OPERATIONS MANAGAMENT
MAN233
TUTORIAL 2
SEMESTER 2 2021
DUE DATE: 01 OCTOBER 2021
INSTRUCTIONS:
Please use the cover page which was provided to you and ensure that ALL
information is filled in correctly.
Email your submission to 3749668@myuwc.ac.za.
Subject for email: MAN 233 Tutorial Submission 2 (student number 1;
student number 2).
Only one partner needs to submit and please ensure you CC the other partner.
The contribution percentage given to you will affect the final mark you
receive. If your partner did not assist you at all, write 0% for contribution.
If your partner did half of what was expected of them write 50% and if they did all
what was expected of them write 100% etc. E.g., if partner A only contributed
50% of a mark of 80% for the tutorial = partner A will get 40% final mark.
Save your document in Word format, Ariel 12, 1.5 spacing.
Submissions must be made by 23:59 PM.
Tutorial MUST be done in your pairs. No individual submission will be accepted
without any valid reason.
No late submissions will be accepted.
If you submit more than one tutorial, only the first one will be marked.
Failure to follow the above instructions will result in a further 5% deduction
from your final mark.
Please read the following case study and answer the questions that follow:
This case study deals with condom production.
How a condom is made
Background
Condoms are thin sheaths worn by men during sexual intercourse to prevent
pregnancy and venereal infections. According to the 1995 National Survey of Family
Growth, conducted by the National Center for Health Statistics in Hyattsville, Maryland,
male condoms or prophylactics are the third most popular form of birth control—
preceded only by female sterilization (29.5%) and birth control pills (28.5%)—with
usage at 17.7%. They are also one of the most effective: research indicates that with
correct use, failure rates are 2-3%. Most condoms are made of latex rubber, but they
can also be made from lamb cecum or polyurethane.
In addition to their contraceptive value, condom use has been found effective in
preventing the spread of sexually transmitted diseases. In 1986, the U.S. Surgeon
General endorsed the use of condoms as the only currently available effective barrier
against the transmission of Acquired Immunodeficiency Syndrome (AIDS). The spread
of many other sexually transmitted diseases, such as chlamydia and gonorrhea, can
also be virtually eliminated with the use of a latex condom. With the government touting
the health benefits of condom use, manufacturers openly advertise their products, and
retailers stock condoms in visible, accessible locations. Condoms, previously kept
behind the prescription counter, are now found on most store shelves. Today in the
U.S., 450 million condoms are sold each year.
Despite the wide variety of styles, there are few differences among the many latex
condoms available on the market today. They can be straight-sided, contoured, ribbed,
sensitive, or smooth. They may be treated with lubricants or spermicides. They can be
blunt-ended or have a reservoir tip. Because the condoms undergo stringent testing
before they are sold, quality is generally not a marketable issue. Hence, manufacturers
attempt to build brand loyalty and market their products to specific target consumers.
Condoms made from lamb cecums—the blind pouch in which the intestines begin and
into which the ileum opens from one side—are also available. However, they are more
expensive than latex condoms, and while they prevent pregnancy, "skin" condoms are
ineffective in preventing the transmission of sexually transmitted diseases. In 1994,
the Food and Drug Administration (FDA) approved a polyurethane condom for sale in
the U.S. The new condom has not been extensively tested for effectiveness in
preventing pregnancy and sexually transmitted diseases.
History
The first recorded use of condoms was in Egypt in 1350 b.c. In 1564, the Italian
anatomist Fallopius described a linen condom used to prevent venereal disease. The
term condom is actually a corruption of the name of an 18th-century British physician,
Dr. John Conton, who provided condoms to France's King Charles II. The legendary
lover Giovanni Casanova (1725-1798) used pieces of sheep intestine to protect
himself against venereal disease. The first condom manufacturer in the U.S. was
Schmid Laboratories. In 1883, Julius Schmid, a former sausage skin-maker, acquired
a business that manufactured bottle seals from animal membranes.
Five years later, Schmid used his experience with sausage casings and capping skins
to manufacture prophylactic sheaths from lamb cecum.
Even as Schmid was marketing his skin condoms, technology was progressing to
allow thinner, more pliable, and less expensive condoms to became available.
Vulcanization, the chemical linking of rubber particles that was originally developed in
1839 for use in automobile tires, made condoms strong, durable, and fit for consumer
use. A form of rubber called latex was developed in the 1930s; this new material,
combined with a mechanized dipping process, facilitated the mass production of
condoms and lowered manufacturing costs.
Raw Materials
The first condoms manufactured by Julius Schmid were formed from the cecum of
lambs. As of 1990, condoms made from lamb cecum accounted for 5.5% of the
market, and because of their higher price, for 20% of retail sales. This manufacturing
process remains relatively unchanged since Schmid first manufactured condoms: the
cecums are washed, defatted, and salted. The raw skins are then shipped to the
finishing plants. New Zealand, which raises large numbers of sheep, is the primary
source and initial processing center for most "skin" condoms.
Latex condoms account for most of today's market. Because rubber latex is a natural
material, it can vary greatly in strength and elasticity. Manufacturers add chemicals to
the latex to stabilize and standardize the composition of the latex. Many brands also
add talc, lubricants, or spermicides to the condoms before they are packaged.
The manufacturing process
1. Collecting the raw materials
Rubber latex is obtained from the milky fluid produced by various tropical plants. Latex
is actually an emulsion or dispersion of tiny rubber particles in water, and ingredients
added to the latex must be able to attach to the rubber particles during compounding.
2. Compounding
Next, chemical additives are mixed to form a paste. This paste is then blended with
the liquid latex in a process called compounding.
3. Storage
The latex and chemical compound is then unloaded into drums for storage, where it
remains for approximately seven days. During this period, vulcanization chemically
strengthens the bonds of the rubber. The storage time also allows any air, which might
have been trapped in the mixture during compounding, to escape.
4. Dipping
The compound is then added to the dipping or condom-forming machine. The dipping
machine is a long, hooded machine approximately 100 feet (30.5 m) in length. Thick
tempered glass rods move along a closed belt between two circular gears. The belt
drags the rods, which are called mandrels, through a series of dips into the latex
compound. The mandrels rotate to spread the latex evenly. Several coats are required
to build the condom to its required thickness. Between each dip, the latex is hot air
dried.
5. After the final dipping and drying, the condoms automatically roll off the mandrels.
A machine shapes and trims the ring of latex at the base of each condom.
Tumbling
6. Next, the condoms are put in a tumbling machine, where they are coated with talc
or another similar powder to prevent the rubber from sticking to itself.
Testing
7. After a curing period of several days, the condoms are sampled by batch and tested
for leaks and strength. The first such test is the inflation test, in which the condom
is filled with air until it bursts. Condoms are required to stretch beyond 1.5 cubic
feet, about the size of a watermelon, before bursting. This test is considered most
important because the elasticity of the condom keeps it from tearing during
intercourse.
8. In the water-leakage test, the condom is filled with 10 ounces (300 ml) of water and
inspected for pin-sized holes by rolling it along blotter paper.
9. Condoms are also tested electronically. This involves mounting each condom on
a charged stainless steel mandrel. The mandrel is passed over by a soft,
conductive brush. If pin holes are present, a circuit will be established with the
mandrel, and the machine will automatically reject the condom.
Packaging
10. Condoms that have successfully passed these tests are rolled by a machine.
Rolling the condom makes it easier to package and use. Lubricant and spermicide
may be applied by a metering pump just before the top wrap is added in the foiling
process.
Quality control
Condoms are classified as Class II Medical Devices. According to the Medical Device
Amendments of 1976 of the FDA, the FDA is required to inspect each condom
manufacturing plant at least once every two years. All electrical and mechanical
equipment must be impeccably maintained. Condom-dipping machines are designed
to operate continuously; if they remain idle, their mechanisms can get clogged and
rust. During any downtime, partially cured compound cannot be left in the dip tank
because it could contaminate future production.
All condoms sold in the U.S. must comply to specifications that were voluntarily
developed by condom manufacturers and adopted by the FDA. Condom
measurements can range from 5.8-7.8 inches (150-200 mm) in length, 1.8-2.1 inches
(47-54 mm) in width, 0.001-0.003 inches (0.03-0.09 mm) in thickness (although most
condoms range between 0.002 and 0.0024 inches), and the weight cannot exceed
0.07 ounces (2 grams). Additionally, physical characteristics must include a minimum
tensile strength of 15,000 pounds psa and elongation before breakage of 625%.
The FDA reviews U.S. company records and spot checks batches for cracking,
molding, drying, or sticking latex. The organisation also tests every lot of imported
condoms. Upon sampling, lots will not pass inspection if they reveal greater than 4%
failure with respect to the above dimensions, 2.5% failure with respect to tensile
strength and elongation, and 0.4% failure due to leakage.
The future
Manufactured by Chicago-based Female Health Co., the Reality condom for women
has been on the market and available through family-planning clinics in the U.S. since
August 1994. It has been sold in 12 European countries since 1993. The female
condom is a long polyurethane sheath with one open ring and one closed ring that is
anchored between the women's cervix and vagina.
According to Female Health Co., these condoms are 40 times stronger than latex;
each costs approximately $3, compared to about $.64 for male latex condoms.
Research, started in 1988, lead to the development of the new polyurethane male
condom, which also went on the market in 1994. The new condom is said to be just
as strong but only one-tenth as thick as the latex condom. It is recommended for
people who are sensitive to latex condoms.
Accessed from http://www.madehow.com/Volume-2/Condom.html [1 February 2009].
QUESTIONS:
Question 1
In your own words define the term ‘process’.
[5 marks]
Question 2
In your opinion, in which ways could condom manufacturing be improved? [5marks]
Question 3
Which process type is discussed in the above case study?
Motivate your anwer, using examples
[5marks]
Question 4
Briefly explain the four (4) key process structures in the field of manufacturing
[5marks]