Laundry Detergent Tablets - Sepawa

Laundry Detergent Tablets
SEPAWA Norden
Göteborg 13-14 May
2002

Patent Search

35
30
25
20
15
10
5
0
Field Patents
Nr. of Patents
1976-1980 1981-1985 1986-1990 1991-1995 1996-2002

History
• 60’s Tablets introduced in the north
American market – discontinued in
1978. (Savo by P&G)
• Re-launched in Europe by Unilever in
1998
• Been sold in Spain since the mid-80’s

” What's not likely to catch on with U.S.
consumers, though, is washing tablets. While
their popularity is growing in Europe, no major
marketer here plans to roll them out,
especially considering that previous attempts
have failed miserably, several marketers said.
Furthermore, tablets require that they be
placed in a bag. Other product forms include
washing gel, introduced in Europe, but there is
little discussions about a possible U.S.
introduction.”
Happi magazine cover story January 2000

History
• September 2000 P&G introduced Tided
Tablets
• January 2001 Lever launched Wisk Tablets
• March 2001 Purex tablets by Dial Corp.
• By summer 2001 tablets reportedly
achieved nearly 10% market share in the
U.S - REVOLUTION

90
80
70
60
50
40
30
20
10
0
Market Trends
Eropean laundry market (%)
1998 2000 2001
Powder
Liquid
Other

Compaction and Dissolution
Strong enough to withstand handling and
transport
Vs.
Should be readily dissolved and
dispersed

•Use of a binder
Remedy
• Coating the tablet
• Use of disintegrants
• Avoiding gel formation

Binder
• Helps holding the tablet together -
lower compact pressure
Example: PEG1500

Coating
• Increased surface hardness
•Improved aesthetics
• Applied as melt or solution
• Improved hydrophobicity
• Should include a disintegrant

• Four classes
Disintegrants
– (i) cause disintegration by evolving gas, such as sodium
bicarbonate in the presence of citric acid or tartaric acid
– (ii) those which promote water absorption, such as
starch, colloidal silicon dioxide, carbocymethyl cellulose
and rice starch
– (iii) those which swell, for example crossed linked
polyacrylic acids, cross linked gum arabic, carboxymethyl
cellulose
– (iv) those which increase porosity such as potato and
corn starch, an finally those which undergo
physiochemical bonding such as cellulose and kaolin.

Disintegrants
Used in combination
– Same class: swellable cellulose and
polyacrylic acids
– Different classes: swellable polyacrylic
acid with water transporting colloidal
silica.

Disintegrants
Highly water soluble salts
Material Water solubility
(g/l)
Sodium citrate dihydrat 720
Potassium carbonate 1120
Urea >1000
Sodium acetat, anhydrous 1190
Sodium acetat, trihydrat 760
Magnesium sulphate, heptahydrat 710
Potassium acetat >2000

Avoiding Gel Formation
• Acute when using spray-dried
powders, surfactant evenly
distributed in tablet.
• Better to keep the anionic surfactant
in discrete regions.

Tower vs. Non-tower
• Tower process
powders
– Involves drying
– Homogeneous product – no segregation
problems
• Non-tower process
– Dry blend, post addition, no drying
– Heterogeneous product – segregation
problems

Tablets
• Compressed in to a single element –
segregation can not occur.
• Preferably produced by dry blending
• No drying necessary – cost efficient

The Future
• Tablets have settled at 10-15% market
share
• Market characterized by ever-new
products
• Tablets give formulation freedom
• Platform for new products