Tier 1 Supplier Approval for Butyl Materials: APQP, PPAP & IATF 16949

When an automotive Tier 1 asks a materials supplier for "PPAP documentation," they are asking for the output of a much larger process. That process is APQP — Advanced Product Quality Planning — the structured product development framework that the automotive industry has used for decades to make sure a new part is capable before it reaches a moving assembly line. Understanding where PPAP sits inside APQP is the difference between a smooth approval and a six-month document tennis match.

APQP is conventionally described in five phases. A butyl compound or sealing tape supplier is involved in all five, though the intensity shifts:

1. Plan and define the programme — Customer requirements are translated into material requirements. For a sealing material this is where service temperature, substrate, adhesion targets, flammability class and restricted-substance rules must all surface. Requirements discovered later are the most expensive kind
2. Product design and development — The material specification is fixed, and design FMEA thinking is applied: what can go wrong with this seal, how would it be detected, what is the severity? For a material supplier this usually means supporting the customer's DFMEA with property data rather than owning the DFMEA
3. Process design and development — The manufacturing process is defined: flow diagram, process FMEA, control plan, work instructions, packaging and labelling standards. This phase is where a materials plant does most of its real work
4. Product and process validation — A significant production run is made under normal conditions, measurement systems are validated, initial process capability is established, and the PPAP package is assembled and submitted
5. Feedback, assessment and corrective action — After approval, ongoing performance is monitored, variation is reduced, and any change goes through a formal change-notification route

Two ideas from APQP cause more confusion than the rest, so they are worth stating plainly.

• PFMEA and control plan must agree. Every significant failure mode identified in the process FMEA should have a corresponding control in the control plan. Auditors check this linkage directly, and a mismatch is one of the most common findings
• Special characteristics drive everything downstream. Characteristics designated as special or critical by the customer determine which dimensions and properties need capability studies, tighter sampling and dedicated reaction plans. Agree the special characteristic list early, in writing

Underpinning all of this is IATF 16949, the automotive quality management system standard built on ISO 9001. IATF 16949 is what makes the APQP and PPAP disciplines auditable: it requires the documented processes, the traceability, the change control and the supplier management that a Tier 1 will inspect before it lets a new material into a vehicle programme. Garmy Materials operates under IATF 16949 alongside ISO 9001 and ISO 14001, and holds a Hyundai SQ mark — supplier quality recognition earned through exactly this kind of assessment.

PPAP — Production Part Approval Process — is the formal evidence package proving that the supplier's production process can repeatedly make product that meets the agreed requirements. It is submitted at a defined level, and the level determines how much of the evidence is sent to the customer versus retained at the plant. Level 3, in which a full documentation package plus samples is submitted, is the most common default for a new material at a new customer.

Submission level	What goes to the customer	Typical use
Level 1	Part Submission Warrant only	Low-risk change on an established part
Level 2	PSW with samples and limited supporting data	Minor change, established relationship
Level 3	PSW with samples and complete supporting data	New material at a new customer — the usual default
Level 4	PSW plus whatever the customer specifically defines	Customer-specific requirement
Level 5	Full package reviewed on site at the supplier plant	High-risk or safety-critical applications

The elements a materials manufacturer is normally expected to produce, in the order they tend to be requested:

• Design records and material specification — The agreed specification sheet with properties, methods and tolerances. For butyl compounds this anchors on values such as specific gravity and peel strength — for example HY-1 at 1.45 ± 0.1 and 81.07, or SD-1 at 1.65 ± 0.1 and 42.82 — each with its test method stated
• Engineering change documents — Any authorised deviation or change approval relevant to the submitted material
• Process flow diagram — From raw material receipt through mixing, forming, packaging and shipping
• Process FMEA — Failure modes, effects, severity/occurrence/detection ratings and the actions taken to reduce risk
• Control plan — What is measured, by whom, how often, with what method, and the reaction plan when a result falls outside limits
• Measurement systems analysis (MSA) — Gauge R&R and related studies proving the measurement method itself is capable of judging the characteristic
• Initial process studies — Capability indices on the designated special characteristics from a significant production run, not from a hand-made sample
• Material and performance test results — Property data against the specification, plus any customer-specific or standard-based testing agreed
• Sample parts and master sample — Retained reference material from the qualifying run
• Checking aids and packaging standard — Where applicable, plus labelling and identification method
• Material composition reporting — Substance data submitted through the industry material data system, plus any restricted-substance declarations the customer requires
• Part Submission Warrant (PSW) — The signed cover document declaring conformity and requesting approval

Approval comes back in one of three states: approved (ship production), interim approval (ship for a limited quantity or period with an agreed action plan), or rejected (correct and resubmit). Interim approval is common and not a disgrace — but it always carries an expiry, and letting one lapse quietly is a serious escalation risk.

If you are qualifying a new sealing material into an automotive programme, starting from a compound already produced under IATF 16949 removes a substantial part of the documentation burden.

IATF 16949 is often described loosely as "ISO 9001 for automotive," which undersells it. It adds a set of requirements that exist specifically because automotive volumes make defects expensive and recalls catastrophic. For a butyl compound or tape manufacturer, these are the requirements that shape day-to-day operations — and the ones a Tier 1 audit team will probe.

• Full traceability — Every shipped lot must be traceable back to raw material lots, production date, equipment and operator, so that containment can be bounded quickly if a problem emerges months later in the field
• Change control — No unnotified change to formulation, raw material source, process parameters, plant location or packaging. Any of these normally triggers customer notification and often a PPAP resubmission. This is the single most common cause of Tier 1 disputes with materials suppliers
• Contingency planning — Documented plans for equipment failure, utility interruption, labour shortage, cyber incident and supply disruption, because a stopped assembly line is charged by the minute
• Supplier management — The materials plant must in turn monitor and develop its own raw material suppliers, with defined selection criteria and performance monitoring
• Embedded core tools — APQP, PPAP, FMEA, MSA and SPC are not optional add-ons; they are the expected working method throughout the product lifecycle
• Continual improvement and problem solving — Structured root-cause analysis with a defined format, containment, corrective action and verification of effectiveness

A practical readiness checklist for a materials supplier approaching a first Tier 1 approval:

1. Confirm certification scope. Check that the IATF 16949 certificate actually covers the site and the product family being supplied, not a sister operation
2. Agree the special characteristics in writing before any capability study is run, so the study measures what the customer intends to judge
3. Nominate a single quality contact with authority to sign the PSW and to commit to corrective actions
4. Pre-build the standing documents — process flow, PFMEA and control plan templates can exist before a specific programme starts and be tailored per customer
5. Set up substance data reporting early. Material composition submissions frequently become the critical path item because they depend on data from upstream raw material suppliers
6. Plan the qualifying production run under genuinely normal conditions — normal tooling, normal rate, normal operators. A run made under special care produces capability numbers that cannot be sustained
7. Diary the interim approval expiry if one is issued, and close the action plan before it lapses

Garmy Materials has manufactured butyl products since 1999 and produces over 3,400 tonnes per year at its 4,200 m² plant in Eumseong, Chungbuk, Korea, operating under IATF 16949, ISO 9001 and ISO 14001 with three patents and a Hyundai SQ mark. That certification base means the standing documentation, traceability and change-control disciplines a Tier 1 expects are already in place before a specific programme begins, rather than being built during it.

Tell us which Tier 1 programme you are qualifying into and at which PPAP level, and we will map out the documentation package with you.

Q: What is the difference between APQP and PPAP?

A: APQP is the overall product quality planning framework, running from requirement definition through design, process development, validation and ongoing feedback. PPAP is the evidence package produced near the end of that framework, in the validation phase, which formally demonstrates that the production process can consistently make conforming product. In short, APQP is the process and PPAP is the proof.

Q: Which PPAP level will a Tier 1 typically ask a new material supplier for?

A: Level 3 is the usual default for a new material at a new customer — the Part Submission Warrant plus samples and the complete supporting documentation set. Level 1 or 2 may be accepted for low-risk changes on an established part, while Level 5 involves the customer reviewing the full package on site. Always confirm the level in writing before assembling the package, because the effort difference is substantial.

Q: Does IATF 16949 certification alone make a supplier approved?

A: No. IATF 16949 certification is a prerequisite that qualifies the quality management system, but approval is granted per part or per material through the PPAP submission for that specific application. A certified plant still has to demonstrate capability for the particular compound, process and characteristics in question. The certification shortens the path considerably; it does not replace the submission.

Q: What triggers a PPAP resubmission after initial approval?

A: Changes to the formulation, a change of raw material source, modification of process parameters or equipment, relocation of production, a change in packaging, or a lapse in production for an extended period. Any of these normally requires customer notification and often a fresh submission. This is why change control discipline matters more than almost anything else in an automotive supply relationship — an unnotified change discovered later is treated far more seriously than a notified one.

Q: How long does a first Tier 1 approval take for a butyl material?

A: It depends heavily on the customer and the application risk, but for a material based on an existing qualified compound it is realistic to plan several months from requirement definition to approved PSW. The critical path items are usually the customer's own application testing, the substance data reporting that depends on upstream raw material suppliers, and the scheduling of a qualifying production run under normal conditions.

Q: What documents should we ask a butyl material supplier for up front?

A: The IATF 16949, ISO 9001 and ISO 14001 certificates with their scope pages, the material specification sheet with test methods and tolerances, a sample certificate of analysis showing lot-level traceability, the process flow and control plan format, the change notification procedure, and confirmation of substance data reporting capability. Requesting these before the programme starts avoids discovering a gap during the submission window.

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