Bottles prepared from compositions of polypropylene and inorganic nucleating agents

1. A process for preparing bottles with a two-machine system comprising the steps of:

a. providing a composition comprising polypropylene, prepared with a Ziegler-Natta catalyst system and a non-sorbitol nucleating or clarifying agent comprising aluminum hydroxybis{2,2′-methylenebis[4,6-di(tert-butyl)phenyl]phosphate};

b. preparing a pre-form by injection moulding on a multi-cavity mould at injection temperature of 215° C.;

c. cooling the pre-form at room temperature;

d. transporting the pre-form to the blow-moulding machine;

e. re-heating the pre-form in the blow-moulding machine to a temperature of from 90 to 140° C., following a pre-determined temperature profile;

f. passing the re-heated pre-form through an equilibrium zone;

g. stretching the pre-form axially with a centre rod having a speed of 1400 to 1800 mm/s;

h. blowing the stretched pre-form radially with high-pressure air;

i. retrieving bottles having low haze values.

2. The process of claim 1 wherein the resin has a melt flow rate of from 10 to 20 dg/min.

3. The process of claim 1 wherein the amount of non-sorbitol nucleating or clarifying agent is of up to 10000 ppm.

4. The process of claim 3 wherein the amount of non-sorbitol nucleating or clarifying agent is of up to 2000 ppm.

5. The process of claim 1 wherein the polypropylene is a homo- or a co-polymer of propylene.

6. The process of claim 5 wherein the polypropylene is a copolymer of propylene, wherein the comonomer is ethylene and wherein the amount of comonomer is of up to 20 wt % based on the weight of the polymer for block copolymers.

7. The process of claim 5 wherein the polypropylene is a copolymer of propylene, wherein the comonomer is ethylene and wherein the amount of comonomer is of up to 10 wt %, preferably up to 4 wt %, based on the weight of the polymer, for random copolymers.

8. The process of claim 1 , wherein the bottle is adapted for hot-fill applications.