How to Adjust Production Parameters for Eco-Friendly Paper Bags of Different Thicknesses?

2025-11-06 08:56:18

Eco-friendly Paper Bags, available in types like Pasted Bottom Bags, Sewn Bags, and Valve Bags, are workhorses across industries—from retail luxury packaging to industrial bulk storage. But here’s the catch: paper thickness (measured in grams per square meter, gsm) changes everything. A thin 60gsm bag for bakery takeaways needs different production settings than a heavy-duty 200gsm valve bag for organic grains. Getting these parameters right ensures bags are strong, well-formed, and cost-effective. Let’s break down how to tweak settings across key production steps, why it matters for different industries, and answers to common questions.

Boutiques and cosmetic stores use 80–120gsm Pasted Bottom Bags for gift packaging. Too tight a printing pressure on thin paper causes ink bleeding; too loose, and logos look faint—hurting brand image. For example, a 100gsm bag printed with a luxury brand’s gold logo needs lighter flexographic printing pressure than a 150gsm bag, to keep the paper smooth and the design crisp.

Cafes and bakeries rely on 60–90gsm Sewn Bags for takeaways. Thin paper tears easily if the tube-making machine’s tension is too high; thick paper (like 120gsm for sandwich bags) needs more heat in bottom-pasting to seal properly. A 70gsm bag for pastries, if made with too much tube tension, will crease—making the food inside look unappetizing.

Companies packing grains or coffee use 150–250gsm Valve Bags. These thick bags need stronger bottom-pasting adhesive and higher pressure to ensure they hold 5–10kg of bulk goods. A 200gsm Valve Bag for coffee beans, if pasted with weak adhesive, will split open during shipping—leading to product loss.

E-tailers use 100–140gsm bags for shipping small items. Thin bags need extra care in tube-making to avoid holes; thick bags need adjusted printing speed to prevent smudges. For export, where bags face long transit, a 120gsm Pasted Bottom Bag with correctly tuned parameters stays intact, protecting products and maintaining brand consistency.

Thin paper (60–100gsm): Lower printing pressure (2–3 bar) and slower speed (80–100m/min) to avoid ink bleeding and paper damage. Use water-based inks for better absorption.

Thick paper (150–250gsm): Higher pressure (4–5 bar) and faster speed (120–150m/min) to ensure ink penetrates evenly. UV inks work well for bold, long-lasting prints.

Thin paper: Reduce tension (10–15N) to prevent creasing; narrow the tube diameter gap to keep the bag shape neat.

Thick paper: Increase tension (20–25N) to hold the paper straight; widen the gap slightly to accommodate the thicker material.

Thin paper: Use low-temperature adhesive (50–60°C) and light pressure (3–4kg) to avoid paper warping.

Thick paper: Use high-temperature adhesive (70–80°C) and heavy pressure (6–8kg) to create a strong seal.

Q1: How do I know if the printing pressure is right for a specific thickness?

A: Do a test run! Print 10–20 bags: if thin paper has ink smudges, lower pressure; if thick paper has faint prints, raise it. The goal is crisp design without paper damage.

Q2: Can I use the same tube tension for all thicknesses?

A: No. Thin paper needs less tension—too much causes tears. Thick paper needs more tension—too little leads to loose tubes. Check the tube’s straightness after production: if it’s curved, adjust tension.

Q3: What adhesive works best for thick Valve Bags?

A: Use solvent-based adhesive for 150–250gsm paper—it has stronger bonding power than water-based adhesive. For food-safe bags, choose FDA-approved adhesive.

Q4: Will adjusting parameters slow down production?

A: Initially, but it saves time long-term. Correct parameters reduce waste (fewer torn or poorly printed bags) and avoid rework—boosting overall efficiency.

Q5: How often should I check parameters when switching thicknesses?

A: Every time you change paper thickness. Even a 20gsm difference (e.g., from 100gsm to 120gsm) needs parameter tweaks—don’t skip this step!

Getting production parameters right for different paper thicknesses isn’t just technical—it’s key to making eco-friendly paper bags that meet industry needs. With these adjustments, businesses get strong, good-looking bags that protect products and build brand trust.