Manufacturing of collapsible toothpaste tubes:\nWhich extrusion process is commonly used to produce thin-walled, seamless collapsible tubes (e.g., for toothpaste)?

Introduction / Context:
Collapsible tubes for toothpaste, ointments, and creams are traditionally made from soft metals (e.g., aluminum) by an extrusion process that forms seamless, thin-walled shells. Identifying the specific extrusion style helps distinguish bulk metal-shaping methods used for containers versus those for bars, rods, or profiles.

Given Data / Assumptions:

• Tubes are thin-walled, seamless, and closed at one end after heading.
• Material is a ductile, low-strength metal slug (often Al alloy).
• High-speed production requires cold forming.

Concept / Approach:
Impact extrusion is a cold extrusion process in which a punch strikes a metal slug at high speed, forcing material to flow backward around the punch and up the die walls. This produces seamless, uniform tubes suitable for collapsible packaging. Direct and indirect extrusion are continuous/profile-forming operations, not optimal for thin, closed-end tube shells; hydrostatic extrusion targets difficult-to-deform materials in continuous forms, not discrete tubes.

Step-by-Step Solution:

Verification / Alternative check:
Packaging manufacturing references consistently cite impact (backward) extrusion for aluminum toothpaste tubes and aerosol can bodies (with variations).

Why Other Options Are Wrong:

• Direct/indirect extrusion: suitable for long profiles or hollow sections with mandrels, not collapsible tubes from slugs.
• Hydrostatic extrusion: a niche method for continuous forms, not discrete collapsible tubes.

Common Pitfalls:
Confusing deep drawing (for cups/cans) with impact extrusion; toothpaste tubes are typically produced by impact extrusion of metal slugs.

Final Answer:
Impact extrusion