A preform configured to form a container by stretch blow molding. The preform includes a finish portion and a tip portion. The finish portion is at a first end of the preform and is a container finish of the container. The tip portion is at a second end of the preform opposite to the first end. The tip portion is configured to form a container base and a container heel of the container. An outer surface of the tip portion includes a flat surface, a first radius on a first side of the flat surface, a second radius between the first radius and the flat surface, a third radius extending from the flat surface on a second side of the flat surface, and a fourth radius extending from the third radius towards the second end of the preform through which a longitudinal axis of the preform extends.

The present disclosure relates to an aerosol container made of plastic, the container having a neck, the opening of which is closeable in a pressure-tight manner by a valve unit that can be actuated by a pushbutton, the container being Tillable with a liquid or gaseous propellant and a liquid to be sprayed. The aerosol container can be an injection cast preform with an elongated tubular preform body. The preform body is closed by a dome-shaped convex preform base, beyond which an integrally formed stand region projects in an axial direction. The preform body adjoins the opening of the neck at the opposite axial longitudinal ends of the preform body.

A hollow container manufacturing method comprises: an injection molding step of forming a preform having a neck portion and a barrel portion, at least a part of the barrel portion being solid, by injection molding; an intermediate product formation step of inserting a boring rod 134 from the neck portion side into the barrel portion 23 to form a space part of at least a predetermined depth in the barrel portion, thereby converting the preform into an intermediate molded product; and a final blow molding step of blow-molding the intermediate molded product within a final blow mold to form a hollow container which is a final molded product.

Disclosed is a preform for a plastics container, which includes: a rotationally symmetrical body about a central axis; an open neck which extends in continuation of the body from an upper end of the latter; a bottom which closes the body starting from a lower end of the latter, the bottom being rotationally symmetrical about the central axis and having a central concavity and a protruding bulge around this concavity, the bottom having a thickness E, measured from an external face, that is variable in accordance with three different criteria respectively applied to three sections of the bottom, namely a central section [0; S.sub.1], an intermediate section [S.sub.1; S.sub.2] and a peripheral section [S.sub.2; L].

Preform, made of plastic material for the manufacturing of hollow bodies through a blow-molding process, in which said preform comprises a substantially cylindrical body (1) having an open end (2) and a closed end {4), in which said closed end (4) has an outer surface with a varying curvature which is entirely enveloped within a hemispherical surface having a radius equal to the outer radius (R) of the cylindrical body (1) of the preform, said outer surface with varying curvature being tangent to the hemispherical surface in which it is enveloped in correspondence of the circular crown C and of the preform vertex.

A generally hollow preform for making a stretch blow-molded container may include a threaded finish portion; a neck portion depending from the finish portion; a transition portion depending from the neck portion; a main portion depending from the transition portion; and a closed, generally rounded tip portion depending from the main portion. The preform may include stretch ratios with respect to the container including an axial stretch ratio of about 3.0 to 3.5, a hoop stretch ratio of about 5.0 to 5.5, and a total stretch ratio of about 15 to 19.25. In some embodiments, high stretch ratios may be achieved with less material, yielding substantial cost savings.

The outer circumferential surface of a bottom 4 of a preform 1 and a lower site 3a of a trunk 3 continuous with the bottom 4 is mechanically brought into intimate contact with a cooling pot 16 to undergo reliable cooling. The trunk 3, excluding the lower site 3a of the trunk 3 continuous with the bottom 4, is heated to a predetermined temperature by a heating block 17. When blow-molded, the so treated preform 1 can provide a container having a bottom of a desired thickness and having a uniformly stretched thin-walled trunk.

A preform for a stretch-blow-molded plastic container includes an elongated, tube-like preform body. An outer wall and an inner wall delimit a bottom thickness (b). An outer wall and an inner wall delimit a wall thickness (w). An inner surface and an outer surface (E1) curved in three-dimensionally convex manners are spaced apart such that a distance from their respective apex (S, S) to the preform body continuously increases. Extensions of the outer wall of the preform bottom along the outer three-dimensionally curved surface (E1), and of the inner wall of the preform bottom along the inner three-dimensionally curved surface (E2) are configured to be interrupted by set-backs area outside of their respective apex (S, S) thereof.

A generally hollow preform for making a stretch blow-molded container may include a threaded finish portion; a neck portion depending from the finish portion; a transition portion depending from the neck portion; a main portion depending from the transition portion; and a closed, generally rounded tip portion depending from the main portion. The preform may include stretch ratios with respect to the container including an axial stretch ratio of about 3.0 to 3.5, a hoop stretch ratio of about 5.0 to 5.5, and a total stretch ratio of about 15 to 19.25. In some embodiments, high stretch ratios may be achieved with less material, yielding substantial cost savings.

An injection moulded thermoplastic preform for blow moulding to form a container, the preform comprising a lower closed base portion, a hollow body portion, a hollow transition portion between the lower closed base portion and the hollow body portion, and an upper open end portion adjacent to an upper part of the hollow body portion, wherein the closed base portion comprises a central portion which extends over at least 50% of an internal radius of a lower end of the hollow body portion and is either substantially flat or has a shallow concave or convex internal curvature, and the transition portion comprises an upwardly and radially outwardly tapering portion extending away from the central portion to connect to the hollow body portion, the tapering portion being inclined at an angle of from 1 to 20 degrees to a longitudinal axis of the preform and the tapering portion increasing in thickness from the central portion to the hollow body portion. Also disclosed is a method of injection moulding the thermoplastic preform.