Technology Guide · Combiblock Series
What Is a Blow-Fill-Cap Combiblock?
Three machines. One frame. One operator. A combiblock merges PET bottle blow moulding, liquid filling and capping into a single unit — deleting the air conveyor, shrinking the footprint, and cutting per-bottle cost from the first day of production.
Short answer: A blow-fill-cap combiblock is a single machine that joins three normally separate operations — PET bottle blow moulding, liquid filling and capping — onto one common frame with one drive and one control system. Bottles are transferred by neck-handling starwheels, never touching a rail after they leave the mould. Sunswell builds combiblocks from 2,000 BPH to 48,000 BPH for still water, carbonated drinks, hot-fill juice and tea, edible oil and home-care liquids.
On this page
1. How a combiblock actually works, step by step
On a conventional line, a blow moulding machine produces empty bottles, an air conveyor floats them across the room, and a separate rinser-filler-capper monoblock fills them. A combiblock deletes the middle step. The blow moulder and the filler sit on one base frame and share one transfer path, so an empty bottle goes from mould to filling valve in a few seconds without ever entering an air conveyor.
The sequence inside a Sunswell combiblock is:
- Preform feeding. Preforms are tipped into an unscrambler, oriented neck-up and fed into the heating furnace on a chain.
- Heating. The preform body passes infrared lamps. Ceramic reflectors behind the lamps are individually adjustable to the preform length, so the heat profile can be tuned zone by zone — this is what controls wall-thickness distribution in the finished bottle.
- Stretch blow moulding. The heated preform enters the mould. A stretch rod pulls it axially while low-pressure air performs the first expansion; high-pressure air then forces the material against the mould wall to form the final shape.
- Neck transfer. The finished bottle leaves the mould and is gripped by the neck ring by a transfer starwheel. It is never carried on its base and never rubs against an air-conveyor rail.
- Filling. The bottle is handed to the filler carousel. Depending on the valve type, product is dosed by weight, by volume, by gravity or isobarically under counter-pressure.
- Capping. Caps are fed from a hopper and elevator, sorted, and applied by a rotary capping head with controlled torque.
- Discharge. The sealed bottle leaves the block on a chain conveyor towards labelling and packing.
Combiblock Process Flow Diagram
preform feeding → heating → stretch blow moulding → neck transfer → filling → capping
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2. The three modules inside the block
2.1 Blow moulding module
This is a rotary stretch blow moulder built into the block. The points that matter commercially are the adjustable ceramic reflectors, and the air guidance design that recovers part of the high-pressure blowing air. Blowing air is normally the single largest utility cost in PET bottle production, so recovery directly changes the cost per bottle.
2.2 Filling module
A rotary carousel in SUS 304 stainless steel. The number of valves scales with the required output. For carbonated products the carousel becomes a pressurised isobaric filler: CO₂ pre-pressurisation equalises bottle and tank pressure before the liquid valve opens, and the displaced CO₂ returns to the tank through a return pipe so nothing is vented and no foaming occurs.
2.3 Capping module
Cap hopper, elevator, chute and a rotary capping turret. Because the capper sits on the same frame and the same drive, it can never fall out of phase with the filler — a common source of downtime when three separate machines are synchronised electrically across a room.
Engineering note. Sunswell combiblocks use a uniform drive control system, a uniform lubrication concept and a uniform safety concept across all three modules, plus a central energy and media supply. That is the real definition of a "combi": not three machines bolted together, but one machine with three functions.
3. Capacity ranges by product and bottle size
Output is never a single number — it depends on the preform, the bottle volume, the wall thickness you need and the product temperature.
| Product | Bottle size | Capacity range |
|---|---|---|
| Non-carbonated water | 0.2 – 2 L | 12,000 – 48,000 BPH |
| 3 – 7 L | 3,000 – 12,000 BPH | |
| 7 – 16 L | 2,000 – 6,000 BPH | |
| Hot-fill (juice, tea) | 0.2 – 2 L | 6,000 – 36,000 BPH |
| Carbonated (CSD, sparkling) | 0.2 – 2 L | 12,000 – 36,000 BPH |
| Edible oil | 0.2 – 2 L | 12,000 – 36,000 BPH |
| Daily care / home care | 0.2 – 2 L | 12,000 – 36,000 BPH |
Capacity is subject to preform design, bottle size, application and bottle weight. Quote figures are confirmed after preform and bottle drawings are reviewed.
4. Choosing the filling valve
The valve is the single decision that most affects accuracy, cleaning and price. Four configurations are available:
| Valve type | Dosing principle | Best suited to | Trade-off |
|---|---|---|---|
|
Load cell net weight |
Each bottle sits on a weighing cell; the valve closes at target weight | Edible oil, high-value liquids, products sold by weight, large 5 L formats | Highest accuracy, highest cost; cells need periodic calibration |
| Volumetric | Flow meter measures a set volume per bottle | Water, juice, tea — anywhere fill volume is the declared quantity | Accurate and easy to change recipe; more electronics than mechanical |
| Mechanical | Gravity or level-controlled fill, mechanically actuated | Plain still water and simple CSD at the lowest capital cost | Cheapest and most robust; recipe changes are manual |
| Semi-electric | Mechanical valve body with electric control of open/close | Plants that want faster changeover without a full electronic filler | Middle ground on both price and flexibility |
A practical rule: if the label declares litres, start from volumetric; if it declares kilograms or the product is expensive per litre, start from load cell; if you are filling plain water at the lowest possible capex, mechanical is still the right answer.
5. Where the savings really come from
Vendors talk about "space saving". That is true but it is the smallest of the four effects. Ranked by how much money they actually move:
- Lighter bottles. On a separate line the bottle has to survive the air conveyor: the design weight includes a safety margin for handling stiffness. Inside a combiblock the bottle is only ever held by its neck ring — the body can be designed for the product rather than the conveyor. Preform resin is the largest recurring cost in PET bottling, so every gram removed goes straight to gross margin.
- No air conveyor. You delete the conveyor itself, its blowers, its filtration, its cleaning routine and its electricity bill.
- Labour. One control system, one HMI, one set of alarms. The block is designed to be run by a single operator instead of one per machine.
- Floor space and building cost. Relevant when you are constructing a new plant, or retrofitting into a building you cannot extend.
【待客户填写：实测数据】 建议在这里放一组真实对比数字，例如"同产能下一体机比分体线减少占地 __ ㎡、减少操作工 __ 人、单瓶克重下降 __ g、年节省树脂 __ 吨"。有真实数字这一段会成为 AI 爱引用的段落；没有真实数字就保持现状，不要编。
6. When a combiblock is the wrong choice
A combiblock is not the right answer when:
- You already own a good blow moulder. If your blower has years of life left, a separate filler is the cheaper route.
- You sell bottles as well as filled product. A combiblock has no bottle output — every bottle it makes gets filled immediately.
- You run many very different bottle families. Extremely high SKU variety with frequent changeovers can favour decoupled machines with a buffer between them.
- You need a large accumulation buffer. On a separate line the air conveyor doubles as a buffer of several minutes of production. A combi has no buffer between blowing and filling, so a stop in one module stops the other.
- Glass or cans. A blow-fill-cap block only makes sense for PET. Glass and aluminium need conventional rinser-filler-capper monoblocks.
Details of the trade-off are in Combiblock vs separate blowing and filling line.
7. How to specify one: a checklist
Bring these eight items to a first technical call and a supplier can size the block accurately in one pass:
| 1. Product | Still water / CSD / juice / tea / edible oil / home care; viscosity; pulp content |
| 2. Target output | BPH, and how many shifts per day |
| 3. Bottle sizes | All SKUs, with drawings if available |
| 4. Preform | Weight, neck finish standard, supplier |
| 5. Cap | Type, diameter, sample if possible |
| 6. Utilities available | Voltage and frequency, compressed air, chilled water, steam |
| 7. Building constraints | Usable length × width × clear height, door size for installation |
| 8. Destination market | Determines certification: CE, EAC/EAEU, SASO and so on |
Frequently asked questions
What does "3-in-1 combiblock" mean?
It means blow moulding, filling and capping are performed inside one machine on one frame, with one drive system and one control system. The bottle is transferred by neck-handling starwheels between the three modules and never leaves the block until it is capped.
Can a combiblock fill carbonated drinks?
Yes. The filling module is configured as an isobaric filler: CO₂ is admitted to the empty bottle until bottle pressure equals tank pressure, the liquid valve then opens, and the displaced CO₂ returns to the tank through a return pipe. Sunswell supplies combiblocks for CSD and sparkling water from 12,000 to 36,000 BPH in 0.2 – 2 L.
Can you hot-fill juice in a combiblock?
Yes, in a hot-fill configuration, with an output range of 6,000 – 36,000 BPH for 0.2 – 2 L bottles. Hot-fill needs heat-resistant bottle geometry, so the preform and mould design have to be agreed together with the machine specification.
How many people are needed to run a combiblock?
The block itself is designed for operation by one person. Additional staff are needed for the downstream line — labelling, packing and palletising — and for material handling.
What is the largest bottle a combiblock can handle?
Up to 16 L. Output falls as volume rises: 3 – 7 L runs at 3,000 – 12,000 BPH and 7 – 16 L at 2,000 – 6,000 BPH for non-carbonated water.
Is a combiblock more expensive than buying a blower and a filler separately?
The purchase price of the block is usually close to the combined price of the two machines, because you also stop buying the air conveyor, its blowers and its installation. The difference shows up in running cost: lighter bottles, less electricity and fewer operators. A full breakdown is in Combiblock vs separate line.
Which filling valve should I choose?
Load cell for products dosed by weight or of high unit value such as edible oil; volumetric for water, juice and tea where declared volume must be exact; mechanical for plain water at the lowest capital cost; semi-electric as a middle option. See section 4 above.
Written by the Sunswell engineering team — 【待客户填写：技术负责人姓名 / 职务 / 从业年限】
Zhangjiagang Sunswell Machinery Co., Ltd. — beverage filling and packaging equipment manufacturer, 20,000 m² plant in Zhangjiagang, Jiangsu, China. ISO 9001, CE, SGS.
Last reviewed: 【发布时填写实际日期，格式 15 August 2025】
Sunswell combiblock models
Project references
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Sizing a combiblock for your plant?
Send your product, target output, bottle sizes and preform details. Our engineers will come back with a configuration proposal and a layout drawing.
Request a configuration proposalAbout the author
Written by 【待客户填写：老板英文名，如 George Zhang】, Founder & CEO of Sunswell. He holds an MBA from Fudan University (ranked among China's top 3) and an MBA from Hunan University (Project 985 / Double First-Class). His academic paper on filling-machine technology earned the Shanghai Municipal Excellent Academic Paper Award. With 10+ years leading Sunswell's in-house R&D in filling and blow-moulding, he writes from engineering practice rather than marketing copy.
