“PP” and “PE” represent the material of which the bags are made. PP is an abbreviation for polypropylene whereas PE stands for polyethylene. These are polymers of respectively propylene and ethylene and have different physical and chemical properties.
The consequence of these differing monomers is that polypropylene can be autoclaved and polyethylene cannot. If you’re looking for a bag which can be autoclaved together with the substrate at 121°C, you’ll need a bag from our PP range.
Luckily there are ways to sterilize PE bags, for instance through gamma irradiation. This guarantees a 100% completely sterile product and is most often used in bulk production processes or in systems where sterilised bags are poured into another bag before inoculation.
The type of filter is mentioned in our codes.
Our model PP75-BEU6-X32-57 is a bag with B-filter, and
the model PP75-SEU6-X37-57 is a bag with S-filter
The S-filter gives approximately 1.5 times more gas exchange against the B-filter. This is why the S-model is mostly used for Substrate and the B-model for Spawn.
Other parameters related to the gas exchange are of course the amount of filters per bag and the volume of the bag.
Only thorough tests will tell which bag is the most suitable for which products and which bag gives the best results for your purpose.
We recommend storing the bags in a clean and dry place at a minimum temperature of 15°C – 60°F. Storage at temperatures below 0°C (frost) can cause heavy damage to PP bags.
We recommend using a heat sealing device for both PP and PE Microsacs. We have tried and tested many different machines and have had best results with the devices we offer. Have a look.
The code of our PP bags seems complicated but includes all the information of the bag type. It consists of three parts: the first part indicates the used film; the second part mentions the type and the final part describes the size.
For PP (polypropylene) bags:
- First part: film
- PP Polypropylene
- 50/75 Thickness of the film in µm
- Second part: type
- B/S Thin zipper/broad zipper
- E Filter material
- U/H/D Filter location on bag: up (near opening)/spread/ down (near bottom)
- 2/4/6 Amount of filter strips
- Third part: size
- V/X Presence of bottom gusset or not
- 00-00 Width and length of bag in cm
For instance: PP75/BEU6/X32-57 is a polypropylene bag, 75µm thick with a thin E-filter zipper where the 6 filters are located on the top of the bag which measures 32 x 57 cm and has no bottom gusset.
For PE (polyethylene) bags:
- First part:
- PE polyethylene film
- 80 thickness of the film in µm
- Second part:
- G/L/T Filter material with T standing for Tyvek©
- 3 Amount of filter strips
- V Vertically orientated filter strips
- (S/M) Small/medium width filter strip
- (3/4/7) Number of perforation rows
- Third part:
- 00-00 Bag dimensions
Standard sterilization through wet steam autoclavation takes place at 121°C and 1 bar overpressure. We advise to place the bags into the autoclave without the filters touching the wet substrate. Sterilization time will differ according to filling volume/weight.
No, there’s a good chance your bags will explode during the cycle. The only reason why you would, is when your autoclave does not exit into a cleanroom, i.e. your cooling room does not meet hygiene requirements.
Our PP (polypropylene) bags are guaranteed to resist temperatures up to 124°C. Sterilization should be done at 121°C. Please note that PE (polyethylene) bags are NOT autoclavable.
Since our polyethylene bags are non-autoclavable but sterility is top priority in the mushroom business, we offer these bags pre-sterilized. This means that the bags have undergone a gamma irradiation treatment to ensure complete sterility. The bags are prepacked per 50 pcs in an overbag, which are then prepacked per 3 packets of 50 in another larger overbag. That way you’re flexible to use less than a full carton after opening the package.
Saco2 takes pride in a wide portfolio of products. Besides Microsacs and Microboxes we also sell related machinery. Whether you need a tumbler or a sealing device, take a look on our machinery page and see what we have on offer.
If you can’t find your fancy in our product range, please know that we’re happy to discuss custom made bags. We have no problem to make whatever you need for your production process within the limits of our machines. Note that we have a minimum order of 20.000 pcs for custom made bags.
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