Blister and Clamshell Packaging: Structure, Materials and Production
UGI Packaging manufactures blister and clamshell packaging with the formed cavity, printed backing card and final assembly developed as one system. A blister joins a formed cavity to a card or lidding material; a clamshell uses two formed halves or one folded piece with an integral hinge. In our factory, product retention, tooling, sealing and opening behavior are approved against the actual product before mass production.
Blister or clamshell: the practical choice
Choose a carded blister when the printed backer carries instructions, branding or hanging features and the product needs a defined cavity. Choose a clamshell when front-and-back visibility, reclosability or a self-supporting formed structure matters. Neither option is automatically tamper-evident: the opening method, seal area, hinge, locks and damage pattern must be deliberately designed.
Material, cavity and backing-card decisions
The formed component may use PET, PVC, PP or another approved sheet, depending on clarity, stiffness, forming depth, sealing method and end-use requirements. The paperboard backer needs enough stiffness for hanging and enough surface compatibility for the selected coating or heat-seal system. If a paper-only alternative may work, compare the project with available paper box structures before committing to a formed cavity.
Production process and equipment
Our production route uses sheet preparation, extrusion where required, thermoforming or vacuum-forming equipment with a matched mold, trimming and cavity inspection. The paper route includes prepress, offset or digital printing, coating, die-cutting, stripping and backing-card inspection. Final assembly uses heat-sealing equipment, radio-frequency sealing where technically appropriate, snap closure or mechanical locking. The die-cutting process is especially important for hang holes, tear features and registration between the printed card and the cavity.
Inputs needed for quotation and tooling
Provide the physical product, dimensions and weight, presentation direction, cavity clearance, hanging or shelf-display requirement, opening method, target material, printed-card specification, quantity, packing workflow and destination. Tooling can include forming molds, trim tools, paperboard dies and sealing fixtures. A CAD drawing is useful, but a real product or controlled dummy is needed because draft angles, undercuts, cables and surface sensitivity change the cavity.
Sampling, seal review and production start
An early formed sample checks cavity shape and product removal. A printed assembly sample checks artwork position, hanging balance, opening force and the seal interface. The production clock should start after the product version, cavity tool, material and thickness, backing card, artwork, sealing specification, quantity and approval sample are released. Where seal strength is a controlled requirement, ASTM F88/F88M is one recognized method for flexible-barrier seal testing; the standard owner’s page defines its scope, but the buyer must select the applicable test and acceptance criteria.
Quality control and capability boundaries
Our inspectors check material thickness, cavity definition, trim edges, product movement, seal continuity, card warp, print registration, hang-hole balance, opening behavior and pack-out damage. UGI Packaging controls the forming, printed backing card, sealing and final pack assembly. Food, medical, child-resistant or other regulated uses require separate material, process and validation evidence for the exact application.
Frequently asked questions
What is the main difference between blister and clamshell packaging?
A blister normally joins a formed cavity to a backing material; a clamshell uses two formed sides or a folded hinged piece. The choice changes tooling, display and opening behavior.
Do you need the physical product to make the forming tool?
It is strongly recommended. Actual surfaces, cables, undercuts, tolerances and removal points are difficult to approve from nominal dimensions alone.
Is a snap-closed clamshell tamper-evident?
Not necessarily. Tamper evidence depends on the locks, seal, opening damage and inspection criteria designed for the specific pack.
Which parts does UGI Packaging manufacture?
Our factory produces the formed blister or clamshell component, printed backing card, sealing or closure assembly and completed packaging according to the approved specification.