Flat Bag-DongGuan RiQiang Machinery Co.,Ltd.

Size Flat Bags (Retail/Food/Promotional) — Complete Equipment Solution: High Speed, Material-Saving, Flexible Printing Options — Maximizing Margins on Small Bags

Author: root Views: 64 Published: 2026-05-23

1. Application Scenarios: Small Bags, Massive Market

Small-size flat bags are among the highest-volume, fastest-turnover product categories in flexible packaging. Core applications include:

Retail Packaging: Garment accessory bags (buttons/zippers), stationery bags, cosmetic sample bags, pharmaceutical sub-packaging;
Food Packaging: Bread & pastry bags, nut & dried fruit bags, candy bags, pre-packaged bags for bulk supermarket foods;
Promotional & Marketing: Exhibition document bags, event gift bags, branded image bags (often requiring single- or two-color logos);
Industrial Supplies: Dust-proof bags for small hardware parts and electronic components.

Market Characteristics: Large order volumes, relatively fixed specifications, and extreme price sensitivity. Therefore, the core competitiveness in this segment lies in “output per unit time” and “raw material utilization rate.”

2. Common Small-Size Flat Bag Dimensions & Weight Reference (Recommended Specifications)

Spec No.	Bag Width (mm)	Bag Length (mm)	Recommended Thickness (μm)	Approx. Weight per Bag (g)	Typical Application
XS	100—150	150—220	20—30	0.5—1.5	Jewelry, buttons, tablet sub-packaging
S	150—200	200—300	25—40	1.5—3.5	Candy, snacks, stationery
M	250—350	350—450	30—50	4.0—8.0	Bread, pastries, dried fruit, small hardware
L (Upper small-size limit)	350—400	450—600	40—60	8.0—15.0	Folded garment bags, promotional gift bags

3. Recommended Equipment Configuration: 600mm Blown Film Line + (Optional) Single-Color Printer + High-Speed Flat Bag Cutting & Sealing Machine

A) Extrusion: 600mm Blown Film Machine (Single-Layer Economy / ABA Co-Extrusion Options)

Selection Rationale	Detailed Explanation
Why 600mm instead of larger widths?	Small flat bags typically have finished widths under 400mm. A 600mm line produces film rolls that can be slit “1-to-2” (e.g., 600mm → two 300mm rolls) or “1-to-3” (three 200mm rolls), with minimal edge trim waste (≤3%). Using a 1000mm machine for small bags results in excessive slitting, unstable web handling, and drastically higher trim waste (8%–12%) — it simply doesn‘t pay off.
Single-Layer vs ABA Co-Extrusion — Which to choose?	- Single-Layer: Lowest investment cost and simplest operation. Ideal for customers with stable orders and single-material formulations (e.g., 100% virgin PE). However, adding fillers (CaCO₃) tends to reduce film strength. - ABA Co-Extrusion: Highly recommended if budget permits. The A-layers use virgin resin to ensure heat-sealability and gloss (critical for food/promotional bags), while the B-layer incorporates 30%–50% filler or recycled resin to reduce costs. For small bags, this “good skin on both sides, economical core” structure cuts raw material costs by approximately 15%–20% without compromising seal strength.
Recommended Output	600mm model yields approximately 50–80 kg/h (depending on formulation), equivalent to 1.2–1.9 tons per 24-hour day.
Key Features	Compact high-efficiency screw (energy saving >30%); precision ceramic temperature control rings; stabilizing cage (small bubbles are prone to flutter — this is essential); single/dual-station winder (dual-station recommended to reduce changeover downtime).

B) Printing: Single-Color / Two-Color Compact Printing Unit (Offline Operation, On-Demand Use)

Selection Rationale	Detailed Explanation
Printing is “Optional,” Not “Standard”	The majority of flat bags (e.g., supermarket bulk bags, basic garment bags) require no printing — plain white bags are the norm. However, promotional bags, branded bags, and certain food bags often require logos or date codes. Riqiang recommends: Start with the extrusion and bag-making lines to generate revenue first. Add the printer as a second-phase investment — avoiding excessive upfront capital lock-up.
Recommended Model	If printing is needed, we recommend a compact benchtop single-color flexographic printer (or gravure). Flexo uses water-based inks, which are eco-friendly and easy to clean during color changes — ideal for small-batch, multi-variety printing orders. Web width adapts to rolls up to 600mm, with printing speeds ≥ 60m/min — fully matching extrusion output.
Why insist on offline operation?	Small flat bag orders are typically “high-volume, low-frequency” — once started, production runs continuously for days on the same specification. Offline printing means: the extruder never slows down for the printing unit, and the bag makers never stop due to printing issues. Each machine runs independently at its optimum speed — maximizing total throughput.

C) Bag Making: High-Speed Flat Bag Cutting & Sealing Machine (Bottom Seal, Hot/Cold Cut, with Automatic Stacking)

Selection Rationale	Detailed Explanation
What are the core demands for flat bag making?	Maximum speed, clean cuts, and neat stacking. Small bags have razor-thin unit margins — only “high speed” delivers profitability. Riqiang recommends dual-servo high-speed flat bag cutting & sealing machines, reaching 120–180 bags/minute (depending on bag length), equipped with automatic counting and conveyor stacking systems — finished bags are neatly piled, requiring only periodic packing by operators.
Hot Cut vs Cold Cut?	- Hot Cut: Sealing and cutting are completed simultaneously, resulting in smooth, strong seal lines. Ideal for thin films (≤0.04mm) at high speeds — this is the mainstream process for small flat bags. - Cold Cut: Sealing and cutting are separate steps, suitable for thicker films (≥0.05mm) or when ultra-clean cut edges are required. For small sizes, hot cut is generally sufficient.
Importance of Standalone Bag Making	The extruder runs 24/7 at full speed, building up film roll inventory in the warehouse. The bag-making shop then schedules 1 or 2 machines flexibly according to actual order urgency. “Extrusion never stops; bag making flexibly adjusts” — this is the most agile and risk-resistant production model.

4. Capacity Matching Recommendations: How Many Lines Should a New Entrant Start With?

Given the high-volume nature of small flat bags, Riqiang recommends the following configurations:

Solution Tier	Blown Film Lines	Printer (Optional)	Bag Making Machines	Approx. Monthly Capacity (25 days/month)	Best For
Entry Level	1 × 600mm Single-Layer Extruder	Not configured (plain bags only)	1 × High-Speed Flat Bag Cutter	approx. 30–45 tons/month	Small processors starting with plain unprinted bag orders
Recommended Level	1 × 600mm ABA Co-Extruder	1 × Compact Single-Color Flexo (Offline)	2 × High-Speed Flat Bag Cutters	approx. 50–70 tons/month	Growing customers with stable demand and some orders requiring logos
Expansion Level	2 × 600mm ABA Co-Extruders	1 × Two-Color Flexo (Offline)	3–4 × High-Speed Flat Bag Cutters	approx. 100–140 tons/month	Large suppliers serving supermarket chains and food factories

Capacity Logic Explained:

1 × 600mm extruder produces approximately 1.2–1.9 tons/day;
1 × high-speed flat bag cutter consumes approximately 0.8–1.2 tons/day of film rolls (depending on bag size and speed);
Therefore, the output of 1 extruder can feed 1.5–2 bag cutters — the “1-to-2” ratio remains the optimal match for small flat bags;
Printing is an offline process — 1 compact printer easily covers the output of 2–3 extruders.

5. Process Flow Chart (Text Version)

text

【Raw Materials: Virgin PE / Virgin + Filler Masterbatch / Virgin + Recycled】
                  ↓
【600mm Blown Film Line】(Single-Layer or ABA Co-Extrusion, continuous high-speed)
                  ↓
          【Film Rolls → Warehouse Storage】
                  ↓
     ┌────────────┴────────────┐
     ↓                          ↓
【(Non-Printing Route)】      【(Printing Route)】
     ↓                          ↓
  Direct to Bag Making      【Offline Single/Two-Color Flexo Printing】
     ↓                          ↓
     └────────────┬────────────┘
                  ↓
【Bag Cutter A + Bag Cutter B】(High-speed hot-cut bottom seal, auto counting & stacking)
                  ↓
   【Finished Flat Bags】→ Neatly stacked → Bundled → Shipping

6. Core Philosophy: Dedicated Machines for Dedicated Tasks (Specifically for Small Flat Bags)

Common Misconception	Riqiang‘s Recommended Philosophy
“Bigger extruders are always better — they look more impressive.”	Small bags must use 600mm-class extruders. Oversized lines cause unstable bubbles, higher trim waste, and higher per-ton power consumption. Bigger machines actually cost you more when making small bags.
“Printing must be in-line, or the line looks unsophisticated.”	Most flat bags need no printing; only a minority do. Offline printing offers the ultimate flexibility — when not printing, the printer sits idle (saving power and labor); when printing is needed, it runs without affecting extrusion or bag-making.
“Buy three bag cutters if one isn‘t enough — more is always better.”	One extruder‘s output can feed at most 2 bag cutters. Adding more cutters blindly only results in machine idling. Start with a “1-to-2” ratio; when capacity is insufficient, add another extruder first, then scale up cutters accordingly. Staged expansion is the most cost-effective approach.

7. Added Value from Riqiang Machinery

Formulation Guidance: For the extreme cost sensitivity of small flat bags, we provide optimal filler ratio formulas — maximizing filler content while maintaining tear strength — and clearly calculate “savings per ton” for our customers.
Custom Die Services: The 600mm extruder can be equipped with multiple air rings and die sizes, enabling precise adjustment from 150mm to 600mm width with minimal slitting loss.
Operator Training Support: Small-size equipment is relatively simple to operate. Riqiang offers “3-day hands-on, 7-day independent” on-site training, reducing your labor training costs.
Spare Parts Express Network: Consumables such as sealing knives, cutting blades, and photocell sensors are stocked globally to minimize your downtime.

Size Flat Bags (Retail/Food/Promotional) — Complete Equipment Solution: High Speed, Material-Saving, Flexible Printing Options — Maximizing Margins on Small Bags

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