LORD TRAINING REPORT

AUGUST 19, 2014

TRAINEE NAME: MOHAMED ABD EL MONIEM MAHMOUD

Table of Contents Manufacturing steps outlines: ..............................................................................2

Notes:.................................................................................................................2

Grinding notes: ...................................................................................................3

Mechanical maintenance notes: ...........................................................................4

Coating steps: .....................................................................................................5

Notes:.................................................................................................................6

Quality Control Notes: ........................................................................................7

Packaging Notes: ................................................................................................8

CNC workshop Notes: ........................................................................................8

Manufacturing steps outlines:

1. Coil SS strip are imported.

2. Punching of strips.

3. Assembly in coils.

4. Passing through furnaces to give the strip the required hardness for grinding.

5. Joining small coils into larger ones by welding them.

6. Printing the large coils.

7. Grinding strips to give it the required cutting edges.

8. Cutting/Separating each blade.

9. Inspection B section.

10. Heat cleaning of the blades.

11. Coating by krytox and chrome if needed.

12. Fixing the coating through heat.

13. Cutting all of the 14 & 17 and some of the 22 blades into halves.

14. Packaging.

Notes:

The thickness of the coil strip is 95 microns. It used to be 0.1 mm but it got

reduced for material saving and increasing the efficiency.

Coils are hot rolled then cold.

Stainless steels coil are used which are imported from different companies

worldwide. (Japan, Sweden, India,..) Within the required specifications.

Stainless steel type being used is martensitic SS.

Chemical composition includes a high level of chromium average 13%.

The chemical composition, mechanical property, metallurgical structure,

strip dimensions and accuracy, and many more specifications are found

exactly in the specification of lord precision industry.

The coil comes with a thin layer of oil and during manufacturing the oil is

removed and specially during the grinding process due to the presence of

water and humidity. So right precautions must be considered.

Carbon is the main constituent responsible for hardness.

Thickness variation in one blade must be less than 5 microns.

Roughness average (RA) is measured by telesafe.

Thaw is the common measuring unit used, 1 thaw = 25 microns

Primary carbides (Chromium + Carbon) are not recommended to exist in the

steel strip. Its maximum area fraction is 0.025% from the total investigated

area.

Secondary carbides (Iron + Chromium + Carbon) Should be evenly

distributed in the matrix (Homogenous) and its area fraction ranges between

12-14% of the total investigated area.

Grinding notes:

Each razor either it is 14, 17 or 22 mm, has 4 cutting edges.

Rough grinding is done first using a grind wheel having 240 particles/inch2

The abrasives particles are aluminum oxide. Which have relatively high

hardiness.

Each of the 4 edges is grinded separately during the rough grinding process

because of the bigger material removal amount. So vibrations must be kept

minimum.

The second step is the normal grinding using a grind wheel having 400

particles/inch2.

In this step 2 cutting edges are grinded simultaneously using 2 grind wheels

facing each other.

Razors are then soft grinded with the 800 particle/inch2 wheel.

Note that during each step the wheel approaches the razor with a different

angle and different amount of feed.

Angles and feed can be measured/maintained by using specific tool of

inspection.

Stropping is then done to make sure that there aren’t any unwanted

irregularities.

Final step is cutting and separating each razor to prepare it for coating.

We always use a timing belt when higher control of motion and accuracy is

needed and this appears in the normal and soft grinding step where two

grinding wheels are rotating together.

Mechanical maintenance notes:

There are two types of mechanical maintenance:

1- Repairing

2- Replacing

1st dies workshop:

Die material is widia.

The most common die problems is wear in the die edges and this defect is

removed by grinding the dies.

Also, one common problem is the failure of the die springs. In this case we

can only replace the springs.

2nd Heat treatment:

The furnace consists of 6 zones.

Temperature increases gradually from the 1st zone to the 6th zone.

1st zone: 760 ±02 ºC, 130 cm

2nd Zone: 980±20 ºC

3rd, 4th, 5th Zones: 1080+20 ºC

6th zone: 1060±20 ºC

The heat treatment purpose is to increase the hardness of the blade to the

required level for the grinding process.

And also to gain different hardness values over specific parts in the blade.

Throughout the heat treatment process the crystalline structure of the steel

changes from ferrite to austenite to martensite.

To transform from ferrite to austenite we need to reach 1000 ºC and hold for

20-25 sec.

To transform from austenite to martensite we need to reach 1080 ºC.

Strip is then passed over the separating wheels )عجل الفواصل( which uses

electricity to heat the middle section only of the blade to decrease its

hardness and make it easier for the cutting process.

Next step is the radiateur which decreases the coil temperature to 30-40 ºC

to make it enter the freezer.

Refrigerator step increases the hardness by 50 vikers which makes the final

coil hardness reaches 780 vickers. The strip reaches -70ºC temperature.

3rd Printing:

Strip is passed over the printing rolls first then it is heated and then passes in cold

rolls to fix the print.

Rolls are kept cold using water and the heating is done by flame.

Coating steps:

First, blades enter the coating laboratory after finishing the grinding and

stropping step.

Blades are sorted out to separate the damaged and the fine blades.

Chrome comes in the form of spiral coil to distribute heat uniformly

Ammonia is used to protect the strip from oxidation

Heating 250 – 350 C to remove impurities

Cooling

Chrome coating if needed

Krytox coating

Fixing the coating at 400 – 450 C

Notes:

Krytox is the liquid form of Teflon

Chromium is used to increase the blade life. (optional)

Krytox is an essential coating step, it is used to increase the shaving quality

and decrease the friction between the skin and the blade.

A thermocouple is attached to the furnace to check if it had reached the

required temperature or not.

Ammonia (NH3( is transformed first to N and H and then it is injected with

the blades to remove all oxidizing effects because the blade is very likely to

oxidize at elevated temperatures.

In case of chromium coating, coating is done under very low temperature.

Two machines are used in chromium coating SVS and CVS.

Plasma chromium coating using argon gas in done inside the machines.

Cryopump pressure reaches 10-5 torr.

Quality Control Notes:

We can specify the defects in the material by either one of two ways:

1- By measurement.

2- By naked eye.

In forming process:

There are 3 devices found on each machine to measure different dimensions in the

strip. (Pitch, distance from the center, Edge chamber).

In grinding process:

There is an inspection section after the grinding and stropping step. And this

section (Inspection section B) is the most important inspection section in the

factory.

Many tools and devices are being used in this section and as an example:

1- T10: Measures the thickness at 10μm. (800 wheel thickness) highest

deviation is 0.3

2- Poppy Force: Simulates the force which acts on the skin while shaving.

≤2.30 Kg

3- Device for measuring the angle depending on the light reflected from the

machining marks of each of the three grinding wheels.

4- Micrometer for measuring profile. The most common error is the carbides.

5- Measuring wear.

6- Device for measuring the hardness in Vickers.

Packaging Notes:

Blades are packed in solofan and it is firmly glued and packed inside it using

a specific machine.

Each 5 blades are packed into a small cartoon box and then 20 of these

boxes are fitted inside the hanger.

The hanger enters the shrink machine which packs it in plastic bag to protect

it from water or oil.

Bags are then packed inside a box and a wrapping machine wraps this box

and it is ready for transportation.

Filling defects:

1- Shortage of glue in the solofan.

2- Profile error in the solofan cover.

3- Not proper solofan cutting.

4- Absence of blades inside the cover.

5- Printing mixing. (Blade is printed Lord and cover with another print). The

worst error.

CNC workshop Notes:

There are about 11 CNC machines inside the workshop.

The purpose of these machines is to:

1- Manufacture spare machine parts for the production line.

2- Design/Redesign new machines and production lines.

Spare machine parts are either standard parts so we can buy it. Or parts that

is manufactured inside the company.

Machines history:

1- Manual

2- Semi manual

3- Automatic

4- Numerical Control (Operator writes the codes and it had no memory)

5- CNC Computer numerical control (operator only writes orders and the

machine generates the code and store it)

6- CAD/CAM CNC machines. (You design using the CAD software and

apply orders in the CAM software and the machines reads it.)

G code, T code, M code, etc. Are the languages with which the machine

takes orders.

Inside the machine program you enter tool type, material type, co-ordinates,

etc. And the machine will do the full work automatically.

Reverse engineering process used in the design section steps: الورشة المركزية

1- Disassembly of machine parts.

2- Measure the machine parts.

3- Identify the standard parts inside the machine.

4- Drawing parts with a CAD software.

5- Assembly of parts in the software.

6- Fixing errors and mistakes.

7- Printing drafts for operators.

8- Manufacturing parts and ordering standard parts.

9- Inspection.

Preparing a mold for inspection steps: (R&D department):

1- Cutting a longitudinal specimen.

2- Folding the specimen.

3- Put the specimen inside the press and fill it with the Bakelite (filler

material).

4- The press will apply pressure and heat to form the mold.

5- The mold is then grinded by 3 different grinders gradually. (240, 600, 1200)

6- This number indicates the number of adhesive particles/inch2 as this number

increases the quality of surface finish increases.

7- The mold is then polished by 5 different diamond suspensions. (9,6,3,1,0.1)

8- These numbers indicates the size of the diamond particles in microns. As

this number decreases the quality of surface finish increases.

9- The specimen is chemically etched to make the primary carbides clear for

inspection.

10- And finally the specimen is tested under the microscope and with the

help of the software primary carbides are specified.