Automatic Pillow Pouch Packing Machine With Film Beneath Feeding
SW-350B · SW-450B
Compact horizontal flow wrap machine with film roll mounted below the infeed conveyor. Designed for small solid products — candy, cookies, snack bars, and hardware — at 40–230 bags per minute. Lower machine profile, easier operator access, and gentle top-open infeed make this the preferred pillow packer for lightweight, delicate items.
Quality
CE Certified
Source
Factory Direct · Guangdong
Customization
OEM · Voltage · Language
After-Sales
2-Year Warranty · 24 h Support
SW-350B / 450B: Film Beneath Feeding Flow Wrap for Small Products
The SW-350B and SW-450B are horizontal form-fill-seal machines built around a film-beneath-feeding architecture. Unlike conventional pillow packers where the film roll sits behind or above the machine, these models mount the film roll directly below the infeed conveyor. Film feeds upward, wraps around each product as it travels along the stainless steel tray, and is sealed by the back seal wheel and end seal jaws — all in continuous motion. The result is a compact machine with a lower overall profile and a completely open top infeed that makes product placement easier and reduces the risk of product tip-over during wrapping.
Both models share the same mechanical frame and the same 3,920 mm footprint — the difference is film width capacity and product size range. The SW-350B handles smaller products up to 190 mm long with film up to 350 mm wide; the SW-450B handles wider products with film up to 450 mm wide. Both run at the same speed range of 40–230 bags per minute, driven by a servo motor under pillow pouch packing machine PLC control.
Film-beneath-feeding is the preferred pillow wrapping configuration for candy, hard-boiled sweets, small cookies, chocolate pieces, and similarly lightweight items that could be displaced by top-tension film feed. It is also widely used for hardware parts, medical devices, and other products where operator visibility of the infeed tray matters. Standard equipment includes Siemens PLC, servo film drive, two-stage heat sealing with cooling, 100-recipe HMI, and SUS304 stainless steel product-contact surfaces.
Max Speed
230 bags / min
Product Length Range
40–240 mm
Recipe Memory
100 products
| Parameter | SW-350B | SW-450B |
|---|---|---|
| Product Length | 65–190 mm | 40–240 mm |
| Product Width | 30–110 mm | 80–200 mm |
| Product Height (max) | 40 mm | 50 mm |
| Max Film Width | ≤350 mm | ≤450 mm |
| Packing Speed | 40–230 bags/min | 40–230 bags/min |
| Film Feed Direction | Film Beneath (film roll below infeed conveyor) | |
| Bag Format | Pillow Pouch (horizontal flow wrap) | |
| Control System | Siemens PLC + Servo Motor + HMI Touch Screen · 100 recipes | |
| Sealing System | Two-stage heat sealing + cooling station | |
| Contact Material | SUS304 Stainless Steel | |
| Film Material | OPP/CPP · OPP/PE · PET/PE · NYLON/PE · PE | |
| Power | 3.2 kW | 4.2 kW |
| Voltage | 220V 50/60 Hz (customizable) | |
| Machine Weight | ~400 kg | ~600 kg |
| Dimensions (L×W×H) | 3,920×670×1,320 mm | 3,920×870×1,320 mm |
Recommended Configurations by Product
The film-beneath design excels with small, lightweight items that benefit from a stable, open-top infeed. Each configuration below is based on tested setups at ShengWei's factory. Contact us with your product dimensions and daily output target for a specific recommendation.
Hard Candy & Bonbons
Individual wrapped sweet, 5–20 g
- Model
- SW-350B
- Infeed
- Manual placement or auto delivery conveyor
- Speed
- ~180 bags/min
- 8 h Output
- ≈ 86,400 bags
- Clients
- Candy manufacturers, confectionery OEMs, gift pack factories
Cookies & Small Biscuits
Single cookie or small sleeve pack
- Model
- SW-350B
- Infeed
- Manual placement by 1 operator
- Speed
- ~120 bags/min
- 8 h Output
- ≈ 57,600 bags
- Clients
- Bakeries, biscuit co-packers, supermarket in-house packing
Snack Bars & Wafer Bars
Single energy bar or chocolate wafer
- Model
- SW-450B
- Infeed
- Auto conveyor or manual placement
- Speed
- ~100 bags/min
- 8 h Output
- ≈ 48,000 bags
- Clients
- Snack food brands, OEM co-packers, health food manufacturers
Hardware & Medical Devices
Small parts, blister packs, retail-packed tools
- Model
- SW-350B / SW-450B
- Infeed
- Manual placement or robot-assisted
- Speed
- ~60 bags/min
- 8 h Output
- ≈ 28,800 bags
- Add-ons
- Date coder, label applicator, checkweigher
The SW-350B/450B is designed for solid products only. For loose granules or powder, see the collar type packing machine family — including the multi-head weigher model (SW-420A) and auger powder model (SW-420E). For premade pouches with stand-up, zipper, or flat-bottom formats, see the premade bag packing machine family.
Output Bag Type: Pillow Pouch (Flow Wrap)
The SW-350B/450B produces one bag format: the pillow pouch — also called a flow wrap bag or fin seal bag. Film feeds from the roll mounted beneath the machine, forms into a tube around the product on the infeed tray, and is sealed with a back seal along the underside and end seals at the front and rear. No pre-formed bag supply is required — all bag forming happens on the machine from rollstock film.
SW-350B — candy, cookies, small snacks
Sealing station — pillow pouch fin seal output
Pillow Pouch (Standard Output)
Fin Seal / Back Seal
Compatible film: OPP/CPP · OPP/PE · PET/PE · NYLON/PE · PE. Send your film sample for sealing parameter confirmation before production.
Note: This machine produces pillow pouches only. For stand-up pouches, zipper bags, or flat-bottom bags, see the SW-D premade bag granule machine or SW-L premade bag powder machine.
How the Film Beneath Feeding Flow Wrap Cycle Works
The film-beneath configuration changes the film path, not the wrapping principle. The product still moves horizontally through a forming collar and receives end seals and a back seal. What changes is that the film approaches from below — keeping the top of the infeed completely clear for operator access and eliminating film tension on the product from above.
01
Product Infeed
Products are placed on the open-top stainless steel infeed tray — manually by one operator, or automatically via a delivery conveyor or sorting device. Because the film roll is below the machine rather than above, the infeed zone is completely unobstructed. Spacing lugs on the tray maintain equal gaps between products, which sets the bag length. A photocell detects missing products and triggers a skip cycle to prevent empty bags.
02
Film Feeding From Below
Film unwinds from the roll mounted beneath the infeed conveyor and travels upward through a series of guide rollers before reaching the forming shoulder. The servo-driven film pull system maintains constant tension and accurate print-mark registration regardless of roll diameter. Because the film path is below the product support surface, the product never contacts the film under tension — preventing displacement of lightweight or fragile items during the forming stage.
03
Back Seal & Tube Forming
As film meets the forming shoulder, it wraps around the product and the two film edges are joined by a heated fin seal wheel running along the underside of the product stream, creating the back seal. The PLC-controlled sealing temperature and wheel pressure are set via the HMI and stored as part of each product recipe — so switching between film types does not require manual readjustment.
04
End Sealing, Cutting & Discharge
Rotating end seal jaws close across the film tube between each product, applying heat and pressure to form the front and rear seals simultaneously. A built-in knife cuts the sealed section to release each finished bag. Two-stage sealing with a cooling station ensures flat, strong seals even on thinner OPP/CPP films. Finished bags discharge to an outfeed conveyor for downstream date coding, checkweighing, or carton packing.
Gallery & Video
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SW-350B control panel and sealing station — HMI touch screen, sealing jaw area, and film forming zone
Four Core Mechanisms That Define the SW-350B/450B
The film-beneath-feeding configuration requires specific mechanical design choices at the film unwind, forming shoulder, sealing station, and infeed tray. Understanding these helps you configure the right setup for your product and your production line.
① Bottom Film Roll Holder & Feed Path
The film roll spindle sits below the infeed conveyor frame. Film travels upward through a multi-roller guide path before reaching the forming shoulder at the product entry point. A constant-tension dancer arm absorbs speed variation between the servo film pull and the mechanical forming shoulder, keeping back seal registration accurate even at 230 bags per minute.
② Open-Top Stainless Steel Infeed Tray
With no film reel or reel support arm above the infeed, the product placement zone is completely open. The flat SUS304 stainless steel tray allows operators to place products quickly and check alignment visually. The tray width is adjustable for different product sizes, and the surface is food-grade compliant. This open-top design is one of the main reasons operators prefer the film-beneath configuration for repetitive manual infeed tasks.
③ Siemens PLC + 100-Recipe HMI
A Siemens PLC manages film feed speed, sealing jaw temperature, end seal timing, and conveyor synchronisation from a single 7-inch HMI panel. Up to 100 product recipes can be saved and recalled by name — switching between candy sizes or film widths takes under two minutes without tool changes. Fault codes are displayed on the HMI with plain-language descriptions.
④ Rotating Constant-Temperature End Seal
The end seal jaws rotate at a constant temperature rather than cycling heat on and off between each bag. This eliminates the cold-jaw problem — where the first few bags of each run have weaker seals because the jaw has not yet reached temperature. Constant-temperature rotation ensures the first bag has the same seal strength as the ten-thousandth. The embossing pattern on the jaw is standard; custom seal patterns are available on request.
Branded Components You Can Verify
Every critical component on the SW-350B/450B is sourced from established industrial brands. Part numbers are listed on the quotation sheet so you can verify pricing and availability independently before you order.
Siemens SMART 700 HMI
7-inch colour touch screen. Stores up to 100 product recipes for fast SKU switching. Language configurable: English, Spanish, Arabic, Russian, and others on request.
Siemens S7-200 PLC
CPU224 programmable logic controller. Synchronises film feed servo, sealing jaws, infeed conveyor, and date coder with fault diagnostics displayed on HMI.
Schneider Frequency Converter
Controls main motor speed for film feed rate. Smooth acceleration and deceleration protect film tension consistency during speed changes between product runs.
AirTAC Solenoid Valve
Controls pneumatic actuation of end seal jaws and cutting mechanism. High cycle-life rating supports continuous two-shift operation without seal pressure drop.
WINPARK Temperature Controller
PID temperature control for end seal jaws and back seal wheel. Maintains set-point within ±1 °C for consistent seal quality across all film types and speeds.
SMC Guide Cylinder
Anti-rotation guided cylinder for end seal jaw actuation. Ensures repeatable jaw alignment and uniform sealing pressure across the full bag width at every cycle.
SW-350B vs SW-350A — Film Beneath vs Standard Film Feeding
Both models produce the same pillow pouch and share similar speed ranges. The difference is where the film roll sits — which affects machine height, infeed ergonomics, and product suitability.
Choose SW-350B / 450B (Film Beneath) When:
- Your product is small and lightweight — candy, cookies, snack bars — prone to displacement if film feeds from above
- You need an open-top infeed with no overhead obstruction for easy manual product placement
- Your facility has a low ceiling or height constraint that limits machine profile
- You want to reduce the risk of film tension misaligning delicate or irregularly weighted products
- You run single-shift manual infeed production and prioritise operator comfort
Choose SW-350A / 450A / 550A (Standard) When:
- Your product is heavier or rigid enough that top-tension film feed does not cause displacement
- You need the largest product size range — up to 500 mm long and 200 mm wide
- You are integrating an auto infeed system (robot arm, sorting conveyor) that requires specific film path geometry
- You run very high-volume production at up to 200 bags per minute on smaller items
When This Machine Is Not the Right Fit
The SW-350B/450B wraps individual solid products only. For loose granules or powder, the correct choice is the collar type packing machine family — including the 4-head linear weigher model (SW-320C) and measure cups model (SW-320D/420D). For liquid products, see the collar type liquid packing machine (SW-420F). For premade bags or stand-up pouches, use the premade bag packing machine family — including the granule model (SW-D200), liquid model (SW-Y200), and vacuum model (SW-130ZK). For spout pouches, see the spout pouch filling and capping machine (SW-CCS6).
Why Choose ShengWei Machine
Factory Direct from Guangdong
Designed and manufactured in our own 8,000 m² factory in Shantou, Guangdong. No trading companies, no middlemen — you work directly with the engineers who build your machine.
Built-to-Order Configuration
Voltage (220V, 50/60 Hz), HMI language (English, Spanish, Arabic, Russian, Portuguese, and more), infeed type, sealing parameters, and accessories are all configurable per order. OEM branding available for distributors.
Lifetime Remote Support
Free remote video technical support for the life of the machine — not just the warranty period. Spare parts ship from our factory within 3 working days. On-site installation available on request.
40+ Export Countries
ShengWei machines are deployed in the UAE, Saudi Arabia, Nigeria, Mexico, Colombia, Indonesia, the Philippines, and 30+ additional markets across food, pharmaceutical, chemical, and hardware industries.
What Our Clients Say
We bought the SW-350B to wrap individual hard candies. The open-top infeed was the main reason we chose this model over a standard machine — our operators can place products quickly without any overhead interference. Speed has been consistent at around 150 bags per minute on our OPP/CPP film. The remote support team helped us dial in the sealing temperature in one session on the day of commissioning.
Ahmed K.
Production Manager — Confectionery Factory, Egypt
We use the SW-450B for wrapping small wafer bars in a two-shift operation. The Siemens PLC and recipe memory made it easy to train our operators — they select the recipe from the HMI and the machine handles the rest. Seal quality is uniform even at the start of a cold run, which was a problem with our previous machine. Spare parts came within 5 days when we needed sealing strips after 14 months of continuous use.
Fatima O.
Plant Supervisor — Snack Food Manufacturer, Nigeria
Frequently Asked Questions
What does "film beneath feeding" mean and why does it matter?
What products can the SW-350B / 450B pack?
How do I choose between the SW-350B and SW-450B?
What film materials are compatible?
What is the packing speed and what affects actual throughput?
What is the lead time and payment terms?
Can the voltage and HMI language be customised?
What warranty and after-sales support is included?
Do you provide installation support and operator training?
Can I send a product sample for a packing test?
Expert Guides
What Is a Pillow Pouch Packing Machine?
How horizontal flow wrap machines work, what products they suit, and how film-beneath and standard configurations compare.
Read Guide →Pillow Pouch vs Stand-Up Pouch
Material cost, retail display requirements, filling flexibility, and production volume compared — which bag format suits your product and budget.
Compare Formats →Horizontal vs Vertical FFS — How to Choose
When a pillow packer is the right choice vs a collar type VFFS machine — product shape, fill type, and throughput considerations explained.
Learn More →Other Pillow & Wrapping Machines
Different film feeding methods and machine formats for food packaging.
Multifunctional Top-Film Pillow Machine
Multifunctional top-film pillow machine. Standard film path for most snack and candy products.
Back-Feeding Pillow Machine
Back-feeding pillow machine. Compact single-servo design for light-duty packaging needs.
Pendular Small Granule Vertical Machine
Pendular small granule vertical machine. VFFS alternative for small candy and snack items.
Ready to Pack Your Product?
Tell us your product dimensions, target speed, and production shift length. We will recommend the right model, confirm compatibility with your film, and provide a detailed quotation within 24 hours.
info@shengweimachine.com · +86 181 2511 2025
