Specify recycled PP packaging by its input stream, claim basis and required finished-product performance. Post-industrial and post-consumer describe origin; neither label alone establishes purity, colour, price or suitability. Compare traceable proposals and samples against the same application requirements.
The two sources
Post-industrial or pre-consumer material. Ask which manufacturing stream supplied it, its composition and processing history, and how it is controlled. Do not assume every offcut, purge or in-process regrind qualifies for a recycled-content claim under the chosen scheme. Confirm the definition and evidence rather than treating factory origin as proof of virgin-equivalent properties.
Post-consumer material. Identify the collected product stream, sorting, recycling and contamination controls, and any blending. Controlled streams can differ substantially from mixed collections. Require batch identification and relevant test evidence; origin alone neither proves contamination nor rules out a demanding application.
Agree whether the customer requires post-consumer content, qualifying pre-consumer content, a combination or a specific chain-of-custody model. State the denominator and whether the claim covers the sheet, one layer or the complete package. A requested percentage does not automatically mean post-consumer unless the requirement says so.
What recyclate does to sheet properties
Reprocessing and blending can change polymer properties, and feedstock, stabilisation and process controls affect the result. Qualify the proposed formulation and finished construction rather than predicting a fixed deterioration from the number of heat cycles alone.
Impact and mechanical performance. Measure the required impact, stiffness and load behaviour at the service temperatures and after the agreed reuse cycle. Include joints, creases and concentrated loads. Recycled percentage alone cannot establish a safe temperature or payload.
Processing consistency. Agree relevant melt-flow and composition controls for the formulation, plus finished-sheet thickness, mass and rib geometry. Check trial and production samples. A change in processing behaviour is a reason to investigate the actual stream and process, not a universal increase in melt flow for every recycled grade.
Colour, odour and cleanliness. Establish an approved colour range and measurement method, and specify odour, visible inclusions or residue limits where relevant. Ask which colours are available for the controlled input stream. Neither dark colour nor recycled percentage by itself proves cleanliness or rules out a light-coloured product.
Lot controls. Identify the approved formulation, permitted substitutions, sampling and acceptance limits. Compare samples from more than one relevant production lot where variation matters. Require notification and requalification when the input stream, process or additive system changes.
Qualify the requested percentage
There is no general recycled-percentage band that qualifies all PP packaging. Build the acceptance plan around the actual product:
- Define the claim: input type, qualifying scheme, physical or allocated accounting basis, percentage by weight and denominator.
- Define the duty: geometry, loads, support, handling, temperature and expected cleaning and reuse.
- Trial the proposed grade: assess the complete product using agreed property and appearance limits.
- Control production: tie lot and feedstock records to deliveries and agreed retest triggers.
- Confirm special requirements: food contact, electrical, flame or other regulated uses need their own applicable evidence.
Recycled content and reuse count do not, on their own, prove a lower environmental impact. Compare systems performing the same delivery function, including production, actual returns, cleaning, losses and end-of-life assumptions. ISO 14040 provides the framework for a life-cycle assessment, including goal and scope, inventory, impact assessment, interpretation and limitations. State the study basis and measured inputs before publishing a comparative benefit.
Check food contact and other special duties
For food contact, identify the destination, food type, contact temperature and duration, and whether use is repeated. Obtain evidence covering the actual recycling process, formulation and article. The FDA overview of recycled plastics explains the importance of source controls, contaminants and intended conditions of use in the US. It does not establish permission for every recycled PP grade or for another market.
For electrical, flame-performance, medical or other controlled applications, check the governing requirement and qualification of the actual formulation and assembly. Recycled content is neither a universal ban nor an automatic approval. A virgin contact layer or a generic recycled-content certificate does not, by itself, establish complete food-contact suitability.
Substantiating the claim
Require evidence for the exact wording of the claim. For US marketing, the FTC Green Guides summary explains that recycled-content claims concern material recovered or diverted from waste streams and that partly recycled products need qualified claims. A certification mark does not remove the need to substantiate the express and implied claim. Check the requirements of the actual destination and customer.
Request the input type and source controls, percentage calculation and tolerance, production site and lot records, and delivery documents linking the claim to the goods. If the customer requires independent certification, verify its scheme, validity and scope rather than accepting a logo or an unrelated site certificate.
Ask whether the certification describes physically traceable content, segregated material or an allocation model such as mass balance. Obtain the scheme's rules and permitted claim wording. Do not translate an allocated certificate into a promise that each delivered sheet physically contains that percentage; confirm that the customer's requirement accepts the actual model.
Appearance alone cannot verify the recycled-content percentage. Combine traceability and accounting checks with appropriate finished-product testing. Documentation supports the content claim; mechanical, chemical or other tests address the separately specified performance.
Specifying it
State the input category, minimum qualifying content, denominator, claim and accounting model, required records or certification, colour and cleanliness limits, dimensions and retained performance. Include tests at the relevant temperatures and after the specified cleaning or reuse duty.
Approve a formulation and construction that meet both the content requirement and the application tests. Keep change control and rejection criteria in the purchase specification so a compliant percentage cannot substitute for the required performance.
Request a recycled-PP specification review. Send the application, drawing, loads, service and cleaning conditions, destination, required content claim and any certification rules. Include the proposed stream, sample and reports so the missing evidence and quotation scope can be identified.