Plastic Material Types for Industrial Packaging Decisions

By XCX · Updated October 2026

Types in the Plastic material series are good starting points, but a family name like PET, HDPE, or PP doesn’t specify a finished product. Completing a specification requires consideration for the type or grade, construction and additives, the service conditions, the equipment with which it’s to be used, the route of recovery, the behavior of the product, and evidence to demonstrate that the product meets the requirements of the specification.

Thermoplastics vs. Thermosets: The First Classification Split

Thermoplastics soften when heated and can be remolded, whereas Thermosets, which cure to a cross-linked structure, can’t be remelted. The split explains processing behavior, but it does not reveal an exact grade, finished construction, permitted use, or service life.

The British Plastics Federation thermoplastics overview describes this structural difference. It also shows why broad plastic types cannot replace an application specification. For example, a crystalline polymer may be changed with orientation and cooling history, and a nominally identical resin may be extruded to film, drawn to fiber, or molded to other forms.

Most familiar packaging resins are synthetic plastics built from monomers such as ethylene, propylene, or the precursors of polyethylene terephthalate and polyvinyl chloride. Cellulose-based materials show that polymer doesn’t automatically mean a petrochemical plastic. Plastic production route, feedstock, and chemistry are different from the thermal properties and the performance that the buyer must evaluate.

Procurement objection: Both candidates are thermoplastics. This by itself doesn’t make them interchangeable. The buyer must also have the polymer family, grade, additives, process route, geometry, and validation state. These factors explain why plastic products made from the same family can behave differently.

Seven Common Plastic Families Compared

Seven familiar resin-code families are PET, HDPE, PVC, LDPE, PP, PS, and the mixed “other” category. They offer a practical orientation map. They don’t rank materials from best to worst, and the seventh code number groups unlike polymers rather than defining one consistent kind of plastic.

“This classification system is not intended for the selection of materials.”

ASTM D4000 organizes plastic materials into families, groups, classes, and grades, and finally draws the above mentioned line. That line is more important than any other ranking. A broad table can help a team choose what to investigate; approval requires a grade data sheet, construction record, applicable declarations, and a trial or test plan.

Illustrative comparison scenario: A buyer gets one quotation each for rigid containers from high-density polyethylene and PP. According to the different types of plastic materials, neither family is superior based on name alone. The buyer first records the fill product, the rigid container’s geometry, the closure, the stacking period, the drop conditions, the temperature in degrees Celsius, the destination, and the recovery route. Each supplier provides the exact grade and finished-container evidence; the decision follows the matched service record, not a generic claim that one of these types of plastic materials is always tougher or easier to recycle.

What are the 7 different types of plastic?

The seven resin-code groups are #1 PET, #2 HDPE, #3 PVC, #4 LDPE, #5 PP, #6 PS, and #7 other. The lists allow the identification of broad resin families in different products, for example, in water bottles, detergent containers, film, food containers, and protective foam. Code #7 doesn’t indicate a single polymer. None of the seven codes proves a commercial grade, safe use, local recyclability, recycled content, or industrial-load performance.

What the Family Name Leaves Out: Form, Grade, Additives, and History

A family name omits variables that typically define performance: physical form, exact grade, molecular design, additive package, recycled-content basis, orientation, crystallinity, layer construction, processing history, and conditioning. ASTM D4000-23 separates plastic materials into families, groups, classes, and grades, while stating that the classification is not intended for material selection. Therefore, “PET,” “PE,” or “PP” defines a chemistry family not a complete industrial specification.

1. Name the family: record the polymer or resin family and any blend.
2. Describe the form: state film, sheet, fibre, strap, moulded part, foam, coating, or container.
3. Lock the grade: retain the supplier designation, revision, additives, colour, and recycled-content basis.
4. Map the construction: list each substrate, tie layer, coating, print layer, orientation, and nominal thickness.
5. Preserve the history: record processing, conditioning, aging, lot, and any previous reuse or regrind step.

Consider a controlled hypothetical: two quotations both say “PE stretch film.” Offer A is a 3-layer, 23 µm construction; Offer B is a 5-layer, 17 µm construction. Those figures don’t prove which film performs better. They show why the comparison must include layer functions, resin grades, orientation, cling system, puncture response, containment test, equipment settings, and pallet trial.

Multi-layer identity is important outside film. Coatings, labels, sleeves, adhesives, closures, and pigments can affect separation and recovery, even when the main container uses a familiar polymer. A material passport has to capture both component layers and the final product that was tested.

What are different types of plastic grades?

Plastic grades are supplier-defined formulations within a polymer family. Grades may differ in molecular design, density, flow behavior, fillers, stabilizers, colourants, recycled content, food-contact scope, or target process such as film extrusion, blow moulding, or injection moulding. Compare the exact designation and revision; “HDPE grade” or “PP grade” alone still does not identify the supplied formulation.

Choose by Service Conditions, Not Resin Name Alone

Material selection rejects candidates that don’t fall within the service envelope before consideration is given to price. The Service-Condition Knockout Sequence checks peak and sustained load, temperature, chemicals, handling damage, barrier duty, equipment compatibility, regulatory scope, and the intended recovery route. Evidence presented has to be tied directly to the grade and construction of the material.

What is the strongest type of plastic?

By tensile strength, one published properties table puts unfilled PA66 polyamide highest among standard plastics at about 80–90 MPa, followed by PA6 at about 70–85 MPa. Strength could mean maximum tensile strength, impact strength, puncture strength, joint strength, stiffness, or the ability to retain a load for a long time. Compare the exact grade and finished form under the temperature, time scale, geometry, and test method that match the application.

The time-scale boundary deserves special consideration. ASTM D882-26a (Film less than 1.0 mm) points out that tensile data may become irrelevant when the application operates on an entirely different force-time scale. ASTM D2990-17 (2025) addresses creep and creep rupture under long term load. The methods address different sets of concerns.

Chemistry needs the same discipline. ASTM D543-21 frames chemical evaluation through reagent, concentration, exposure time, temperature, stress, and service similarity. An illustrative screening brief might state 5% detergent solution, 40 °C, 72 h, and a defined applied stress. Those inputs define a test question; they are not a performance claim.

Illustrative load scenario. A pallet strap survives a 60 s pull at room temperature, while the shipment must remain unitized for 30 days through hot storage and repeated handling; the pull result answers a peak-load question. It doesn’t quantify tension loss after 720 h, joint behavior, edge damage, or the effect of the actual package. The approval plan therefore keeps the tensile report, adds time-dependent evidence, and runs a package trial using the selected strap, joint, tool settings, corner protection, pallet pattern, and route. Price review begins only after both candidates cleared the reject gates.

Plastic Packaging Forms: Film, Strapping, Containers, and Components

The form and content of the package influences failure and its load carrying capability. Flexible film is evaluated based on gauge, orientation, layers, seals, and puncture response. Strapping is evaluated based on joint performance and retained tension. Rigid containers are evaluated based on wall geometry, closures, impact, and stacking. Each form and content of the package needs evidence to show that it meets requirements.

A packaging engineer is able to use plastic packaging materials as a commercial handoff after requirements are defined. UD Packaging’s supplied company profile provides information about PET strapping, industrial stretch film, seals and strapping equipment. That first-party information doesn’t replace a grade data sheet, scoped certificate, or application trial.

Other forms of the package (e.g. plastic film) also need method discipline. The site’s guide to tensile testing of plastic film provides context for the test. ASTM D882 states that films, laminates and coatings are within its scope, but a coupon test does not prove pallet stability or integrity of seals and barriers.

Why Resin Codes Do Not Prove Recyclability or Load Fitness

A resin identification code addresses the question, “what broad resin family is present?” It doesn’t answer whether the final format will be collected by a local program, whether the product contains verified recycled material, whether the construction can be separated, or whether it can take an industrial load. Those require other pieces of evidence.

How do I identify different types of plastics?

Start with the supplier declaration, grade label, drawing, or resin identification code, then confirm physical form and construction. Visual inspection can help identify a family but can’t reliably identify every blend, additive package, coating, or multilayer construction. When identity affects safety, process settings, or acceptance, use documented material records or qualified analysis.

The public page for ASTM D7611/D7611M-26 states that a resin code identifies the family, but does not indicate recyclability. The US EPA recycling FAQ also states that accepted materials vary by community. Even a material that is technically easy to recycle may be rejected because of format, contamination, color, attachment, or lack of a local route.

Resin codes also do not answer every health and the environment question. Number 6 plastic identifies a polystyrene family and doesn’t estimate migration or microplastics, nor does it address exposure or risk for a given product. Plastic food containers, lunch boxes, and baby bottles require evidence based on product and use.

Bio-based, biodegradable, and compostable plastics need another separation. The European Commission policy framework explains that bio-based origin does not necessarily mean biodegradable or compostable. Compostable products normally need defined conditions and compatible collection and treatment; an item does not simply disintegrate into an accepted recovery route because of one label.

The Five-Layer Material Passport Buyers Should Request

A five-layer material passport allows the quotation comparison of identity and evidence. It records the polymer family, physical form and finished construction, exact grade, declaration or authorization scope, and application validation. Each layer identifies a document owner and revision or date. Also lot identification and acceptance status are recorded.

Testing records must retain sufficient information to allow comparison. UD Packaging’s plastic material testing resources, the guide to specimen and report details, and the comparison of ASTM D882 vs ISO 527-3 explain why method, specimen, conditioning, speed, and result definition must remain visible.

Food packaging needs a conditional regulatory field rather than a blanket label. FDA guidance on food-contact components ties status to substance identity, specifications, and conditions of use. For a Food Contact Notification, the effective authorization also attaches to the identified manufacturer, substance, and conditions of use. A certificate for another formulation or use condition cannot be silently transferred.

Evidence for the use of recycled content materials also needs limitations. The RecyClass traceability guidance addresses the origin and physical traceability through the value chain. That record is different from local recyclability, chemical recycling potential, reuse suitability, energy consumption, greenhouse gas emissions, or a general circular economy for plastics claim.

Supplier Approval Questions Before Production

The scope of the approved supplier should bind the offered material to the actual product, the destination, equipment, test method, lot and change-control process. FDA guidance makes food-contact status conditional on substance identity, specifications, conditions of use and, in the FCN pathway, the identified manufacturer. The same scope questions should be posed to all bidders. Define what will be tested on the samples and what will be tested on production lots. The acceptance decision should be made based on what’s defined in a given document.

These fields should be included in an RFQ. The “recommended range” is the buyers’ tolerance or envelope rather than universal material value.

A generic compliance pack can look complete while omitting key elements such as the actual manufacturer or components, intended use or test conditions. Approval should stop when a document covers a different construction or lot. The cost of an additional clarification is usually smaller than qualifying evidence that cannot be traced to the supplied product.

Illustrative approval scenario. A supplier offers a multilayer pouch for a food product and attaches a declaration for one resin component. A buyer doesn’t accept that file as authorization for the complete pouch. The RFQ seeks disclosure of all food-contact components, manufacturer or formulation identity, as applicable, layer and coating construction, intended food, and the duration and temperature of food contact, and the intended end use. The supplier also identifies the actual production site and change-notification process. The team approves the sample only after the evidence scope matches the offered construction and the finished pouch passes the defined seal, barrier, and handling checks.

What Is Changing in Plastic Packaging Material Selection

Evidence is starting to play a role in packaging selection to align design, recovery, and traceability. Buyers should date regulatory claims, confirm the current edition of cited standards, separate material origin from end-of-life behavior, and retain change-control records. No single resin family becomes future-proof because a policy or label changes.

As per the European Commission packaging-waste page, Regulation (EU) 2025/40 came into force on 11 February 2025 and will generally apply from 12 August 2026. It sets a target for packaging to be recyclable in an economically viable way by 2030. A buyer planning a 2026 supply agreement should therefore preserve destination, construction, collection assumptions, and evidence dates in the approval record.

Changes to designs can require modifications to the finished system rather than a simple substitution of materials. A mono-material structure can be in conflict with barrier or durability requirements, and a multi-layer structure can protect the contents but be difficult to recycle in an available system. Bio-based feedstock can reduce reliance on petroleum or natural gas without proving compostability. Compostable claims require collection, treatment, and conditions. Chemical recycling can increase options for some plastic waste streams, but the existence of a process doesn’t ensure local acceptance.

Standard status changes too. Date the standard edition in a specification and check it before renewal. A current revision can widen the scope or change the terminology, even though the supplier continues to cite the older document. This is especially important when brand literature names a test standard: the article should not call an older edition “current” without a live status check.

Frequently Asked Questions About Plastic Material Types

The answers below keep chemistry family, commercial grade, finished form, local recovery, and application proof separate.

What are the four main types of plastic?

Short answer

There is no universal set of four main plastic types; teaching schemes group plastics by resin code, chemical family, performance class, source, or end use. For packaging procurement, identify the chosen scheme before comparing materials.

Rubber-like elastomers and fibres can overlap with packaging components, but a family label still doesn’t define the grade or finished construction.

How many types of plastic are there?

Short answer

Seven, if you count resin identification codes, though the #7 group contains unlike materials. Chemistry adds many polymer families, and commercial suppliers create numerous grades through different monomers, molecular designs, fillers, additives, colours, and process targets.

The correct count depends on whether the question concerns chemistry, recycling labels, engineering classes, or purchasable grades.

What type of plastic cannot be remelted?

Short answer

Thermosetting plastics can’t be remelted and reshaped like thermoplastics after curing because cross-links lock the network. Reheating may damage or decompose the cured material instead. That behavior doesn’t by itself decide disposal or recovery; the exact thermoset, reinforcement, contamination, and available route still matter.

Melamine and phenolic systems are familiar examples, but use the product record rather than appearance to identify them.

Which plastics are recyclable and which are not?

Short answer

In the U.S., a 2020 Greenpeace survey of the country’s 367 material recovery facilities found that only PET #1 and HDPE #2 plastic bottles and jugs are being recycled with regularity. Acceptance depends on the resin, format, colour, size, contamination, labels, closures, collection system, and processor demand. Check the local program for the finished item; a recycling code identifies resin but doesn’t guarantee collection.

What plastic is typically used for stretch film?

Short answer

Industrial stretch film commonly uses linear low-density polyethylene, often with other polyethylene grades or additives in a multilayer construction. The family explains flexibility and process fit only at a broad level. Select the film by finished gauge, layer design, stretch behavior, puncture response, cling, containment force, wrapper settings, pallet geometry, and transport trial.

Plastic bags and stretch film may both use low-density polyethylene families, yet their grade, layer, seal, and load requirements differ.

What plastic material is commonly used for strapping?

Short answer

PET and PP are common plastic strapping families. Choose between exact products using load duration, elongation, retained tension, joint method, tool compatibility, package edges, storage temperature, weather exposure, and distribution validation rather than the family name alone.