Product Design & Prototype Lab

Section 1

Product Overview

Development status snapshot and 8-angle product visualisation. All geometry is concept-stage. CAD and physical prototype not yet completed.

Visual direction

Approved

Product dimensions

Provisional

Internal architecture

Under evaluation

Refill mechanism

Unverified

Crystal manufacturing

Unconfirmed

Cap ventilation & sealing

Untested

CAD model

Pending

Physical prototype

Not built

Manufacturer RFQ

Pending

Performance claims

Unvalidated

Front view — Side A (face, flat oval) at top · Side B (body, convex) at bottom

Back view

Left side profile — oval cross-section

Right side profile

Top view — Side A cap removed · flat oval crystal face

Bottom view — Side B cap removed · convex oval crystal face

Three-quarter front view

Three-quarter rear view

Field	Value
Concept name	PURALUM Dual Crystal Applicator
Status	Concept direction approved
Purpose	Dual-surface natural potassium alum personal care applicator
Phase	Pre-prototype concept definition
Est. height	~115 mm (provisional)
Est. weight	~80 g (provisional)
Surfaces	Side A — face, flat oval · Side B — body, convex oval

Section 2

Scale & Ergonomics

Provisional size references. All dimensions require confirmation through CAD modelling and ergonomic prototype testing.

In an adult hand

Product shown at scale relative to average adult palm (~180mm). Grip zone ~35mm wide.

Face application

Side A (◯) held at cheek level. Circular or press-and-lift motion.

Underarm application

Side B (△) upward. Glide motion with light pressure.

Standing on counter

Product upright on flat surface. Stability requires P1 prototype test.

Measurement	Value	Status
Total height	~115 mm	Provisional
Maximum width	~42 mm	Provisional
Grip width	~35 mm	Provisional
Side A crystal contact	~28 × 22 mm	Provisional
Side B crystal contact	~30 × 24 mm	Provisional
Cap depth	~18 mm	Provisional
Total weight	~80 g	Provisional
Refill weight	~40 g	Provisional

📐 All measurements provisional. Final dimensions require CAD modelling and ergonomic prototype testing.

Section 3

Product Architecture

Conceptual exploded view of 11 components. Internal construction is NOT confirmed. Engineering review required.

#	Component	Material	Method	Est. Wt.	Status
1	Side A Cap	PP or ABS	Injection mould	~5g	Concept
2	Side A Crystal	Potassium alum	TBD	~18g	Unconfirmed
3	Side A Support Cup	PP	Injection mould	~4g	Concept
4	Upper Seal Ring	Silicone	Moulded	~1g	Untested
5	Central Core	PP	Injection mould	~12g	Concept
6	Silicone Grip	LSR Silicone	Over-moulded	~15g	Concept
7	Lower Seal Ring	Silicone	Moulded	~1g	Untested
8	Locking Ring	PP	Injection mould	~3g	Under evaluation
9	Side B Support Cup	PP	Injection mould	~4g	Concept
10	Side B Crystal	Potassium alum	TBD	~18g	Unconfirmed
11	Side B Cap	PP or ABS	Injection mould	~5g	Concept

Component architecture is a working concept. Internal construction is NOT confirmed. Engineering review required before finalising.

Section 4

Internal Cross-Section

Conceptual sectional diagram showing proposed internal layout. Actual construction depends on architecture selected in Section 5.

Wet-use cross-section

Crystal A wetted and applied to skin
Water drains via channels in support cup
Seal rings prevent water entering centre
Central channel — no water pathway between ends
Silicone grip provides moisture-resistant hold

Water ingress testing required. Seal ring placement and drainage are design concepts — not validated.

Dry-storage cross-section

Both caps sealed with ventilation holes
Airflow passes through cap vent holes
Crystal moisture evaporates naturally
No moisture trapped in sealed centre
Seal rings protect central core from residual water

Ventilated cap design is a concept. Airflow testing and cap retention validation required.

This is a working concept diagram. Actual internal architecture depends on engineering concept selected in Section 5.

Section 5

Engineering Architecture Options

Three concept architectures under evaluation. No final architecture selected. Requires product engineer consultation and manufacturer feasibility review.

Concept A

Single Double-Ended Cartridge

One internal cartridge holds both crystal surfaces. Quarter-turn releases from central housing. Refill = one purchase, one swap.

Scoring

Hygiene

3/5

Manufacturability

4/5

Crystal protection

3/5

Water resistance

2/5

Refill simplicity

5/5

Component count

5/5

Tooling cost

4/5

Est. COGS

4/5

User intuitiveness

5/5

Travel suitability

3/5

Visual elegance

4/5

Air drying

3/5

Concept B

Two Independent Modules

Side A and Side B crystal modules replace independently. Maximum hygiene isolation. Replace only the worn crystal.

Scoring

Hygiene

5/5

Manufacturability

3/5

Crystal protection

4/5

Water resistance

3/5

Refill simplicity

3/5

Component count

2/5

Tooling cost

2/5

Est. COGS

2/5

User intuitiveness

3/5

Travel suitability

4/5

Visual elegance

3/5

Air drying

4/5

Concept C

Rotating Protective Housing

Crystals retract into housing during storage. Rotation exposes correct surface. No loose caps. Most complex mechanism.

Scoring

Hygiene

3/5

Manufacturability

2/5

Crystal protection

5/5

Water resistance

2/5

Refill simplicity

2/5

Component count

3/5

Tooling cost

1/5

Est. COGS

1/5

User intuitiveness

4/5

Travel suitability

5/5

Visual elegance

4/5

Air drying

2/5

⚠ No architecture is selected. Final selection requires product engineer consultation and manufacturer feasibility review. These scores are founder estimates — not engineering analysis.

Section 6

Crystal Manufacturing Options

Four methods compared. Manufacturing method selection drives refill system design, COGS, and product positioning. No method confirmed.

Method 1 — Grown Crystal

Natural

Flat/convex surface: Possible but requires controlled growth or post-growth machining

Strength: Moderate

Brittleness: High — significant drop risk

Surface smoothness: Very high (natural growth)

Water dissolution: Slow surface dissolution (normal)

Manufacturing complexity: High — growth time variable

Tooling: Minimal, controlled environment needed

Refill compatibility: Yes — grow to shape

Open questions: Shape consistency, batch variation, growth defects

Method 2 — CNC-Cut Alum Block

Machined

Flat/convex surface: Excellent precision

Strength: High if block is dense

Brittleness: Lower than grown (fewer internal stress lines)

Surface smoothness: Very high (machined + polished)

Water dissolution: Same as grown

Manufacturing complexity: Moderate — requires CNC

Tooling: CNC machinery

Refill compatibility: Yes — consistent geometry

Open questions: Minimum batch size, unit cost at MOQ

Method 3 — Compressed Composite

⚠ Additive risk

Flat/convex surface: Good — mould tooling

Strength: Moderate — depends on binder

Brittleness: Lower than crystal

Surface smoothness: Mould-dependent

Water dissolution: May dissolve faster if porous

Manufacturing complexity: Low — compression moulding

Tooling: Compression moulds

Refill compatibility: Excellent — moulded to exact shape

⚠ Any binder or additive required would change the formulation from 100% potassium alum. This affects product positioning, marketing claims, and potentially regulatory classification. Full ingredient disclosure required if this method is adopted.

Method 4 — Crystal in Polymer Carrier

Hybrid

Flat/convex surface: Carrier provides geometry; crystal is insert

Strength: High — carrier absorbs impact

Brittleness: Protected by carrier

Surface smoothness: Crystal insert determines feel

Water dissolution: Only exposed crystal face contacts water

Manufacturing complexity: Two-part assembly

Tooling: Carrier mould + crystal sourcing

Refill compatibility: Excellent — carrier standardises fit

Open questions: Consumer perception, crystal sourcing at volume

Section 7

Side A & Side B Geometry

Contact geometry for each surface. Dimensions provisional. No medical or skin-treatment claims are made.

Side A — Face Applicator

◯ symbol · Forest green cap

ShapeFlat or very slightly crowned oval

Contact area~28 × 22 mm

Edge radius~3 mm

Grip angle~15° natural tilt

MotionCircular or press-and-lift

Cap symbol◯

Cap colourForest green #1B3A2D

Side B — Body Applicator

△ symbol · Sage green cap

ShapeConvex oval

Crown height~8 mm

Contact area~30 × 24 mm

Edge radius~4 mm

MotionGlide with light even pressure

Cap symbol△

Cap colourSage green #5C8A70

No medical or skin-treatment claims are made. Crystal deodorant function is cosmetic. Contact geometry is under engineering evaluation.

Section 8

Hygiene System

Intended use routine and physical hygiene design features. All hygiene performance claims require prototype validation.

1

🫳

Remove cap

Side A (◯) for face. Side B (△) for body. Non-interchangeable by design.

2

💧

Wet crystal

Run the crystal under clean water for 2–3 seconds.

3

🔄

Apply

Light, even pressure. Circular motion (face) or glide (underarms).

4

🚿

Rinse

Rinse crystal surface under clean water after use.

5

🌬

Air dry

Do not cap until crystal is fully dry. Min. 10 minutes uncapped.

6

✅

Cap when dry

Replace cap only when crystal is fully dry to prevent moisture trapping.

7

📦

Store correctly

Upright on drying dock (concept) or open-air. Avoid sealed pouches when wet.

Physical hygiene features

Separate surfaces

Physically separate crystal surfaces for face and body. Not a shared crystal.

Non-interchangeable caps

Different symbols, different colours, different sizes (concept). Prevents incorrect capping.

Drainage channels

Crystal seat has drainage channels to prevent water pooling at crystal base (concept).

Ventilated cap

Cap ventilation holes allow airflow when capped. Concept pending cap design finalisation.

⚠ Contamination prevention is a design intention. These features require physical prototype validation. Do not make hygiene performance claims until P3 testing is completed.

Section 9

Cap & Drying Concepts

Three cap mechanisms under evaluation. Drying dock and travel configuration concepts — none finalised.

Ventilated Snap Cap

Under evaluation

Simple tooling, low cost

Allows airflow through crown

May loosen over time

Holes could trap residue

Twist-Lock Cap

Under evaluation

More secure retention

Clear locked/unlocked feedback

Slightly higher tooling cost

User must learn twist action

Magnetic Cap

⚠ Assess before adopting

Premium feel

No mechanical failure

Corrosion risk in wet conditions

Significantly higher COGS

Magnet/alum interaction unassessed

Drying Dock Concept

Product elevated on two-post stand. Both crystal ends uncapped and exposed to air. Moisture evaporates naturally from both surfaces.

Concept stage

Travel Configuration

Both caps secured. Product stored in breathable cloth drawstring pouch — not sealed plastic. Sealed pouches trap moisture and extend crystal wet time.

Concept stage

Section 10

Refill Experience

Five-step refill sequence concept. Mechanism architecture not yet selected — quarter-turn shown corresponds to Concept A. Steps may change.

1

Crystal depleting

Crystal depth nearing minimum. Replace when <5mm remaining (provisional).

2

Unlock housing

Quarter-turn rotation unlocks mechanism (Concept A). ~30° turn required (provisional).

3

Remove module

Depleted crystal module separates from housing. Dispose or recycle responsibly.

4

Insert new refill

New crystal module slides into housing. Keyed orientation prevents incorrect insertion (concept).

5

Lock + confirm

Quarter-turn to lock. Alignment marks line up. Audible or tactile click (design goal — not validated).

Detail	Specification	Status
Unlock force	~1–2 N·m rotation (estimated)	Not tested
Click/lock feedback	Audible click + alignment marks	Not validated
Orientation markers	Keyed insert prevents rotation mismatch	Concept
Sealing on refill	O-ring or snap seal at module junction	TBD
Disposal	General waste (alum is soluble mineral)	Under review
Face + body refilled together	Concept A: yes · Concept B: independently	Depends on arch.

Refill mechanism design depends on architecture concept selected (Section 5). Quarter-turn shown corresponds to Concept A only.

Section 11

Drop & Breakage Protection

Potassium alum crystal is naturally brittle. Drop protection relies on design features — not material strength. All test results pending.

Protection design intentions

Crystal recessed within support cup (not flush with edge)
Silicone outer grip absorbs some shock on impact
Cap protects crystal surface during storage
Central grip zone positioned for secure hold
Rounded silicone perimeter reduces corner impact forces

These are design intentions. Drop resistance is NOT promised until P3 testing is completed.

Crystal risk factors

Natural alum crystal has internal cleavage planes — brittle
Wet crystal is weaker than dry crystal
Edge impacts more likely to crack than face impacts
Tile floor is worst case (hard, unforgiving)
After breakage: replacement should be quick and low-cost

Drop test matrix (to be conducted on P3 prototype)

Test	Height	Surface	Condition	Pass Criteria	Status
Drop 1	30 cm	Ceramic tile	Capped, dry	No crack	Not tested
Drop 2	30 cm	Ceramic tile	Uncapped, wet	No crack	Not tested
Drop 3	60 cm	Ceramic tile	Capped, dry	No crack	Not tested
Drop 4	60 cm	Ceramic tile	Uncapped, wet	Crack acceptable — no shattering	Not tested
Drop 5	100 cm	Ceramic tile	Capped, dry	No complete shattering	Not tested
Drop 6	30 cm	Timber floor	Capped, dry	No crack	Not tested
Drop 7	60 cm	Vinyl floor	Capped, dry	No crack	Not tested

Drop resistance is NOT promised or implied. Crystal breakage is expected at some drop heights. Replacement must be simple and low-cost. Do not market product as drop-proof.

Section 12

Materials & CMF

Colour, material and finish board. All material selections are proposals pending manufacturer confirmation.

Warm Ivory Silicone

Grade: Food-grade LSR

Finish: Matte soft-touch

Cleaning: Soap and water

Discolouration: Low risk

Wet/dry: Excellent

Recyclability: Limited

Status: Unconfirmed

Rigid PP Core

Grade: PP homopolymer

Finish: Smooth (hidden under silicone)

Cleaning: Internal — N/A

Discolouration: Low risk

Wet/dry: Excellent

Recyclability: ♻ PP Type 5

Status: Unconfirmed

Potassium Alum Crystal

Grade: Cosmetic/food grade

Finish: Natural or polished

Cleaning: Clean water only

Discolouration: Yellowing w/ metal contact

Wet/dry: Dissolves slowly in use (normal)

Recyclability: Natural mineral — safe

Status: Mfg method TBD

Cap — Forest Green (Side A)

Grade: PP or ABS

Finish: Matte semi-gloss

Cleaning: Wipe clean

Discolouration: Low risk

Wet/dry: Good

Recyclability: PP Type 5 or ABS

Status: Concept

Cap — Sage Green (Side B)

Grade: PP or ABS

Finish: Matte semi-gloss

Cleaning: Wipe clean

Discolouration: Low risk

Wet/dry: Good

Recyclability: PP Type 5 or ABS

Status: Concept

Silicone Seal Rings

Grade: Food-grade silicone

Finish: Smooth

Cleaning: Soap and water

Discolouration: Low risk

Wet/dry: Excellent

Recyclability: Limited

Status: Concept

Section 13

Prototype Generations

Five prototype stages from ergonomic clay model to manufacturer sample. All stages are planned — none started.

P0Clay

P0 — Ergonomic Clay Model

Test basic size, hand grip, and reach geometry. No functional components.

Objectives: Grip comfort · Facial reach · Underarm reach · Basic size feel
Materials: Air-dry clay or foam
Expected output: Size adjustments, grip diameter confirmation
Result: Not started

Not started No CAD required

P13D Print

P1 — 3D-Printed Appearance Model

Verify geometry, cap sizing, and standing stability. Photograph as realistic concept.

Objectives: Geometry verification · Cap size · Standing stability · Concept photography
Materials: PLA or resin 3D print, painted
Requires: CAD file
Expected output: Final geometry approval for P2
Result: Not started — awaiting CAD

Not started Requires CAD

P2Functional

P2 — Functional Mechanical Prototype

Test refill mechanism, cap retention, drainage and assembly. No real crystal yet.

Objectives: Refill mechanism · Cap retention · Water ingress · Drainage · Assembly
Materials: 3D print housing + silicone over-mould + dummy crystal inserts
Tests: 100 refill cycles · cap shake test · submersion · drainage timing
Expected output: Architecture decision + seal validation
Result: Not started — awaiting arch. selection

Not started Awaiting arch. selection

P3Crystal

P3 — Crystal-Integrated Prototype

Real potassium alum crystal in P2 housing. Tests wear, wet/dry cycling, and drop resistance.

Objectives: Crystal cracking · Wear rate · Wet/dry cycling · Drop resistance
Materials: P2 housing + real potassium alum crystal
Tests: 200 use cycles · drop matrix · hygiene surface test
Expected output: Crystal method decision · drop protection validation
Result: Not started — awaiting P2 completion

Not started Crystal method TBD

P4Mfr Sample

P4 — Manufacturer Sample

Production-intent sample from manufacturer. Full test matrix, beta testing, authentic photography.

Objectives: Material confirmation · Tooling validation · Beta user testing · Photography
Materials: Production-intent materials from selected manufacturer
Tests: Full test matrix · 20-person beta · packaging transit
Expected output: Production approval or revision list
Result: Not started — awaiting P3 + manufacturer selection

Not started Manufacturer not selected

Section 14

Testing Matrix

20 validation tests across 5 prototype stages. All results pending. Click column headers to sort.

Test ↕	Stage ↕	Method	Qty	Pass Criteria	Result	Owner ↕	Status ↕	Next Action
Grip comfort	P0	User handling	10 users	Rating >7/10	—	Founder	Not started	Commission P0
Face contact	P1	Application trial	10 users	No edge pressure complaints	—	Founder	Not started	Build P1
Underarm contact	P1	Application trial	10 users	Comfortable coverage	—	Founder	Not started	Build P1
Cap retention	P2	Inversion + shake 100×	5 units	No cap loss	—	Engineer	Awaiting arch.	Finalise architecture
Cap ventilation	P2	Humidity test 24h capped	5 units	<20% humidity inside cap	—	Engineer	Awaiting arch.	Finalise architecture
Water ingress	P2	Submersion 30s	5 units	No water in central core	—	Engineer	Awaiting arch.	Finalise architecture
Drainage	P2	Apply water, invert, observe	5 units	Full drainage <60s	—	Engineer	Awaiting arch.	Finalise architecture
Crystal cracking	P3	100 wet/dry use cycles	5 units	No structural cracks	—	Engineer	Not started	Crystal method TBD
Crystal wear rate	P3	200 cycles, measure mass	5 units	<5% mass loss/month (est.)	—	Engineer	Not started	Crystal method TBD
Refill removal	P2	50 refill cycles	3 units	<5N removal force	—	Engineer	Awaiting arch.	Finalise architecture
Refill locking	P2	50 lock cycles	3 units	Positive lock every cycle	—	Engineer	Awaiting arch.	Finalise architecture
Product stability	P1	Upright on wet tile	5 units	No tipping at 15°	—	Founder	Not started	Build P1
Silicone staining	P2	30-day water exposure	3 units	No visible discolouration	—	Engineer	Awaiting arch.	Finalise architecture
Heat exposure	P2	24h at 50°C	3 units	No distortion	—	Engineer	Awaiting arch.	Finalise architecture
Cold exposure	P2	24h at 0°C	3 units	No cracking	—	Engineer	Awaiting arch.	Finalise architecture
Wet/dry cycling	P3	100 cycles	5 units	No seal degradation	—	Engineer	Not started	Crystal method TBD
Travel durability	P2	500km vibration simulation	3 units	No internal damage	—	Engineer	Awaiting arch.	Finalise architecture
Packaging transit	P4	Drop test boxed product	10 units	No product damage	—	Mfr	Not started	Select manufacturer
Hygiene validation	P3	Microbiological surface test	5 units	Meets cosmetic hygiene guidelines	—	Lab	Not started	Protocol TBD
Customer comprehension	P4	First-use instruction test	20 users	>90% correct first use	—	Founder	Not started	Build P4

Section 15

Packaging System

Retail box, refill packaging and shipping concepts. All dimensions provisional — final packaging depends on product prototype.

Retail Box

FSC kraft board preferred. Crystal impact and moisture protection required.

Opened Box

Die-cut paper insert. Instruction card fold-out. Both caps facing outward.

Refill Packaging

Small kraft box. Indicates Side A or Side B. Crystal wrapped in tissue and protective paper.

Item	Proposed Spec	Status
Retail box dimensions	~55 × 55 × 130 mm	Provisional
Retail box material	FSC-certified kraft board preferred	Concept
Plastic window	Avoided (eco positioning)	Concept
Crystal impact protection	Die-cut paper insert, no movement in transit	TBD
Refill box dimensions	~50 × 50 × 60 mm	Provisional
Retail box weight (full)	~130 g (product + packaging)	Provisional
Shipping carton	24 units per carton (provisional)	Provisional

Final packaging dimensions depend on physical prototype. Moisture protection requirements to be tested.

Section 16

Manufacturer Handoff

Full manufacturer brief available at manufacturer-brief.html. All CAD and engineering files are pending.

📐

STEP Assembly

Full product assembly file

📋 Pending product engineer

📐

Component STEP Files

Individual component files

📋 Pending product engineer

🖨

STL Appearance Model

For 3D print visualisation

📋 Pending product engineer

📏

Dimensioned PDF Drawings

Orthographic views with dimensions

📋 Pending product engineer

💥

Exploded View PDF

Component assembly diagram

📋 Pending product engineer

🎨

CMF Specification

Colour, material, finish board

📋 Pending product engineer

📊

Bill of Materials

Full BOM spreadsheet

📋 Pending product engineer

🧪

Prototype Test Plan

P0–P4 test protocols

📋 Pending product engineer

📦

Packaging Dieline

Retail box and refill box

📋 Pending product engineer

📋

RFQ Document

Request for quotation

📋 Pending product engineer

Ready to discuss manufacturing?

View the full manufacturer brief including component list, provisional dimensions, RFQ fields, and supplier response form.

View Manufacturer Brief →

Section 17

Design Decision Log

Dated record of design decisions, alternatives considered, and rationale. Updated as decisions are made.

Ver.	Decision	Alternatives	Reason	By	Status	Cost Effect
V1	Dual-ended format	Single-ended, set of two separate products	One product for two uses — stronger value proposition	Founder	Approved	Neutral
V2	100% potassium alum only — no additives	Compressed composite with binder	Brand positioning as "one ingredient" product	Founder	Approved	TBD
V3	Separate caps for each end	Rotating housing (Concept C)	Simpler mechanism, easier to prototype, lower tooling cost	Founder	Provisional	Lower
V3	Quarter-turn refill (Concept A)	Two independent modules (Concept B)	Simpler refill experience for consumer	Founder	Under evaluation	TBD
V3	Silicone over-mould grip	All-polymer housing	Comfort, premium feel, moisture grip	Founder	Provisional	+$2–3/unit est.
V3	Forest/sage two-colour caps	Uniform single cap colour	Visual side differentiation without reading label	Founder	Provisional	Minimal
V4	Three architecture concepts under evaluation	N/A — V3 selected Concept A prematurely	Architecture was selected without engineering validation. V4 returns to open evaluation.	Founder	Current	Depends on selection

Section 18

Development Gates

Eight gates must pass in sequence before production. Progress is tracked by gate completion, not calendar dates.

⚠ Paid advertising and customer pre-orders must not launch before Gate 5 is passed.

G1

Gate 1 — Concept & Architecture Approved In progress

Brand defined · dual-surface concept validated · visual direction approved · architecture under evaluation (not yet complete)

G2

Gate 2 — CAD & Ergonomic Prototype Approved Pending

CAD files completed · P0 and P1 prototypes built · grip and geometry confirmed · final dimensions locked

G3

Gate 3 — Functional Mechanism Validated Not started

P2 prototype passes: refill mechanism · cap retention · water ingress · drainage · assembly test

G4

Gate 4 — Crystal Prototype Passes Durability Not started

P3 prototype passes: wet/dry cycling · crystal cracking · drop test · wear rate · hygiene surface test

G5

Gate 5 — Manufacturer Sample Passes Quality Review Not started

P4 manufacturer sample passes full test matrix · materials confirmed · tooling validated

G6

Gate 6 — Beta Testing Completed Not started

20+ real users test product · feedback documented · issues resolved · comprehension test passed

G7

Gate 7 — COGS, Regulatory & Claims Confirmed Not started

Unit economics locked · regulatory review completed · all marketing claims validated against test results · shipping economics confirmed

G8

Gate 8 — Production Order Approved Not started

All above gates passed · funding secured · purchase order issued to manufacturer · production begins

Current position: Gate 1 in progress

Concept approved · architecture evaluation underway · no CAD, no prototype, no manufacturer

View Manufacturer Brief Customer Website