, and rejection rate all logged. For a liquid collar type machine that means verifying liquid pump fill accuracy at your product's viscosity, checking seal integrity on liquid-wetted seals across your bag sizes (80–300 mm bag lengths, 80–200 mm widths), and holding output stable across the 15–70 bags/min range. Send your product and film and the FAT runs on your recipe, not on a generic substitute.
Approve Before We Crate
Before crating, our QC team sends you the FAT report, a test video of your machine running, and photos for approval. If your order requires it, we coordinate SGS, Bureau Veritas, or TÜV pre-shipment inspection and provide full access to the machine and test records. See how the 4-person QC team works at our Factory & Quality Center.
Frequently Asked Questions
What types of liquids can the SW-420F pack?
How does collar type VFFS differ from a premade bag machine?
How accurate is the liquid fill volume?
Can I adjust bag length and fill volume without stopping the machine?
What film materials are compatible with the SW-420F?
What is the lead time and payment terms?
Can the voltage and HMI language be customized?
What warranty and after-sales support is included?
Can I send a liquid sample for a packing test before ordering?
Does the machine include a date printer? Can it print batch codes?
Expert Guides
Seal Strength vs Seal Integrity
Why a strong-looking seal can still leak, which seal-integrity test finds what, and how the four sealing methods compare.
Read the Sealing Guide →Multi-Head Weigher vs Auger vs Cup
The accuracy mechanism, give-away cost, cleaning, and failure modes of the three dosing methods compared.
Compare Dosing Methods →How to Choose the Right Packaging Machine
A step-by-step buyer's path — product type, bag format, dosing, speed, and budget walked through in order.
Read the Choosing Guide →Other Collar Type Machines
Same platform, different filling systems — choose by product type.
Collar Type Auger Powder Machine
Auger screw filling for powder products. Same collar type platform, different filling system for dry materials.
Measure Cup Packing Machine
Volumetric measure cup filling for granules and free-flowing products. Compact collar type with simple dosing system.
Premade Bag Liquid Machine
Rotary premade bag liquid machine. Uses pre-formed pouches for premium liquid packaging with stand-up and spout options.
Ready to Discuss the SW-420F?
Send us your liquid product type, fill volume, target speed, and bag dimensions. We will confirm suitability and return a quotation within 24 hours.
info@shengweimachine.com · +86 181 2511 2025
Usually replies within one business day · Helps packaging buyers across 80+ countries
