Field problem
Japan’s Mitsumura Printing announced on October 29 that it plans to exhibit paper flexible packaging and provide samples at Next Package 2026 in Tokyo on November 26. Its product page describes high-definition offset printing, use of existing heat-seal and barrier papers, and possible heat-seal coating depending on contents and converting method. Since the exhibition is still ahead, the announcement cannot establish water resistance, seal strength or food-contact compliance for a particular finished pack.
Evidence to check
The supplier describes low-migration ink and Swiss-ordinance conformity, saying its photoinitiators are listed in Part A. That is a supplier statement, not independent certification of every printed structure and intended food-contact use. The product page itself distinguishes an outer paper pack from inner individual packaging. A buyer must therefore define whether the proposed structure is primary or secondary packaging before assessing it.
Practical deliverable
A sample request should specify basis weight, coating structure, print and seal sides, intended contents, filling conditions and storage. Test the sealing window across actual machine temperature, pressure and dwell time, then record peel strength and leakage after cooling. For wet or fatty contents, measure the relevant moisture, grease and barrier performance over the intended contact period. For food uses, ask the supplier for migration tests and compliance documentation for the complete structure and use conditions.
| Validation | Evidence requested | Owner |
|---|---|---|
| Sealing | Sample-level settings, strength and leakage data | Packaging and quality |
| Barrier | Tests for actual contents and shelf life | Product development |
| Ink migration | Documentation for printed structure and use | Regulatory and quality |
| Recyclability | Local collection and recycling criteria for the coated structure | Sustainability |
Hold conditions
Do not equate an exhibit preview with a market launch, universal food-contact authorization or a verified plastic replacement. Offset print quality cannot substitute for package protection. Defer adoption and environmental performance figures until sample specifications and relevant independent tests are available.
About the Author
PackingMaster edits PaperPackLog, translating public packaging-industry information into purchasing, quality and site-operation checks.