Abstract: The invention concerns a high strength polyethylene fibre, which is prepared by melt spinning polyethylene having a high density through a spinnerette, by cooling the fibre coming out from the spinnerette and by stretching the fibre obtained at 50.degree.-150.degree. C. The polyethylene used in the melt spinning is a homopolymer of ethylene having a weight average molecular weight M.sub.w between 125000-175000 g/mol, a number average molecular weight M.sub.n between 26000-33000 g/mol, polydispersity (M.sub.w /M.sub.n) below 5 and the density higher than 955 g/dm.sup.3. The stretching degree in the drawing step is at least 400%.

Abstract: The carbamate content of cellulose carbamate products is reduced by treating such products with solutions of a base, which solution also contains one or several alkali metal salts, particularly carbonates, sulfates, phosphates, borates and acetates.

Abstract: The carbamate content of cellulose carbamate products is reduced by treating such products with solutions of a base, which solution also contains one or several alkali metal salts, particularly carbonates, sulfates, phosphates, borates and acetates.

Abstract: The present invention concerns a cyclic process for producing an alkali solution of cellulose carbamate, for precipitating the cellulose carbamate from the alkali solution and for recovering and recycling the chemicals.

Abstract: The present invention concerns a cyclic process for producing an alkali aqueous solution of cellulose carbamate, for precipitating the cellulose carbamate from the alkali solution and for recovering and recycling the remaining chemicals. The process comprises the following steps: (a) an alkali solution of cellulose carbamate is prepared by dissolving cellulose carbamate in an aqueous solution of sodium hydroxide, (b) the solution obtained in step (a) is contacted with a precipitation aqueous solution containing sodium carbonate, whereby the cellulose carbamate is precipitated and can be removed, (c) from the solution in step (b) sodium carbonate is crystallized and is returned to the precipitant solution in step (b), and (d) mother liquor containing sodium hydroxide, obtained, i.e. remaining from, step (c), is returned to step (a) for dissolving cellulose carbamate. The crystallizing in step (c) is accomplished in two or several steps by cooling.