BIO-PLASTIC HANKBOOK 2011

BIO-PLASTIC HANDBOOK

http://issuu.com/oi-ying

CHEMICAL STRUCTURE FORMULA

Edit by Oi-Ying Kwong 2011

Contents Abstract = natural history PART I

Definition of Synthetic Plastics and Renewable Plastics

1.

Synthesis, Structure and Properties of Synthetic Plastic 1.1 Synthetic Ploymer from Raw Resources 1.11 Synthetic Ploymer from Raw Resources

2.

Synthesis, Structure and Properties of Renewable Plastic 2.1 Synthetic Ploymer from Raw Resources 2.11 Formula: Milk + Vinegar 2.12 Formula: Starch + Glycreol + Vinegar = Bio-Plastic 2.121 Chemisty of Thermoplastic Starch Compound 2.122 Chemisty of Acetic Acid (Vinegar) Compound 2.123 Chemisty of Water Compound 2.124 Chemisty of Sodium (Salt) Compound 2.125 Chemisty of Glycerol Compound 2.13

PART II 1.

Formula: Gelatine + Glycreol = Bio-Plastic 2.131 Chemisty of Gelatine polymer

Tests of Renewable Plastic

Making Method and formula of Bio-Plastic Formula 1: Milk + Vinegar Formula 2: Starch + Vinegar + Water + Glycerol Formula 3: Gelatine powder + 1% Glycerol Solution Formula 4: Gelatine power + Glycerol + Water Formula 5: Starch + Vinegar + Water + Glycerol + Gelatine powder + 1% Glycerol Solution Formula 6: Starch + Water + Glycerol + Gelatine powder Method 1: Making method of Vinegar Method 2: Making method of Starch Formula 6: Starch + Water + Glycerol + Gelatine powder + salt Formula 7: Starch + Water + Glycerol + salt Formula 8: Gelatine powder + Water + Glycerol + salt

INDEX ii

Abstract Almost every product brought into NZ seems to be “made in China”. I started to notice all the low priced products that I bought were made in not only from China, but made in plastic. My research revealed that the manufacturing of plastic materials benefits the producer because it’s character allows it to be cast, pressed, molded into any form and can replace the quality expensive materials such as glass and steel.

I became aware of the toxicity when I researched further into this synthetic material.

I questioned why we as society would continue to produce plastic products that cause so much harm to the environment. The answer was clear for me: if we do not solve this problem, not only would the environmental issues but we would be the recipients of our own destruction. Therefore I tried to address the underlining problem by studying the chemical structure of plastic and its’ related materials. I experimented with different formulas to make bio-plastic, and tested which was the most stable and the most suitable to use for producing alternative plastic forms.

At beginning, the DIY style ‘studio laboratory’ allowed me to criticize my personal act and give a new position to concern about my responsibility in regard to current public environmental concerns. I then worked to explore an industrial- type mass production by fabricating steel trays to improve the process and systemisation. This action has to be considered to be a long term transition. I provide awareness to society of the harm that we are causing, and attempt not to resort to current production all for the benefit of preserving nature and for following generations.

iv

PART I Definition of Synthetic Plastics and Renewable Plastics 1.

Synthesis, Structure and Properties of Synthetic Plastic

1.1 Synthetic Ploymer from Raw Resources

Formula: Polymer(s) + Plasticizer(s) + Other Additive(s) = Plastic

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Fig 1. The basic structure of synthetic plastic ploymer

H H H

H

H

H

C

C

C

H

H

H

H

Fig 2. Chemisty of Common Thermoplastics Ploymer

1

1.1 Synthetic Ploymer from Raw Resources

~~

~~

CH

CH

CH2

CH

= CH

CH2

CH

=CH

CH2

CH

=CH

S

S

S

S

S

S

S

S

CH2

CH

= CH

CH2

CH

=CH

1

CH2

CH

= CH ~~

CH2

CH

=CH

CH2

CH

= CH ~~

S S S S

~~

CH

CH2

CH

= CH

CH2

CH

=CH

CH2

CH

=CH

CH2

CH

= CH ~~

CH

=CH

CH2

CH

=CH

CH2

CH

= CH ~~

CH2

CH

= CH ~~

S S S S

~~

CH

CH2

CH

= CH

CH2

S S S S

~~

CH

CH2

CH

= CH

CH2

Fig 3. Structure of Thermoplastics Ploymer

CH

=CH

CH2

CH

=CH

1.1 Synthetic Ploymer from Raw Resources

3

Amorphaus

Lamella

Fig 4. Lamella and Amorphaus sstructure of Thermoplastics Polymer

1.1 Synthetic Ploymer from Raw Resources

4

c

Volume (g)

3

2 b 1

0

a

5

10

15

25

20

30

35

40

45

50

55

Tg( oC ) Fig 5. Glass Transistion Temperature

a

b

c

60

65

70

4

2.

Synthesis, Structure and Properties of Bio Plastic

2.1 Synthetic Ploymer from Raw Resources 2.11 Formula: Milk + Vinegar O CH

N

R

H

C

n

Fig 6. The basic chemical structure of Poteins Compound

H

~~

C

N

R

H

H

C

C

N

R

H

O

O

H

C

C

N

R

H

-

H

C

O

-

R

H

-

N

-

C

O

C

~~

Fig 7. Structure of Poteins Compound

Fig 8. Milk plastic 5

2.12

Formula: Starch + Glycreol + Vinegar = Bio-Plastic

2.121 Chemisty of Thermoplastic Starch Compound

Formula: Bio-Polymer(s) + Bio-Plasticizer(s) + Other Additive(s) = Bio-Plastic

CH3 HO

CH

O CH2

O

C

O

CH3 CH

CH2

C

CH 3 O

O CH2

CH

CH 3 O

C

CH

Fig 9. The basic structure of Starch Compound

CH2 OH

CH2 OH

~~

O

H

O

OH

H

H

OH

H

O

H

O

OH

H

H

OH

H

O

OH

H

H

OH

CH2 OH H

H

O

H

O

H

O

CH2

CH2 OH

~~

CH2

O

OH

H

H

OH

OH

H

H

OH

H O CH2

H

O

H

O

OH

H

H

OH

H

O

~~

Fig 10. Structure of the amylose molecule

6

2.121 Chemisty of Thermoplastic Starch Compound

7

OH O

O

HO

HO OH O HO

O HO O O HO

OH HO O

OH HO

O HO O O HO

OH HO O

HO O

O HO O HO

O HO O

Fig 11. Structure of the amylopectin molecule

Fig 12. Potato Starch in drying process, grey colour due to oxidation.

2.122 Chemisty of Acetic Acid (Vinegar) Compound H

O

H

OH

C H

O C O

H

Fig 13. Basic Structure of Acetic Acid

OH OH HO

O

OH OH

HO OH

O OH OH

Fig 14. Molecular Structure of Apple cider vinegar

Fig 15. Apple cider vinegar in development chopped fruit rise up to the top with the chemical reaction.

8

2.123 Chemisty of Water Compound H

H O

H

O H

H O

O

H

H

O

H

H

H O

H O H

O

O H O

H Fig 15. The basic sturcture of Water Compound

Fig 17. Rain Water

2.124 Chemisty of Sodium (Salt) Compound

I O I

I O

CI

COO

CI

CI

OI

. 2Na+

CI Fig 20. Sodium (salt)

9

2.125 Chemisty of Glycerol Compound

(CH2) CH3

O

OH

OH

OH OH OCH3 OH

Fig 16. The basic sturcture of Glycerol Compound

CH2OH

~~

HO

O

HO

O

CH2 OH HO

HO

CH2 OH HO

HO

OH O

O

CH2OH

OH O

O

HO CH2OH

OH HO

HO

O

HO

O

O

O~~

~~ CH2 OH

O OH

O

HO CH2OH O

O

O

HO CH2OH

OH

CH2OH O O

O

OH

HO CH2OH

HO

Fig 17. Structure of the Celulose

O~~

HO

HO

O

O

O~~

O

CH2 OH 10

2.13

Formula: Gelatine + Glycreol = Bio-Plastic

2.131 Chemisty of Gelatine polymer COOH NH2

C

H

R Fig 18. The basic sturcture of Gelatine polymer

OH O

O C

H N

C

CH CH2

O

~~ H N

CH CH3

C

O H N

CH

C

N

H

O H N

CH H

C

O H N

CH

CH2

CH2

C

NH

O

NH2

+

N

CH2

CH2

C

C

O C

O

HN CH

NH2

C O

N C O

~~

Fig 19. Sturcture of Gelatine polymer

11

Safety Considerations/ Safety rules: 1) Handle hot liquids with care - the mixture are heated to nearly the boiling point (95 degree).

2) Wash your hands after every laboratory session.

3) Do not put the final products in your mouth for any reason.

4) Young children should not experiment without adult supervision.

Tips: 1) Let it dry completely in the tray; do not remove so it will shrink its size in thickness instead of the area size. If it is too hard to remove when dry completely, spray water on top to soften the plastic then remove.

2) Disinfect the tray before use to avoid the growth of bacterial and mould.

3) Do not touch mixture while drying, finger print can cease the bacterial and mould to grow when the material is not dry.

4) Ripple or wrinkles in the final product means there is too much plasticizer. *Fixed tools were applied through production: elements, spoon, and bow.

PART II Tests of Renewable Plastic 1. Making Method and formula of Bio-Plastic Formula 1: Milk + Vinegar Proportion Milk(ml) Vinegar(ml) 500 100

Implement*

process

Result

-Pot -Spoone

-able to sharpe -trun soft and mouldly after 3 months Video 2

500

-Pot -Spoone

-Boil milk till 95 degree then pour vinegar into warm milk and stir until the solids are separated from the liquid -Boil milk till 95 degree then pour vinegar into warm milk and stir until the solids are separated from the liquid -bake in 190 degree for 5 minutes

100

-able to hold the shape and harden the material texture Fig 1

Fig 1. Milk plastic after baking

13

1. Making Method and formula of Bio-Plastic

14

Formula 2: Starch + Vinegar + Water + Glycerol Proportion Vinegar (ml) 127.5 1400

127.5 200

Water (ml) 1400

1400

Implement*

Glycerol (g) 102 -pot -300 x 400mm Perspex

102

-Non-stick pan -300 x 1000mm PVC sheet

process

Result

-Mix well then boil 95 degree until the mixture turn into a thick white gel

-able to mould into shapes while setting - breaks into parts when dry completely after 2 days -colour turned into yellow - shrink into a half size after 4 months

-Mix well then boil 95 degree until the mixture turn into a thick white gel

-plastic gets to stick to the bottom and burn Fig 2 -able to mould into shapes while setting -cannot spread evenly onto a plastic sheet -never set -non-stick pan could avoid burning well

127.5 200

1400

102

-Non-stick pan -100 x 80 x 60mm mould -oven

- Mix well then boil 95 degree until the mixture turn into a thick white gel - put the gel into mould evenly and bake in oven for 1 hour with 150 degree Fig 3

127.5 200

1400

102

-Non-stick pan -300 x 1000mm PVC sheet

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-Shrink about 1/3 size after baking, -only the top layer is dry completely -Therefore the rest of it is still jellied.

-Shrink about half size when it dried completely after 1 month -able to spread onto a plastic sheet evenly -dried completely in 1 day because I could smooth it as a thin plastic sheet -quite hard, brittle -resulted in a uncontrollable form, especially around the edges Video 3

1. Making Method and formula of Bio-Plastic Proportion Starch Vinegar (g) (ml) 257 200

Water (ml) 1400

Glycerol (g) 102 -Non-stick pan -300 x 400mm Perspex

127.5

200

1400

0

127.5

0

1400

127.5

200

191.5

200

Fig 2.

Implement*

15

process

Result

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-very hard to stir because too much starch made the gel too thick.

-very hard to spread and smooth out on the Perspex

-Non-stick pan -300 x 1000mm PVC Sheet

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-did not make any different during cooking -very brittle of the end result

102

-Non-stick pan -300 x 1000mm PVC Sheet

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-did not make any different during cooking -les smell -because no vinegar to add acid to the starch, the end result broke apart when dried

1400

102

-Non-stick pan -100 x 80 x 60mm mould -oven

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-able to spread onto a plastic sheet evenly -dried completely in 1week because I could smooth it as a thin plastic sheet

1400

102

-Non-stick pan -plastic mould

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-a thicker base allow it to dry in solid form -take 5 days to dry -get mouldy Fig 4

Fig 3.

1. Making Method and formula of Bio-Plastic

Proportion Starch Vinegar (g) (ml) 8 16

Implement*

Water (ml) 140

127.5

200

1400

127.5

200

700

102

-Non-stick pan -Plaster brick

127.5

200

1000

102

-Non-stick pan -Plaster brick

127.5

200

700

102

-Non-stick pan -Plaster mould

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

191.5

200

1200

102

-Non-stick pan -plastic mould

127.5

200

1400

102

-Non-stick pan -300 x 1000mm PVC Sheet

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid Video 5 -Mix well then boil with MAX heat until the mixture turn from a thick white gel to a clear liquid

Glycerol (g) 5 -Non-stick pan -30 x 100 mm plastic case 102 -Non-stick pan -Plaster brick

16

process

Result

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid -Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid -Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid -Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

shrink about 1/10 when dry completely

-dry in 2 day -brittle, because the plaster absorb too much water from bioplastic Video 4 -a very thick base -take 4 days to dry completely -breaks into parts -liquid base -take 1 week to dry completely -struck on the plaster, cannot speartate easily fig 7 -a very thick base -take 1 week to dry completely -struck on the plaster, cannot speartate easily -never set fig 8 -never set

-decrease cooking time -easier to get burn -the burned part of plastic release sticky stuff like sugar and breaks into parts when dry

1. Making Method and formula of Bio-Plastic

Proportion Implement* Starch Vinegar Water Glycerol (g) (ml) (ml) (g) 127.5 200 1400 102 -Non-stick pan -1000 x 1000mm PVC Sheet

Fig 4.

Fig 5.

17

process

Result

-Mix well then boil with MAX heat until the mixture turn from a thick white gel to a clear liquid

-able to spread onto a plastic sheet evenly video 6 -dried completely in 1 day because I could smooth it as a thin plastic sheet -quite hard, brittle -resulted in a uncontrollable form, especially around the edges -break into pieces when dry compelety Fig 5

1. Making Method and formula of Bio-Plastic

18

Formula 3: Gelatine powder + 1% Glycerol Solution Proportion Gelatine 1% Glycerol Solution power(g) (ml) 36 480

Implement*

process

Result

-pot -250 x 380mm trays

-Mix gelatine powder with cold water

-never set -crake into parts in jelly form -the powder was clearly have not dissolve Fig 6

36

480

-pot -250 x 380mm trays

-a thin layer plastic sheet that is very hard and struck to the tray -dry in 3 days

180

2400

-pot -500x500mm - temporary tray made with tinfoil and stick together with tape

-Boil the 1% Glycerol Solution then mix with the gelatine power.

Stir until the it dissolve -Boil the 1% Glycerol Solution then mix with the gelatine power.

Stir until the it dissolve

180

2400

-pot -500x500mm temporary tray made with tinfoil and stick tape all over the tinfoil

Fig 6

-a thick layer plastic sheet -I could easily spate the part that was place on top of the tape but the tinfoil -dry within a week Fig 7

-Boil the 1% Glycer- -a thick layer plastic sheet ol Solution then mix -easily removed with the gelatine -dry within a week power. Stir until the it dissolve

Fig 7

1. Making Method and formula of Bio-Plastic

19

Formula 4: Gelatine power + Glycerol + Water Proportion

Implement*

process

Result

Gelatine power(g) 360

Glycerol (g) 50

Water(ml) 4800

-pot -710 x 1500 mm steel tray

-Boil water then -takes about 2 weeks to mix it with gelatine dry and glycerol - 3mm thick plastic sheet -very heavy ,soft and flexible, very easy to break by cuts and cannot hold its weight at all

252

25

3360

-pot -710 x 1500 mm steel tray

-Boil water then -takes about 2 weeks to mix it with gelatine dry and glycerol - 2mm thick plastic sheet -able to hold its shapes and not easy to break -can be soften and reshape in water

252

25

2400

-pot -710 x 1120 mm steel tray

-Boil water then -takes about 2 weeks to mix it with gelatine dry and glycerol - 1.5mm thick plastic sheet -able to hold its shapes and not easy to break -can be soften and reshape in water -easy to make bags or folder with sealer

180

25

2400

-pot -710 x 1120 mm steel tray

-Boil water then -takes 1-1.5 weeks to dry mix it with gelatine completely and glycerol - 1mm thick plastic sheet -able to hold its shapes but it is easy to break as too much glycerol in the proportion -easy to make bags or folder with sealer

1. Making Method and formula of Bio-Plastic Proportion Gelatine power(g) 252

Glycerol (g)

37.5

Water(ml) 3360

Implement*

process

Result

-pot -710 x 1120 mm steel tray

-Boil water then mix it with gelatine and glycerol

-takes 2.5 weeks to dry completely - 1mm thick plastic sheet -able to hold its shapes but it is easy to break as too much glycerol in the proportion -easy to make bags or folder with sealer -start to mould as it could not dry within its normal time and the weather condition Fig 8

Fig 9.

Fig 8.

20

1. Making Method and formula of Bio-Plastic

21

Formula 5: Starch + Vinegar + Water + Glycerol + Gelatine powder + 1% Glycerol Solution Proportion Vinegar (ml)

Water Glyc(ml) erol (g)

127.5 200

920

63.75 100

460

102

51

Gelatine powder (g) 36

18

1% Glycerol Solution (ml) 480

240

Implement* process

Result

-pot -710 x 1120 mm tray

-very hard to mix well gelatine into clear gel perhaps the temperature was already too high for the gelatine during process -4mm thick plastic sheet -take about 3 weeks to dry complete -quite hard but flexible

-pot -710 x 1120 mm tray

-mix starch, glycerol, vinegar and water together, boil in 95 degree until it turns into a clear liquid gel - add gelatine and 1% glycerol solution into mixture

Fig 9 -Mix well -it was hard then boil to control the 95 degree temperature until the because the mixture gelatine burn turn from a easily during thick white a long time gel to a cooking clear liquid - never set

1. Making Method and formula of Bio-Plastic

22

Formula 6: Starch + Water + Glycerol + Gelatine powder Proportion Water(ml) 127.5

480

102

Gelatine powder(g) 18

30

300

15

30

Fig 10.

Implement* process

Result

-pot -710 x 1120 mm tray

-boil starch and half amount of water in 95 degree until it turns into clear gel -boil half amount of water in 95 degree then mix it with gelatine and glycerol -mix gelatine mixture a bit at a time to the starch mixture

-method did not work. Both mixture is not even after 10 mins stir

-pot -710 x 1120 mm tray

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

-1mm thick -viscose -never set Fig 10

1. Making Method and formula of Bio-Plastic

23

Method 1: Making method of Vinegar Proportion Fruit

Water(ml)

Implement*

process

Result

-4 fruit skin

-about 200ml for a 500 ml size bottle

-glass bottle

-warm up glass bottle in oven in 75 degree Fig 11 - chop the fruit sin into little pieces -put the chopped skin into bottle and fill up with water

-explodion caused by reaction during process as fruit juice will turn to wine and then vinegar - turn sour in 6 months

- 2whole fruit

-about 20ml depend on the size of bottle

-glass bottle

- 4fruit juice

0

-pot -glass bottle

-warm up glass bottle in oven in 75 degree - chop the fruit sin into little pieces -put the chopped skin into bottle and fill up with water -boil fruit juice for 10 minutes and remove foam always -warm up glass bottle in oven in 75 degree - chop the fruit sin into little pieces -put the chopped skin into bottle and fill up with water

-explodion caused by reaction during process as fruit juice will turn to wine and then vinegar - turn sour in 6 months -explodion caused by reaction during process as fruit juice will turn to wine and then vinegar - turn sour in 6 months

Fig 11.

Fig 12. Cover the bottle with cloth to avoid dust and allow air to entre.

1. Making Method and formula of Bio-Plastic

24

Method 2: Making method of Starch Proportion potato(g)

Implement*

process

Result

3 kg

-peeler -chopper -cloth -3 trays

-peel the skin off -put pptatos into chopper -dehydrate the potato by the chopper otherwise use a cloth, twist to separate water -put dehydrated potato into trays evenly and place them in dorect sun light till dry - use chopper to make starch powder Video 8

-Grey colour because of oxidation and bleach was not used -Dry in 3 days in direct sun light but also depend on weather condition Fig 13.

a.

Fig 13. (a) Strach dring in direct sun light. (b) Finished starch powder after process.

b.

1. Making Method and formula of Bio-Plastic

25

Formula 6: Starch + Water + Glycerol + Gelatine powder + salt Proportion Implement* process Result Starch(g) Water(ml) Glycerol(g) Gelatine Salt(g) powder(g) 30 300 15 30 6 -pot -Mix well then -1mm thick -mm tray boil 95 degree -viscose until the mix- -never set ture turn from a thick white gel to a clear liquid Formula 7: Starch + Water + Glycerol + salt Proportion Starch(g) Water(ml)

Glycerol(g) Salt(g)

30

15

300

6

Implement* process

Result

-pot -mm tray

-1mm thick -takes about 1 week to dry depend on the weather condition -salt was able to keep it dry in one piece and avoid mould -this formula is good for cast but does not work well with sealer

-Mix well then boil 95 degree until the mixture turn from a thick white gel to a clear liquid

Formula 8: Gelatine powder + Water + Glycerol + salt Proportion Implement* process Gelatine Water(ml) Glycerol(g) Salt(g) powder(g)

Result

180

-less than 1mm thick plastic sheet -almost transparent -takes 1 week to dry completely -able to seal into a elastic plastic bag with low temperature -plastic sheet become sticky if mouldy

2400

25

6

-pot -mm tray

-Boil water, salt and glycerol with 95 degree then mix with gelatine powder

1. Making Method and formula of Bio-Plastic

Fig 14. Gelatine plastic bag

26

INDEX Polymer

Something made of many units as a chain. Each link of chain is the “-mer” or basic unit that is made of carbon,hydrogen,oxygen and/ or silicon. Many links or “-mer” are hooked or polymerized together to make a chain. For plastic, the more fible the polymer has, the more strength the final product has.

Plasticizer

Additives that increase the plasticity or fluidity of the material to which they are added. If addded in food, it can increase the volume but remain the same taste.

Thermoplastics

The plastics that do not undergo chemical change in their composition when heated and can be moulded again and again.

Lamella

The folded chains of polymer in a stacks form.

Amorphaus crystal.

Non-crystalline solid is a solid that lacks the long-range order characteristic of a

Glass Transistion Temperature

Tg, structure does not chage during Tg but start to move and turn into a rubber-like state. Tg is not melting but it is a stage before melting.

Bio Plastic use.

Made by bio-degradable resource and it is able to return to the ecosystem after

Raw Resources

Resources that come from natural, opposite to synthetic.

Compound

A pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions.

Glycerol

A simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. It is normally made by vegatable oil or animal fat.

Starch

Starch is found in potatoes, and in grains such as corn and wheat. Starch is made up of glucose repeat units. Its structure is similar to cellulose.

Vinegar

An organic compound, its main component of vinegar (apart from water), and has a distinctive sour taste and pungent smell. It is mainly produced as a precursor to polyvinylacetate and cellulose acetate.

Sodium As know as salt, is a mineral that is composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of ionic salts. Sodium can keep starch to dry in one piece.

28