Granted Patent B2

US 12,612,739 · App. 17/786,857 · Granted Apr 28, 2026

Inventor: Harald John Kuiper (Leeuwarden, NL)

Assignee: HUHTAMAKI MOLDED FIBER TECHNOLOGY B.V.

D21J3/00B65D65/466D21J7/00B65D85/324

Abstract

Claims (61)

1 . A method for producing a moulded pulp material for a packaging unit, the method comprising the steps of:

preparing a raw pulp material;

wettening a raw pulp material in a tank;

providing the raw pulp material to an extruder;

anionically charging the raw pulp material;

adding one or more additives;

extruding the raw pulp material; and

providing the moulded pulp material at the outlet of the extruder,

wherein adding one or more additives comprises adding a cationic fixative followed by a biodegradable anionic pigment to the raw pulp material,

wherein a weight ratio of pigment to fixative is in the range of 2-25, and

wherein extruding the raw pulp material comprises:

reacting the fixative with cellulose fibers of the raw pulp material; and

attaching the pigment to the cellulose fibers of the raw pulp material.

2 . The method according to claim 1 , further comprising the step of selecting one or more dimethylamine polymers as fixative.

3 . The method according to claim 1 , wherein a weight ratio of additive to fixative is in the range of 4-19.

4 . The method according to claim 1 , wherein the raw moulded pulp material comprises a mixture of soft wood and hard wood, and/or comprising the step of providing an amount of natural fibers.

5 . The method according to claim 1 , further comprising the step of adding an amount of a biodegradable aliphatic polyester, wherein the amount of biodegradable aliphatic polyester in the moulded pulp material is in the range of 0.5-20 wt. %, wherein the biodegradable aliphatic polyester comprises at least an amount of polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polyglycolic acid (PGA), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), or Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV).

6 . The method according to claim 1 , further comprising:

providing a laminated multi-layer to the extruder;

extruding the laminated multi-layer with the raw pulp material; and

deep-drawing the extruded laminated multi-layer and raw pulp material into a packaging unit,

wherein the laminated multi-layer comprises:

an inner cover layer comprising an amount of a biodegradable aliphatic polyester;

a first intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers;

a functional layer comprising a vinyl alcohol polymer;

a second intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; and

an outer cover layer comprising an amount of a biodegradable aliphatic polyester,

wherein the laminated multi-layer renders the food packaging unit as a compostable packaging unit.

7 . The method according to claim 6 , further comprising the step of providing a biodegradable top seal film.

8 . A packaging unit from a moulded pulp material, the packaging unit comprising a food receiving and/or carrying compartment, wherein the moulded pulp material is provided by a method according to claim 1 .

9 . The packaging unit according to claim 8 , wherein the moulded pulp material comprises an amount of fibers, wherein at least 80% of the fibers has a length above 1.1 mm.

10 . The packaging unit according to claim 8 , wherein the fixative comprise dimethylamine polymers.

11 . The packaging unit according to claim 8 , further comprising a biodegradable laminated multi-layer, with the multi-layer comprising:

an inner cover layer comprising an amount of a biodegradable aliphatic polyester;

a first intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers;

a functional layer comprising a vinyl alcohol polymer;

a second intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; and

an outer cover layer comprising an amount of a biodegradable aliphatic polyester, and

wherein the packaging unit is a compostable packaging unit,

wherein the thickness of the individual layers is within the range of 5-50 μm, and

wherein the total thickness of the laminated multi-layer is in the range of 20-150 μm.

12 . The packaging unit according to claim 11 , wherein the laminated multi-layer is a co-extruded laminated multi-layer,

wherein the laminated multi-layer is melted or fused with the compartment,

wherein the packaging unit comprises a layer of biodegradable aliphatic polyester on a product contact surface to improve melting or fusing of the laminated multi-layer thereon,

wherein the laminated multi-layer is melted in a moulded pulp material matrix.

13 . The packaging unit according to claim 11 , further comprising a biodegradable top seal film,

wherein the packaging unit comprises a circumferential edge comprising a connecting surface for the top seal film that is substantially free of the laminated multi-layer, and

wherein the top seal film comprising a biodegradable aliphatic polyester.

14 . A method for producing a moulded pulp material for a packaging unit, the method comprising the steps of:

preparing a raw pulp material;

wettening a raw pulp material in a tank;

providing the raw pulp material to an extruder;

anionically charging the raw pulp material;

adding one or more additives;

extruding the raw pulp material; and

providing the moulded pulp material at the outlet of the extruder,

wherein the additives comprise a biodegradable anionic pigment, wherein the biodegradable anionic pigment is added after adding a fixative, wherein the fixative is a cationic fixative, and wherein the weight ratio of pigment to fixative is in the range of 2-25, and

wherein extruding the raw pulp material comprises:

reacting the fixative with cellulose fibers of the raw pulp material; and

attaching the biodegradable anionic pigment to the cellulose fibers of the raw pulp material.

15 . The method according to claim 14 , further comprising the step of adding an amount of a biodegradable aliphatic polyester, wherein the amount of biodegradable aliphatic polyester in the moulded pulp material is in the range of 0.5-20 wt. %.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (40)