Last updated 8 August 01

Musing With Sin – Year 2001

[Disclaimer]

Due to the number of illustrations, it could take a few minutes to download them all. Please be patient.

[Jan 01] [Feb 01] [Mar 01] [Apr 01] [May 01] [Jun 01]

[Jul 01] [Aug 01] [Sept 01] [Oct 01] [Nov 01] [Dec 01]

[Musing With Sin – Year 2000, Item 1-75]

“Beauty without grace is like a bait without a fish” – Emerson

A main-bar kaki of mine recently commented that Asians are generally not high on the score with respect to “graciousness”. This came after the Penang State annual awards. Rather than congratulate and address our new Datuks, we tend still to call them by their nick-names.

Sin Rubtech™ is a vendor of polymer bound predispersed chemicals. Under ISO 9000 requirements, bless ISO, our users need to audit us on a periodic basis. Everybody needs some form of encouragement to strive for continuous improvement and excellence. We are very pleased and encouraged by some of these ISO audit reports, two of which are reproduced here.

110. Soft-Feel Elastomeric Products

We are familiar with soft toys made of microcellular/ sponge formulations. However solid elastomeric products of Shore A < 30 are not easy to formulate and process as people like K.S.Lim (Kossan) and I can well appreciate years back trying to make oil-resistant NBR printer rollers.

It was therefore quite refreshing to listen to a paper by S.M.Leong & Sam Angove at the PRIM AGM Seminar 28^th July 2001 pointing out that TPE manufacturers like GLS Corporation can now offer “extremely soft” easy to process thermoplastic elastomers Dynaflex^® TPE’s with Shore A < 10 and they have products to prove it. Examples are:

Gillette^® Mach 3 Triple Blade Razor

Questech “Too Hot™” Infant Feeding Spoon

Mattel toys

Etc.

Again the oft repeated advice:

“Find A Niche Market Need, Go And Fill It”

109. Rubbers, Elastomers, Thermoplastic Elastomers, Thermoplastic Olefins, Thermoplastic Vulcanisates and Melt Processable Rubbers.

Life is getting more confusing to this senior rubber man brought up amongst Hevea brasiliensis trees. In the old days a rubbery material like NR means that the rubber vulcanisate can be stretched to about 3X its length and upon release of its stress, it will rapidly return to its original length. The NR vulcanisate can behave rubbery even when tested at sub-zero or up to 170^OC. We can accept the rubbery behaviour of some 15 classes of synthetic rubbers. Then the plastic boys got into the act with initially thermoplastic elastomers that can exhibit rubbery behaviour at room temperature and up to about 70^OC service temperature. They can’t really call these materials thermoplastic rubbers, elastomers are more acceptable, as they are not really rubbery materials. However today there are thermoplastic elastomers with service temperatures of ~170^OC and polymer chemists have combined rubber and plastic monomers/ polymers using various processes and tweaked them to suit various applications. We have a vast array of such thermoplastic elastomers today with so many combinations that I think they are running out of abbreviations and some of these can behave differently depending on their manufacturing process and hence trade-names are often necessary to differentiate them. Readers are alerted to some of these relatively new thermoplastic elastomers which are making rapid in-roads into traditional rubbery niche markets.

	Abbrev.	Tradename	Company
Thermoplastic Elastomers (TPE)	SBS SEBS SEP SEB	Kraton* Steoron Europrene	Shell Firestone Eurochem
	* Now sold to Ripplewood Holdings USA

Thermoplastic Polyolefin Elastomers (TPO)	--- POP POE	Cattalog^® Affinity^® Attane Engage^®	Montell Dow Dupont

Thermoplastic Polyurethane Elastomers (TPU)	TEEE	Elastollan^® Pellethane^® Bayflex^® Texin^® Morthane^® Hytrel^® Riteflex^® Arnitel^®	BASF Dow Bayer Bayer Morton Dupont Ticana DSM

Thermoplastic Polyamide Elastomers (TPE)	PEBA	Pebax^®	Elf Atochem
Melt Processable Rubber (MPR)		Acrylyn^®	Advanced Polymer Alloys

Thermoplastic Vulcanisate Elastomers (TPV)		Santoprene^® Geolast^® Trefsin^®	AES AEI AES

All above have been developed for niche commercial markets. I hope NR chemists can do more of tweaking NR-based grades for the speciality thermoplastic elastomeric markets rather to be content at its present low price as the single largest market share elastomer and the oldest general purpose elastomer.

Abbreviations Used

SBS - Styrene butadiene

SEBS - Styrene ethylene/ butylene styrene

SEP - Styrene ethylene propylene

SEB - Styrene ethylene butylene

POP - Polyolefin Plastomers

POE - Polyolefin Elastomers

TEEE - Thermoplastic etherester elastomers

PEBA - Polyether block amides

108. Mullin’s Effect, Payne Effect, Joule Effect etc.

Whenever we tried to explain the importance of good dispersion and distribution of curatives in any formulation, we are invariably drawn to comparative examples of carbon blacks and silicas more familiar to rubber technicians and which can help us to explain the equal importance of good dispersion/ distribution of curatives. Rubber technicians can readily accept that the full effect of a reinforcing filler can only be realised if its surface is thoroughly wetted by the polymer in which it is dispersed and distributed. For example in a poorly dispersed tread formulations, rubber technicians can see lower tensile strength, higher Akron Abrasion loss and Goodrich Heat Build-Up (HBU).

Considerable R&D work has been done over the past 50 years on the dynamic properties of rubber and there are theories that can explain the effects of reinforcing fillers and their wetting etc. on dynamic properties. Some of the terms used are not so familiar with younger rubber technicians.

Most of us should be familiar with the “Mullin’s Effects” first published in 1950¹. this refers to stress softening of gum or filled vulcanisates, (Fig.1). When rubber vulcanisates are stretched and then allowed to retract subsequent extensions to the same strain require a lower force. This is more pronounced in carbon black or silica filled vulcanisates than gum vulcanisates.

The dynamic properties of filled vulcanisates are more difficult to unravel and in the late 1970’s, Medalia’s² review of past R&D work especially his explanation of the contributions to the dynamic complex modulus G^* versus strain has stood the test of time.

We can all accept that polymer network i.e. cross-linked polymeric structure contributes to G^*, the higher the cross-link density the higher G^* and this independent of strain.

The “hydrodynamic or hydrodynamic-occlusion effect” is due to dilution of the rubber by the filler particles. If the filler particles are perfectly spherical such as glass beads or lamp blacks, then the resulting increase in elastic modulus is partially accounted for by Einstein’s equation:

E = E_o(1+1.25C+14.1C²);

where

E = modulus of filled elastomer

E_o = modulus of gum elastomer

C = volume fraction of filler

However highly structured carbon blacks such as N110, N121, N220, N234, etc. and precipitated silicas produced modulii larger than predicted by Einstein’s equation. This increase is partially due to rubber filling of the voids in the carbon black/ silica structures. The rubber occluded in these voids is shielded from any imposed deformation/ strain with the net result that the total rubber volume available for deformation is reduced i.e. as if volume fraction of filler is increased in formulation. This occlusion together with the dilution effect predicted from the Einstein equation means an increase in elastic modulus.

The “Paynes Effect” has only been introduced in recent publications. This refers to stress softening of filler vulcanisates at small deformations as example in the flexing of an automobile tyre. In 1971, Payne³ first studied the variation in dynamic modulus G^* with strain amplitude in phenyl-b-naphthylamine (PBN) loaded natural rubber which can form a crystalline network with the rubber, and he noted that both the low amplitude G^* and variation of G^* with amplitude closely resembled those of carbon blacks. Payne postulated then that the carbon black filler structure disrupted or broken by strain can explain both high modulii at low strain and the decline in modulus as the strain increases. Over the years this was confirmed by various researchers now with more sophisticated instrumentations like the RPA or MDR2000 to elucidate for example the “Payne Effect” (filler- filler interaction) as well as silica-silane coupling to the polymer main chain or the so-called “In-Rubber Structure⁴” (polymer-filler interaction) this being independent of strain.

Text Box: Source of Heat Energy The “Joule Effect” was discovered in 1859⁵. Joule noted that if a vulcanised rubber strip was fixed to a support at one end and was elongated by suspending weight at its other end, a sudden introduction of surface heat to the rubber sample caused the sample to retract. This thermal phenomena is called the “Joule Effect”. Wiegand W.B in 1925 made his Wiegand Pendulum which demonstrates so dramatically the Joule Effect and to students of thermodynamics, an almost perpetual machine if your ignore the heat source.

References

1.	Mullins, L	(1950)	:	J.Phys.Chem. 54, 239
2.	Payne, A.R & Whittaker, R.E.	(1971)	:	Low strain dynamic properties of filled rubbers. Rubb.Chem.Technol. 44, 440
3.	Medalia, A.I.	(1978)	:	Rubber Chem. and Technol., 51, p. 437
4.	Frolich, J. & Luginsland, H.D.	(2001)	:	RPA – Studies into the silica/ silane system. Rubber World, Vol. 224, No. 1 April.
5.	Dr. Jean Le Bras	(1957)	:	Rubber – Fundamentals of its science and technology – p. 96-97

107. Hardness Meter – Digitised

We are familiar with bench-top as well as portable durometers used to measure rubber hardness and specified in ASTM D2240, D531 and D1415. Because of tradition we are very familiar with durometers from Shore Instrument & Manufacturing Co., examples Shore A for normal rubbers, Shore D for hard rubbers and Shore C for soft rubbers and sponge/ microcellular products. It has recently been pointed out that durometers made from non-Shore companies should not be called Shore A but rather Durometer A or their proprietary names. Digital durometers like the Instron SI are a boon to laboratories fanatic on traceable results and not subject to the rubber technician’s sometimes off-day’s written records.

106. Sin Rubtech™ Testing Equipment

We have a comprehensive range to offer at very affordable prices.

The MDR2000DG rotor-less rheometer pictured here illustrates.

Indicative Prices:

Computerised Rheometer MDR2000DG: FOB USD14,500

Computerised Mooney Viscometer: MN200DG: FOB USD12,500

The MN200DG can be viewed at our laboratory.

105. High-Tech Shoes

We know that polymers are getting a lot of publicity in new automotive uses, medical products and even Nobel winning R&D wok on Polymeric LED TV/ PC screens (Items 74 & 79). I am glad that my interest in high-tech athletic shoes (Item 94) is also shared by Lev Grossman “Living Digital” Time, June 18, 2001, which illustrated 9 shoes ranging from the Velcro-free and lace-free Nike Air Resto Faze ultimate running shoe to Reebok’s Start Train DMX fitness shoe featuring a built-in computer chip with speedometer, odometer and calorie counter and the Street Flyers skating shoes with retractable wheels.

Who says the rubber industry is a sunset industry? In this E-Economy & K-Economy, Reebok has made a fitness shoe digital.

104. Foam Science is a Gas

Having just completed our Technical Bulletin #14 on the Art & Science of microcellular rubber products manufacture, I was rather tickled that a Sidney Perkowitz* actually wrote about - Universal Foams – anything with foams, froth and bubbles ranging from ice creams, foam mattresses and could possibly extend to our dear Dr. Jaspar’s famous soft naans (that go with his Tandoori Chickens next to our watering hole) with his secret blowing agent. Apparently we gather that we still can’t nail down exactly how and why a liquid foam structure behaves as they do. The rubber industry is not alone – in many other fields art has preceded science. *Publd by Vintage UK. ISBN: 0-099-28656

103. Amine Silane Cure System for Epoxidised NR (ENR)

The use of 3-aminopropyltriethoxysilane (OSI A1100) (See our Short Notes #5) with a catalyst such as an aromatic dihydroxy compound Bisphenol A, the 4,4’ isopropylidene bisphenol, in a joint paper by Dr. Azanam S Hashim – USM* caught my attention. Readers are aware that most ENRs are sulphur cured. The amino silane cure is through epoxy group ring opening. The rather long cure time ~ 30’/180^OC needed may limit the commercial exploitation of this cure system.

* Azanam, S. H et al (1995) : Silica Reinforcement of Epoxidised Natural Rubber by the Sol-Gel Method. Journal of Sol-Gel Science and Technology, 5, 211-218.

102. Grubbs’ Catalyst: A Vulcanising Agent

We are familiar with the use of the unsaturated diene: dicyclopentadiene (DCPD) used in EPDM to make it sulphur curable. A group of scientists at University of Illinois has mixed in microcapsules of DCPD in their epoxy compounds containing a ruthenium alkylidene catalyst known as Grubbs’ catalyst such that as the epoxy surface cracks, the stress breaks the DCPD capsules which are then crosslinked in minutes at ambient temperatures when in contact with Grubbs’ catalyst – thus self-repairing the epoxy material. A possible RTV repair putty!

Ref: Chemistry in Britain. April 2001: Polymers that heal naturally.

101. Made-in-Malaysia Dehumidifiers

Having just talked about molecular sieve desiccants (Item 93), I was pleasantly surprised to learn that there is a factory Bry-Air Malaysia in Bangi, Selangor already manufacturing/ assembling dehumidifying dryers, desiccant dehumidifiers, heat recovery systems, energy saving ventilators, treated fresh-air units and the latest product, a rotor-based mould dehumidifying system to eliminate mould sweating, a big problem in injection/ blow moulding machineries.

100. Centennial

A “centum” (latin) always invoke something special. Companies which survived 100 years history are revered. Presidents and Prime Ministers are assessed after only 100 days in office.

The 100^th item in our “Musing With Sin” is reached after 1½ years or 548 days after the launching of our website on 1^st Jan 2000 and after 2486 hits. What are my thoughts? Have I met the objectives set out in my “Introduction”? I would like to take this occasion to crystallise some thoughts from our previous 99 Items.

· Albert Einstein “ If A is a success in life, then A equals X-Plus-Y-Plus-Z. Work is X; Y is play; and Z is keeping your mouth shut”

I certainly am not one to agree on the Z component. Communications are vital to success

· Communications – IT, E-Economy & K-Economy

I still believe in Ralph Larsen famous saying in Item 63:

“ All the successes you see come because of strong business-line ownership, not IT ownership. Business-line ownership with strong IT support.”

However this may mean different things to different persons. Believe me, a lot of people are very confused when learned writers try to compartmentise things under E-Economy, K-Economy or dot.com companies. Even Ralph Larsen’s saying is not strictly correct as I know of no IT ownership which does not have business-line objectives. What Ralph Larsen implies is that IT + Production (P) Economy has a better chance of success as evidenced by his own Johnson & Johnson, Baxter etc. selling their products On-Line to American hospitals. This brings is to knowledge-driven or K-Economy. It is naïve to think that companies like Johnson & Johnson etc. with strong R&D, creativity, innovations, intellectual properties etc. cannot adopt IT and E-Economy themselves to enhance their productivity/ efficiency.

IT and E-Economy simply means that we now have the means to gather, store, analyse, retrieve and communicate information at the speed of electrons. Whether it is in the service or production sector, it means enhancement of productivity/ efficiency. The present USA leadership as the No. 1 economic power is a window to the power of IT & E-Economy in enhancing their competitiveness through productivity/ efficiency enhancements.

I can illustrate one Sin Rubtech example. I came back from an ASEAN country with an ultramarine blue masterbatch suspect problem. Took us 2 days to do the lab work, an hour to write up the report, 5 seconds to take a picture of the colour sample with our digital camera and seconds to send these through the Internet/ email to my customer. This would have not been possible without IT + E-Economy. However having IT + E-Economy, but you cannot solve the problem means zero, hence K-Economy comes into play.

· Productivity/ Efficiency Enhancement

I have lamented in Item 82 that it is no easy task trying to sell Product X which can reduce bottom-line costing by productivity/ efficiency enhancement. Fortunately we have many successes with our polymer bound predispersed chemicals. (PBPCs)

We have assisted a retread compounder to enhance their productivity by 100%. Same goes for many footwear factories (Items 83, 87 & 94). We have already reduced rejects or enhanced efficiencies in a transfer moulding operations by switching over to our PBPC curatives, compounders switching over to our polymer bound PEPTSIN S, compounders with poor insoluble S dispersion problems especially in polar + non-polar elastomeric blends (Item 31), enhanced efficiencies in using our PBPC form curatives, blowing agent, ZnO and TiO2 (Items 59 & 89) in microcellular products manufacture and many other examples.

What all this means is that PBPCs is a Sustainable 21^st Century Technology.

Finally, this Centennial has given Sin Rubtech much satisfaction and we wish our valued customers and potential customers the same.

I look forward to our “Millennial” or 1000^th Item.

99. Peroxides

Rubber technicians in NR producing countries are paying more attention to synthetics and the use of peroxide cure systems. Now peroxides have jaw-breaking chemical names and surprisingly manufacturers in the past have only coined the abbreviation, DCP, for dicumyl peroxide and we can easily identify Vanderbilts’ Varox DCP-40 MB, Sin Rubtech™ DCP-40G and Hercules Di-Cup T & Di Cup R. For others it is tough to convince purchasers that Akzo’s Trigonox 17-40 Bpd can be replaced by Vanderbilts’ Varox 230XL. It is refreshing to find that Laporte Speciality Organics Division (Degussa has recently taken over UK-based Laporte) Product Selector Issue 2 August 1999 has given abbreviations for all their organic peroxides. We do not agree that their DCup abbreviation should be used for DCP. Anyway, we have revised our Short Notes #11 with abbreviations for all the peroxides cited. It is timely the industry comes to terms on abbreviations for peroxides.

98. High Cis 1,4 Polybutadiene: Sin Rubtech™ BR9000

Yes, Sin Rubtech™ is also involved in synthetic rubbers, rubber machineries and test equipment besides polymer bound predispersed chemicals. High Cis 1,4 Polybutadiene rubbers (BR) were first introduced in the late 1950’s using Ziegler-Natta (Z.N.) type catalysts. Today high Cis BR’s ( > 90% Cis 1,4) are offered by several companies. The better known ones are:

Producer	Trade Name	% Cis	Catalyst Type
Bayer	Buna CB22 Buna CB 11 Taktene 1203	97 92 96	Nd Ti Co
JSR	JSR	~ 96	Ni
Nippon Zeon	Nipol	~ 96	Co
Kumho	Kosyn	96	Ni
TSR	Taipol	~ 96	Co
UBE	Ubepol	~ 98	Nd
Enichem	Europene Cis Neocis	92 98	Ti Nd

Goodyear	Budene 1208	98	Co
ASR	Cisdene	High	ZN
BYPC	Yanshan BR9000	96	Ni

Our BR9000 is a solution polymerised Cis 1,4 Polybutadiene using an aliphatic solvent (paraffins) and a carboxylic nickel (Ni), alkyl aluminium (Al), boron halide ether complex and a polar chemical compound. The rubber is almost water white i.e. clear transparent and consistently so because the polymerisation technology used is such that the reactor vessel does not foul-up for at least 1½ years use.

For footwear, tyres and retread compounding we have often been asked, what is the difference between 96% Cis and the 98% Cis BR’s with respect to wear resistance, skid resistance and rolling resistance or heat build-up properties. In pure 100PHR BR formulations, you may be able to detect slightly better tensile, tear, wear and resilience but not skid resistance for the 98% Cis BR’s, but in practical blend formulations, it is difficult to discern any difference between 96% & 98% Cis BR’s. We have had 10 years experience using BR 9000.

97. Bloom in Chocolates!

Rubber technicians can take solace that bloom problems (See our Short Notes #3) are not confined only to the rubber industry. Chocolates bloom when tiny crystals that can reflect light giving it a glossy appearance melts and on recooling the fat crystallises and the crystal uncontrolled growth reaches a size that can diffuse the reflection of light from the surface and gives it a dull appearance or bloom. Chocolate manufacturers try to prevent this by a tempering process, cooling down from 45^OC to 27^OC and raising the temperature again to 30^OC which ensures that the fat crystallises in a thermodynamically stable crystal form. But then exposing a bar of chocolate in a hot car and then cooling it down again with the air-con one can easily upset fat crystal thermodynamics. Apparently a long lasting chocolate that remains glossy on storage has yet to be discovered.

96. The TPES, TPVS & MPRS Factor

We have touched on the plight of the NR industry and the prolonged depressed prices such that today a kg of NR cannot even buy me a mug of beer at my watering hole. I have hinted that perhaps it is due to an oversupply of NR and we should try to balance the supply and demand situation. However lately, studying the statistics of total elastomers production and consumption for Year 2000, it just struck me how much progress the elastomeric thermoplastic elastomers (TPEs), thermoplastic vulcanisates (TPVs) and melt processable rubbers (MPRs) have made since 1950’s. The International Rubber Study Group IRSG revealed that for Year 2000, total elastomeric market was 17.8m MT with synthetic rubbers accounting for 10.5m MT and NR at 6.3m MT. Simple arithmetics show that for Year 2000, TPEs+TPVs+MPRs must have accounted for 1m MT. Now statistics can be confusing as another report claims that consumption of TPES alone accounted for 1.1m MT in Year 2000. This brings us to statisticians’ understanding and inclusion of what elastomers are elastomers besides the traditional SRs. With the introduction of TPEs , TPVs & MPRs, the old definition for elastomers is now obsolete.

Whatever it is, more than 1m MT a year of TPEs, TPVs & MRPs must have encroached into the NR markets and a new factor has to be considered. Hence R&D is more vital for the NR industry at this point of time.

The launching of Elgem Technology and Kraiburg in Malaysia of a new heat and oil resistant TPE grade called E² based on R&D work on expoxidised NR at MRB – Tun Abdul Razak Research Centre is certainly welcomed news.

95. Malaysia – A net importer of NR!

Lee Iacocca predicted years ago that USA would one day buy more foreign brand cars than American brand cars. It has happened in April 2001 where foreign brand cars outsold American cars 50.6% to 49.4%. However 349,712 American car brands sold a month is no chicken feed.

The recent NR monthly production figures in Malaysia have shown an alarming rate of decline and that day when Malaysia becomes a net importer of NR cannot be too far away – perhaps even in the short term within the next 3 years, if prices remain as they are in the last few years. Producers and consumers of NR must consider the ramifications and strategies. Fortunately for NR consumers there is still no shortage of NR from our neighbours at least in the short term.

94. Badminton Shoes – “D MaQ™” Breathable

I am one of those who grew up with our BATA Badminton Masters in the late 1950’s and still play a bit of Doubles and have gone through pairs of Power, Carlton and Nike badminton shoes. I am aware of the High-Tech shoes worn at Thomas or World Cup series but these are rather expensive and often not even available in this country.

My dear wife Cathryn and I used to regularly visit Hatyai, she for her shopping and Thai tit-bits and I for my indulgences in Thai ancient massages (not at The Pink Lady please). On a trip for her tennis shoes, we were drawn to a shoe in a demo watertank (Fig.1). It was obvious that the tongue and that part between the Vamp Wings are breathable. We appreciate that breathable fabrics are readily available but to make the whole tongue breathable requires special efforts. On closer examination, I found the 6mm sockliner red microcellular material good and the outsoles of MaQ™ Grip antislip compound a bonus and with double flex grooves to give better flexibility.

(Fig 2.)On trying on the shoes I was pleasantly surprised that they now have non-slip laces i.e. you tie the knot and it stays put.

I bought a pair of the D Maq™ Network, not because it is made by Union Footwear, a customer of ours for PBPCs, but because the shoe design is also suitable for tennis, a slower game (at least they allow the ball to drop before you hit it) which I have to switch over soon as my team mates have recently relegated me more to Mixed Doubles.

It is nice to note that an ASEAN country is coming out with high-tech badminton shoes and with their own brand name to boot. For more info – www.d-maq.com

93. Molecular Sieve Dessicant – Zeolite

Writers have a tendency to redefine words to describe things or processes in their own fields, examples of some are given in Item 92. Another example is “pneumatogen” used for CO₂ and N₂ liberated by blowing agents in microcellular rubber manufacture.

My interest in dehumidifying drying of wet rubber granules has led me to discover a “molecular sieve dessicant” in industrial dehumidifying drying units. Zeolite is not precipitated silica like “Zeosil”. There are some 80 zeolites which occur naturally and more than 200 synthetic zeolites are known after 30 years of aluminosilicate material synthesis. As molecular sieve dessicants, zeolite usage is minor. Main usages are as ion exchange materials. One zeolite “Clinoptilolite” used to mop up caesium and strontium in the Chernobyl disaster. Another Zeolite P is used in conjunction with water sensitive percarbonate bleaching agents to remove calcium ions rapidly from hard water.

Yes, besides synthetic ultramarine blue (Item 10) we can learn quite a bit more from Mother Nature old rocks.

92. English As She Is Spoken.

I have touched on the difficulties of Technical English (Item 81). Charles A. Harper’s Glossary of Terms and Definitions¹ for the plastics industry raised this rubber-man’s eyebrows. Some examples are given below and the readers can draw their own conclusions.

1.	Penetration	:	Entering of one part or material into another.
2.	Necking	:	Localized reduction of the cross-sectional area of a tensile specimen that may occur during loading.
3.	Cleavage	:	Imposition of transverse or opening forces at the edge of adhesive bond.
4.	Allowables	:	Statistically derived estimate of a mechanical property based on repeated tests. Value above which at least 99 percent of the population of values is expected to fall with a confidence of 95 percent.
5.	Alcohols	:	Characterised by the fact that they contain the hydroxyl (OH) group, they are valuable starting points for the manufacture of synthetic resins, synthetic rubbers and plasticisers.

Note 1 – Modern Plastics Handbook. Publd. by McGraw Hill 2000.

91. Athletic Footwear Outsole Wear Resistance.

Rubber technicians involved in R&D often wonder which Abrasion test DIN, Taber or Akron gives the best results to predict service performance. We don’t know. SATRA seems to favour DIN¹ and Nike uses their own in-house standard based on Akron Abrasion volume loss (cc) at 3000revs/ 6lbs/ 15^O. Readers may wonder what athletic shoes require the best Akron Abrasion resistance. Readers may also believe that Polyurethanes (PU) should give the best Akron Abrasion results and not often used because of price factor. Readers trying to find such answers in published literature will face difficulties due to limited publications and where published, wear resistance are measured either in DIN, Taber or Akron or their indices making it difficult to draw comparisons.

A publication on Nike beach sandal outsoles R&D² revealed that it is possible to achieve Akron Abrasion loss of 0.08cc with non-PU formulations and opted for one with a good compromise of wear + wet grip properties at 0.20cc loss based on a non-aromatic oil extended High Styrene Resin Rubber + a high styrene SBR. This is already as good as a 80NR + 20BR truck tyre retread formulation³ if we convert mm³/500 rev to Nike standard Akron Abrasion test.

A rare publication on Millable Polyurethanes For Athletic Footwear⁴ revealed that the best Akron Abrasion loss 0.096 – 0.132cc results can be obtained by the use of less light stable polyester PU’s whilst the millable polyether PU surprisingly can only give Akron Abrasion loss of > 0.78cc.

From our knowledge we are aware that the best Akron Abrasion resistant outsoles are used in tennis shoes achievable without PU but with silane coupled silica formulations. Akron Abrasion loss of such outsoles can be < 0.10cc and I can assure you that my wife’s tennis shoe soles outlast the uppers.

Reference

1.	Carter, A.R. & Turner, R.H.	(1999)	Thermoplastic rubber as a shoe soling. Rubber World. Sept.
2.	Winston, J. & Ames, K	(1997)	Development of an outsole compound for outdoor footwear. Rubber World, Dec.
3.	MRPRA	(1984)	The Natural Rubber Formulary and Property Index. Chp. 13.3
4.	Ahnemiller, J & Patterson, D	(1993)	Millable polyurethanes for athletic footwear. Rubber World, April.

90. Biodegradable Plastics From Palm Oil.

The Chapter 12 on “Plastics Recycling and Biodegradable Plastics” by Dr. Susan E. Selke in Modern Plastics Handbook makes very interesting reading with 257 references. I particularly like her pointing out “One way to obtain biological plastics is to use natural polymers, that is those formed by living organisms.” We wished she could have mentioned natural rubber as well and not just referred to plastics.

I am also proud that she acknowledged the R&D work done at the University Sains Malaysia (Ref. 16) using example a local bacterium Pseudomonas sp. USM4-55 on oleic acid and glucose as the carbon source to obtain a thermoplastic polyester containing poly(3-hydroxybutyzate) (PHB) and poly(3-hydroxyalkanoate) (PHA). Syabas!. See also Item 47.

89. Nucleating Agents.

We have touched on cell nucleating agents such as precipitated CaCO₃, MgCO₃ and silica used in the manufacture of microcellular products. (See Item 59 and our Technical Bulletin #14). Most of us are aware that nucleating agents are also used in pearls cultivation. Maybe not many rubber technicians are aware that nucleating agents are also added usually < 3% by synthetic polymer producers to partly crystalline polymers to change the polymers’ crystalline temperature, crystal spherulite size, density, clarity, impact and tensile properties. For polymers such as PET, Nylon & PP which are processed at high temperatures, nucleating agents like talc, silica, CaCO₃, Clay and silica can be used to control crystallisation. Faster crystallisation means faster cycle times in example injection moulding operations. In EVA/ LDPE microcellular moulded sheets production, we know both EVA & LDPE are partially crystalline polymers and above mentioned inorganic fillers are often used in formulations. Unwittingly their crystallisation temperatures may be lowered. Hence the choice of LDPE and/ or EVA grade with different vinyl acetate content can change the crystallisation temperature and degree of crystallinity. How these can affect expanded microcellular quality as they pop out of the hot press has not been properly studied/ documented.

88. Beer & Microcellular Rubbers.

I love both because they have something in common. What makes beer bubbles when you open the cap and the microcellular compound pops out when you open the press can be explained by a little known law “Henry’s Law” first discovered in 1803. Simply put, under pressure greater than 1 atmosphere (1.03 kg/cm²) CO₂ or N₂ can dissolve in water in the case of beer or a rubber compound in the case of microcellular rubber. Others have tried to use Le Chateliers’ Principle to explain the formation of CO₂ bubbles in a freshly opened bottle of beer but it is less precise with respect to these 2 situations. For more information on microcellular rubber production ask for our new Technical Bulletin #14.

87. Solvent Free Cold Process Sport Shoes Manufacture.

There has been a lot of talk of switching over from solvent based primers and adhesives to eco-friendly aqueous systems these last few years. Nike Inc. Dick Crosbie embarked on this R&D some 5 years back. Courtesy of Juliet Bautista Nike Inc.Vietnam, Siew Mun and I finally saw such cold process lines in operation using aqueous based primers and adhesives. The Cold Process lines are necessary longer (over 50m) but there was not a whiff of toluene, MEK, hexane or IPA. Furthermore soles units now are not even buffed but only detergent washed.

Nike Inc. has now made both their toll manufacturers’ mixing rooms and laminating areas relatively free of hazardous dust (Items 82 & 83) and solvents.

Picture below shows that Siew Mun (far left) and I (far right) did visit and can confirm the cleanliness of Samyang factory’s mixing room. (Item 83).

The pretty Vietnamese lady Ms. Trang (married) is our Behn Meyer representative.

86. Canvas & Sport Shoes Manufacture: Hot & Cold Processes.

In Item 53, we talked a little about Hot & Cold Retreading processes. In hot retreading only unvulcanised tread compounds are used for mould curing at > 140^OC, whilst cold or precure retreading makes use of a previously mould cured tread to attach to the casing using solvent cement and a thin layer of Cushion Gum to bond to a buffed casing at relatively lower temperatures < 115^OC.

It just reminded me that a similar situation exists in Canvas and Sport shoes manufacture. Most of us are familiar with Canvas shoes manufacture. The stitched upper is lasted onto a last and this is dipped in latex adhesive and dried. The unvulcanised calendered/ embossed sole/ heel are solvent finished and hand-built onto upper followed by foxing strips etc. Such shoes are then cured > 60’ in an autoclave (hot-air) at < 135^O.

When sophisticated sport shoes became fashionable in the 1970’s onwards, the traditional hot process used for canvas shoes became outdated as soles had to be at least 3-colours and these can either be compression moulded or injection moulded if the sole design is for long runs. Furthermore companies like Nike Inc. sport shoes can have microcellular outsoles or midsoles which can shrink and airbags which can be damaged at canvas shoes autoclave conditions.

Cold lamination lines were developed whereby buffed soles and midsoles etc. can be combined by use of solvent primers and usually CR or PU solvent adhesives these dried and then IR heat activated at surface temperatures of < 90^OC before pressure combination. The stitched uppers are similarly treated and then pressure combined with the laminated sole. A modern line now can produce about 50,000 pairs sport shoes a month, with built-in flexibility of required maximum shoe components & even 2 steps lasting operations. Old shoe dogs refer to such lines as cold laminating lines – or Cold Process as against the Hot Process canvas shoe operations.

85. One Man Can Make A Difference

This is true in the case of the Indian Rubber Institute’s (IRI) K.S.Loganathan. To commemorate its Golden Jubilee, IRI in association with (Tata)McGraw-Hill has just published “Rubber Engineering” [ISBN-0-07-135875-7, 907 pages, Publd. 2000]. The editor and author is K.S. Loganathan with over 30 years of industrial experience and an ardent promoter of IRI educational activities. The uniqueness of this book is that it is tailored for the IRI’s Diploma & Licienteship examinations and of course our PRIM Diploma examinations. Understandably, some subjects coverages and bibliographies given are a bit dated. Some typo errors are to be expected, example, page 309, 2-ethylhexaic acid should be 2-ethylhexanoic acid and on page 408 the colour description of Rutile as cold bluish white an Anatase as creamy white titanium dioxides must have been interchanged.

Congrats to K.S. Loganathan and IRI. This book can definitely make a difference in the training of much needed rubber technicians and technologists in this part of the world.

84. Training of Rubber Technicians For the Rubber Industry

Training of graduates and technicians and their continuing education is of concern in most industries. It is the same in the Polymer Industry. Employers lament on ‘fresh graduates’ skill shortages. Understandably employers want graduates/ technicians not only knowledgeable in polymer science and technology but also possess practical hands-on skills, commercial acumen and good communication skills. This is too tall and order for universities and polytechnics especially in recent years where most courses have been shortened. Furthermore progress in polymer science and technology is moving so fast that universities/ polytechnics have lagged behind in example new pivotal technologies (Item 50). It must be accepted that universities’/ polytechnics’ task is to produce graduates with a certain foundation of knowledge and an understanding and capability tp acquire more knowledge. We know some polymer chemistry graduates/ technicians who went on to learn a second or even a third language, familiarised themselves with the latest IT gizmos, acquired skills in the latest analytical testing procedures, polymer engineering, material science, adhesion science, production operations, management, etc. and employers love these “chemical science geeks” as they are no more just polymer chemists/ technicians. To encourage this, industry must also do its part, especially in continuing education. For SMI’s they often face a problem as fresh intakes may have no peership or the company lacks certain leading edge skills.

The role played by The Plastics & Rubber Institute of Malaysia (PRIM) in providing formal Diploma level training for the past 42 years is very commendable. Lately Sime Darby Technology Centre (SDTC) has been offering very hands-on training in physical testing, compounding, etc., and RRIM, USM & PRIM have also followed suit. No doubt as our industry matures, one day, we may find the RRIM, PRIM or SDTC etc. able to offer more hands-on pivotal technology courses as done in USA, example, Rubber Extrusion Technology – University of Wisconsin – Milwaukee Centre for Continuing Education. (Rubber World, Dec 2000, p. 52). The contents of this course are impressive.

The industry wants hands-on skills in the latest technologies. The PRIM, universities etc. besides providing formal degree/ diploma courses should consider the possibility of creating and recognising such specific courses as Continuing Education Units and students accumulating sufficient such units be awarded a Diploma.

83. How Clean Can A Mixing Room Be?

The previous item talked about sustainable and eco-friendly rubber compounding. Nike Inc. embarked on a polymer bound masterbatch project in early 1999 and we were one of the early vendors to offer our PBPCs in Vietnam. The eco-friendly benefits of switching over from powder/ liquid forms to polymer bound predispersed granules are best illustrated by 3 pictures courtesy of Juliet Bautista, Chemical Engineering Manager Nike Inc. Vietnam. Juliet has a production background. Hence the transformation of traditional mixing rooms into what is possible with dust free PBPCs has to be seen to believe. A picture is worth a thousand words. We must thank Juliet for providing these pictures. Siew Mun and I have seen similar Nike toll factories in Thailand just as clean, using Sin Rubtech PBPCs of course.

Finally and yes, the girl in the picture is Vietnamese and quite typical of those working there.

82. Sustainability And Sustainable Development.

Since our market launching of our Polymer Bound Predispersed Chemicals (PBPCs) in 1998, we have been preaching PBPCs for sustainable and more eco-friendly rubber compounding. Basically we are trying to convince potential users that in switching over from powder grades to PBPCs in most instances, there are bottom-line cost savings. This has not been an easy task. The concepts of Sustainability And Sustainable Development are often poorly understood as different people have different priorities and each has to balance these priorities. It is good to note that the Royal Society of Chemistry through its Environment, Health and Safety Committee is currently drafting a note on “Sustainable development and the professional chemist”. (See Nov. 2000, Chemistry in Britain). Any professional society’s views are expectedly to be idealistic. We rather like the more practical approach taken by the UK Engineering and Physical Sciences Research Council (EPSRC) announcing its first call for £30m Sustainable Technologies Initiative (STI) programme. ( See Materials World Jan 2001). The programme aims to get industry, in conjunction with the science base to develop and adopt new technologies that are more sustainable and that will contribute to sustainable development and competitiveness. The first call asks for submissions in the area of novel research within the manufacturing, process and service industries to develop novel technologies for exploitation within industry to develop simplified assessment tools for industrial sustainability, to increase uptake of sustainable design and production and to develop innovative uses of existing technologies.

Now it does appear that Sin Rubtech’s initiatives in our PBPCs development fit most of EPSRC objectives. We have given at least 6 examples of our PBPCs sustainability in our Technical Bulletin #11. There are many satisfied customers in this part of the world. My old friend and a shoe-dog, Dick Crosbie, Nike Inc. revealed that in one large footwear factory, he estimated that in switching over to PBPCs, there was an estimated drop of ~500kg/ month of fly loss as evidenced by the difference in disposal weights of the caught dust in their dust extractor systems. This cost savings in addition to possible increase in productivity and lower rejects/ remills have been realised in bottom-line costings. Alas some factories are still giving overwhelming authorities to purchasers to buy raw materials at lowest cost possible.

We are not alone. Promoters of water based primers, adhesives and mould releases face the same problems – to demonstrate sustainability and sustainable development.

We hope manufacturers take a closer look at these developments. Ultimately what we do today “we should not be cheating on our grandchildren.” Not that I have any grandchild yet but hopefully at least half a dozen soon.

81. NR: A Beleaguered Industry

I have highlighted some problems and possible solutions for NR’s future (Item 28). NR producers are praying that Year 2001 may bring more equitable prices as the INRO stockpiles are gradually run down. We must thank the extensive coverage given to NR and especially Don Smith’s editorial in Rubber World November 2000 issue. The past R&D efforts of the Malaysian Rubber Board (MRB)/ RRIM/ TARRC have benefited the entire polymer industry but with Malaysia’s diminishing production of NR such R&D efforts which benefited all NR consumers are not expected to be sustained. Not many end-users realise that MRB now has to source for additional funds besides the Malaysian Cess on export of raw NR.

One such source is the Common Fund for Commodities CFC (www.common-fund.org) which unfortunately USA and France have yet to join as members. That there is a future for NR is acknowledged with depleting crude oil supplies and rising costs of SR’s. NR is still the preferred major rubber component in Truck/ Bus Green Tyres, and synthetic rubber producers are still spending millions in R&D for lower rolling resistance new synthetics.

Even Japanese companies are willing to do R&D on deprotenised rubber latex e.g. USP. 5908893 & USP 5910567 both issued in 1999. However such privately funded R&D do not directly benefit all NR producers in the same manner as MRB or CFC funded R&D projects.

Alas, world commodity economies are dictated by free supply-demand situations. It is sad to read about depressed coffee bean prices and an equitable price this year can only be hoped for if bad weather strikes one of the 3 major producing countries. Free supply-demand situation can be good or bad. Who is to blame when coffee consumption is approximately 6.7m MT/year and supply exceeds this by some 600,000 MT/year or 9% too much. That NR is a bio-renewable polymer is recognised but major consuming countries are unwilling to act despite a kilogram of NR costs less than a cup of brand name coffee. That R&D for NR has to be sustained such as projects to combat the dreaded Conynespora leaf disease, NR/ SR blends for wider product applications etc. for the long term benefits of all major rubber consumers cannot be over-emphasised.

Malaysia and Thailand may soon follow the footsteps of India & P.R.China that NR produced will only be sufficient for domestic consumption, if the depressed NR prices continue.

The beleaguered NR industry should not be a problem to be faced only by the producing countries. I hope the major consuming countries will act fast before a real shortage occurs. Mind you, Hevea Brasiliensis trees take at least 4 years before we can extract the latex and in Malaysia’s case, the wood if NR prices are still no equitable.

80. Economy of Scale

We can all appreciate that in general unit cost comes down as we increase output. In labour intensive products manufacture like footwear, it is expected that the workforce is large, but how large is large. In Malaysia, 1000 is large. In Vietnam, 10000 is large, in Indonesia 20000 is large. Dr. Lee, Siew Mun and I visited one Nike toll footwear factory in Guangdong P.R.China with more than 80000 workers. When you consider that the leading non-tyre product manufacturer Hutchinson S.A. (Musing with Sin Item 51) has world-wide less than 23000 employees, it is food for thought. How to manage? What sort of capital investment are we talking about? What sort of person is the GM willing and able to take up the challenge? Is footwear manufacture necessarily that labour intensive? Meet us at our usual watering holes for more details.

79. Rapid Freeze Prototyping (RFP)

Rapid prototyping (RP) of products/ parts are used initilally as design aids for visualisation, form and fit, testing etc. In the polymer industry, rapid prototyping of new products can be from wood and this is used in sand casting to obtain metal moulds or the wood plasticiser wax prototype used to obtain silicone moulds from room temperature vulcanising (RTV) silicone.

The Rapid Freeze Prototyping (RFP) is a novel environmentally conscious RP process. It builds a 3-D ice part from a computer aided design (CAD) module by depositing and rapidly freezing water in a layer by layer manner. RFP process has demonstrated that such ice prototypes can be used to make silicon moulds using ultraviolet light curable RTV silicones. Advantages of ice patterns over plastic or wax are :

· Easier to remove

· More complex moulds can be made

· No demoulding step is needed before injection of liquid silicone or polyurethane.

Details of this are reported in Materials World, December 2000 “A Cool Way to complex parts” by Ming C. Leu.

78. Nobel Prize for Chemistry: 2000

Readers should be informed that Polymer LED TV/ PC Screens (Item 74) would not be possible without the pioneering work of Alan G. MacDiamid, Hideki Shirakawa and Alan J. Heeger on the “Synthesis of Electrically Conducting Organic Polymers: Halogen Derivatives of Polyacetylene (CH)_x”. In his review Richard Stevenson reported that this year’s science Nobel Prizes have been awarded for practical discoveries. There are at least 6 new potential commercial applications. Researchers should read the full review in Chemistry in Britain Nov. 2000.

The carbon-based organic polymer (CH)_x developed by the Nobel Laurates is a new polymer with as yet no abbreviations that I know of and similarly so are the many new “organic metals” in the pipelines such as poly(ethylenedioxythiophene) etc.

77. Frozen NR

Natural rubber’s high structural regularity enables it to crystallise spontaneously when it is kept at low temperatures or when it is stretched. For stored bales of NR, the crystallisation rate is fastest at –26^OC. A pallet of NR stored over winter in temperate countries will result in “Frozen NR” which is difficult to cut and even more difficult to mix without pre-warming. During my travels, it is observed that older NR warehouses use piped warm air during the cold season to keep the entire warehouse at summer conditions. However, new warehouses have installed hot-aired controlled NR thawing tunnels for JIT deliveries. Apparently this is more efficient than keeping the entire warehouse warm. It is not often known that a pallet of frozen NR the previous year cannot naturally thaw itself out by next summer. Thawing frozen NR can add USD 0.05 to 0.10 per kg. Buyers of frozen NR from stockpiles are inclined to offer only current prices less this cost of thawing.

It is interesting to note that current hue & cry over high fuel costs for heating homes is also affecting the selling price of our frozen NR.

76. English in the Rubber Industry

There are quite a few local articles on the importance of English which is recognised more and more as the global language. My colleague Dr. Lee A.K. and I had a few deliberations over this. He is currently translating our Short Notes into Chinese and believe me we had quite a few sessions over the English used and their exact meanings in Chinese.

It is not easy for most developing countries to exuviate their mind-set over keeping their national language as the primary language and according English of parallel importance.

Mastering English is one thing, mastering Technical English in the rubber industry is much more difficult. When I read about the pending Polymer Physics Group (a joint group of the Royal Society of Chemistry & The Institute of Physics) Founders Prize to Sir Sam Edwards for his work on polymer physics including “the theory of reptation”, I had to quickly run to my English dictionary as I could not find anything in my old text books. You may be more fortunate if you have a copy of a new book “Rheology for chemists – an introduction” by J.W.Goodwin and R.W. Hughes, Cambridge ISBN 085404616X.

The same thing occurred again when I read about Jack Harris (Materials World Vol. 8 No.12 Dec. 2000 page 47) continuing his ‘panegyric’ on the exhibitions in UK.

To have to be jolted a third time when I read about Nike’s new Shox shoes and could not figure out what are “jounce” bumpers. (The Star Nov 27 2000) makes me feel rather humbled as Technical English cannot be taught and mastered in schools/ colleges only and must be a life-long learning process and I still have to learn.

I would love to be able to translate our stuff into Bahasa Malaysia but as you can see, I can hardly cope up with the Technical English used in our industry. Perhaps one day, Siew Mun or my 2 boys can take up the challenge.

[Back]