Abstract: Disclosed is a method and apparatus for making stress free plastic articles from plastic particles such as powder utilizing heat and pressure in which a quantity of plastic particles is supplied to a first member, a flexible diaphragm is disposed in opposed relationship to said first member with said plastic particles therebetween, a microporous air release means is positioned between said plastic particles and said flexible diaphragm, a fluid-like pressure is applied to said diaphragm to cause said diaphragm to apply an even fluid-like pressure through said air release means to said plastic particles, heat is applied to said plastic particles while under said fluid-like pressure and any entrapped gases between the particles is vented by means of the air release means. The pressure and heat are controlled to effect a consolidation of the plastic particles into the article.

Abstract: A method and apparatus for laminating a plurality of plastic layers together is disclosed in which the lamination is carried out under heat and pressure with at least all but one of the layers being gas permeable in order that any gases within or between layers may be vented to the atmosphere during lamination under said heat and pressure. If desired, all of the layers may be gas permeable. One or more of the gas permeable layers may be plastic powder which meets and consolidates into a continuous, integrated ply during lamination.

Abstract: Disclosed is a method and apparatus for making stress free plastic articles from plastic particles such as powder utilizing heat and pressure in which a quantity of plastic particles is supplied to a first member, a flexible diaphragm is disposed in opposed relationship to said first member with said plastic particles therebetween, a microporous air release means is positioned between said plastic particles and said flexible diaphragm, a fluid-like pressure is applied to said diaphragm to cause said diaphragm to apply an even fluid-like pressure through said air release means to said plastic particles, heat is applied to said plastic particles while under said fluid-like pressure and any entrapped gases between the particles is vented by means of the air release means. The pressure and heat are controlled to effect a consolidation of the plastic particles into the article.

Abstract: Disclosed is an apparatus for making stress free plastic articles from plastic particles such as powder utilizing heat and pressure in which a quantity of plastic particles is supplied to a first member, a flexible diaphragm is disposed in opposed relationship to said first member with said plastic particles therebetween, a microporous air release means is positioned between said plastic particles and said flexible diaphragm, a fluid-like pressure is applied to said diaphragm to cause said diaphragm to apply an even fluid-like pressure through said air release means to said plastic particles, heat is applied to said plastic particles while under said fluid-like pressure and any entrapped gases between the particles is vented by means of the air release means. The pressure and heat are controlled to effect a consolidation of the plastic particles into the article.

Abstract: Disclosed is a method and apparatus for making stress free plastic articles from plastic particles such as powder utilizing heat and pressure in which a quantity of plastic particles is supplied to a first member, a flexible diaphragm is disposed in opposed relationship to said first member with said plastic particles therebetween, a microporous air release means is positioned between said plastic particles and said flexible diaphragm, a fluid-like pressure is applied to said diaphragm to cause said diaphragm to apply an even fluid-like pressure through said air release means to said plastic particles, heat is applied to said plastic particles while under said fluid-like pressure and any entrapped gases between the particles is vented by means of the air release means. The pressure and heat are controlled to effect a consolidation of the plastic particles into the article.

Abstract: In a process for producing plastics sheet or film having a face which conforms to a face of a master, e.g. a ground glass surface, comminuted plastics material is placed in a layer on the master and a parting sheet is placed over the plastics material. Force is applied evenly over all of the area of the plastics layer, e.g. as by fluid pressure through a diaphragm, and the plastics material is heated to its fusion temperature such that the plastics materials flows into a coherent sheet or film. Relatively low fluid pressures, e.g. atmospheric and less, may be used. In a further step, the flat face of plastics sheet or film formed in this way is metallized and then covered with an abrasion resistant transparent coating, to result in a high quality mirror. In a preferred process, the transparent coating is cured rapidly by application of radiant heat.