| 摘要 |
<p>A composite or laminate film or sheet of plastics material for envelopes, pouches, or other containers for use in microwave ovens comprises at least three layers of plastics material bonded and/or adhered together and with the central layer 10, 24 being of unoriented plastics material or of less oriented material relative to the orientation of the plastics material(s) of the outer layers 9, 11, 23 and 25 and/or being of lower melting point materials than the outer layers. The outer layers may be polyester or polypropylene or polyamide and the middle or inner layer may be polypropylene, polyethylene or polyamide. A pressure relief valve including an area between two of the three sheets which is free from adhesive or bonding and a slit 4 may be incorporated in a container made from laminate. The film or sheet prevents or minimizes hot spots created by drops of oil 21 or other foodstuffs.</p> |
