Question 1

What is the recommended lubrication for MPO/MTP polishing?

Accepted Answer

Water (general usage)

Fiber optic polishing fluid like Aluminum Oxide and Silicon Carbide (for better fiber height control)

Final polishing liquid like Cerium Oxide and Silicon Dioxide (for Ultra Polishing)

Avoid excessive water, as it affects pressure distribution.

Question 2

Which polishing machines are compatible with MPO/MTP polishing films?

Accepted Answer

XYT lapping films work with:

Domaille

NTT-AT / Ipolish machines

Seikoh Giken

Bulls

Hanxin

Wekon

HUXUE / KL

and more polishing machines

All standard MPO fixtures

Question 3

Are the polishing parameters the same for 12F, 24F, 16F, 32F, 48F connectors?

Accepted Answer

Generally similar, but:

Higher fiber counts require stricter geometry control

US Conec vs. Generic ferrules may need slight adjustments
XYT can provide SOPs matched to connector type and machine model.

Question 4

What size of lapping film is used for MPO/MTP polishing?

Accepted Answer

Common sizes:

127 mm (5-inch) discs for polishing machines
8.5×11 sheets for cutting custom sizes
140mm x 50 m for Automatic polishing machine

XYT can also provide pre-cut MPO film sets.

Question 5

How important is end-face geometry for MPO/MTP polishing?

Accepted Answer

Very important. Correct geometry ensures:

Low insertion loss

Stable return loss

Proper fiber-to-fiber contact

Lower risk of connector damage
Diamond films help maintain strict end-face geometry.

Question 6

What is the correct polishing sequence for MPO/MTP connectors?

Accepted Answer

Common sequence (industry standard):
D30 / SC30 / SC15 → SC9 → SC3 → SC1A → Final (CE0.5/SiO₂)
Some customers may add intermediate grades depending on ferrule type or height requirements.

Question 7

Can MPO/MTP polishing increase fiber height?

Accepted Answer

Yes. Certain films (example: SC1A, SC1B) can slightly increase fiber height if needed.
The height gain depends on:

Polishing pressure

Time

Ferrule type
Diamond films generally do not increase fiber height.

Question 8

Can lapping films be used on hard metals like carbide or hardened steel?

Accepted Answer

Yes. Diamond lapping films (6–30 µm for cutting and 1–0.5 µm for finishing) are specifically designed for very hard materials.

Question 9

Which abrasive type avoids deep scratches on softer metals?

Accepted Answer

For aluminum, brass, or copper:

Use ALO (Aluminum Oxide) instead of diamond to avoid aggressive cutting.
ALO provides a smoother, more controlled finish.

Question 10

Can lapping films improve roundness or geometry?

Accepted Answer

Yes. Using rigid-backed films (5 mil PET) with controlled pressure helps:

Correct roundness deviations

Remove surface waviness

Enhance roller uniformity
However, geometry correction is limited to surface-level adjustments.

Question 11

Which abrasive type is best for defect removal on rollers?

Accepted Answer

For deep scratches, dents, or uneven surfaces:

Diamond 30 µm or SiC 30–45 µm
Diamond is preferred for hard-coated rollers (e.g., chrome, tungsten carbide).

Question 12

How do I know when to replace a lapping film?

Accepted Answer

Replace your film when you see:

Reduced cutting speed

Visible clogging or loading

Uneven polishing marks

Scratches or debris trapped on the surface

Worn abrasive coating
Consistent replacement ensures uniform performance.

Question 13

What industries commonly use lapping films?

Accepted Answer

Lapping films are used in:

Fiber optic connector polishing (MPO/MTP/LC/SC)

Precision metal finishing

Electronics & semiconductor components

Optical glass & lens manufacturing

Hard disk & magnetic head polishing

Medical device finishing

Aerospace components

Automotive precision parts

Question 14

Can I order custom-sized lapping films?

Accepted Answer

Yes. XYT offers custom:

Sheet sizes (any dimension)

Disc diameters

Roll width and length

Micron sizes and abrasive types

Private label packaging

Question 15

How long does lapping film last?

Accepted Answer

Film lifetime varies by:

Abrasive type

Pressure and polishing speed

Workpiece material

Coolant or lubrication
Diamond films typically last longest, followed by ALO and SiC.
Final polishing films (CE, SiO₂) may last several cycles depending on workload.

Question 16

What surface roughness (Ra) can lapping films achieve?

Accepted Answer

Depending on the micron grade:

30–15 µm: Ra 0.3–0.6 µm

9–6 µm: Ra 0.1–0.2 µm

3–1 µm: Ra 0.03–0.1 µm

0.5 µm: Ra < 0.02 µm

0.1 µm: Mirror finish Ra < 0.01 µm

Actual results depend on material hardness and machine parameters.

Question 17

How do I prevent contamination during polishing?

Accepted Answer

To avoid scratches and inconsistent surfaces:

Store films in sealed bags

Keep polishing plates clean

Use lint-free wipes

Handle films by the edges

Do not touch the abrasive surface with bare hands

Question 18

Are lapping films compatible with coolant or water?

Accepted Answer

Most films can be used with:

Water

Polishing lubricants

Slurries (depending on the abrasive type)
Diamond and ALO films are typically water-friendly, but CE (cerium) films perform best with glass polishing fluid.

Question 19

Do lapping films produce consistent results?

Accepted Answer

Yes—precision films are engineered with:

Uniform abrasive particle size

Controlled coating thickness

Even distribution across the entire surface
This ensures predictable performance and repeatable surface finish.

Question 20

Can lapping film be used for manual polishing?

Accepted Answer

Yes. Lapping film works with both manual polishing blocks and automatic polishing machines.
For manual use, films with more flexible backing (3 mil or 5 mil PET) are preferred to maintain consistent pressure.

Question 21

What is the difference between diamond, SiC, and aluminum oxide lapping films?

Accepted Answer

Diamond: Highest hardness, fastest cut rate, ideal for ceramics, glass, ferrules, and hard metals.

Silicon Carbide (SiC): Sharp and fast, suitable for softer metals and plastics.

Aluminum Oxide (ALO): Durable and economical, excellent for general metal polishing and intermediate steps.

Question 22

What is the difference between lapping film backing types?

Accepted Answer

PSA (Pressure-Sensitive Adhesive): Peel-and-stick backing for secure bonding.

Non-PSA / Plain: For reusable polishing plates with slurry or carrier film.

3-mil or 5-mil PET backing: Adjusts flexibility and rigidity for different applications.

Question 23

Can lapping film be used for MPO/MTP fiber optic polishing?

Accepted Answer

Yes. Lapping film is essential for multi-fiber connector polishing.
Typical film sequence: 30 µm or 15 µm → 9 µm → 3 µm → 1 µm → CE0.5
Specialty films may be added depending on connector type, ferrule height requirements, or customer standards.

Question 24

What sizes are available?

Accepted Answer

XYT lapping films are offered in:

Sheets: 4"×6", 6"×6", 8.5"×11", custom sizes

Discs: 3", 4", 5", 6", 8", custom diameters

Rolls: 114 mm × 50 m / 305 mm × 50 m / customized length

Question 25

What is the typical lifetime of a lapping film?

Accepted Answer

Film life depends on abrasive type, pressure, and workpiece hardness.
General guidelines:

Diamond films: longer life, stable cut

SiC and ALO: economical, shorter life

Final glass polishing film (CE): multiple uses depending on load & slurry

Question 26

Can lapping film be reused?

Accepted Answer

Diamond films: Often reusable if cleaned properly.

SiC/ALO films: Generally single-use for consistent quality.

CE films: Can be reused until cut rate or finish degrades.
Always evaluate under microscope for scratches or loading.

Question 27

What equipment is lapping film compatible with?

Accepted Answer

Fiber optic polishing machines (NTT, Seikoh Giken, Domaille, KL-300, etc.)

Automated lapping tools

Hand lapping stations

Precision polishing machines for metal, ceramic, or semiconductor parts

Question 28

How should lapping film be stored?

Accepted Answer

Store in a clean, dry environment away from:

Dust contamination

Direct sunlight

Excess humidity

Strong chemicals
Keep films flat to avoid wrinkles that affect polishing results.

Question 29

Do you offer custom micron sizes or specialized grades?

Accepted Answer

Yes. XYT can produce:

Custom micron ranges

Modified coating weights

Special high-cut diamond grades

Ultra-uniform films for semiconductor and optical applications

OEM private label packaging

Question 30

What industries use lapping film?

Accepted Answer

Fiber Optics (MPO/MTP/LC/SC polishing)

Optical glass processing

Semiconductor wafer edge polishing

Hard disk & precision metal finishing

Automotive & aerospace components

Medical device polishing

Question 31

How do I choose the right micron size for industrial polishing (Rollers / Metal parts)?

Accepted Answer

Choosing the correct micron size depends on your required surface finish, material hardness, and whether you are doing stock removal, intermediate polishing, or final finishing.
Below is a general guideline widely used in industrial metal and roller polishing workflows.

Micron Size Selection Guide
1. Heavy Stock Removal (Defect Removal / Geometry Correction)

Use 30–15 µm

Removes deep scratches, wear marks, or surface distortion

Suitable for hard metals, tool steel, stainless steel, and coated rollers

Common products: Diamond 30 µm, SiC 30 µm, ALO 30 µm

2. Intermediate Polishing (Surface Refinement)

Use 12–9–6 µm

Smooths the surface after coarse polishing

Reduces visible scratch patterns

Essential before moving to fine finishing

Common choices: Diamond 9 µm / 6 µm

3. Fine Polishing (Pre-Final Finish)

Use 3–1 µm

Produces a uniform, satin-to-semi-mirror surface

Removes micro-scratches left by intermediate grades

Great for precision metal components and plating preparation

Question 32

Short Summary

Accepted Answer

Polishing Stage	Micron Size	Purpose
Coarse	30–15 µm	Heavy removal, defect elimination
Medium	12–6 µm	Scratch reduction, surface leveling
Fine	3–1 µm	Pre-finish smoothing
Final	0.5–0.1 µm	Mirror finish, low Ra

Question 33

How to choose the correct micron size for Industrial polishing?

Accepted Answer

Ask yourself:

1. What is the current condition of the surface?

Deep scratches? → Start with 30–45 µm

Light marks only? → Start with 9–6 µm

2. What finish do you need?

Functional finish (Ra 0.1–0.2 µm) → End at 1 µm

Mirror finish (Ra < 0.05 µm) → End at 0.5 µm or 0.1 µm

3. What is the material hardness?

Hard metals (Steel, Carbide): Prefer Diamond

Soft metals (Aluminum, Copper): Prefer ALO or SiC to avoid deep scratches

Question 34

Suggested Polishing Sequence for Metal / Rollers?

Accepted Answer

A typical industrial metal polishing workflow looks like:

30 µm → 9 µm → 3 µm → 1 µm → 0.5 µm

For extremely hard materials (tungsten carbide / hardened steel):
45 µm → 15 µm → 6 µm → 1 µm → 0.25 µm

For softer metals (aluminum / brass):
20 µm → 9 µm → 3 µm → 0.5 µm

Question 35

How do I choose the right micron size for fiber optics LC SC FC ST MU MT MTP MPO?

Accepted Answer

The micron size determines how much material is removed:

30–15 µm: Heavy stock removal, shaping, or defect removal.

12–6 µm: Mid-range polishing and geometry correction.

3–1 µm: Fine polishing and pre-final finishing.

0.5–0.02 µm: Final finishing, scratch removal, mirror surface.

Question 36

What materials are used in lapping films?

Accepted Answer

Lapping films are made using precision-graded abrasive minerals coated onto a high-strength polyester (PET) backing. The most common abrasive materials include:

1. Diamond (D)

The hardest and most efficient cutting abrasive

Ideal for glass, ceramic, carbide, sapphire, ferrules, and fiber optic connectors

Available in micron sizes from 0.1 µm to 60 µm

2. Silicon Carbide (SiC)

Sharp, fast-cutting abrasive

Best for softer metals, plastics, and general stock removal

Common in 15–80 µm grades

3. Aluminum Oxide (ALO / AO)

Durable, cost-effective abrasive for metals, plastics, precision parts

Used for mid- and fine-polishing

Available from 1–30 µm

4. Cerium Oxide (CeO₂ / CE)

Specialized abrasive for optical glass and fiber optic final polishing

Used in sub-micron grades (0.3–0.5 µm)

5. Silicon Dioxide (SiO₂) / Final Polishing Film

Ultra-fine abrasive for super-smooth finishing

Used in the final step of optical and precision surface polishing

Question 37

What is lapping film?

Accepted Answer

Lapping film is a precision-coated abrasive film used to achieve controlled material removal and fine surface finishing. It provides consistent particle distribution, predictable cut rate, and stable surface quality across optical, electronic, metal, and industrial applications.

Film/Slurry	Micron	Pad	Comments
SiC or Diamond	15–30 µm	Glass / Hard	Rapid removal of epoxy and surface peaks
✔ Polish ~30–60 sec; low speed
Explanation: This step clears epoxy flash and begins shaping the ferrule surface for subsequent geometry control. Lapping Film

Film	Micron	Pad	Comments
SiC or Diamond	9–3 µm	Glass	Establish smooth geometry
Aluminum Oxide	3–1 µm	Glass	Refine geometry
Explanation: Intermediate grit progression smooths transitional scratches and improves uniformity. Lapping Film

Film/Slurry	Micron	Pad	Comments
Diamond / SiC / Alumina	1 µm	Glass	Prepares surface for final polish
Explanation: A fine pre‑polish step reduces roughness and minimizes defects before final finishing. Lapping Film

Media	Micron	Pad	Comments
Silicon Dioxide (SiO₂) or Cerium Oxide (CeO₂) slurry/film	Sub‑micron (0.3–0.05 µm)	Glass/Pad	Final high quality endface finish
Explanation: Final ultra‑fine sub‑micron abrasives produce the smoothest surfaces and best optical performance (low IL, high RL). Lapping Film+1

Production‑Ready MTP® / MPO Ferrule Polishing SOP

(Compliant with IEC 61755 / Telcordia GR‑326 standards)

1. Purpose

2. Equipment & Consumables

3. Safety & Cleanliness

4. Standard Polishing Sequence – Multi‑Step Workflow

Step 1 – Epoxy Removal & Pre‑Geometry

Step 2 – Geometry Shaping & Fiber Height Control

Step 3 – Fine Pre‑Polish

Step 4 – Final Optical Polish

5. Process Parameters

6. Inspection & Criteria

7. Notes & Tips (Industry Practice)

8. Summary: Recommended Grit Progression

Key Takeaways