Discussion created on 11/19/2016

Extrusion of fish feed

I need help on extrusion of fish sinking feed .I reach 50:50 of sinking and i need 99 % but i just can not make feed to sink is it from formulation or from adjustments of the extruder.

Denis Dimovski
Fish feed
remove_red_eye 2794 forum 59 bar_chart Statistics share print
Share :
close
December 14, 2016
By decreasng the temperature and speed of screw rotation in the barrel may help you.
Reply
Denis Dimovski Denis Dimovski
Fish feed
December 14, 2016
I'm glad that with my problem we open something that is interested and good to share each of us
For any help that i can do and with my knowledge for extrusion please post and we can keep these channel open for discussion.

Happy Holidays
Denis
Reply
Robbert Veenendaal Robbert Veenendaal
Sales and Marketing Director
December 15, 2016
sinking feed use pelletmill or twinscrew extruder, for the latter one needs to count on serious investment

Urs is a highly respected expert in the industy, as such he is correct by mentioning that with 17 to 18% of water in a pelleting process good gelatinization is just not possible. There is not sufficient shear in this process to get better result.

here the expander technology can be of interest. Placing expander on top of pelletmill will provide shear and one still can do without dryer. Tests can be done at the FeedDesignLab (FDL) in Wanssum Netherlands where an Almex AL150 expanderi s available on top of pelletmill.
Reply
PRAKASH P. AMBALKAR PRAKASH P. AMBALKAR
Agricultural Engineer
December 15, 2016
Dear all!
Many things are possible the target should always be that of sustainability first later would be profitability. For that R&D is required, new opportunities needs to be explored and discussed. If improved and affordable technology is an available option then multi culture and multi uses of machine to grow variety of food items would also generate more assured returns and that too at reduced risk factor.
Thanks
PP AMBALKAR
Reply
December 15, 2016
Dear All,
I like to have the details on suitable type of feed for Mangrove Crab.As you may please be aware that, mud crab require soft pellet and they initially chew the pellet and break the feed with mandibles .
The feed should not break and pale ability There are more potential for crab feed in many SE Asian countries such as India, Srilanka,Vietnam, Indonesia,Philippines etc., How to make such feed and what type of machinates required to make such feed
Reply
Matteo Calligaris Matteo Calligaris
Fish Nutritionist and Aquaculture Consultant
December 16, 2016
It's not difficult ro produce a sinking feed, but it depend on formulation and extrusion parameters... You should give more datailes
Reply
Denis Dimovski Denis Dimovski
Fish feed
December 17, 2016
Dear Matteo

First of all let me thank you for your interest in the problem.

We use wary simple formula

wheat flower,………………….. 5 %
soya(44%)……………………… 48%
sunflower seed meal,………… . 3 %
Triticale……………………….. 25%
soya protein(65%)…………… 2%
fish meal(70%)…………………….. 3%
Oil(animal origin) ……………….. 2%
CaCo3 ……………………………. 1%
Salt ……………………. 0,5%
fine corn starch ………… 10 % because like i read that 10 % fine starch is for sinking and everything more than 20 is for floating?
Water is added in mixer (we don’t have steam generator)and is 35 to 40 %

The parameter of the extruder are like these

First heating zone 70 degree
Second heating zone 90 degree
Third heating zone 95 degree

Speed of the extruder 25 Hz(approximately 600 rpm)
Opening dice 6 mm(one hole)

Like these we have 80 % sinking and 20 slow sinking after 20 min we need fast sinking

The fish feed is for Carp

Thanks in advance
Reply
Matteo Calligaris Matteo Calligaris
Fish Nutritionist and Aquaculture Consultant
December 20, 2016
Dear Denis,

Sorry for my late in answer you.
Could you write me to this address please?
mattucel@gmail.com

Regards
Reply
Denis Dimovski Denis Dimovski
Fish feed
December 24, 2016

Dear Matteo

Did you receive my mail?

Regards
Denis

Reply
Matteo Calligaris Matteo Calligaris
Fish Nutritionist and Aquaculture Consultant
December 27, 2016
Dear Denis,

Unfortunately I found your mail in late but I answered you.

Regards
Matteo
Reply
Katie Mayo Katie Mayo
Applied Nutrition Technologist, M Sc.
January 3, 2018

Hello Denis,

Here are a few key takeaways I see with your issue to create consistent sinking fish feed.

1. You still need to reduce starch in your overall diet formulation if you want the feed to sink. The replacement ingredient, triticale, you are using in place of wheat flour, is still almost all starch. Starch will assist in pelleting but also expands your pellet making it float. You can substitute for an ingredient that is low in starch and has a higher fiber content. I believe wheat bran was mentioned in previous posts.

2. You also will need to add more fat in the diet formulation. This will assist in the sinking of the fish feed. You can use mechanically extruded and pressed soybean meal, which has a higher residual oil content (5-9%). This is also a good source of energy in the diet, meaning you can reduce or replace other higher cost high energy ingredients.

3. Reducing the water in the formulation from 35-40% down to 20-25% will assist in several things. First, you will get a better cook and mixing of the ingredients during extrusion. Second, adding too much moisture will help to stabilize the pellet as well.

To comment further on the process itself, the temperature and amount of time the ingredients are cooked will make a difference . Many ingredients in your formulation have already been processed from their raw state and do not require too high of temperature to process, With that being said, the processing temperatures you are using seem a little low, meaning you will not get a sufficient cook. In addition, increasing dwell time may help with pellet expansion, which could be attributing to the floating versus sinking issue.

Overall, you should reduce the starch and moisture and increase the fat in your overall formulation and make proper adjustments to your process to achieve a more uniform sinking fish feed. It is important to both understand the nutritional quality of the end product and how extrusion affects this. If you have any additional questions, I would be happy to discuss this further with you. 

Reply
Carl Eidsforth Carl Eidsforth
Agricultural Engineer
January 3, 2018
I would also suggest that we dont have a detailed screw configuration, Denis has the configuration changed?
is this the same machine you have used for years?
are the screws and liners worn?
has the formula changed?
could you use hot process water say 60-70c ?
you mention 600rpm shaft speed, is this the input shaft at 25htz or the actual extruder shaft speeds?
my thoughts are that you seem to be only using mechanical energy to create cook it does not sound like you are using thermal energy which may be to aggressive. even a single screw would not turn anywhere near this speed to give 700g/L feed density.
Reply
Denizzo Denizzo Denizzo Denizzo
Factory Director
January 19, 2018
Good day, Denis!
What is your extruder model?
Do you have a technological hole to drain excess pressure?
Reply
Ekundayo Victor Ekundayo Victor
Student
September 5, 2019
Please, if you are having size variation in your pallet what could be the cause?
Reply
March 19, 2020
how do you calculate the open area, L / D for die floating?
Reply
print
(2794)
(59)
Engormix reserves the right to delete and/or modify comments. See more details
Post a comment
Create new discussion :
If this discussion does not cover topics of interest or raises new questions, you can create another discussion.
Consult a professional in private:
If you have a specific problem you can perform a consultation privately to a professional in our community.
Kurt A. Rosentrater
Kurt A. Rosentrater
Associate Professor
  Ames, Iowa, United States
Professional Services
Dave Albin, Ph.D. Dave Albin, Ph.D.
Grimes, Iowa, United States
Kurt A. Rosentrater Kurt A. Rosentrater
Ames, Iowa, United States
Katie Mayo Katie Mayo
Grimes, Iowa, United States
Royce Samford Royce Samford
Stanfield, Arizona, United States
 
   | 
Copyright © 1999-2020 Engormix - All Rights Reserved