Breathable Polyethylene bags with filters, PE filted bags for sale

Breathable PE bags with filters are much used in spawn production. Because these bags are not autoclavable, sterilization is by irradiation. It is noted here that if PP is irradiated, PP disintegrates. PE filtered bags are often used by large spawn producers in sizes of 35 by 60 cms. Large spawn producers often use bulk sterilization of grain spawn. This is done by sterilizing the grain in jacketed mixers which heat and cool in fast cycles and grain introduction into the already sterilized and cooled by proprietary methods and then mixed. The mixed, and spawned substrate is filled into the PE bags and sealed to incubate. Apart from fast cycles, the finished PE bags have a smooth surface unlike PP spawn bags are often dented by protrusion of grain during autoclaving. However, the bulk sterilizing is very expensive and difficult to maintain.

Filters for these bags can be PE non-wovens like Tyvek, or other proprietary PE non wovens and membranes. PP filters can also be laminated to PE by introducing an intermediary non woven that heat sealable on PP and PE. Most PE filter bags use a large panel of filter material but instead of a large hole cut in the bag below the filter, under the large panel sealed within the panel of filter is a series of small holes. The size of the holes are very critical to allow low evaporation of humidity, and yet give the spawn fast growth. If a large hole is cut under the filter. There usually is an area below the filter that humidity is low and no colonization results, and at times, this is a considerable amount of loss to the user. The large panel of filter distributes gas exchange over a large area, and is the guarantee for fast and uniform spawn colonization.

pp filter bags

pp and pe bags